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Categories of research reported GERMPLASM IMPROVEMENT

genetic resources genetics breeding methods yield potential grain quality and nutritional value disease resistance insect resistance drought tolerance excess water tolerance adverse temperature tolerance adverse soils tolerance integrated germplasm improvement seed technology research techniques data management and computer

modeling

CROP AND RESOURCE MANAGEMENT

soils and soil characterization soil microbiology and biological N

physiology and plant nutrition crop management soil fertility and fertilizer management disease management insect management weed management managing other pests integrated pest management water management farm machinery environmental analysis postharvest technology farming systems research methodology data management and computer

fertilizer

modeling

SOCIOECONOMIC AND ENVIRONMENTAL IMPACT

environment production livelihood

EDUCATION AND COMMUNICATION

training and technology transfer

communication research information storage and retrieval

research

CONTENTS GERMPLASM IMPROVEMENT

Genetic resources 4 Screening for duplicates in the germplasm collections

Breeding methods 4 Propagation of Porteresia caarctata using immature seeds 4 Performance of anther-derived rice lines 5 Oryza nivara sources of cytoplasmic male sterility (CMS) in rice 6 Floral characters of CMS and maintainer lines in hybrid rice 6 Effect of row ratio and leaf clipping on MR365A outcrossing and

6 Somatic embryogenesis in rice cultivar IR50 7 A medium-duration. high-yielding, scented hybrid rice 7 Evaluation of some F 1 rice hybrids developed using MR365A as

8 Identification of restorers and maintainen for four CMS lines of rice 8 Media conditioning to convert nonembryogenic rice calli to

seed yield

CMS line

embryogenic calli

Yield potential 9 A path-coefficient analysis of rice panicle characters

10 Heterosis and heterobeltiosis for high density grain index (HDI) and

11 Adaptability of rice varieties to low light intensity 12 Correlations between allogamic and agronomic traits in rice 12 Screening long-duration rice cultivars for ratooning ability 13 Effect of high temperature on rice spikelet fertility

other rice panicle characters

Grain quality and nutritional value 14 Using silica gel desiccant to dry rough rice samples

Disease resistance 14 Resistance to sheath blight (ShB) in China 15 A new inoculation technique for rice blast (Bl) 15 Rice sheath blotch incidence in Haryana

Insect resistance 16 Registration of brown planthopper (BPH)-resistant germplasm lines

16 Rice resistance to whitebacked planthopper (WBPH) Sogatella

17 A potential donor for resistance to the gall midge (GM) population

17 Screening for resistance to rice gall midge (GM) 18 Resistance of rice varieties to brown planthopper (BPH),

in Japan

furcifera in Bangladesh

of Srikakulam District, Andhra Pradesh

whitebacked planthopper (WBPH), and gall midge (GM) in India

Excess water tolerance 19 Heritability of stem elongation ability in rice

Integrated germplasm improvement 20 IET9783: a salt-tolerant rice for coastal saline soil 20 Performance of upland and rainfed lowland rice varieties in farmers’

21 Ranbir Basmati--an early-maturing aromatic rice 21 RAU4045-10, a new variety for rainfed areas 21 CN705-18--a promising rice variety for deepwater rice areas 22 SiPi 692033: a promising rainfed lowland rice variety

fields in Mali

Seed technology 23 Influence of Acrocylindriun oryzae Sawada on rice seed

germination and seedling vigor

CROP AND RESOURCE MANAGEMENT

Soil microbiology and biological N fertilizer 23 Boiling water treatment to improve germination of Sesbania

rostrata

Crop management 24 Effect of sowing and planting method on rice yield 24 Selecting rice varieties for double transplanting in flood-affected

25 Effect of a new abscisic acid analog on chilled rice leaves 26 Yield ability of tillers separated from standing transplanted aman

26 Effect of Triacontanol on rice seedling weight and grain yield

areas

rice and replanted

Soil fertility and fertilizer management 26 Large granule urea efficiency in rice 27 Synergistic effect of organic manure and N fertilizer on irrigated

27 Effect of zincated diammonium phosphate (Zn-DAP) on rainfed

28 Efficiency of prilled urea (PU) and urea supergranules (USG) in

29 Sesbania rostrata— a lowercost same of N for rice 29 Nitrogen-use efficiency with hand- and machine-applied N

30 Effect of Zn and Cu on growth and nutrition of rice 30 Biofertilizer production of stem-cut planted and seeded Sesbania

31 Effect of sesbania green manure and wheat straw on ammonia

32 Soil test fertilizer recommendations increase economic yields of rice 33 Source and time of phosphate application in irrigated rice

rice

lowland rice

rapidly percolating soil

fertilizers in wetland rice soils

rostrata

volatilization loss in wetland soil

Disease management 34 Suitability of iodine test for detecting rice tungro virus (RTV)

34 Biological control of rice blast (Bl) with antagonistic bacteria infection

Insect management 35 Effect of plant age on whitebacked planthopper (WBPH) feeding 35 Virus diseases of some lepidopterous rice pests in the Philippines 36 Weed hosts of rice hispa Dicladispa armigera Olivier (Coleoptera:

37 Effect of parasitization on food consumption of rice leaffolder (LF)

38 White stem borer (WSB) effect on upland yield

Hispidae)

Marasmia patnalis

Weed management 38 Effect of herbicides on Ischaemum rugosum 39 Weed management in rainfed rice - lentil crop sequence

Managing other pests 40 Effect of bund dimensions on rodent infestation in irrigated

ricefields

Farming system 40 Rice-based cropping sequences for rainfed conditions in midhills of

41 Vegetables for high return and water use efficiency in irrigated rice-

42 Supplementary irrigation using shallow groundwater for soybean

Uttar Pradesh

based systems

after wetland rice

ERRATA

GERMPLASM IMPROVEMENT Genetic resources

Screening for duplicates in the germplasm collections

R. K. Sahu, Indira Gandhi Agricultural University, Raipur, India

Rice researchers in the tropics often have difficulty maintaining a large germplasm collection in limited storage facilities. Often the advice is to reject duplicates within a collection. Usually samples are discarded when two of them have similar names, identical grain features, identical maturity and other morphoagronomic features, and the same or neighboring places of origin.

Results from screening similarly named germ- plasm for BB and WBPH resistance.

Raipur Reaction a

Cultivar accession no. BB WBPH

Badshahbhog B54 S S Badshahbhog B189 S R Badshahbhog B220 S S Badshahbhog B227 S S Badshahbhog B236 S S Badshahbhog B248 R S Badshahbhog B466 S S Badshahbhog B670 S S Badshahbhog B799 S S Badshahbhog B973 S S Badshahbhog B1005 S S Badshahbhog B 1209 R S Badshahbhog B1322 S S Badshahbhog B1899 S S Bhata dudgi B1627 S S Bhata dudgi Chhatri Chhatri Dubraj Dubraj Dubraj Dubraj Dubraj Gurmatia Gurmatia Gurmatia Gurmatia deshi Jhilli Jhilli J273 Jhilli J274 Jhilli J388 Jhilli parag J105

B2177 C90 C364 Dl2 D61 D341 D422 D1026 G123 G185 G245 G7 J107

R S S S R S S R R S S S S MR S R S R S R S S R R S R R R R MR S R S S

We have a collection of about 19,000 indigenous rice varieties, many with identical names. We screened a small sample of accessions with similar names, maturity, grain features, and origins for resistance to bacterial blight (BB) caused by Xanthomonas campestris pv. oryzae and to whitebacked planthopper (WBPH) Sogatella furcifera at IRRI.

Of the 14 accessions of Badshahbhog evaluated, B248 and B1209 were rated resistant to BB. B189 was found resistant to WBPH. Other accessions were susceptible to both. Other accessions having identical names (Bhata dudgi, Chhatri, Dubraj,

The results are presented in the table.

Breeding methods

Propagation of Porteresia coarctata using immature seeds

G. D. Encarnacion and F. J. Zapata, Tissue Culture Laboratory, Plant Breeding Department, IRRI

P. coarctata Tateoka (n=48) (formerly Oryza coarctata Roxb.), a wild rice species native to the coastal regions of India and Bangladesh, abounds along the mouths of estuaries. Because it flourishes in highly saline water, it could be a source of genes for salt tolerance to transfer into cultivated rices.

Part of the problem with hybridization is that mature seeds of P. coarctata do not germinate. At IRRI, we have been limited to using runners and cuttings for propagation.

We experimented with different conditions for inducing germination of P. coarctata seeds. Mature seeds did not germinate, even after they were treated with varying concentrations of sodium chloride and the embryos excised and

Gurmatia, and Jhilli) showed variable reactions to the pest and disease under study.

This study examined a small sample against only BB and WBPH. More variable reactions might be expected if the materials were evaluated for other traits and with various pathotypes or biotypes of diseases and pests. These results suggest that land races collected from different fields or villages that have identical names and morphoagronomic features may not have the same pest resistance. They should not be discarded from a collection before thorough evaluation.

immature seeds (soft dough stage) germinated (average 90%) in both distilled water and 1/4 concentration MS medium.

Some germinated seeds failed to develop fully. Some lacked shoots or roots. Others dried up after emergence. Of 36 seeds that germinated, 12 plantlets survived and were transferred to Yoshida’s water culture solution.

Propagating P. coarctata through immature seeds could be important in germplasm exchange, since immature seeds are more easily transported from place to place than runners or cuttings.

Performance of anther- derived rice lines

S. R. S. Rangasamy, S. K. Raina, W. W. Manuel, K. Natarajamoorthy, S. Palanisamy, and M. Gurunathan, Paddy Breeding Station, Tamil Nadu Agricultural University (TNAU), Coimbatore 641003, Tamil Nadu, India

Seven anther-derived cultures from the inoculated in Murashige and Skoog F 1 s of Vaigai/Co 40 (developed in a (MS) culture medium. However, TNAU-Indian Agricultural Research susceptible.

4 IRRN 14:2 (April 1989)

a R = resistant, MR = moderatrely resistant, S =

Institute collaboration) were tested in insensitive (duration 134-137 d); Culture 433A-R1 is resistant to blast seven trials against check Co 43. duration fluctuated 11-20 d in other (Bl) and rice tungro virus (RTV); 433A- Cultures 433A-R5 and 433A-R6 cultures. All cultures are semidwarf R5 is resistant to Bl and moderately performed better than Co 43 during kar (plant height 57-76 cm) and all have 6.9- resistant to RTV and bacterial blight (Jul-Oct) season (8.8 and 11.4% yield increase) (see table). short and bold; in 433A-R6, it is long moderately resistant to RTV, BB, and

Culture 433A-R6 was photoperiod and slender. Rice color is white. brown spot.

Performance of anther culture-derived rice lines at Coimbatore, India, 1982-83 to 1986-87. a

Culture Productivity Plant Panicles 1000-grain Mean grain yield (t/ha) Duration (d)

Kar Cold Navarai Overall (kg/d) Kar Cold Navarai Mean height (no./hill) wt (g) weather mean weather (cm)

433A-R1 5.2 4.5 5.9 5.2 37.1 141 148 132 140 76 7.1 19.6 433A-R2 5.0 4.5 5.5 5.0 35.8 136 150 132 139 72 7.3 20.9 433A-R3 5.3 4.1 4.8 4.8 34.1 139 151 134 141 75 7.7 19.4 433A-R4 5.2 4.2 5.5 5 .0 35.8 138 151 132 140 69 6.9 19.0 433A-R5 5.4 4.9 5.8 5.4 38.6 137 152 132 140 75 7.5 18.8 433A-R6 5.6 4.6 5.7 5.3 39.1 137 136 134 136 57 7.3 19.0 433A-R7 5.1 4.8 4.7 4.9 34.9 138 149 134 140 76 7.1 19.0 Co 43 (check) 5.0 4.9 5.9 5 .22 38.4 139 141 130 136 74 7.2 20.0

a Kar = Jul-Oct, navarai = Feb-Apr.

Oryza nivara sources of cytoplasmic male sterility (CMS) in rice CMS A-line Days to 50% Height exsertion stigma Typical Round

Table 1. Comparison of N-Zhen Shan 97A with W-Zhen Shan 97A. Puzhou, China, 1987.

Panicle Exserted Pollen fertility (%)

heading (cm) (cm) (%) abortive abortive C. Yang, N. Y. Wang, and K. J. Liang, Fujian Agricultural College, Fuzhou, China N-Zhen Shan 97A 68.5 57.0 –6.1 25.9 92.1 7.9

W-Zhen Shan 97A 70.0 56.3 –5.8 24.1 89.3 10.7

Cytoplasmic diversity is an important problem in hybrid rice breeding and production. Only a few CMS sources are being used in China, making hybrid rice potentially vulnerable to a disease or insect epidemic.

To find new sources for hybrid rice breeding and to study the cytogenic interaction in Oryza spp., we have used O. nivara introduced from IRRI (acc. 101508 and 101466) as donors of CMS cytoplasm in crosses with one set of cultivars. So far, we have developed four CMS lines—Chao Yang 1A (indica), Zhen Shan 97A (indica), Nan Jin 56A (japonica), and Rei-Min A (japonica)— that have the cytoplasm of O. nivara acc. 101508.

significant difference between Zhen Shan 97A (nivara cytoplasm) and Zhen Shan 97A (WA cytoplasm) in agrocharacter, floral characters, and pollen fertility (Table 1), and in cytogenic interaction (Table 2). The two

Preliminary studies show no

Table 2. Pollen fertility of F 1 progenies. a Hainan, China, 1988.

Female parent

N-Zhen Shan 97A W-Zhen Shan 97A Male parent

Plants (no.)

F 1 plants (no.) in pollen fertility class Plants

(no.) F PF PS CS F PF PS CS

IR22 20 16 4 0 0 20 17 3 0 0 IR24 20 20 0 0 0 20 18 2 0 0 Ming 63 20 19 1 0 0 18 18 0 0 0 Taiyin 1 18 16 1 1 0 20 18 2 0 0 Milyang 46 20 18 2 0 0 20 19 1 0 0 IR46826B 20 0 0 3 17 20 0 0 2 18 IR46827B 20 0 0 1 19 20 0 0 1 19 IR46828B 20 0 0 4 16 20 0 0 2 18 Hong 410 20 0 3 13 4 20 0 4 12 4

F 1 plants (no.) in pollen fertility class

a Pollen fertility classes: F = fertile, 91-100% pollen fertility; PF = partially fertile, 51-90% pollen fertility; PS = partially sterile, 6-50% pollen fertility; CS = completely sterile, 0-5% pollen fertility.

CMS sources seem to be genetically Milyang 23, and Milyang 46 were similar. classified as effective restorers; Hong 410

In a crossing experiment based on F 1 as a partial maintainer; and IR46826B, pollen fertility, IR22, IR24, Ming 63, IR46827B, and IR46828B as complete Taiyin 1, IR1055, Yin Ni Ai He, maintainers to both A-lines.

IRRN 14:2 (April 1989) 5

Floral characters of CMS and maintainer lines in hybrid rice

C. R. Anandakumar, G. Soundrapandian, and M. Subramanian, Agricultural Botany Department, Agricultural College and Research Institute, Madurai, Tamil Nadu, India

We screened five male sterile lines and their maintainers for pistil and stamen length during 1986 wet season (kharif). Fifty spikelets/line were measured.

Among the A lines, IR46830A had the longest pistil, V41A the shortest. Among B lines, Zhen Shan 97B had the longest stamen, IR54752B the shortest. V20A and Zhen Shan 97B had the longest filament (see table).

The long Zhen Shan 97B stamen, prominently protruding from the gap

Expression of floral characters in A, B, and R lines of hybrid rice.

Stamen (mm) Pistil (mm) Line

Filament Anther Anther Stamen Ovary Style Stigma Pistil length length breadth length length length length length

V20A 2.75 2.78 0.32 5.53 0.801 0.840 1.280 2.921 V20B 3.59 2.39 0.50 5.98 0.944 1.024 1.240 3.208 V41A 2.12 2.03 0.37 4.15 0.704 0.640 0.816 2.160 V4 1B 3.05 2.08 0.41 5.13 0.816 0.832 0.936 2.584 Zhen Shan 97A 2.99 2.12 0.48 5.11 0.576 0.872 1.112 2.560

IR46830A Zhen Shan 97B 3.48 2.57 0.48 6.05 0.728 0.984 0.992 2.704

IR46830B 2.65 2.13 0.38 4.78 1.104 0.881 1.080 3.065 3.30 2.21 0.42

IR54752A 5.51 1.267 1.216 1.320 3.803

1.33 1.68 0.34 IR54752B

3.01 0.760 0.720 0.826 2.306 1.70 1.73 0.36 3.43 0.770 0.760 0.880 2.410

SE 0.44 0.22 0.09 0.45 0.21 0.17 0.17 0.28

between lemma and palea, facilitated In general, all the male sterile (A) easy transfer of pollen to the stigma of lines had smaller stamens and pistils corresponding A lines in the adjoining than their respective maintainers. row.

Effect of row ratio and leaf clipping on MR365A outcrossing and seed yield

Satoto, Plant Breeding Department, Sukamandi Research Institute for Food Crops, Subang, Indonesia

We evaluated the effect of row ratio and leaf clipping on outcrossing rate and seed yield of MR365A (a CMS line developed at IRRI) during 1984-85 wet

season, in a split-plot design with three replications. Seedlings (21 d) were transplanted at 1 seedling/hill with 20- × 20-cm spacing.

Among the three male-to-female ratios tested, seed yields of 1B:4A and 1B:2A were significantly higher than that of 2B:4A (Table 1). Seed set was not significantly different among the ratios.

significantly reduced grains/ panicle, Leaf clipping increased seed set, but

Table 1. Effect of row ratio on seed yield, seed set, number of grains, and number of filled grains of MR365A.

Seed Seed set/ Grains/ Filled

(g/m 2 ) (%) (no.) (no.) Row ratio yield panicle panicle grains/panicle

2B:4A 67.6 b 23.76 a 94.16 b 22.28 b 1B:4A 85.4 a 22.82 a 98.96 ab 22.33 b 1B:2A 88.5 a 23.41 a 107.32 a 24.95 a

CV (%) 6.5 17.29 7.81 15.04

Table 2. Effect of leaf clipping on seed yield, seed set, number of grains, and number of filled grains of MR365A.

Seed Seed set/ Grains/ Filled Leaf clipping yield panicle panicle grains/panicle

(g/m 2 ) (%) (no.) (no.)

Clipped 83.21 a 25.14 a 92.19 b 23.26 a Unclipped 77.75 a 21.52 b 108.10 a 23.12 a

CV (%) 15.96 10.15 8.69 12.55

6 IRRN 14:2 (April 1989)

perhaps because of lower panicle exsertion. Filled grains/panicle and seed yield/ m 2 were not affected by leaf clipping (Table 2). There was no interaction between row ratio and leaf clipping.

Somatic embryogenesis in rice cultivar IR50

M. Maheswaran and S. R. S. Rangasamy, Tamil Nadu Agricultural University, Coimbatore 641003, Tamil Nadu, India

Initiation and development of embryos from somatic tissues in rice have been achieved by culturing seed-derived callus of IR50. Mature dehulled seeds were inoculated on Murashige and Skoog (MS) medium with varying concentrations of 2, 4- dichlorophenoxyacetic acid (2, 4-D) and kinetin (see table). Medium pH was adjusted to 5.8. The cultures were kept in light for 14 h daylength at 24 ± 2 °C.

Calli were initiated from the hypocotyls of the seedlings within 15 d after inoculation. Callus induction increased with increasing concentrations of 2, 4-D to 2 mg/liter. Higher concentrations inhibited callus growth.

Effect of 2,4-D and kinetin on callus induction and plant regeneration with IR50 seeds in MS medium.

Callus induction medium Regeneration medium a

2,4-D Kinetin Seeds Seeds Callus Calli Calli Regene- (mg/liter) (mg/liter) inoculated producing production transferred regenerated ration

(no.) calli (no.) (%) (no .) (no.) (%)

0.0 0.5 0.5 0.5 1.0 1.0 1.0 1.5 1.5 1.5 2.0 2.0 2.0 5.0 5.0 5.0

0.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0

74 68 74 72 74 73 72 68 74 69 72 68 67 72 74 74

10 12 12 31 34 36 37 42 42 46 42 29 26 28 25

– 14.7 16.2 16.6 41.8 46.6 50.0 54.4 56.7 60.8 63.8 61.7 43.2 36.1 37.8 33.7

– 36 38 42 44 44 42 40 38 42 32 44 42 32 32 36

– – 3 4 6 8

11 7 9 8 6 2

18 + + + +

– 8.3

10.5 14.3 18.2 25.0 16.6 22.5 21.4 14.3

6.2 40.9 b

– – – –

a Regeneration medium = basal medium + 1 mg kinetin/liter + 1 mg NAA/liter. + = rhizogenesis. b Formation of somatic embryos.

Callus pieces were transferred to regeneration medium containing kinetin and NAA at a concentration of 1 mg/ liter each. Regeneration was better from calli induced from the C medium containing 2 mg 2,4-D/liter and 0.5 mg kinetin/ liter through the process of somatic embryogenesis (established by histological studies).

distinct poles and were attached to the callus piece through their broader surface. Embryoids of different shapes were also traced out during early stages of embryogenesis. Other treatments did not yield somatic embryos.

The somatic embryos formed had two

Individuals, organizations, and media are invited to quote or reprint articles or excerpts from articles in the IRRN.

A medium-duration, high- yielding, scented hybrid rice

J. P. Sharma and S. C. Mani, Plant Breeding Department, G. B. Pant University of Agriculture and Technology, Pantnagar, India

We have identified tall, late-maturing, scented cultivar Basmati 370 as a

Table 1. Mean performance of the hybrid IR46830A/Basmati 370, and estimates of hete- rosis over the better parent and check variety Pant Dhan 4. a Pantnagar, India, 1988.

Mean Heterosis b

Character for F 1 Better Check

parent

Days to 50%

Plant height (cm) 137.2 –12.50* –30.66* flowering

Effective tillers/ 20.8 44.45* 23.80*

Length of panicle 32.2 5.59 20.81*

Primary branches/ 12.2 19.60* –9.83

Secondary branches/ 40.4 36.50* 34.50*

95.0 –24.60* –20.16*

plant (no.)

(cm)

panicle (no.)

complete restorer for the CMS line IR46830A.

evaluated for yield and quality components (Table 1,2). The hybrid flowered earlier and was shorter than the better parent. Positive and significant heterosis over the better parent was recorded for most characters. Increase in grain yield/ plant was due

Hybrid IR46830A/ Basmati 370 was

primarily to more effective tillers/ plant and higher 1,000-grain weight. Although yield of the hybrid was not significantly higher than that of check variety Pant Dhan 4, better quality attributes make it more suitable for commercial production. Its medium growth duration would make it suitable for a rice - wheat cropping pattern.

Table 2. Mean value for 5 grain quality traits in Basmati 370, hybrid IR46830A/Basmati 370, and Pant Dhan 4. a Pantnagar, India, 1988.

Character studied Basmati 370 Hybrid Pant Dhan 4

Length of grain (mm) 7.88 7.38 6.34 Breadth of grain (mm) 1.72 2.04 2.10 L/B ratio Alkali digestion value

3.11

Aroma 3.50

4.58 3.61 2.25 3.00

Strong Intermediate – a AV of 5 replications.

Evaluation of some F 1 rice Jan-May 1984. The hybrids, Cisadane, hybrids developed using and IR36 were transplanted at 20- × 20- MR365A as CMS line cm spacing in 2- × 5-m plots, with 2

panicle (no.) replications. Fertilizer was 135-45-45 kg

Grains/panicle (no.) 164.0 19.80* 17.64* for Food Crops, Subang, Indonesia Hybrid combinations MR365A/ IR36,

Spikelets/panicle 202.6 35.25* 30.20* B. Sutaryo, Sukamandi Research Institute (no.) NPK/ha.

1000-grain weight 22.9 31.24* –0.62 MR365A/IR52, and MR365A/BR10

Grain yield/plant (g) 63.0 83.89* 16.50 a Av of 5 plants. b * = significant at 5% level. MR365A (CMS line developed at IRRI) heterosis (14.63-27.65%) (see table). For

(g) We evaluated yield and heterosis of yielded about 1 t/ha more than eight F 1 rice hybrids developed using Cisadane and showed significant

IRRN 14:2 (April 1989) 7

Yield components and standard heterosis for yield in some F 1 rice hybrids evaluated in Sukamandi, Indonesian conditions, MR365A could Indonesia, 1984 wet season. be used in developing F 1 rice hybrids

Panicle Filled 1000- Growth Disease or insect Standard using IR36, JR52, and BR10 as restorer

stable for pollen sterility. Hybrid length grains/ grain duration score a Yield b heterosis lines. However, the CMS line is not

(cm) panicle wt (d) GM BLS (t/ha) to Cisadane (%) (g) (%)

MR365A/BR10 23.4 74.4 22.9 120 0 MR365A/IR36 22.8 74.2 23.0 112 1

0 4.8 a 27.65 1 4.6 a 22.87

MR365A/IR52 23.2 73.1 24.0 109 1 1 4.3 b 14.63 MR365A/IR54 23.8 64.2 23.6 116 1 1 3.5 d MR365A/IR60 22.0 61.4 19.8 130 1 1 3.5 d

–7.44

MR365A/IR46 21.7 79.5 23.0 132 –7.97

1 5 3.4 de MR365A/IR26 23.5 77.7 23.5 134

–9.04 1 1 3.2 e –16.22

MR365A/IR50 22.6 62.4 21.0 120 1 1 3.2 e –15.69 Cisadane c 23.7 81.9 28.9 142 1 1 3.8 c IR36 22.9 83.9 20.7 120 3 3 3.6 cd –

a Scoring based on 1980 Standard evaluation system for rice. GM = gall midge, BLS = bacterial leaf streak. b Means followed by a common letter are not significantly different at the 5% level by DMRT c Best check variety.

–

The International Rice Research Newsletter is published to expedite communication among scientists concerned with rice research and the development of improved technology for rice and rice-based farming systems. Readers are encouraged to write authors at their published addresses to discuss the research and obtain more details.

Identification of restorers and Fertility restorers, partial restorers, and maintainers for 4 CMS lines. Pantnagar, India.

maintainers for four CMS CMS line Fertility restorer Partial restorer lines of rice

Maintainer

IR46830A Narendra 1 IET7613 Ratna

J. P. Sharma and S. C. Mani, Plant Saket Narendra 2 N22 Basmati 370 Mahsuri Rasi

Breeding Department, G. B. Pant University of Agriculture and Technology, Pantnagar, India

Govind IR58 Manhar UPR82-42

We crossed 17 cultivars of early, medium, and late duration (as male parents) with 4 cytoplasmic genetic male sterile lines (IR46830A, IR46831A, Zhen Shan 97A, and V20A) to identify their fertility restorers and maintainers.

dishes, transferred to pots, and transplanted in the field 30 d after germination.

Varieties were classified on the basis of spikelet fertility in their F 1 hybrids: restorers = >80% spikelet fertility, partial restorers = 10-79%, and

The F 1 seeds were germinated in petri

IR46831A –

Zhen Shan 97A V20A

– –

maintainers = <10%. Narendra 1, Saket 4, and Basmati 370

were effective restorers for IR46830A. Ratna, N22, and Rasi were identified as maintainers for this CMS line (see table). Pant Dhan 4 was a maintainer

Pant Dhan 6 Manhar Pant Dhan 4 Pant Dhan 6

Govind Saket 4 – Pant Dhan 4 –

UPR79-123

for the CMS line IR46831A. No fertility restorer was identified for

Zhen Shan 97A, V20A, and IR46831A. There was segregation for fertility in the F 1 when V20A was crossed with Pant Dhan 4.

Media conditioning to convert nonembryogenic rice calli to embryogenic calli

M. B. Sticklen, Forestry Department, Michigan State University, East Lansing, MI 48824; and M. E. Rumpho and R. A. Kennedy, Horticulture Department, Ohio State University, OH 43210, USA

We investigated the effect of media conditioning on converting rice

nonembryogenic (NE) callus to embryogenic (E) callus.

were dehulled mechanically, surface sterilized in 5% sodium hypochloride solution for 30 min, and rinsed 3 times with sterile distilled water. Seeds were sown in basal salts and vitamins of Murashige and Skoog (MS) medium supplemented with 200 mg myo- inositol/liter, 100 mg thiamine HCl/liter, 3% (wt/vol) sucrose, and

Rice ( Oryzae sativa L. cv. S201) seeds

8 IRRN 14:2 (April 1989)

0.7% Difco Bacto agar (pH 5.7). Cultures were incubated under complete darkness at 22 ± 2°C.

Ten-day-old seedlings were cut in 2- to 3-mm pieces and cultured in a callus formation medium consisting of germination medium supplemented with 20 µM 2,4-dichlorophenoxyacetic acid (2,4-D). Five petri dishes each containing pieces of four seedlings were used per treatment. All cultures were subcultured every 4 wk.

Two weeks after the second subculture, five samples of callus from each treatment were microscopically examined to identify E and NE calli (see figure, a). The E calli were smooth and yellowish and were composed of small compact cells with dense cytoplasm. The NE calli were pale and loosely packed and were composed of larger, crescent- shaped cells.

To condition the medium (5 ml of MS medium supplemented with 20 µ M 2, 4-D), 5 g E callus were subcultured to 10 15-mm petri dishes (conditioned medium). Ten petri dishes with medium but without E callus were the control (unconditioned medium). All dishes were sealed and kept in darkness for 10 d.

E calli were removed from the conditioned medium and 5 2-3 mm NE

Rice somatic embryogenesis: a) E callus vs NE callus formed in cultures; b) a normal somatic embryo with distinct coleoptile (CP), coleorhiza (CR), and scutellum (SC), ×80; c) plants grown from somatic embryos, × 0.17.

callus pieces were transferred onto all 20 petri dishes. NE calli that produced E calli were counted after 2 wk.

medium produced E calli; 16% of the NE calli grown in conditioned medium produced some organized cells. Those cells were subcultured onto medium containing 2.5 µ M 2, 4-D and incubated

No NE calli cultured in unconditioned

under dim light (30 µ E/m2 per s). The nodules that were produced developed into normal-appearing embryos 2 wk after they were subcultured onto growth regulator-free differentiation media. All somatic embryos looked normal (see figure, b), germinated in 5-7 d, and produced plants (see figure, c).

Yield potential

A path-coeff icient analysis of rice panicle characters

S. Mallik, A. M. Aguilar, and B. S. Vergara, Plant Physiology Department, IRRI

The relationship between high density (HD) grains (those with specific gravity of 1.20 or higher) and other panicle characters could be an effective selection criterion,

parents, 50 panicles from 6 F1s, and 250 We studied 50 panicles from 9

panicles from F2s. HD grain index (HDI) was calculated by dividing the number of HD grains by the total number of spikelets per panicle on primary and secondary branches. Path- coefficient analysis was used to assess the direct and indirect influence of different panicle characters on HDI on primary branches (HDIPB).

number of spikelets on primary branches had a strong positive association with HDIPB in all generations (see table). Those characters are probably controlled by an additive gene action. The number of secondary

The number of primary branches and

Direct (underlined) and indirect effects of associated traits on high density grain index on primary branches (HDIFB). a IRRI, 1988.

Trait Generation Tiller PB SB SPB SSB StPB StSB HDISB r

Tiller P –0.19 –0.02 – –0.01 – 0.01 –0.02 0.64 0.40* F 1 0.26 0.02 – 0.03 0.01 – – 0.34 0.65** F 2 0.04 0.01 –0.01 –0.01 0.01 0.01 –0.04 0.23 0.39**

Primary P –0.03 –0.14 0.04 0.28 – –0.01 –0.11 0.38 0.44** branch (PB) F 1 0.07 0.08 – 0.07 – 0.01 – 0.26 0.49**

Secondary P – –0.09 0.06 0.24 0.01 0.02 –0.22 0.33 0.34* branch (SB) F 1 0.01 – – 0.01 0.13 –0.07 – –0.15 –0.07

Spikelet on P – –0.11 0.04 0.34 – –0.03 –0.11 0.39 0.54** PB (SPB) F 1 0.07 0.06 – 0.11 – 0.02 – 0.31 0.56**

Spikelet on P SB (SSB)

F 2 – 0.14 –0.02 –0.10 0.03 0.06 –0.02 0.20 0.31**

F 2 0.01 0.08 –0.04 –0.05 0.06 0.05 –0.01 0.06 0.17*

F 2 – 0.13 –0.02 –0.15 0.03 0.09 –0.02 0.21 0.31**

F 1 0.01 – – – 0.18 –0.08 – –0.19 –0.17 F 2 0.01 0.07 –0.04 –0.05 0.07 0.05 –0.01 0.03 0.13

F 1 – – – –0.01 0.06 –0.23 0.01 –0.32 –0.49** F 2 –0.01 –0.02 0.01 0.03 –0.01 –0.36 0.16 –0.48 –0.70**

F 1 –0.01 –0.01 – –0.01 0.05 –0.20 0.01 –0.37 –0.56** F 2 –0.01 –0.01 – 0.01 – –0.28 0.22 –0.56 –0.63**

0.01 –0.09 0.05 0.24 0.01 0.02 –0.22 0.40 0.43*

Sterility on P PB (StPB)

–0.02 0.01 0.01 –0.09 – 0.11 –0.33 –0.08 –0.39*

Sterility on P SB (StSB)

–0.01 –0.03 0.03 0.08 – 0.09 –0.44 0.15 –0.13

HDI on SB P –0.13 –0.06 0.02 0.14 – –0.01 –0.07 0.91 0.81** (HDISB) F 1 0.14 0.03 – 0.05 –0.06 0.12 – 0.61 0.90**

F 2 0.01 0.03 – –0.03 – 0.22 –0.15 0.81 0.89** a – indicates value almost equal to zero. Residual effects: parent (P), 0.41; F 1 , 0.31; F 2 , 0.39.

IRRN 14:2 (April 1989) 9

branches and of spikelets on secondary branches was correlated positively with HDIPB only in parents; it was not consistent in the F 1 and F 2 . HDI on secondary branches (HDISB) was correlated positively with and had direct effects on HDIPB in both segregating

(see figure) and nonsegregating generations. In most cases, negative correlations and direct and indirect effects were found between HDISB and sterility.

primary branches and more spikelets on Higher HDI depends on more

primary branches, and not on number of spikelets on secondary branches. A plant type for increased yield should have more primary branches and spikelets on primary branches, with few secondary branches and spikelets on secondary branches.

Path diagram and coefficients of factors influencing HDIPB in F 2 .

Heterosis and heterobeltiosis for high density grain index (HDI) and other rice panicle characters

S. Mallik, A. M. Aguilar, and B. S. Vergara, Plant Physiology Department, IRRI

We assessed heterosis and heterobeltiosis for 9 quantitative characters in 6 crosses, using 6 high density (HD)-grain parents (at least 30% of grains with more than 1.20 specific gravity) and 2 low density (LD)-grain parents. HDI was calculated

10 IRRN 14:2 (April 1989)

as number of HD grains divided by total number of spikelets/panicle on primary (PB) and secondary (SB) branches.

Estimates of overall degree and direction of heterosis (Fmac 1 -Pmac) were significantly positive for number of tillers (1.74*), PB (1.27*), SB (3.28*), spikelets on PB (8.65*), spikelets on SB (8.41*), and sterility on SB (5.37*), indicating dominance of higher values. Heterosis was negative only for number of spikelets on PB (-3.01*). Low or nonsignificant heterosis for other characters may be due to little genetic

interactions or differences among parents.

The individual F 1 family differed from overall estimates for different characters showing positive, negative, or no heterosis. The F 1 means deviated conspicuously from parental and midparental values, indicating involvement of nonadditive gene action in the expression of most characters.

Substantial heterosis in the desirable direction was observed in PB number, spikelets on PB, and HDI on PB and SB. Three crosses among HD-grain

Heterosis and heterobeltiosis (%) of 7 quantitative characters in 6 crosses. a IRRI, 1988.

H or Hb (HD/HD) (HD/HD) (0.05) LSD

Trait (HD/HD) (HD/HD) (HD/LD) (HD/LD) P 3 /P 4 P 5 /P 2 P 2 /P 6 P 3 /P 7

Tiller (no.) H 25.6 2.1 11.1 13.7 –11.6 19.6 7.6 Hb H 28.4

–11.1 –7.4 – –25.9 1.8 6.1 Primary branch - PB (no.) – 4.1 30.6 11.1 5.4 21.3

Hb 28.3 –11.0 27.0 4.2 –8.5 12.1 9.8 7.9

Secondary branch - SB (no.) H 29.0 –12.9 57.4 65.4 10.3 23.8 16.9 Hb 1.1 H

–34.3 42.3 48.5 –18.7 10.4 18.9 45.6 Spikelet on PB (no.) –7.4 56.4 19.1 –2.5 31.0 14.8

Hb 45.4 – 9.6 43.3 9.7 –7.8 19.6 Spikelet on SB (no.) H 28.4 49.3 72.5 –0.7 38.4 18.8

13.9 –16.3

Hb –4.3 –38.5 21.6 46.8 –22.1 30.4 Sterility on PB (no.) H

19.0 –28.7 87.9 –12. 9 9.9 –25.7 –66.2 30.2

Hb –35.6 24.3 Sterility on SB (no.) H

–22.6 18.8

–7.9 –27.2 146.7 25.7 93.1

–70.2 18.0

Hb 9.0 68.7 –15.8 –59.9 43.0

15.9 37.2 –25.6 –65.1 27.1

–

a H = heterosis, Hb = heterobeltiosis. P 1 = IR32307-75-1-3-1, P 2 = IR30, P 3 = IR34615-75-1-1, P 4 = IR29725-135-2-2-3, P 5 = IR29692-117-1-2-2, P 6 = IR35337-61-2-2-2, P 7 = IR32419-102-3-2-3, P 8 = IR32385-37-3-3-3.

P 3 /P 4 and P 3 /P 7 , showed negative heterosis for almost all characters.

Number of HD grains was higher on PB of parents and hybrids. Substantial heterosis for this character may lead to higher yield, since HD grains have higher test weight and higher head rice recovery. The cross P 2 / P 8 had positive heterosis for all desirable traits and exceeded the highest parent for HDI on both PB and SB.

Percentage of heterosis and heterobeltiosis for HDI. IRRI, 1988.

parents (P 1 /P 2 , P 5 /P 2 , P 2 /P 6 ) and one manifested positive heterosis and cross between HD- and LD-grain heterobeltiosis for HDI on PB (see parents (P 2 /P 8 ) exhibited positive figure). The cross P 2 /P 8 showed positive heterosis and heterobeltiosis for number heterosis for all characters except of PB and spikelets on PB (see table). sterility on PB and SB, where negative Only two crosses, P 5 /P 2 and P 2 /P 8 , heterosis is desirable. Two crosses,

Adaptability of rice varieties to low light intensity

M. S. Islam and M. Z. Haque, Plant Physiology Division, Bangladesh Rice Research Institute (BRRI), Joydebpur, Gazipur, Bangladesh

A major cause of low yields in the aus season in Bangladesh is low light intensity at later growth stages, mostly at ripening, due to continuous cloudy weather Jul-Aug. Wide variation in grain yield is also observed.

We studied varietal adaptability to low light intensity at ripening. Five modern and five traditional varieties were seeded so that the ripening stage would occur at the same time, late in the aus season to avoid cloudy weather. We transplanted 25-d-old seedlings in pots fertilized at 40-80-60 kg NPK/ ha; 80 kg N/ ha and 40 kg N/ ha were topdressed in modern varieties and traditional varieties, respectively.

IRRN 14:2 (April 1989) 11

P 1 /P 2 P 2 /P 8

As soon as panicles began to emerge, with six replications. both light intensities, and was the least the plants were covered with cloth Grain yield in all varieties decreased affected modern variety. The highest screens to provide 22-26% of full significantly with low light exposure yield reduction was in BR6, followed by sunlight for 28 d. Check plants were (see table). Hashikalmi was least BRl. Filled spikelets were more affected grown in full daylight. The experiment affected, followed by BR9 and than 1,000-grain weight. was in a randomized complete block Kataktara. BR9 had the highest yields at

Effect of low light intensity at ripening on yield and 2 yield components of aus varieties. a BRRI, Bangladesh.

Grain yield Filled spikelets 1000-grain weight Variety Normal light Low light Reduction Normal Low light Reduction Normal light Low light Reduction (%)

due to low light (g/pot) (g/pot) (%) due to light (%) (%) due to (g) (g) low light (%) low light

BR1 10.98 g 3.96 ef 64 e 73 cd 47 d 36 cd 19.89 e 16.50 BR3 25.24 b 10.74 b 57 de 81 abc 52 cd 35 cd 25.64 ab

g 17 cd

BR6 14.73 f 3.47 f 76 f 85 ab 48 d 44 de 23.82 c 21.91 ab 15 bc 20.03 de 19 d

BR9 31.81 a 17.19 a 46 b 77 bc 56 bcd 26 bc BR12

21.64 d 20.55 cd 18.69 de 7.73 c e 58 de 90 a 65 b 28 bc 20.98 de 17.42 fg 17 cd

5 a

Hashikalmi 17.14 ef 11.93 b 30 a 90 a 80 a 11 a 24.56 bc 23.03 a Dharail 16.37 e 6.45 de 61 de 69 d 32 e 52 a 23.65 c 21.76 bc

6 a

Morichboti 21.23 cd 9.30 bc 56 cde 83 ab 54 cd 34 bcd 26.33 a 23.21 a 13 b 7 a

Dular 24.31 b 12.04 b 51 bcd 82 ab 57 bc 30 bc 23.50 c 21.99 ab 14 bc Kataktara 22.43 bc 11.63 b 48 b 83 ab 65 b 22 ab 21.82 d 19.12 e 12 b

a In a column, means followed by the same letter are not significantly different at the 5% level (DMRT). Within a variety, treatment effect was significant at the % level (DMRT).

Correlations between allogamic and agronomic traits in rice

P. de C. F. Neves, E. P. Guimarães, and J. Taillebois, EMBRAPA/ Centro Nacional de Pesquisa de Arroz e Feijão (CNPAF), Caixa Postal 179, 74000 Goiânia, Goiás, Brazil

We studied the correlations between allogamic and agronomic traits in F3- derived lines from the BC2 generation of the cross Oryza sativa L. / Oryza longistaminata A. Chev. The male parent possesses well-developed floral parts. The F3 lines were evaluated in a completely randomized block design with four replications at two locations in 1986-87.

Allogamic traits evaluated were stigma and anther length, agronomic characters were spikelet and panicle length. Variance and covariance analyses were used.

Table 1 shows the very high coefficients of heritability found for stigma, anther, and spikelet length (0.92, 0.94, and 0.92, respectively). These results indicate that visual selection can be used efficiently for these traits.

12 IRRN 14:2 (April 1989)

Table 1. Coefficient of heritability and average length of stigma, anther, spikelet, and panicle.

Trait Coefficient of heritability

Average length

Stigma length (mm) 0.9163 1.53 ± 0.27 Anther length (mm) 0.9413 2.62 ± 0.33 Spikelet length (mm) 0.9215 7.39 ± 0.50 Panicle length (cm) 0.6389 19.11 ± 2.81

Table 2. Genetic (G), phenotypic (P), and envi- ronmental (E) correlations between stigma, anther, spikelet, and panicle length. Screening long-duration rice

Anther Spikelet Panicle cultivars for ratooning ability Stigma G 0.5548** 0.1565 0.0900

P 0.5138** 0.1393 0.0349 S. Gupta and S. K. Bardhan Roy, Rice E 0.2980 0.1614* 0.2278 Research Station, Chinsurah, West Bengal,

P –0.0076 0.1881 E

Spikelet G

Anther G –0.0280 0.1979 India

0.2020 0.1231 We screened 210 entries from IRTP

P –0.1336 –0.3006 nurseries (1986 International Rice

E 0.3785 Shallow Water Observational Nurseries [IRSWON], 1986 International Rice Deepwater Observational Nurseries

Table 2 shows significant and positive [IRDWON], and 1985 International genetic and phenotypic correlations Upland Rice Yield Nurseries [IURYN]) between the allogamic characters, to select semidwarf long-duration or indicating that selection for one photoperiod-sensitive rice cultivars that, character can positively change the when sown in November, could be other. harvested in April/ May with a ratoon

between the two allogamic traits and Entries were sown 28 Nov 1986 and spikelet and panicle length. transplanted 16 Jan 1987 in 2 rows at

No significant correlations were found crop flowering in late Sep.

20- × 15-cm spacing. Plant height, Ratooning ability of semidwarf photoperiod-sensitive rice varieties. Chinsurah, India, Nov 1986. flowering duration, and yield/ plant were Main crop recorded for the main crop. Ability to produce ratoon tillers and flowering

Entry Source

behavior of the ratoon were the bases

Ratooning Ratoon ability flowering Plant ht Days to 50% Yield

(cm) flowering (g/plant) (%) date

for selecting suitable varieties. Entries with plants less than 100 cm

tall were favored for ratooning, since the main crop was grown under controlled conditions and at higher fertilizer rates (100-22-42 kg NPK/ha) for maximum yield. Nine entries were identified for further study (see table).

RAU4057-35-20, Leuang Yai 148, and C924-9 have semidwarf plant type, high yields, and 1% ratooning ability. Their ratoons flowered the end of Oct,

SPR7292-0-0-0-0-1 RAU4057-35-20 Leuang Yai 148 IR13149-43-2-P RTN90-4 TKM9

NC500 IR38787-26-2-1-2

C924-9

IRSWON 83 ± 4 155 IRSWON 77 ± 2 136 IRSWON 77 ± 2 144 IRSWON 96 ± 4 15 3 IRSWON 96 ± 3 158 IRDWON 93 ± 2 123 IRDWON 100 ± 5 127 IRDWON 96 ± 7 161 IURYN (M) 87 ± 6 140

20 ± 7 86 25 Sep 1987 8 ± 4 100 29 Oct 1987

20 ± 7 100 29 Oct 1987 16 ± 4 100 3 Oct 1987 11 ± 4 100 26 Oct 1987 8 ± 4 100 17 Oct 1987 9 ± 3 100 18 Oct 1987 6 ± 4 100 26 Oct 1987

19 ± 6 100 31 Oct 1987

probably because the lines have shorter IR13 149-43-2-P in early Oct. These critical photoperiod. SPR7292-0-0-0-0-1 dates are more or less desirable for planted in late Sep, followed by establishing the next crop in Nov.

Effect of high temperature rice spikelet fertility

on different heading dates. Spikelet fertility SFP differed significantly among percentage (SFP) was measured on 7-41 plants with different heading dates from randomly selected plants, 3 the same cultivar. SFP at normal

Xu Yunbi, Shen Zongtan, and Shi Chunhai, panicles/plant, for each cultivar and temperatures 24-28 Jun was higher than Agronomy Department, Zhejiang each planting date. at high temperatures 2-14 Jul (see table Agricultural University, Hangzhou, China

An abnormally high percentage of Empty spikelets in first crop indica rice occurs in ricefields south of the Yangtze River when flowering takes place in the heat of July. Daily maximum temperatures of 35.5-38.9 °C 1-20 Jul 1988 in Hangzhou lowered rice yields.

We studied the effect of high temperature on spikelet fertility by using different seeding dates to result in

Spikelet fertility at different heading dates. a

Hangzhou, China, 1988.

Spikelet fertility (%) at Variety heading date

27 Jun 1 Jul 5 Jul

Yuanfengzao 93.9 a 84.3 b 76.8 c (15) (15) (15)

Erjiunan 1 89.1 a 80.5 b 34.9 c (11) (15) ( 10)

Zhe 85-2 (15) (15) 88.2 a 87.2 a 76.2 b

(15) Guangluai 4 85.3 a 78.5 b 70.5 c

(8) (15) (15) Zaolian 31 85.2 a 74.3 b 68.5 c

(15) (15) (15) Erjiufeng 79.6 a 78.4 a 58.1 b

(7) (15) (15) Relationship between mean spikelet fertility percentage ( Y ) of varieties with the same heading date and mean maximum temperature 3 d after heading ( X ) ( r YX = –0.9570, Y = 73.47 – 0.44 X ). Cultivars: 1 =

a Figures in parentheses are sample sizes. In a Erjiufeng, 2 = Zhefu 802, 3 = Erjiuqing, 4 = Guangluai 4, 5 = Zhong 83-49, 6 = Erjiunan 1, 7 = w, figures followed by the same letter are not Yuanfengzao, 8 = Zhe 85-2, 9 = Zaolian 31, 10 = Ainanzao 39, 11 = Guiluai 8, 12 = Zhuxi 26, 13 = significantly different at the 5% level by DMRT. Guangliuzao, 14 = Qingganhuang, 15 = Zhuyunnuo, 16 = Ezao 6, 17 = IR58, 18 = IR28, 19 = IR50.

IRRN 14:2 (April 1989) 13

and figure). Yuanfengzao and Zhe 85-2 respectively). after heading. SFP decreased with that headed at >35 °C had higher SFP There was a significantly negative increasing MMT. The critical day for (76.8, and 76.2, respectively) than correlation between SFP and mean significantly decreased SFP was 30 Jun, Erjiunan 1 and Erjiufeng (34.9 and 58.1, daily maximum temperature (MMT) 3 d when MMT was 35.9 °C for 3 d.

Grain quality and nutritional value

Using silica gel desiccant to dry rough rice samples

P. A. Clarke, Overseas Development Natural Resources Institute (ODNRI), Culham, Abingdon, Oxon OX14 5PR, UK; and M. A. Quasem, Bangladesh Rice Research Institute (BRRI), Joydebpur, Gazipur, Bangladesh

Grain quality was measured as grain results at least as good as, and some breakage on milling. The table compares better than, traditional methods, with gel-dried samples with sun- and air-dried higher control and resource samples. The gel technique produced optimization.

Moisture content and milling quality of rice dried in a contact mix with ID silica gel and by air and sun.

Moisture content (%) Milling quality (% brown rice) Drying process

Initial Residual Degree of milling Broken grain

The method and rate by which rough rice is dried changes the characteristics by which grain quality is judged. We have developed a method that achieves high standardization of large numbers of small samples of grain (less than 1 kg). It is based on the sorptive capacity of a special grade of silica gel mixed directly with field-wet rice.

Intermediate density (ID) grade silica gel is dried, cooled, mixed with field-wet rice in the ratio 1:2 by weight, and the mixture sealed in a moistureproof container. After 24 h, the 2 constituents are separated by screening.

The figure shows the linear regression of field (input) moisture content on residual (output) moisture content within 20-30% wet basis for the model

Y = 4.17 × 0.38; r = 0.91, p=0.01.

Gel Air Sun

Gel Air Sun

Gel Air Sun

Gel Air Sun

19.2 19.2 19.2

24.6 24.6 24.6

27.1 27.1 27.1

28.9 28.9 28.9

BR1 12.4 14.3 14.1

BR3 13.7 14.1 14.5

BR4 14.5 15.6 13.2

BR10 15.2 14.8 13.9

16.1 a 15.8 a 15.9 a

13.5 a 13.0 a 12.5 a

13.2 a 13.9 b 13.0 a

14.0 a 15.1 b 14.4 a

20.2 a 21.2 ab 21.7 b

10.4 a 10.4 a 9.1 a

5.0 a 5.3 a 5.6 a

6.2 ab 6.6 b 5.9 a

In a column for a variety, means followed by the same letter are not significantly different by DMRT at p = 0.05.

Disease resistance susceptible parent to study the inheritance of reaction to artificial ShB inoculation at booting by virulent isolate

Resistance to sheath blight RH-9, collected in Jiangsu Province. (ShB) in China The F 1 of four combinations of

moderately resistant and susceptible Xue-Yan Sha and Li-Hong Zhu, Nanjing parents showed intermediate reaction to Agricultural University, Nanjing, China inoculation; the F 2 distributions tended

ShB caused by Rhizoctonia solani resistance to ShB is controlled by [ Thanatephorus cucumeris (Frank) multiple genes (see figure). Broad and Donk] is a major disease in the rice narrow sense heritabilities estimated areas along the middle and lower from the cross IR9752-71-3-2/IET4699 reaches of the Yangtze River and in were h 2 B = 0.516+0.0654 (broad) and South China. In 1985-87, we used Tetep, h 2 N = 0.373+0.063 (narrow). IET4699, Jawa no. 14, and Yedao as Analysis of combining abilities based resistance donors and IR9752-71-3-2 as on the performance of 28 diallelic F 1 s

to be continuous. That implies that

Effect of contact mix with ID silica gel on rice input and output moisture content.

14 IRRN 14:2 (April 1989)

Analysis of variance in combining abilities of reactions to rice ShB, 1986.

Distribution of resistance to ShB in F 2 of PI- Tetep, P2-IET4699, P3-Jawa no. 14, P4-Yedao, and P8-IR9752-71-3-2.

A new inoculation technique for rice blast (BI)

Sun Guochang and Sun Shuyuan, Plant Protection Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou; and Shen Zongtan, Agronomy Department, Zhejiang Agricultural University, Hangzhou, China

We studied a smear method for inoculating with the rice Bl pathogen Pyricularia oryzae Cav. for resistance screening. Smear inoculation conditions are similar to natural infection.

The method requires only a small amount of spore suspension and gives a high infection frequency. Inoculation is carried out by smearing the mixture 1-2 × 10 5 conidia/ ml suspended in 1-2% carboxymethyl cellulose onto the rice leaf with a brush.

at several stages, but especially at the 2- 4-leaf stage. A spore suspension of 1 × 10 5 conidia/ml gives nearly 100% leaf infection. Smear inoculation produces a higher disease index than spray inoculation, but lower than injection inoculation (Table 1).

This method also is useful as a simple and precise method for evaluating neck Bl resistance (Table 2).

The method is suitable for inoculation

Sum of Mean DF squares square

F values a

Source of variation Model 1 2

General combining ability 7 16.0891 2.2984 257.67** 18.87** Specific combining ability 20 10.5383 0.5269 59.07** 4.33** Error Model 1 924 0.0089

2 54 0.1218

a ** = significant at 0.01.

without reciprocals among Tetep, IET4699, Mianhuatiao, Jawa no. 14, Yedao, 84-3019, Shuidaobawang, and IR9752-71-3-2 showed that general combining abilities were more prominent than specific combining abilities. That means that additive gene effects play a more important role in inheritance of resistance to ShB (see table). It would not be possible to derive

an elite line with a resistance level similar or superior to that of moderately resistant parents through recurrent selection.

For informatton on ordering IRRI publications, write Communication and Publications Dept., Div. R, IRRI, P.O. BOX

933, Manila, Philippines.

Table 1. Effect of smear inoculation on leaf B1. Hangzhou, China, 1987.

Bl index a Bl score b

Injection Smear Spraying Injection Smear Spraying Variety

Indica Chei-Tang Nong 8506 Gui-Chao 2 Hou-Zeng-Zao Zao-Shuang 1 Zhong 83-40 Zhong 83-49

B40 Hong-Tu 3

8004 Er-Jiu-Qing Zuo 5 Japonica Pi-4 Kusabue BL 1 Dong-Nong 363 Li-Jiang-Xing-Tuan-He-Guo

0 0 0 5.6

14.8 69.6 76.4 86.9 83.0 96.9 95.1 94.8

0 18.3 87.2 71.8

100.0

0 0 0 0 0 0 4.9 1.5

14.3 4.0 29.4 17.8 68.6 45.5 71.2 48.9 80.4 45.8 73.9 48.3 85.8 53.5 80.4 56.2

0 0 24.3 3.5 52.4 41.0 68.6 42.7

100.0 92.4

0 0 0 0.5 1.3 6.3 6.9 7.8 7.5 8.7 8.6 8.5

0 1.6 7.8 6.5 9.0

0 0 0 0.4 1.3 2.6 6.2 6.4 7.2 6.6 7.7 7.2

0 2.2 4.7 6.2 9.0

0 0 0 0.1 0.4 1.6 4.1 4.4 4.1 4.4 4.8 5.1

0 0.3 3.7 3.8 8.3

a Disease index = (number of plants with a given score × value of that score)

b Based on Standard evaluation system for rice. total number of plants × value of the highest score

Table 2. Effect of smear inoculation on neck Rice sheath blotch incidence Bl. Hangzhou, China, 1987.

Inoculation Plants Plants with Infection

in Haryana

(no.) (%) Agricultural Research Institute, New Delhi, method (no.) Bl infection frequency U. Bhan and S. C. Ahuja, Indian

Injection 10 10 100.00 India Gear 22 22 Spraying 10 6 60.0

100.00 Sheath blotch caused by Pyrenochaeta oryzae Shirai ex Miyake is increasing in

IRRN 14:2 (April 1989) 15

S

Resistance a of rice varieties to sheath blotch in Kaul, India.

Lesion length Group Variety (mm)

10-15 1 IET7662, IET7738, IET7753, IR13420-6-3-3-1, IR17494-32- 1-1-3-3, RP2151-21-1, RP2151-33-4, RP2151-7752, RP2240-86-84, CN758-1-1-1, UPR80-149.

15-30 2 Jaya, Ratna, HKR101, HAU3800-1, HAU3855-1, RP1832-23-34, RP2151-27-1.

30-45 3 HAU101-88, RP2151-76-1. 45-60 4 HAU47-6045-1, HAU101-60. >60 5 IET7641,1R19661-23-3-2-2.

tant = group 3, susceptible = groups 4 and 5. a Resistant = groups 1 and 2, moderately resis-

Insect resistance

Registration of brown planthopper (BPH)-resistant germplasm lines in Japan

H. Nemoto, E. Shimura, and C. Kaneda, National Agriculture Research Center, Tsukuba, Ibaraki 305, Japan

Breeding to introduce the BPH resistance gene from indica to japonica rice varieties started in 1968. Since then, we have developed four japonica type lines, each with one of four different resistance genes ( Bph 1, bph 2, Bph 3, and bph 4 ) (see table).

Norin PL 3, with the Bph 1 gene, was selected from the cross F 6 324/ Akitsuho // Tsukushibare. F 6 324 is the donor parent, with Bph 1 from Hoyoku/ Mudgo/2/ Kochikaze/3/ IR781-1-94/4/Hoyoku. In 1984, Norin PL 3 was registered as a germplasm line by the Ministry of Agriculture, Forestry, and Fisheries (MAFF), Japan.

Norin PL 4 inherited bph 2 from IRI 154-243 through the cross combination of Asominori/ IRI 154- 2431 / 2*Asominori. It was registered in 1985.

Tsukushibare *2/ Babawee inherited bph Norin PL 7 from the cross

16 IRRN 14:2 (April 1989)

ricefields in Haryana. The disease appears as irregular and brownish lesions that enlarge and become sepia- colored. The middle portion of the lesion finally turns whitish and is studded with pycnidia, the characteristic symptom of the disease.

We conducted a roving survey 15-1 8 Oct 1986, when the rice crop was at the dough to maturity stage. Disease incidence was recorded on both sides of the road every 8 km. Of 52 villages, in Ambala, Jind, Karnal, and Kurukshetra districts, disease was found in 11 villages, more in Kurukshetra than in other districts. No disease was found in

Hisar and Sirsa districts. Disease incidence was higher on rice variety PR107, followed by Jaya, Basmata, and PR106.

Incidence on varieties or genotypes grown under field conditions at Haryana Agricultural University Rice Research Station, Kaul, was measured during 1986 wet season. Those varieties were categorized into five groupings on the basis of lesion length on the outer leaf sheath. Entries with lesion lengths 1-30 mm were categorized as resistant; 30-45 mm, moderately resistant; and more than 45 mm, susceptible (see table).

Germplasm lines with BPH resistance.

Line Resistance

gene Donor parent Days to heading

Culm length (cm)

Norin PL 3 Bph 1 Mudgo 128 71 Norin PL 4 bph 2 IR1154-243 128 67 Norin PL 7 bph 4 Babawee 127 83 Norin PL 10 Bph 3 Rathu Heenati 131 80 Tsukushibare – – 130 73 Asominori – – 130 76

4 from Babawee. It was registered in 1987.

Norin PL 10, selected from the cross Tsukushibare/3/Tsukushibare*3/ Rathu Heenatil /Tsukushibare, inherited Bph 3 from Rathu Heenati. It was registered in 1988.

The antibiosis of these lines to BPH is similar to or slightly weaker than that of the donor indica varieties. The lines show inhibitory effect on BPH survival and population increase and different reactions to the biotypes.

Their morphological characteristics are mostly those of japonica varieties, except for a few traits, such as the amylose content of Norin PL 10.

When these lines are crossed with other japonica varieties, the F 1 does not show hybrid sterility, except with Norin PL 7. Partial seed sterility was observed in F 1 plants of Norin PL 7/a Japanese line.

These four lines are being used to breed BPH-resistant varieties in Japan.

Rice resistance to WBPH incidence has increased in recent whitebacked planthopper years, particularly in the irrigated boro

Bangladesh (WBPH) Sogatella furcifera in (Dec-Mar) crop. We screened BRRI

varieties BR1-BR12 and BR14-BR21 and 22 IR varieties, using the standard

A. N. M. R. Karim and Q. M. A. Razzaque, seedbox test. TN1 was the susceptib1e Entomology Division, Bangladesh Rice check. Research Institute (BRRI), Gazipur, Seedlings (20/ 12-cm row) were Bangladesh infested with 2d- and 3d-instar nymphs

from a stock culture, at 5 nymphs/seedling. Plant damage was

measured (Standard evaluation system for rice 0 to 9 scale) 10 d after infestation, when all TN1 seedlings were killed.

All test varieties except IR64 were susceptible (see table). IR64, which exhibited moderate resistance, is not grown in Bangladesh.

We screened 18 BRRI elite breeding lines, 41 promising exotic varieties, and 23 local germplasm collections using the same procedure. Only BR1711-7-24-2

Reaction of BR and IR varieties to WBPH in Bangladesh. BRRI, Gazipur, 1987.

Plant

score a Variety damage Reaction b

BR1 9.0 S BR2 8.3 S BR3 7.7 S BR4 8.3 S BR5 9.0 S BR6 9.0 S BR7 8.3 S BR8 7.0 S BR9 7.0 S BR10 8.3 S

7.7 S 7.7 S

BR14 7.7 S BR15 8.3 S BR16 7.7 S BR17 9.0 S BR18 7.7 S BR19 9.0 S BR20 9.0 S BR21 9.0 S IR5 8.3 S IR 8 9.0 S IR20 9.0 S IR22 9.0 S IR24 9.0 S IR26 9.0 S IR28 7.7 S IR29 8.3 IR30 8.3 S IR32 8.3 S IR34 8.3 S IR36 8.3 S

and BR2070-15-6, exotic variety Lua Ngu (Vietnam), and local varieties Rajasail 3 and Rajasail 8 (BRRI acc. no. 2436 and 2440) were moderately resistant.

While varieties with moderate resistance may be planted if WBPH incidence is low, the breeding lines identified will require further

improvement and evaluation before they can be released.

Babawee, Hondarwala, Rathu Heenati, and Gangala are resistant to WBPH at IRRI, but susceptible at BRRI. Further studies are needed to determine whether the differential varietal reactions are due to differences in WBPH populations.

A potential donor for resistance to the gall midge (GM) population of Srikakulam District, Andhra Pradesh

P. Subbarami Reddy, M. A. Khader, I. N. Rao, and R. Radhakrishna, Andhra Pradesh Agricultural University, Agricultural Research Station, RA GOLU-532484, Srikakulam District, A. P., India

We evaluated four donors and two derivatives against the GM population of Srikakulam during rainy season 1988. Twenty-day-old seedlings of each entry were planted in 3-m rows at 15- × 15- cm spacing. GM incidence was recorded

in 21 hills at 30 and 50 d after transplanting (DT).

Only Banglei showed no GM (see table), and could be a donor for resistance to the GM population of Srikakulam District. The other potential donors (Eswarakora, Leaung 152, and Velluthacheera) showed no resistance. The two GM-resistant derivatives, W 1263 (MTU 15/ Eswarakora) and Phalguna (IR8/Siam 29), also did not show resistance reaction to the local GM population.

donors and derivatives, we strongly suspect the existence of a new GM biotype in the district.

In view of these reactions of proven

Reaction of donors and derivatives to GM. Srikakulam District, A. P., India, 1988.

GM incidence (%) Variety Parentage

30 DT 50 DT

Hill Tiller Hill Tiller

Eswarakora W1263

Donor 23.8 2.9 MTUlS/Eswarakora 38.1

Phalguna IR8/Siam 29 5.5

42.9 Leaung 152

7.5 Donor 28.6 4.5

Velluthacheera Donor 9.5 Banglei

1.0 Donor 0

TN1 0

Susceptible check 69.0 8.9

47.6 3.1 81.0 9.8 90.5 24.1 85.7 13.9 57.1 6.2

0 0 100.0 27.2

IR38 8.3 S IR40 9.0 S Screening for resistance to rice crop in the plateau region of Bihar, IR42 9.0 S IR44 S 7.7 IR45 7.0 S biotypes have been identified (one each IR46 7.0 S S. C. Prasad, J. B. Tomar, and S. D. Tomar, in China, Indonesia, Sri Lanka, IR50 7.7 S IR52 7.0

Plant Breeding and Genetics Department, S

Thailand, and in Andhra Pradesh and

IR56 6.3 MS Birsa Agricultural University, Kanke, Ranchi Orissa in India). The biotype at Ranchi IR64 5.0 MR 834006, India appears to be different (Table 1).

In 1986 wet season, 60 rice genotypes S = susceptible, MS = moderately susceptible, received from the All India Coordinated R = moderately resistant. major pest in India. This pest attacks the Rice Improvement Project, Hyderabad,

rice gall midge (GM) both upland and lowland. Six GM

Average of 3 sets, scored on a scale of 0-9 GM Orseolia oryzae Wood-Mason is a

IRRN 14:2 (April 1989) 17

BR11 BR12

a b

S

Table 1. Reaction of the Ranchi GM biotype and of 6 established biotypes to 5 differential varieties.

Origin Reaction a

Eswarakora Siam 29 OB677 PTB Leaung 152 group derivative derivative

China R R R S Indonesia S R R S R Sri Lanka S R R R R India (Andhra Pradesh) R R R R R India (Orissa) S R R R R Thailand R S S S S India (Ranchi) R S S MR S

a R = resistant, MR = moderately resistant, S = susceptible.

–

No silvershoots were found in RP1579-92-85-203. Resistance levels of cultivars are given in Table 2. Cultivars scoring 0-3 can be used as donor parents in the breeding programs.

For information on ordering IRRI publications, write Communication and Publications Dept., Div. R, IRRI, P.O. Box 933, Manila, Philippines.

Table 2. Evaluation of rice cultivars for field resistance to GM.

Score a Cultivars

0 RP1579-92-85-203 1 RP2199-3-3-5-1, RP2190-104-64-18-1,

RP2434-24-2-2, Phalguna 3 RP2235-163-33-8, RP2235-48-54-6,

RP2091-272-34-8, WGL 48684, R270- 3188, RP2431-6-62, RP2434-79-2-6

RP1125-638-1-1, RTN81, RP2435-50- 1, RP2434-24-1-2, RP2434-22-3-3, RP1579-34-54, RP2235-136-65-10, RP2235-91-15-1, RP1579-43, RP1579- 43-48, CR400-16, CR406-16,OR447- 3, RP2199-32-30-47-46, RP1607-1629- 44-221, RP1606-29-232, RP2431-5-3-4

5 Rp1125-606-637-1, W1125-630-667~1,

7 RP1125-604-1-1, RP1125-637-673-1, RP2199-84-2, WGL 44645, RP2432- 34-3-1 ,RP2432-34-3-4, RP2434-22-3-2, RP1579-38-48, RP1579-36-33, RP2235-85-62-8, RP2235-62-33-1, RP2199-34-6-1, CR404-6, CR400-15, CR404-9-1, R278-3528,OR633-7, RP2199-3-3-3-2, RP1528-86-43-220, RP1579-59-227, RP2434-79-2-4, RP2434-22-3-3, Vikas

9 RP2432-34-4-5, RP2432-34-5-4, OR706-4, RP2432-34-3-4, RP2432-34- 5-1, Jaya

a Based on Standard evaluation system for rice scale.

were screened against GM. The genotypes were sown in 4.50- × 2.0-m plots at 20- × l5-cm spacing with 2 replications. All recommended agronomic cultural practices were used.

Maximum GM infestation was in the last week of Sep to the first week of Oct. At 50 d after transplanting, 15 randomly selected hills were scored for number of hills having silvershoot and for number of silvershoots/infested hill. Susceptible checks Jaya and Vikas had severe infestation (more than 40%).

18 IRRN 14:2 (April 1989)

Resistance of rice varieties to Test lines with damage scores of 5.0 or lower against BPH, WBPH, and GM at Hyderabad, India.

brown planthopper (BPH), whitebacked planthopper (WBPH), and gall midge (GM) Accession no. Cultivar Damage in India score

Brown planthopper

R. K. Sahu and M. N. Shrivastava, Indira A440

Gandhi Krishi Vishwa Vidyalaya, Raipur A61 i B2112

Anjania 4.1 Bainspath 5.0 Bhakwa 5.0

492012, Madhya Pradesh: and M. B. C62 iii Chhatri 3.8 Kalode, Directorate of Rice Research, Hyderabad, India

BPH, WBPH, and GM cause substantial yield losses in Chattisgarh region (the rice bowl of Madhya Pradesh State). We screened about 400 accessions using the standard seedbox screening technique at Hyderabad 1983- 87. For BPH and WBPH, damage was scored on the Standard evaluation system for rice scale 1-9; absence of silvershoots was rated resistant to GM.

in replicated tests are presented in the table. Most of these varieties possess

Entries with damage scores 5 or lower

K2351

S644 L289 ii

Dl061 D307 i

Dl064

B2712

E.B. 17 Kabari Lalbasant Safeddhanwar

Whitebacked planthopper Batri Dihula Dihula Dihula Karanphool Khalasu

Gall midge Bhakwa Dehradodi Gurmatia Jhitpiti Kudunjan Lalbogri Tulasimanjari Viruppu

4.7 2.0 4.1 1.9

2.9 3.0 2.8 2.7 3.0 2.0

resistance to one pest; Bhakwa was resistant to both BPH and GM.

The International Rice Research Newsletter invites contributions of concise summaries of significant current rice research for publication. Contributions should be limited to no more than 2 pages typed double-spaced accompanied by no more than 2 figures, tables, or photographs. Contributions are reviewed by appropriate IRRI scientists and those accepted are subject to editing and abridgment to meet space limitations. Authors are identified by name and research organization. See inside front cover for more information about submissions.

Resistant Resistant Resistant Resistant Resistant Resistant Resistant Resistant

– – –

– – – – – –

Excess water tolerance

Heritability of stem elongation ability in rice

P. K. S. Ray, Plant Breeding Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh; and D. HilleRisLambers, IRRI

Inheritance of stem elongation ability in four semidwarf rice crosses was found to be controlled by two dominant genes.

Four semidwarf, nonelongating advanced lines were crossed with IR11288-B-B-69-1, which has stem elongation ability in addition to a dwarfing gene, and F 1 and F 2 seeds sown in 5- × 5-cm plastic pots. The pots were placed in galvanized iron trays in the glasshouse. At 35 d after seeding, the trays were placed in a tank and the water level raised, at 5 cm/day, to a maximum depth of 90 cm. This depth was maintained 7 d, then the tank was drained.

Stem length was measured from the root base to the uppermost node and plants categorized as elongating (stem length >20 cm) and nonelongating (stem length <20 cm).

Plants of all crosses survived a water depth of 1 m (see figure). Mean stem length of the F 1 and F 2 of all crosses was >20 cm. Most plants tended toward the elongating parents, indicating dominance of the stem elongation genotype over the nonelongating genotype. Distribution and means of parent, F 1 and F 2 plants for stem elongation ability in 4 crosses. Arrows show

were unimodal and continuous with Distributions of all F 2 populations

the mean.

single peaks. The segregation ratios of all crosses in the F 2 suggest that stem elongation ability was dominant.

observed in the F 2 , 13:3 for the cross

and 151 for the others (see table). Such ratios can be explained by the presence of a minimum of two genes. When the two dominant genes remain together, the typical stem elongating feature develops and plants carrying the genes resist about 1-m water depth.

Two types of segregation ratios were

BKNFR76106-16-0-1/IR11288-B-B-69-1

Inheritance of stem elongation ability in 4 crosses. IRRI, 1987.

Cross F 2 seedlings (no.)

F 1 Total Ratio x 2 P> Elongating Nonelongating

BKNFR76106-13-2/ Elongating 78 6 84 15:l 0.11 0.70

BKNFR76106-16-0-1/ Elongating 80 11 91 13:3 2.60 0.10 IR11288-B-B-69-1

IR11288-B-B69-1 IR8234-OT-9-2/ Elongating 154 16 170 15:l 2.90 0.05 IR11288-B-B-69-1 IR42/IR11288-B- Elongating 149 7 156 15:l 0.83 0.30 B-69-1

IRRN 14:2 (April 1989) 19

Integrated germplasm improvement The WS crop was rainfed; the DS crop was irrigated with poor quality lift irrigation water.

IET9783 : a salt-tolerant rice fine clayey, mixed, hyperthermic family, IET10676 yielded highest (4.0 t/ ha) in

experimental site was 7.2 in WS and 8.0 crop maturity in DS 1149 d, and yields for coastal saline soil Vertic Halaquept; pH of the WS (see table). Soil salinity delayed

P. N. Jagadev and D. Jena, National in DS. EC values were 1.2-6.8 dS/m did not differ significantly. Agricultural Research Project, Motto, during Jul-Nov and 2.7-13.5 dS/m Balasore District 756132, Orissa, India during Dec-Mar.

In 1987-88 DS, we evaluated 28 Coastal saline soil occurs in a narrow cultivars from the All India Coordinated Peformance of upland and strip along the Bay of Bengal, 375 km Rice Improvement Project, Hyderabad, long and 2.25 km wide and covering 2 resistant checks, and local checks

rainfed lowland rice varieties

2.54 million ha. Rice is the main crop of SR26-B in WS and CSR4 (Mohan). in farmers' fields in Mali wet season (WS), fields are fallow in The experiments were in a randomized dry season (DS). In a year of poor block design with three replications. R. B. Kagbo OHV/USAID, 12411 monsoon, the crop fails. Three 35-old seedlings/variety were

The Regional Research Station, transplanted on 25 Jul 1987 and 9 Jan Motto, is situated on the coast 10 km 1988 at 20- × 15-cm spacing in 4-m 2

away from the Bay of Bengal. Soil is plots. Fertilizer was 60-26 kg NP/ ha.

Antoine #413, Houston, TX 77067, USA

Rice variety trials in farmers' fields of the Operation Haute Vallée (OHV) were carried out in collaboration with the

Performance of rice varieties and cultivars in coastal saline soil at Motto, Balasore, India, 1987-88 WS and DS.

Cultivar Grain yield

Parentage Duration (d) (t/ha)

ws DS ws DS

IET10344 SAR41/Jaya 111 123 2.1 1.0 IET10345 SAR43/IR8 110 130 2.0 0.6 IET10346 IR1702-74-3/IR2061464-2 129 156 1.7 0.8 IET10348 CSRl/Basmati370//CSR5 134 154 2.2 1.l IET10349 M40-431-24-114/Jaya 110 143 1.8 1.3 CSRl Mutant CSR 1 111 134 1.3 1.1 IET10354 – 113 133 2.3 1.4 IET10357 Rasi/IET6238 114 156 1.3 0.7 IET10358 IET6238/IR36 116 150 1.2 0.3 IETT9783 – 115 155 1.6 IET10672 CO 22 / Vaigai 105 153 1.3

2.0 0.7

IET9784 – 115 126 1.1 0.4 IET10675 – 115 137 3.0 1.2 IET10683 TNl/CO 29 102 141 3.1 0.4 IET10676 – 127 166 4.0 0.7 IET10684 IR13240-108-2-2-3/ 120 137 2.0 1.1

IET10685 T22/Mahsuri 117 166 2.2 0.5 IET10689 TNl/CSR5 122 167 2.9 0.5 CSR 1 Mutant CSRl 120 137 2.6 0.7 IET10692 – 106 139 2.4 0.9 ET10693 M40-431-24-114/ 122 154 2.9 0.8

IR9129-209-2-2-2-1

Basmati 370 IET10694 M40-431-24-114/Jaya IET10696 IR36/MR340 IET10697 IET6238/MR340 IET10698 IET6238/Mk340 IET10699 IET6238/MR342 Pokkali (resistant check) – Vikas (resistant check) – SR26-B (local check) – Damodar (local check) – Mohan (local check) –

LSD (0.05)

116 141 3.2 1.4 115 139 2.9 106 141 2.8 1.0

1.1

125 139 2.3 113

1.4 138 3.1

125 136 1.9 0.8 1.7

125 141 0.8 0.8 155 – 2.7 –

– 140 – 0.8 – 152 – 1.6

2.3 10.9 0.5 n.s.

Multilocational Unit of the Institute of Rural Economy and USAID farming systems research (FSR/ E) project.

Upland soils were sandy loam, lowland soils were hydromorphic with some standing water during some periods of the cropping season. Ammonium phosphate and urea were applied at 100 kg/ha in lowland and 50 kg/ ha in upland. Urea was applied at planting and at panicle initiation. Two farmers each for upland and lowland conditions conducted trials, with four replications.

In upland conditions, the introduced varieties had almost three times the yield of the local check (see table). In lowland

Grain yield and approximate duration of selec- ted rice varieties in farmers' fields testing in the Operation Haute Vallée project, Mali, 1987-88 cropping season.

Variety Yield Duration (t/ha) (d)

Linke a 0.6 100 IRAT144 1.8 110 Dourado 1.6 103

Upland conditions

BG90-2 Lowland conditions

2.5 124 IET2911 2.5 127 BKNLR75001 2.2 129

a Local check; farmers in lowland conditions did not have a local variety.

20 IRRN 14:2 (April 1989)

conditions, the three varieties yielded similarly. The participating farmers were generally satisfied with the performance of the new varieties. OHV has undertaken seed multiplication of all three varieties.

Ranbir Basmati — an early- maturing aromatic rice

J. S. Bijral, K. S. Kanwal, and Y. P. Khanna, SKUAST, Regional Agriculture Research Station (RARS), R.S. Pura, J & K, India

The quality basmati rices of India and Pakistan, characterized by late maturity, are difficult to fit into multiple farming systems, and are grown on limited hectarage. Development of early- maturing basmati types would help bring larger areas under superfine rices.

In 1982, we isolated an early- maturing, slightly dwarf plant from farmers' fields. The strain, Ranbir Basmati, was evaluated against Basmati 370 for 2 yr at RARS, and in farmers' fields for performance, stability, and adaptability. Ranbir Basmati duration is 115-120 d from sowing to maturity, 30- 35 d shorter than that of Basmati 370, with comparable yields. Yield per day of Ranbir Basmati was 20-25% higher. Grain quality equaled or surpassed that of Basmati 370 (see table).

Comparative qualities of Ranbir Basmati and Basmati 370.

Character Ranbir Basmati Basmati 370

Plant height (cm) 155 170 Duration (d) 115 150 Threshability Easy Easy Grain length (mm) 7.2 7.1 Grain breadth (mm) 1.8 1.9 Length/breadth ratio 3.9 3.8 Chalkiness 5 9 1,000-grain wt (g) 22.8 21.5 Amylose content (%) 24.0 21.3 Gelatinization temperature a I/L H/I Average proportional elongation ratio 2.05 2.03 Protein content (%) 7.7 7 .0 Aroma Strong Strong Cooking quality Good Good Eating quality Good Good

a L = low, H = high, I = intermediate.

RAU4045 for rainfed

-10, a new variety Project (AICRIP) experiments. In the areas 1984 Preliminary Varietal Trial 1 (PVT-

1), it yielded 5.5 t/ha at Hyderabad. In S. C. Prasad and J. B. Tomar, Plant Breeding and Genetics Department, Birsa Agricultural University, Kanke, Ranchi 834006, India

RAU4045-10 (IET7978), a semidwarf variety derived from Finegora/ IET2832, is moderately resistant to blast and averages 70 d to 50% flowering. Mean yield over 4 yr of experimental trials was 3.6 t/ha, significantly higher than that of check varieties Akashi (2.3 t/ha) and Brown gora (2.1 t/ha).

IET7978 was tested for 3 yr in All- India Coordinated Rice Improvement

the 1985 Uniform Varietal Trial in 15 locations all over India, it yielded an average 2.6 t/ha and took 74 d to flowering under direct seeded rainfed conditions (Table 1) and 3.7 t/ha under direct seeded irrigated conditions. It ranked third in transplanted conditions in 16 locations.

In 1986, IET7978 was the top yielder (3 t/ha) over all locations (Table 2). It significantly outyielded national as well as local checks under rainfed conditions in Bihar and Orissa and has been recommended for rainfed fields in Bihar and Orissa.

Table 1. Performance of RAU4045-10 in station trials at Birsa Agricultural University, Kanke, Ranchi, India.

Yield (t/ha)

1983 1984 1985 1986 Mean Variety

RAU4045-10 4.2 3.8 3.0 3.4 3.6 (IET7978) Akashi 2.5 2.4 2.1 2.4 2.3 Brown gora 1.9 2.0 2.2 2.3 2.1

LSD (0.05) 0.3 0.4 0.4 0.5 0.4

Table 2. Performance of RAU4045-10 in All India Coordinated Rice Improvement Project trials during 1986.

Yield (t/ha)

Zone III Zone 5 Zone 8 Transplanting Variety Mean condition

Assam Assam and Kanke Faizabad Himachal Tamil Tripura Bihar (U.P.) Pradesh Nadu Delhi Rajasthan

3.1 4.1 4.1 3.1 3.7 5.0 5.9 3.0 Akashi 2.1 3.0 3.2 4.4 2.9 2.1 4.0 3.4 2.4 Cauvery 1.4 2.2 2.4 3.2 2.3 1.8 4.5 4.8 2.9 Local checks – – 2.2 3.6 2.8 4.7 – –

RAU4045-10 2.6

(N22) (HPU741) (IR50)

CN705-18 — a promising rice variety for deepwater rice areas

S. Mallik, C. Kundu, and B. K. Mandal, Rice Research Station, Chinsurah 712102, India

Based on overall performance in 1985- 87 national trials, CN705-18 (IET9065 =

Mahsuril CN643) is a promising variety for deepwater rice areas (water accumulates up to 1 m during the wet season) in West Bengal, Bihar, Andhra Pradesh, and Assam.

Photoperiod-sensitive CN705-18 flowered 28-30 Oct in West Bengal. Depending on water depth, it attained 175-210 cm height, with 10-12 tillers/ hill. It has very good submergence

IRRN 14:2 (April 1989) 21

Performance of CN705-18 in multilocational trials in India, 1985-87. a

Site b Grain yield c (t/ha)

CN705-18 Local check

Max water depth (cm)

Bhubaneswar CRRI Patna Chinsurah

Chinsurah Malda Pusa Ranital

Cuttack Patna

CRRI Bhubaneswar North Lakhimpur Chinsurah Pulla

Chinsurah Maruteru

Mean (1 7 sites)

Preliminary Variety Trial 5, 1985 2.1* 1.0 (Khajuniachar) 3.6* 1.2 (CR1030) 2.5 2.7 (Janki) 3.3* 1.8 (NC492)

Uniform Variety Trial 5, 1986 3.3* 1.2 (TCA212) 3.6 3.2 (CN540) 1.2 1.8 (TCA214) 2.2 1.7 (CR1030)

4.7* 3.4 (CR1018) 3.2* 2.2 (Janki) Uniform Variety Trial 5, 1987 3.5 * 1.9 (na) 2.1 2.0 (Rambha) 2.9 2.9 (Panikekau) 3.4 2.9 (NC492) 2.0* 1.1 (CN540)

4.0 2.0* 0.7 (Marutan) 2.9 2.1

Physiology screening

Physiology screening 4.0 (Jogen)

na 40 na 55

110 62 85 65

50 50

75 50

108 85 75

65 50

a na = data not available. b CRRI = Central Rice Research Institute. c * = significant at the 5% level of probability.

tolerance, elongation ability, kneeing ability, and drought tolerance at the early vegetative stage. Panicles are about 24 cm long with good exsertion and about 215 grains/panicle. Grain is medium and bold (length-5.9 mm, breadth-2.9 mm, L/B 2.0), 1,000-grain weight is 27.3 g. It has a yellow-colored hull at maturity, red kernel, and strong (3 mo) seed dormancy.

On average, CN705-18 outyielded check varieties (2.9 t/ha to 2.1 t/ha) over 17 sites (see table), with an overall yield increase of 38%. CN705-18 yield was significantly higher than check at 9 sites, superior at 4, equal at 2, and lower at 2. Yield varied from 4.7 to 1.2 t/ha. This variation under similar water depths over sites reflects the role of time, duration, and intensity of water stagnation in determining variety adaptability.

large-scale demonstration trials in farmers’ fields.

CN705-18 has been recommended for

SiPi 692033: a promising rainfed lowland rice variety

J. K. Kehinde, S. O. Fagade, and P. G. Pillai, National Cereals Research Institute, Private Mail Bag 5042, Ibadan, Nigeria

SiPi 692033 (introduced from Taiwan), seven FAROX rice lines (Table 1), and FARO 27 (a widely cultivated rice variety) were evaluated at six sites across the country in 1986. Sites 1, 2, and 3 lie within the rain forest and sites 4, 5, and

Table 1. Yield of rice lines and varieties in multilocation trials in Nigeria, 1986. a

Grain yield (t/ha)

1 2 3 4 5 6 Mean Line or variety Parentage

FAROX 228-3-1-1 FARO 15/IR28 1.1 5.4 4.4 6.1 8.2 8.2 5.6 FAROX 228-4-1-1 FARO 15/IR28 1.3 5.7 5.0 5.1 7.8 7.1 5.3 FAROX 239-3-3-2 IR28/FARO 12 1.0 4.8 6.4 6.5 5.7 7.6 5.3 FAROX 233-7-1-2 FARO 12/IR28 1.3 3.9 4.5 5.8 4.6 6.9 4.5 FAROX 239-2-1-1 IR28/FARO 12 1.0 3.3 3.6 5.5 4.1 6.4 4.0 FAROX 233-1-1-1 FARO 12/IR28 1.1 5.5 5.9 5.7 5.2 7.0 5.1 FAROX 234-3-1-1 FARO 12/TOS103 1.5 4.5 5.7 7.0 6.0 6.8 5.3 SiPi 692033 SiPi 661044/ 1.5 5.9 5.9 8.9 8.3 8.8 6.6

FARO 27 (check) – 1.3 5.2 5.0 6.9 3.6 7.2 4.9 SiPi 651020

Mean 1.2 4.9 5.2 6.4 5.9 7.3

6 lie in the Sudan savanna vegetational a Locations: 1 = Ogoja, 2 = Ibadan, 3 = Bende, 4 = Wurno, 5 = Birnin-Kebbi, 6 = Kadawa.

zones.

control were common to all locations. Grain yield (14% moisture) was taken Plant

Line or variety height from the middle 6 m2 of each test plot. ( cm)

All cultural operations except weed Table 2. Agronomic characteristics of rice lines and varieties. a Nigeria, 1986.

Panicles Maturity Grain (no./m 2 ) (d) type b

SiPi 692033 was the highest yielder overall and at five sites. Its yield FAROX 228-3-1-1 110 335 117 MB

FAROX 228-4-1-1 106 311 114 MB advantage ranged from 18% over FAROX 239-3-3-2 109 362 114 MB FAROX 228-3-1-1 to 65% over FAROX 233-7-1-2 97 356 110 LS

FAROX 239-2-1-1. FAROX 239-2-1-1 78 362 108 LS FAROX 233-1-1-1 108 379 115 LS

In general, grain yields were higher at FAROX 234-3-1-1 94 371 119 LS 106 339 122 LS

FARO 27 (check) 95 355 120 MB the Sudan savanna sites with low annual SiPi 692033

rainfall (<1,000 mm) than at the rain forest sites with high annual rainfall a Mean of 6 sites. b LS = long slender, MB = medium bold.

22 IRRN 14:2 (April 1989)

R. Velazhahan, R. Ramabadran, and R. Sudhakar, Plant Pathology Department, Faculty of Agriculture, Annamalai University, Annamalainagar 608002, Tamil Nadu, India

(>1,500 mm). Rice in the savanna ripens were semidwarf ( £ 110 cm). gel consistency (26-35 mm). SiPi 692033 under higher solar radiation. Both SiPi 692033 and FARO 27 have has long, slender grains and higher yield

varieties tested (Table 2). All varieties Panicles/m 2 were similar for all high amylose content (>25%) with hard than FARO 27.

Seed technology Influence of Acrocylindrium oryzae on seed germination and rice seedling vigor. Tamil Nadu, India, 1988.

Seedling vigor a

Influence of Acrocylindrium oryzae Sawada on rice seed germination and seedling vigor

Seed germination (%) Cultivar Shoot length (mm)

Healthy Inoculated Root length (mm)

Day 4 Day 7 Day 4 Day 7

NI I NI I NI I NI I

IET9233 95 93 15.3 10.7 32.4 29.1 14.6 13.9 32.2 29.1 ET8611 89 84 6.6 4.8 19.1 18.7 16.2 14.8 33.0 31.3 IET8584 96 92 5.3 3.6 25.9 25.2 15.0 13.2 30.4 30.3 IR62 90 87 4.8 3.6 15.4 7.8 12.0 10.3 29.6 27.2 AU1 90 86 10.5 7.3 26.1 23.1 20.3 17.2 59.9 47.2 J58 92 89 ADT37 94 91

7.6 6.3 33.5 24.7 15.7 13.6 41.8 40.4 4.3 3.6 9.7 1.9 16.8 15.6 44.0 39.3

We studied the influence of Sarocladium oryzae (Sawada) W. Gams and D. Hawksw. (syn. Acrocylindrium oryzae Sawada) on seed germination and seedling vigor of seven rice varieties. Seeds were thoroughly washed with sterile distilled water and 10 seeds were lated on moistened filter paper in a petri dish, with 10 replications. The

LSD (P = 0.05) 4.34 2.35 3.42

a NI = not inoculated, I = inoculated.

seeds were sprayed with a 4 × 10 6 after inoculation. spores/ml suspension of the fungus. Inoculation considerably reduced seed (Control seeds were sprayed with sterile germination in all varieties (see table). distilled water.) Seed germination and Shoot and root lengths of all the rices seedling vigor were assessed 4 and 7 d also were reduced.

CROP AND RESOURCE MANAGEMENT Soil microbiology and biological N fertilizer

Boiling water treatment to improve germination of Sesbania rostrata

M. N. Sheelavantar, S. Rao, P. S. Matiwade, and A. S. Halepyati, Agronomy Department, University of Agricultural Sciences, Dharwad 580005, India

The hard seed coat in Sesbania rostrata can be broken by treating seeds with concentrated sulfuric acid for 40 min. However, sulfuric acid is costly and requires care. Dormancy due to hard seed coat in many legumes could be

Germination of S. rostrata seeds treated with boiling water (98 °C). Dharwad, India, 1988.

Germination (%) at indicated period after treatment Treatment

3 d 4 d 5 d 6 d 7 d

Control (no boiling water) 2 4 4 4 Treatment with 98 °C water

4

15 s 34 40 30 s 42

50 62 52

62

45 s 54 70

42 70

52 60 s

60 52 66

72 76

75 s 42 66 74 76

60 90 s

66 54

78 62

78

120 s 62

64 70 72 (4) a

150 s 76 76 76

50 76 (8)

60 180 s 50 68 68 (10)

60 68

60 68

60 (10)

a Figures in parentheses = percent deformed seeds.

IRRN 14:2 (April 1989) 23

broken using boiling water. We studied the effect of boiling water treatment for varying times on the germinability of seeds of S. rostrata.

Welldeveloped seeds were selected, 50/set, and treated with 98 °C water for

Crop management

Effect of sowing and planting method on rice yield

D. Rout and A. Mishra, Agronomy Department, OUAT, Bhubaneswar 751003: and T. Barik, Regional Research Station, Bhawanipatna 766001, Orissa, India

Performance of two dwarf and one tall indica varieties—OR152-2-17, Pratap, and Mahsuri, all with 135-140 d duration-was compared under different sowing and planting methods during 1982 wet season.

Treatments were broadcast seeding with and without beushaning (operating narrow wooden plow in standing crop under 10-15 cm standing water 30-35 d after germination), line sowing sprouted seeds in puddled soil, line transplanting, and skip-row planting with full and 75% recommended fertilizer (80-40-40 kg NPK/ ha). The design was split plot with varieties in the main plots and sowing or transplanting method as subplots, with

Selecting rice varieties for double transplanting in flood- affected areas

B. K. Singh, Agronomy Department, Rajendra Agricultural University, Pusa 813210, Bihar (present address: National Agricultural Research Project, RAU Campus, Bihar Agricultural College, Sabour 813210, Bihar), India

Large areas on the riverbanks in northeastern India frequently become flooded two to three times during the wet season, severely damaging the rice crop. Some farmers risk transplanting

24 IRRN 14:2 (April 1989)

15-180 s at intervals of 15 s. Treated Treatment with boiling water seeds and untreated seeds were arranged increased germination from 4 to 78% on filter paper, placed in petri dishes, with 75-s treatment (see table). Boiling and moistened with distilled water. The water treatment beyond 75 s began to germination test was carried out at deform seeds. room temperature (27-30 °C).

Influence of sowing and transplanting methods on yield and yield attributes of rice. Orissa, India, 1982 kharif.

Panicles Grains grain Grain Cost of Net 1000-

(no./m 2 ) (no./panicle) weight (g)

Sowing or planting method yield cultivation profit (t/ha) ($/ha) ($/ha)

Broadcast seeding 298 82 19.7 3.4 156 246 Broadcast seeding followed by 265 83 20.2 3.2 175 210

Line sowing sprouted seeds 313 82 20.3 3.8 185 264

Transplanting at 15- × 10-cm spacing 344 83 20.0 4.3 232 285 Skip-row (3:1) transplanting with 290 87 20.4 4.3 202 314

Skip-row (3: 1) transplanting with 295 85 20.6 4.3 221 295

beushaning

15 cm apart

60-30-30 kg NPK/ha

80-40-40 kg NPK/ha

SE (m) ± LSD (0.05)

5 1 0.3 0.1 – – 3 16 ns 0.2 – –

three replications. Soil of the experimental site was

sandy loam with pH 6.1. Total N content was 0.031%, 17.3 kg available P/ ha, and 104 kg available K/ ha.

The interaction between variety and planting method was not significant. Grain yields under normal line planting, skip-row planting with 75% normal fertilizer, and skip-row planting with

normal fertilizer were not statistically different (see table). Skip-row planting with 75% normal fertilizer produced the highest net profit, followed by skip-row planting with full fertilizer. These methods saved 25% of the cost seedlings or fertilizers. Broadcast seeding followed by beushaning produced the lowest grain yield and net profit, probably because of low plant population.

rice in early Jul. If flooding comes late transplanted crop gives yields higher or is mild, the transplanted crop suffers than a single-transplanted crop. least. Most farmers, however, do not We conducted a field trial on silty- want to risk transplanting early because clay loam soil at the Rajendra they cannot afford to manage seedlings Agricultural University Farm, Pusa for retransplanting if the Jul crop is (Bihar) during wet season using six flooded. They usually transplant in Sep, photoperiod-sensitive rice varieties— when the chance of flooding ceases. Janaki, BR8, T141, B14, C62-68, and

seedlings brought directly from the first transplanting—1 Sep, 16 Sep, and 1 nursery and kharuhan seedlings Oct. uprooted from the first nursery and The trial was in a split-plot design, transplanted closely in a second with date of transplanting in the main nursery—are transplanted. Seedlings of plot and varieties in subplots, with three any available photoperiod-sensitive rice replications. Kharuhan seedlings (30 d in variety are used. The double- first nursery + 45 d in the second) were

Two types of seedlings-conventional Bakol (local check)—and three dates of

transplanted at 15- × 10-cm spacing with 2 seedlings/ hill. A uniform 40 kg N, 8.8 kg P/ha was applied at transplanting. The crop was irrigated as needed and harvested in the second week of Dec.

The grain yield differed among varieties and with date of transplanting (see table). Variety C62-68 and Janaki gave significantly higher yields (C62-68 grain weight was lower than that of Janaki, but it had more grains/ panicle).

Grain yield decreased significantly with delay in transplanting. The crop transplanted 16 Sep gave 27.6% lower grain yield than that transplanted 1 Sep; the 1 Oct crop gave 72.4% lower yield.

The variety by date of transplanting interaction also significantly influenced grain yield. Reduction in yield of C62-68 and Janaki due to delay in transplanting was less than that with other varieties.

Effect of a new abscisic acid analog on chilled rice leaves

A. A. Flores and K. Dörffling, Institut für Allgemeine Botanik und Botanischer Garten, Universitat Hamburg, Federal Republic of Germany; and B. S. Vergara, Plant Physiology Department, IRRI

One factor that limits rice growth and yield in many rice-growing countries is chilling injury. One measure to minimize this problem is chemical treatment. New abscisic acid analogs developed by BASF, Ludwigshafen, FRG, and coded LAB 173711 and LAB 144143 have been reported to increase chilling tolerance in cucumber, tomato, and wheat.

analog in chilled rice leaves. Pregerminated seeds of IR42 and Fujisaka 5 were seeded directly in 1-liter pot containing Maahas soil and kept at 29/21 °C, 12 h photoperiod, and 80% relative humidity. Uniform seedlings were selected and sprayed with LAB 173711 at 10 -3 mol/liter, and 10 -4

mol/liter. After 24 h, plants were transferred to 5 °C for 1, 2, 3, 5, and

returned to 29 °C for recovery.

We investigated the effects of the

d. After chilling exposure, they were

Grain yield of double-transplanted, photoperiod-sensitive rice varieties by transplanting dates in flood-affected area of Pusa (Bihar), India.

Grain yield (t/ha)

1 Sep 16 Sep 1 Oct Mean

Janaki 3.6 BR8 2.2 T141 2.5 BR14 2.8

Bakol (local check) 2.3

Mean 2.9 LSD (0.05)

C62-68 3.8

For variety For date of transplanting For variety at same date of transplanting For date of transplanting of same variety

2.7 1.2 2.5 2.2 0.9 1.8 1.6 0.3 1.5 1.9 0.4 1.7 3.0 1.5 2.8 1.1 0.5 1.3 2.1 0.8

0.3 0.6 0.5 0.6

Panicle exsertion in the two varieties consequently higher grain yields under was complete even with the last extremely late transplanting. In other transplanting date. This probably varieties, incomplete panicle exsertion resulted in higher percentage of fertile occurred with delay in transplanting. spikelets in C62-68 and Janaki, and

2. Differences in leaf fresh weight of LAB 173711- treated plants chilled at 5 °C and transferred to

1. Percent leaf area injury in LAB 173711-treated 29 °C for recovery. Data are means ± SE of 10 rice plants chilled at 5 °C for 24 h and transferred measurements. to 29 °C for recovery. Data are means ± SE of 10 measurements.

Injured leaf area was markedly lower

Damaged leaf area was observed visually (wilted and brown color) and estimated using the formula

length of Injured injured portion the applied abscisic acid analog may

leaf area = = 100 length of be due in part to its water

in LAB 173711-treated plants (Fig. 1), and leaf fresh weight in control was much lower than in LAB 173711-treated plants (Fig. 2). This protective effect of

(%) whole leaf blade conserving-activity.

IRRN 14:2 (April 1989) 25

Yield ability of tillers separated from standing transplanted aman rice and replanted

P. K. Biswas, S. K. Roy, and A. Quasem, Regional Agricultural Research Station, Hathazari, Chittagong, Bangladesh

To help farmers in postflood agricultural rehabilitation when new seedlings are not available, we conducted an experiment using rice tillers separated

from a standing crop. We examined the number of tillers/ hill needed for an economic yield and using old seedlings for late planting. In fields that had been planted with 45-d-old BR11 seedlings, we pulled the hill 35 d after transplanting and separated the tillers with roots. The uprooted tillers were replanted 17 Sep 1987 at 1, 3, 5, and 7 tillers/ hill. Control was 65-d-old seedlings.

Plots were 5 × 3 m in a randomized Soil was silty loam with pH 6.0-6.5.

block design with 4 replications. All plots were fertilized with 80-60-40 kg NPK/ ha, using urea, triple superphosphate, and muriate of potash.

Tiller counts were done at 2-wk intervals from 10 randomly selected hills/plot. Grain and straw yield was measured at 15% moisture.

detaching tillers from mother hills and replanting at 3 tillers/ hill (see table). Planting 65-d-old seedlings could cause heavy yield loss.

It is possible to multiply seedlings by

Plant development, yield components, yield, and harvest index (HI) of replanted tillers of transplanted Mukta rice in Bangladesh. a

Days to Plant Panicles Grains (no./panicle) Treatment

Flowering Maturity height (no./m 2 ) (cm) Filled Unfilled

65-d-old seedlings 74 104 88.0 266 93 21 Retransplanted 1 tiller/hill 68 99 100.5 218 149 Retransplanted 3 tillers/hill

21 62 96 100.3 228 149

Retransplanted 5 tillers/hill 59 91 105.0 230 147 23 22

Retransplanted 7 tillers/hill 56 87 106.8 228 149 24

LSD (0.05) 1 2 4.2 10.2 10 CV (%) 1.5 1.3 2.6 2.7 4.7 9.6

ns

1000- grain wt (g)

21.62 20.78 21.00 21.20 21.35

ns 3.2

Yield (t/ha)

Grain Straw

3.8 4.4

7.1 5.5

5.3 5.3 5.3 5.0 5.2 5.2 0.938 1.2

12.2 13.3

HI

0.35 0.44 0.48 0.51 0.50

– –

a Mean of 4 replications. ns = not significant.

Effect of Triacontanol on rice seedling weight and grain yield

M. Mahadevappa, R. A. K. Murthy, and B. B. Biradar, University of Agricultural Sciences, Bangalore 560065, India

Triacontanol has been found to stimulate growth of several crop plants. We treated seeds of rice cultivars Jaya, IR20, and Mukthi with Triacontanol (source: Trianol-CF) at 3 concentrations: 0.01, 0.1, and 1.00 ppm.

Table 1. Dry weight 22 d after sowing of 3 rice varieties grown in pots after 1-h seed treatment with Triacontanol.

Biomass (mg dry wt/plant) Triacontanol (ppm) IR20 Jaya Mukthi

0.01 248 271 410 0.10 309 292 399 1.00 216 249 309 0 (control) 231 226 318

CV (%) 11.3 9.1 11.5 LSD 19 14 17

Seeds were soaked 1 h just before seeding in pots containing evenly mixed soil. Biomass weight was measured 22 d after seeding. Seedlings treated at 0.01 and 0.10 ppm were superior to those with no Triacontanol (Table 1).

In a field experiment, IR54R seedlings were sprayed with the same concentrations of Triacontanol, at 3 d before transplanting (15 Mar 1988), at maximum tillering (15 Apr), and at grain ripening (3 Jun). Grain yield increased slightly with all treatments (Table 2). Tillering capacity did not

Table 2. Grain yield of IR54R treated with Triacontanol.

Triacontanol Grain yield (ppm) (t/ha)

0.01 10.2 0.10 9.8 1.00 9.7 0 (control) 8.9

CV (%) 2.7 LSD 0.4

change, but 1,000-grain weight was higher with 0.01 ppm.

Soil fertility and fertilizer management

Large granule urea efficiency With increasing fertilizer prices, it has

efficiency of applied fertilizer without in rice become important to increase the

B. Rabindra, B. S. Naidu, T. G. Devi, and S. additional cost. One technique is to use N. S. Gowda, University of Agricultural modified large size or large granule urea Sciences, Regional Research Station, (LSU/LGU). We studied the Mandya 571405, Karnataka, India performance of LSU/LGU (6-8 mm) in

26 IRRN 14:2 (April 1989)

transplanted irrigated rice during 1987 wet season (kharif).

Soil was red sandy loam (Alfisols), with pH 6.7, 0.031% available N, 10.9 kg available P/ha, 171 kg K/ha, and cation exchange capacity of 12.6 meq/100 g. Rice varieties were Rasi (120 d) and Mandya Vijaya (145 d).

LGU was applied by broadcasting on drained soil. Prilled urea (PU) was applied according to recommended practice in the area (50% broadcast and incorporated 3-4 h before planting, 25% broadcast without incorporation at tillering, and 25% broadcast at panicle initiation).

Ammonia volatilization loss was measured in the field by direct trapping procedure and leaching loss was measured by periodically inserting leaching tubes (with microporous ceramic base) below the rooting zone, 30 cm deep to collect leachate for determining ammoniacal and nitrate N. Cumulative loss of ammoniacal N and nitrate N was computed on the basis of

Rice yield as affected by LSU/LGU.

Treatment a

Total N uptake (kg/ha)

Fertilizer N b Grain yield (t/ha) in grain + straw Cumulative loss of

Rasi Mandya Vijaya Rasi Mandya Vijaya (kg/ha)

Control, no N 2.0 3.7 43 56 LSU/LGU, all basal 4.8 5.3 94 126 24 PU in 3 splits (recommended 4.5 5.4 95 112 28

–

practice of 50-25-25 at planting, tillering, PI)

(66-34 at planting and LSU/LGU in 2 splits 5.1 5.8 136 129 20

LSU/LGU in 3 splits tillering)

(50-25-25 at planting, 4.9 5.5 105 117 19

tillering, PI) LSD (0.05) 0.3 0.3 CV (%) 7.5 7.5

a N rate is 100 kg N/ha. All treatments received 22 kg P and 41 kg K/ha. b Through volatilization and leaching.

percolation loss of water using drum N through volatilization and leaching. culture technique. Three splits of LSU/LGU did not show

splits increased yield significantly in LSU/ LGU applied all basal did not both varieties (see table). This appeared show any significant reduction in yield to be due mainly to better uptake of N from PU applied in three splits. by the plant and lower loss of fertilizer

Application of LSU/ LGU in two any advantage over two splits.

Synergistic effect of organic manure and N fertilizer on irrigated rice

T. Hussain and G. Jilani, Soil Science Department, University of Agriculture, Faisalabad, Pakistan

We evaluated the efficiency of N source and method of application in irrigated rice KS-282 in a field experiment.

Soil was Typic Camborthids, sandy clay loam in texture having pH 7.9, ECe

0.70 dS/m and CEC 7.8 mmol (I)/ 100 g. Organic matter was 0.52%; N content 0.04%. Plot size was 16 m 2 and plant spacing 20 × 20 cm in a randomized complete block design with 4 replications. All plots received 40 kg PK/ha.

urea (PU) were compared with S. aculeata and S. rostrata as green manure and barnyard manure (BM) in combination with PU. N rate was 87 kg/ ha for each source.

Urea supergranules (USG) and prilled

Effect of organic manure and N fertilizer on growth and yield of irrigated rice. a

Plant Grain Straw (t/ha)

Agronomic N efficiency recovery Treatment b height TilIers/m 2

(cm) (t/ha) (kg rice/kg N) (%)

Control(no N) 80 c 239 d 3.7 c 4.4 e USG 95 a 340 a 5.7 a 7.8 a 23.1 54 PU 87 b 266 cd 5.3 b 7.0 c 18.4 46 S. aculeata + PU 86 b 298 bc 5.2 b 6.5 d 17.2 48 S. rostrata + PU 89 b 307 ab 5.6 a 7.3 b 21.5 52 Barnyard manure 88 b 261 d 5.1 b 7.1 bc 16.7 48

– –

+ PU SE 2 11 0.06 0.08

LSD test. b N source applied at 40 kg N/ha.

a In a column, any 2 means followed by the same letters are not significantly different at 5% level by

USG was superior in all respects (see table). S. rostrata + PU was statistically equivalent to USG. Growth and yield of rice were low with S. aculeata + PU, and BM + PU compared to PU alone, but N recovery from PU alone was the lowest of all sources.

Effect of zincated diammonium phosphate (Zn- DAP) on rainfed lowland rice

R. Ilangovan and S. Palaniappan, Agronomy Department, Tamil Nadu Agricultural University (TNAU), Coimbatore 641003, Tamil Nadu, India

We studied the effect of different grades of Zn-DAP on grain yield of IR50 in wet season (kharif) 1985 and summer 1986. Soils were clay loam with pH 7.5 and 7.9, low DTPA-Zn (0.7 and 1.1 ppm) and organic C (0.21 and 0.34%), low available N (234.5 and 210.6 kg/ha), and high available P (38.5 and 40 kg/ ha) and K (325.6 and 316.9 kg/ ha).

IRRN 14:2 (April 1989) 27

The experiment was laid out in a split-plot design with three replications. Subplot treatments were grades of Zn- DAP (1-6%) applied before transplanting; ZnSO 4 soil application (25 kg/ ha); ZnSO 4 foliar application (0.5% sprayed 30 and 45 d after transplanting); seedling roots dipped in 2% ZnO suspension; and no Zn (control). Main plots were with and without green manure at 12.5 t/ha (sunn hemp Crotalaria juncea L. in wet season and pongam leaves Pongamia glabra Vent. in summer). All plots received 100-21.9-41.5 kg NPK/ha.

Zn application significantly increased grain yield (see table); 6% Zn-DAP was both efficient and economical.

Efficiency of prilled urea (PU) and urea supergranules (USG) in rapidly percolating soil

R. S. Rekhi and M. S. Bajwa, Punjab Agricultural University (PAU), Ludhiana, India; and J. L. Starr, USDA-ARS, Beltsville, Maryland 20705, USA

We studied the fate and efficiency of PU and USG in rice grown on a rapidly percolating loamy sand at PAU farm. Soil was a Typic Ustochrept, CEC 4.5 meq/ 100 g, pH 8.2, 0.3% organic C, 0.06% total N, with an N mineralization rate of 16 mg N/ kg soil after 7 d anaerobic incubation at 40 °C.

N was applied at 0, 37.5, 75.0, and 112.5 kg N/ha in plots measuring 4.8 × 4.8 m. In the plots with 75.0 kg N/ha, 15 N-labeled PU and USG with 5 atom percent excess 15 N were applied in rectangular metal frame microplots (1.2 × 0.8 × 0.3 m) within the main plots. PU was applied in 3 equal splits at transplanting, active tillering, and panicle initiation; USG was placed 8-10 cm deep in the center of 4 rice hills in alternate rows. The experiment was laid out in a randomized block design with four replications.

Rice variety PR106 was transplanted the last week of Jun, 35 d after seeding, and harvested the last week of Oct. Grain and straw samples were analyzed

28 IRRN 14:2 (April 1989)

Effect of Zn-DAP on grain yield of rainfed lowland rice.

1985 wet season yield (t/ha) 1986 summer yield (t/ha) Zn

With GM No GM With GM No GM (kg/ha) added Treatment

No Zn-SSP 5.2 5.1 5.3 5.1 – 1% Zn-DAP 5.9 2% Zn-D AP

5.7 5.6 1.1 6.0 5.8 6.4 5.5 2.2

3% Zn-DAP 6.1 5.9 6.7 6.0 4% Zn-DAP 6.2

3.4 5.9

5% Zn-DAP 6.6 5.7

6.2 4.6

5.9 6% Zn-DAP

6.8 6.4

6.2 6.0

5.8 6.7

ZnSO 4 - basal 6.5 7.1

6.1 5.7 6.5 ZnSO 4 - foliar

5.7 5.9

5.8 5.7 6.1

ZnO root dip 6.2 5.9 –

5.4 6.2 No Z n-D AP

5.6 – 5.6 5.1

LSD (0.05)

5.7

– – –

Green manure (GM) ns Zn treatments GM × Zn ns Zn × GM ns

ns

ns ns

0.5 0.6

Effect of N source and level on growth, yield, and N uptake of rice.

Plant Panicles (no./m 2 )

Yield (t/ha) N uptake (kg/ha) Apparent recovery Treatment ht

(m) Grain Straw Grain Straw (%)

Control 84 PU 37.5 89 PU 75.0 96 PU 112.5 101 USG 37.5 82 USG 75.0 94 USG 112.5 91

LSD (0.05) 7

232 297 308 39 1 25 5 285 267

33

3.7 4.5 36 5.0 6.0 49 5.7 7.3 57 7.0 7.4 77 3.7 4.1 37 4.4 5.5 43 4.8 4.7 45 0.7 2.1 9

11 18 55 25 48 24 48 12 4 14 14 13 10

–

7 –

Balance of 15 N-labeled fertilizer in rice.

for total N content and N uptake. Soil Plant height, number of panicles, was destructively sampled at harvest yield, and N uptake showed that PU with a rectangular soil sampler (30 × was significantly superior to USG (see 13.3 × 50 cm) for total Kjeldahl N and table). Apparent recovery of N was 15 N analyses. higher with PU (48-55%) than with

USG (4-14%). Labeled N utilization was straw N were derived from PU; 13% soil was 68% for PU, 21% for USG; 42% with PU, 30% in grain and 12% in grain N and 12% straw N were derived 32% PU N and 79% USG N was not straw (see figure). Only 8% of the from USG. accounted for in the N balance. The labeled N applied as USG was utilized Soil analysis at harvest showed that large deficit of N from USG was (6% in grain and 2% in straw). 26% of the labeled N from PU and 13% attributed to its rapid movement and

Isotopic composition of rice grain and from USG were retained in the soil. leaching from concentrated zones at straw showed that 40% grain N and 35% Total recovery of labeled N in crop and placement sites.

Sesbania rostrata — a lower- cost source of N for rice

B. Rabindra, B. S. Naidu, T. G. Devi, and S. N. S. Gowda, University of Agricultural Sciences, Regional Research Station, V. C. Farm, Mandya 571405, Karnataka, India

We studied the effect of stem-root nodulating S. rostrata and sunn hemp Crotalaria jancea on transplanted irrigated rice Mandya Vijaya (145-150 d duration) during summer 1988.

Effect of S. rostrata on rice yield. a Karnataka, India.

Treatment

Grain Total uptake

(t/ha) grain + straw yield of N in

(kg/ha)

1. 100 kg N/ha as urea 4.5 in 3 splits: 1/2 at planting + 1/4 at tillering + 1/4 panicle initiation (farmers’ practice)

2. 30 kg N/ha through 5.2 S. rostrata + 70 kg N/ha as urea in 2 splits: 1/2 at planting + 1/2 at tillering

+ 70 kg N/ha in 2 sunn hemp C. juncea

splits: 1/2 at planting + 1/2 at tillering

3. 30 kg N/ha through 4.8

4. S. rostrata to supply 3.4

5. Sunn hemp to supply 3.0 70 kg N/ha

70 kg N/ha

in 2 splits: 1/2 at planting + l/2 at tillering

6. 70 kg N/ha as urea 3.2

7. Control (no N) 2.4 LSD (0.05) 0.3 CV (%) 10.8

92

110

97

76

68

71

47 6 5.3

K/ha. aAll treatments received 22 kg P and 41 kg

Soil of the experimental site was red sandy loam (Alfisols), pH 6.3, medium N (1.1% organic matter), 10.6 kg available Olsen’s P/ha, and 151 kg available K/ha. N content was 4.1% in S. rostrata and 3.2% in sunn hemp.

At the same level of applied N, yield increased significantly (15%) over farmers’ practice (treatment 1), with 30% N supplied through S. rostrata (treatment 2) (see table). The cost

involved in supplying N through S. rostrata was $12, compared to urea cost of $15. Use of S. rostrata increased net profit by $125/ha. S. rostrata (treatment 4) could substitute for fertilizer N up to 70 kg N/ha (treatment 6) without significant yield reduction.

S. rostrata was significantly superior to sunn hemp (treatment 5). Uptake of N was better with S. rostrata.

Nitrogen-use efficiency with hand- and machine-applied N fertilizers in wetland rice soils

N. I. Bhuiyan, M. A. Saleque, and S. K. Zaman, Soil Chemistry Division, Bangladesh Rice Research Institute (BRRI), Joydebpur, Gazipur, Bangladesh

Prilled urea (PU) farmer’s split (F), researcher's split (R), modified split (M), applicator placed (AP); and urea

supergranules (USG) hand placed (H) and AP were compared in a field experiment during the 1986 dry season. BR3 was the test variety.

Soil was clay loam (Paleudults) with pH 6.5, 1.05% organic matter, CEC 24 meq/100 g, 0.07% total N, and incubated 57 ppm NH +

4 -N (incubated at 30 °C for 1 wk). Two rates of N (58 and 87 kg/ ha) and 1 control treatment were used. P at 17.6 kg/ha, K at 33.2 kg/ha, and S at 20 kg/ha were applied

Effect of N fertilizer application method on yield of BR3 and agronomic efficiency of N, 1986 dry season, BRRI, Joydebpur, Bangladesh. a

Plant Grain Agronomic yield

(cm) (t/ha) efficiency

(kg grain/kg N)

Tillers Panicles height (no./m 2 ) (no./m 2 ) Treatment a

Control 86 210 e 195 c 3.6 c - 243 d

58 PU (R) 231 b 4.9 ab 23

91 286 bc 58 PU (M) 89

269 ab 4.6 b 18 267 bcd 256 ab 4.8 ab 20

58 PU (AP) 94 309 a 295 a 5.3 a 30 58 USG (H) 93 299 a 283 a 5.3 ab 29 58 USG (AP) 94 87 PU (F)

285 abc 91

269 ab 5.4 a 31 272 abcd 263 ab

87 PU (R) 5.2 ab

92 19

260 cd 242 b 5.0 ab 16 87 PU (M) 94 281 abcd 268 ab 87 USG (H) 94

4.9 ab 15 293 ab 271 ab 5.4 a 20

58 PU (F) 93

CV (%) 4 2 2 8

a Within a column, means followed by a common letter do not vary significantly at the 5% level of DMRT. b F = 1/3 basal + 1/3 30 d after transplanting (DT) + 1/3 at panicle initiation (PI), R = 2/3 basal + 1/3 at PI, M = 1/3 15 DT + 30 DT + 1/3 at PI, AP = applicator-placed at 10-12 cm depth, H = hand-placed at about 10-12 cm depth.

IRRN 14:2 (April 1989) 29

during final land preparation. minimal. application methods with USG. Regardless of method, 58 kg N/ha Machine application increased yield Placement of N fertilizer in the reduced

significantly improved panicles/m 2 and 0.4-0.7 t/ha over broadcast split with zone as PU by machine or as USG by yield (see table). USG gave a grain yield PU at 58 kg N/ha. There was no hand or machine gave higher agronomic advantage of 0.5 t/ha over PU. difference between hand and machine efficiency. Differences among F, R, and M were

Effect of Zn and Cu on growth and nutrition of rice Nutrient concentration

Effect of Zn and Cu on nutrient concentration in rice. a

Nutrient M. R. Gangwar, M. S. Gangwar, and P. C . levels (ppm)

Srivastava, Soil Science Department, G. B. Zn Pant University of Agriculture and Technology, Pantnagar 263145, India

µg/g tissue mg/g tissue

Cu Fe Mn P

S R S R S R S R S R

We studied the effect of soil application of Zn and Cu on dry matter yield and tissue concentration of Zn, Cu, Fe, Mn, and P in rice grown under submerged soil in a pot experiment in the greenhouse.

ppm Olsen's P and DTPA extractable 0.64 ppm Zn, 0.46 ppm Cu, 11.6 ppm Fe, and 22.5 ppm Mn. Each pot contained 4.56 kg soil.

Basal nutrient application was 100 ppm N as urea, 26 ppm P as diammonium phosphate, and 25 ppm K as potassium chloride. Soil treatments were 0, 5, 10 and 20 ppm Zn and 0, 1, 2, and 5 ppm Cu as sulfates in a factorial combination with 2 replications.

Soil was silty clay loam containing 20

Zn 0 50.8 59.0 27.0 31.6 Zn 5 56.3 60.8 25.4 30.7 Zn 10 69.3 67.6 24.8 28.1 Zn 20 73.7 72.8 20.5 24.1 Cu 0 73.4 73.6 21.5 25.1 Cu 1 62.6 67.6 21.9 29.7 Cu 2 62.6 60.5 26.6 28.6 Cu 5 51.6 58.6 27.8 31.1

LSD (0.05) 5.4 1.8 1.9 1.9

a S = shoots, R = roots.

0.40 4.66 0.20 0.57 1.12 1.30 0.40 4.40 0.20 0.66 1.02 1.15 0.40 4.06 0.20 0.75 1.00 1.26 0.34 3.44 0.19 0.64 0.90 1.26 0.40 4.49 0.20 0.55 1.11 1.16 0.38 3.55 0.19 0.67 1.00 1.00 0.40 4.47 0.20 0.62 0.99 1.28 0.36 4.02 0.20 0.78 0.95 1.53 0.02 0.25 0.01 0.06 0.02 0.04

Five 20-d-old IR8 seedlings were application (see table). Cu in roots and transplanted in each of 32 pots, thinned shoots increased with Cu application but to 3 plants/pot, and grown for 72 d. decreased with Zn application of 10 Additional 20 ppm N as urea was ppm or more. Fe in roots decreased at applied 40 d after transplanting. all Zn levels and at 1 and 5 ppm Cu. Fe

Highest increase in dry matter yield in shoots decreased with 20 ppm Zn and was from 10 ppm Zn + 2 ppm Cu (see 1 and 5 ppm Cu. Mn in roots increased figure). Application of 5 ppm Zn + 1 or with Zn and Cu; in shoots, it decreased 2 ppm Cu also increased yield. The with 20 ppm Zn and 1 ppm Cu. P in highest rates of Zn (20 ppm) + Cu (5 shoots decreased with Zn and Cu. In ppm) failed to increase dry matter yield. roots, it decreased at all Zn levels and at

Zn in roots and shoots increased with 1 ppm Cu. Application of 2 and 5 ppm Zn application but decreased with Cu Cu increased P in roots.

Biofertilizer production of stem-cut planted and seeded Sesbania rostrata

M. Becker, R. P. Pareek, and J. K. Ladha, IRRI; and J. C. G. Ottow, University of Giessen, Federal Republic of Germany

Although S. rostrata is a promising green manure species for lowland rice farming systems, production of seed and

Effect of Zn and Cu on dry matter yield of rice. scarification may be a problem for

farmers. Vegetative propagation appears attractive because nodulation sites constitute primordia of adventive roots able to grow under waterlogged conditions.

We compared biofertilizer production by vegetative propagation through stem cuttings (30 and 20 cm) and broadcast seeding, at 3 plant densities.

The experiment May-Jun 1988 at IRRI farm was laid out in a randomized split-plot design with four replications.

30 IRRN 14:2 (April 1989)

cuttings. To accumulate the same amount of N/ ha, 30-cm-long cuttings require about 2 wk less growth than seeded plants. Only about 2-3 kg of seeds may be needed to produce enough plants for cuttings to plant 1 ha. Broadcast seeding rate is 25-40 kg seeds/ ha.

Although additional labor is needed to make and plant cuttings, it may be economical compared to seeding because it requires less seed, water management, and land preparation. Plants for cuttings might be grown on dikes and borders.

Influence of planting method and planting density on dry matter yield and some yield parameters of S. rostrata biofertilizer. a

Plant Branches/ Dead plants/ Dry weight Treatment Density height plant m 2 (t/ha)

(cm) (no.) (no.) b

5-wk-old plants Seeding 20 kg/ha 39 e l c na 0.15 d

40 kg/ha 41 e 1 c na 0.41 bc 80 kg/ha 37 e 1 c na 0.55 bc

20-cm cutting 25/m 2 52 de 1.2 bc 3.2 bc 0.41 bc 50/m 2 62 d 1.3 bc 7.1 ab 0.64 c

100/m 2 76 c 1.3 bc 8.2 a 1.09 c

30-cm cutting

7-wk-old plants Seeding

20-cm cutting

30-cm cutting

25 /m 2

50/m 2

100/m 2

20 kg/ha 40 kg/ha 80 kg/ha 25/m 2

50/m 2

100/m 2

25/m 2

50/m 2

100/m 2

82 bc 92 ab

101 a

85 e 87 de

104 d 120 c 125 c 146 b 148 b 165 a 178 a

1.9 a 1.5 b 1.3 b

1d 1d 1d 1.1 cd 1.2 c 1.4 b

1.8 a 1.3 b 1.1 c

a Duncan's multiple range test at 0.05. b na = data not available.

1.2 c 2.6 c 3.4 b

na na na

2.9 bc 6.2 ab 8.3 a 1.5 c 2.5 c 4.6 b

0.89 c 2.31 b 3.51 a

0.72 e 1.54 d 2.60 c

1.20 d 1.64 d 3.48 bc 2.19 c 4.31 b 6.23 a

Effect of sesbania green manure and wheat straw on ammonia volatilization loss in wetland soil

C. S. Khind, A. Garg, and M. S. Bajwa, Soils Department, Punjab Agricultural University, Ludhiana 141004, India

N accumulation in S. rostrata.

Plot size was 12 m 2 . Stem cuttings of 8- wk-old plants were pushed about 5 cm deep into newly plowed and water- saturated soil (pH [KCl] 6.3, 1.1 1% organic C, 0.121% total N, 18.5 ppm P Olsen), 1.44 meq exchangeable K/ 100 mg CEC 33.9 meq/ 100 g). Plants were harvested at 5 and 7 wk.

Increasing planting rate resulted in increased biomass and N production. Cuttings showed faster growth and more dry matter and N production than seeds (see table and figure). Highest biomass and N yield were with 30-cm-long cuttings. They exhibited lower mortality and more branching than 20-cm-long

Attempts are being made to identify short-duration leguminous green manure (LGM) crops that can be inserted into intensified cropping systems. High-yielding cultivars also leave large amounts of residue, which is either burned or incorporated into soil.

influence transformations of applied N. We studied the effect of sesbania green manure and wheat straw on ammonia volatilization from urea, in a laboratory study using the forced-draft chamber technique.

Ten pots (10 liters) containing 7 kg air-dry soil (pH 10.0, 0.35% organic C, 0.07% total N, and CEC 9.5 meq/ 100 g) were flooded, puddled, and preincubated with 1 cm standing water for 1 wk. Soil was then fertilized with 26 mg P/ kg as single superphosphate and 50 mg K/ kg as muriate of potash.

combination with Sesbania aculeata green manure or wheat straw. N was applied at 100 and 200 kg N/ha. Finely chopped 2-mo-old fresh sesbania (2.5% N dry weight) was incorporated at

Crop residues and LGM may

Treatments were N as urea alone or in

IRRN 14:2 (April 1989) 31

1. Effect of sesbania green manure and wheat straw on ammonia volatilization in flooded Ludhiana soil, India.

2. Effect of sesbania green manure and wheat straw on floodwater NH +

4 - N concentration. Ludhiana, India.

30 t/ ha. Wheat straw (<2 mm) was incorporated at 7.5 t/ha.

losses were replenished daily, to Soil was reflooded and evaporation

32 IRRN 14:2 (April 1989)

maintain 5 cm standing water. Floodwater temperatures ranged from 28.5 to 33 °C. Two pots/treatment were fitted with chambers continuously flushed with NH 3 -free compressed air.

Soil test fertilizer recommendations increase economic yields of rice

J. C. Sharma, S. P. S. Karwasra, A. P. Sharma, and B. S. Panwar, Haryana Agricultural University, Regional Research Station, Uchani, Karnal 132001, India

We compared bases for N application recommendations—state, soil test, and farmers’ practice in a farmer’s field during 1986.

Soil of the experimental field was sandy loam (Typic Ustochrept) with pH (1:2) 8.4, 0.36% organic C, EC (1:2) 0.10 dS/m, CEC 10.9 meq/100 g soil, 190 kg available N/ha (alkaline permanganate method), 8.0 kg available P/ha (NaHCO 3 extract), and 305 kg available K (ammonium acetate extract)/ha. Available Zn was 0.5 ppm (DTPA

NH 3 that evolved from incubated samples was collected at intervals using a manifold, and estimated by absorbing in 2% boric acid-mixed indicator solution. Floodwater samples also were taken to analyze NH 4 + -N.

Rate of N loss by ammonia volatilization in flooded soil was markedly affected by type of amendment (Fig. 1). Incorporating wheat straw resulted in the greatest N loss due to volatilization. At 16 d, cumulative ammonia volatilization was 11% for wheat straw + N, 4.5% for N alone, and 1% for green manure + N.

No ammonia volatilization occurred in the soil amended with green manure alone. In the soil amended with wheat straw, NH 3 volatilization could already be detected at 2 d, the first sampling.

Ammoniacal N concentration in the floodwater was greatest in soil amended with wheat straw + N (Fig. 2).

These results suggest that higher N losses through ammonia volatilization in straw-amended soil were probably due to the high rate of urea application. Incorporation of wheat straw may have changed the urease kinetic parameters, which seem dependent on the organic material incorporated.

extractable). Nutrient limits used for recommendations were as follows:

Nutrient limits (kg/ha) (elemental form)

Low <250 <5 <125 <0.6 Medium 250-500 5-10 125-300 High >500 >10 >300

Seedlings of PR106 (30-35 d) duration

N P K Zn(ppm)

were transplanted. Each treatment received the following nutrients:

Nutrients (kg/ha) (elemental form) N P K ZnSO 4 . 7H 2 O

State recommendation 125 26.20 50 25 Soil test recommendation 125 17.47 - Farmers’ practice 125 - -

One-third N and all the P, K, Zn were applied at transplanting. The remaining N was applied in 2 equal splits at 3 and

Effect of basis for fertilizer application rate on yield, yield attributes, and profit in rice. a 6 wk after transplanting. The

State experiment was laid out in a practice LSD at 5% recommendation recommendation

Soil test Farmers' randomized block design with three schedule replications.

Rough rice yield (t/ha) 6.7 7.2 5.0 0.2 Soil test fertilizer recommendation Increase in yield (t/ha) 1.7 2.2 – resulted in significantly higher economic

over farmers' practice

($/ha) Expenditure on fertilizers 96.25 67.90 47.50

yields (see table). State fertilizer schedule resulted in significantly higher yields

Increase in fertilizer expenditure over farmers’ practice ($/ha)

48.75 20.40 –

Yield price ($/ha) 939.40 1008.00 701.40 Net profit ($/ha) 550.20 647.15 360.95 Increase in profit over 189.25 286.20

Increase in profit over – 96.95 farmers' practice ($/ha)

state fertilizer schedule

–

–

($/ha) Yield attributes

Plant ht (cm) 111.0 107.7 105.9 1000-grain wt (g) 20.7 21.8 19.2 Number of tillers

3.8 ns

8.1 8.4 6.9 0.9

a Price ($/kg); N, 0.38; P, 0.51; K, 0.19; Zn, 0.27; paddy, 0.14. Expenditure on all agricultural opera- tions ($/ha) = 292.95.

over farmers’ practice.

The International Hybrid Rice Newsletter is published for researchers in hybrid rice development and technology. Its content focuses on discussions of current issues; it does not publish research reports. For more information, write Dr. S. S. Virmani. Hybrid Rice Newsletter editor, IRRI, P.O. Box 933, Manila, Philippines.

Source and time of phosphate Effect of source and time of phosphate application on yield and yield response, Bhubaneswar, India,

application in irrigated rice 1987.

Rate (kg P/ha) and L Pradhan and L Dixit, Agronomy time of application

Department, Orissa University of Basal Tillering (t/ha) (no./m 2 ) wt (g) (kg grain/kg p) Agriculture and Technology, Bhubaneswar (21 d)

Source a Grain Panicles Panicle Yield

751003, Orissa, India

We studied the effect of basal and split application of phosphate through single superphosphate (6.9% P), diammonium phosphate (18-20.0), and ammonium polyphosphate (12-25.2-0) on irrigated rice in 1987 wet season, in a randomized block design with 4 replications.

Soil was sandy loam with pH 6.2, 0.47% organic C, CEC 5.2 meq/ 100 g soil, 9 kg Olsen's P/ ha, 0.15 meq exchangeable K/ 100 g soil, and 1.5 ppm available Zn (DTPA extractable). Daya (125 d) was transplanted 27 Jul with 80- 33.3 kg NK/ha. Diammonium phosphate and ammonium polyphosphate at 80 kg N/ha were applied in 50-25-25 splits. Phosphate was mixed with double the weight of soil, wet to less than field capacity, and broadcast over 5 cm water in the field.

Significantly higher yields were obtained with 26 kg P/ ha, irrespective of source and time of application (see table). Highest yield (4.82 t/ ha) was with split application of ammonium

Control 0 0 DAP 13

2.7 170 1.33 – 0 3.0 213

DAP 26 270 1.86 37.3 1.61

0 22.3

3.6 DAP 6.5 6.5 3.2 DAP 13

228 1.67 13 3.9

41.5 282

SSP 13 1.85

0 48.4

SSP 26 3.2 222 1.54 41.5

0 3.7 SSP

275 1.65 6.5 6.5 3.1 226

39.6

SSP 1.61

13 13 3.7 268 33.8

APP 1.80

13 0 3.6 25 1 37.7

APP 26 0 2.01 53.8

4.3 303 2.02 63.4 APP APP

6.5 6.5 3.8 277 13

2.03 13

84.6 4.8 308 2.19 82.3

LSD (0.05) 0.4 24 0.15 –

a DAP = diammonium phosphate, SSP = single superphosphate, APP = ammonium polyphosphate.

polyphosphate at 26 kg P/ha. Grain Panicle number/m2 and panicle yields in general were low because of weight were highest on split application continuous rain, coupled with strong of 26 kg P/ha as ammonium wind at flowering. polyphosphate.

The International Azolla Newsletter is published for researchers in the development and application of azolla in rice production. Its content focuses on discussions of current issues; it does not publish research reports. For more information, write Dr. I. Watanabe, Azolla Newsletter editor, IRRI, P. O. Box 933, Manila, Philippines.

IRRN 14:2 (April 1989) 33

response yield

Disease management

Suitability of iodine test for detecting rice tungro virus (RTV) infection

P. Narayanasamy, Plant Pathology Department, Tamil Nadu Agricultural University, Coimbatore 641003, India

Sets of 20 20-d-old plants each of TN1, TKM9, and ADT31 rice varieties were inoculated by confining viruliferous green leafhopper Nephotettix virescens Distant at 2 insects/plant. Plants showing typical leaf discoloration and stunting, stunting alone, and no visible symptom were grouped separately, by variety (Table 1).

In iodine tests, most plants showing both leaf discoloration and stunting gave positive reactions (Table 2). No plants showing stunting alone reacted positively with the stain. In ADT3 1, one of three plants showing no visible symptoms of RTV infection reacted

Biological control of rice blast (BI) with antagonistic bacteria

S. S. Gnanamanickam, R. C. Reyes, and T. W. Mew, Plant Pathology Department, IRRI

B1 caused by Pyricularia oryzae Cav. is found in most rice-growing areas of the world. It is common in irrigated and rainfed bunded rice culture, but is more serious in upland rice. Because of the instability of the Bl fungus and the marked variability in its pathogenicity, which results in different races of the organism, control and management are difficult. Use of fungicides is limited by cost and development of host resistance has been only partially successful.

In developing alternate strategies for disease management, we screened strains of bacteria isolated from IRRI ricefields for their antagonism toward P. oryzae.

More than 100 bacterial strains were initially screened in the laboratory. Four

34 IRRN 14:2 (April 1989)

Table 1. Rice plant response to RTV inoculation.

Leaf discoloration + stunting Stunting

No. % No. % No. % Variety

No symptoms

TN1 15 TKM9 13 ADT31 11

Total 39

75 3 15 2 10 65 4 20 3 15 55 6 30 3 15 – 13 – 8 –

Table 2. Reaction of tungro-inoculated rice plants in the iodine test.

Leaf discoloration + stunting Stunting No symptoms

Variety Plants (no.) % Plants Plants (no.) tested a

Tested With positive (no.) Tested With positive reaction reaction

TN1 15 10 66.1 3 2 0 TKM9 13 11 84.6 3 4 0 ADT31 11 9 81.8 6 3 1

Total 39 30 12 9 1

a None showed positive reaction.

positively. should be done cautiously, since 23% of These results suggest that plants showing typical tungro symptoms

interpretation of iodine test results did not give positive reactions.

strains (2 fluorescent and 2 nonfluorescent) that caused maximum inhibition of P. oryzae were chosen for testing. The average diameter of the inhibition zones was 38.5 mm for strain 7-14 (fluorescent), 30.4 mm for strain 4- 15 (fluorescent), 26.3 mm for strain 33, and 21.1 mm for strain 4-03. Using standard procedures, mutant strains were generated by incorporating resistance to rifampicin (R) or rifampicin and nalidixic acid (RN) (100 ppm). The mutant strains retained their ability to inhibit P. oryzae (see figure).

The field experiment in a randomized

Inhibition of Pyricularia oryzae in PDA by fluorescent pseudomonad strain 7-14 and by its mutant 7-14 RN.

complete block design with four replications was conducted at the IRRI with the bacterial suspension and site for upland rice research for acid incubated overnight in polythene bags at soils in Mahipon, Cavinti, the 25 °C. Excess buffer-bacteria mixture Philippines. Seeds of UPLRi-5 rice were was drained and seeds were dried in coated with bacteria as follows. sterile air for 12 h before sowing in

cultures of test strains were scraped into At sowing, seeds had 10 9 colony- a 1% carboxymethylcellulose buffer. forming units (CFU)/g. Seeds coated Seeds (1.3 kg per treatment) were mixed with fungarin (CGA 49104; 8 g/kg seed)

Bacterial cells from 24 h grown 4 × 5 m field plots.

and untreated seeds were sown as checks. The crop also received 3 additional sprays with bacteria (l0 8

CFU/ml) or fungarin when plants were 20, 30, and 40 d old.

monitored from root and shoot samples removed at 10-d intervals on NBY-R or NBY-RN agar. Fluorescent pseudomonad strains 7-14RN and 4-15R had low levels of 0.5 × l0 5

CFU/g tissue up to 40 d, and were not detected in subsequent samplings. Nonfluorescent strains 33R and 4-03R had high levels of 0.9 × l0 6 CFU/g tissue at 30 d, and 1.0 × l0 5 CFU/g tissue at 60 d and 110 d.

table). It appears that the fluorescent

Bacterial multiplication was

Leaf Bl and neck Bl were assessed (see

Insect management

Effect of plant age on whitebacked planthopper (WBPH) feeding

G. Liu and R. M. Wilkins, Agricultural and Environmental Science Department, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, UK; and R. C. Saxena, Entomology Department, IRRI

WBPH is a phloem feeder, with the amount of honeydew excreted regarded as an index of feeding. We studied WBPH feeding and rate of honeydew excretion on potted plants of susceptible and resistant varieties of different ages.

The secondary tillers of 4-, 6-, and 8- wk-old resistant Rathu Heenati and susceptible TNl plants were removed and each main tiller with soil placed in an 8- × 9-cm plastic pot. Each pot was covered with a medially perforated 8- cm-diameter plastic dish through which the tiller emerged. A medially perforated 7-cm-diameter filter paper disc was placed over the dish around the base of the tiller and covered by an inverted perforated plastic cup for a feeding chamber. The feeding chamber was fastened to the dish with “Sellotape.”

Effect of seed bacterization and sprays with antagonistic bacteria on B1 incidence in rice UPLRi-5. Cavinti, Philippines, 1988 wet season.

Severity Grain Treatment yield c

Leaf Bl a Neck Bl b (g)

Bacterial strain 4-03R 3.32 2.96 100.4

33R 3.49 3.70 95.5 4-15R 2.57 2.95 9 2.5 7-14RN 3.29 2.75 102.6

Fungarin Check

1.95 6.27

3.68 3.77

106.7 96.3

LSD (0.05) 2.22 1.79 43.6

a Number of lesions/cm 2 leaf area. b Severity index = n (l) + n (2) + n (3) ....... n (9) × 100, where

n (l), n (2), etc. are number of tillers with disease score 1, 2, or 9. c From 100 panicles/plot. total n

pseudomonad bacteria strains, in spite more effective in reducing leaf and neck of lower population dynamics, were B1 severity.

Five newly emerged macropterous females, starved but water-satiated for 3- 4 h, were introduced into the feeding chamber, and the hole plugged with cotton wool. The females were allowed to feed for 24 h.

The filter paper discs were removed, briefly immersed in a solution of 0.1% ninhydrin in acetone, and dried at room temperature. Purple or violet honeydew spots were cut off the disk and eluted in a solution of 0.8 ml of 1.2% aqueous

Dry weight of honeydew excreted by Sogatella furcifera females on plants of different ages of resistant Rathu Heenati and susceptible TN1. Columns with the same letter are not significantly different at the 5% level by DMRT. Bars indicate ± standard deviation.

copper sulfate and 4.2 ml of 85% ethanol.

Color intensity of the eluent was measured on a spectrophotometer at 475 nm. The quantity of amino acids in honeydew was expressed in glutamic acid standard.

times less honeydew was excreted by WBPH on resistant Rathu Heenati plants than on susceptible TN1 (see figure). The differences possibly are due to the presence of repellents, toxins, or a feeding inhibitor in Rathu Heenati. WBPH feeding on both varieties decreased with plant age, possibly because of a decrease in the nutrient value of the rice plants.

Regardless of plant age, two to four

Virus diseases of some lepidopterous rice pests in the Philippines

D. J. Im, R. M. Aguda, and B. M. Shepard, IRRI

Dead and infected larvae of various lepidopterous pests were collected from ricefields at IRRI and in Laguna, Batangas, Palawan, and South Cotabato Provinces in the Philippines. Live larvae were reared on host plants

IRRN 14:2 (April 1989) 35

Insect viruses found in the Philippines. IRRI.

Host Virus disease a Common name

Mythimna separata (Walker) b Armyworm NPV Spodoptera litura (Fab.) Common cutworm NPV Herpetogramma licarsisalis Grass webworm NPV (Walker) Mocis frugalis (Fab.) c Rice brown semilooper GV Cnaphalocrocis medinalis Rice leaffolder GV (Guenée)

Shape of inclusion

bodies

Tetragonal Tetragonal Hexagonal

Ellipsoidal Ellipsoidal

Host plant found

Collection data

Date Place

Rice Aug 1985 IRRI Rice, taro Jul 1985 IRRI Rice Sep 1984 South Cotabato

Rice Jul 1985 Palawan Rice Oct 1985 IRRI

a NPV = nuclear polyhedrosis virus, GV = granulosis virus. b New species found in the Philippines. c New recorded virus disease of the host insect.

larvae slowly darkened, but the integument remained tough and leathery.

Shape and size of polyhedra in different insect hosts varied (see figure). Polyhedra in Mythimna separata Walker and Spodoptera litura (Fab.) were tetragon mixed with triangular shapes. Polyhedra from Herpetogramma licarsisalis (Walker) were hexagonal. Capsules of GV of Mocis frugalis (Fab.) and Cnaphalocrocis medinalis (Guenée) were ellipsoidal. Some capsules in M. frugalis were irregular and sickle-shaped. The rod-shaped virion of M. frugalis granulosis were embedded singly in capsules, but polyhedra of S. litura were multi-embedded.

Size of polyhedra were 2.12 ± 0.51 µm from S. litura; 1.87 ± 0.24 µm from M. separata, and 1.37 ± 0.17 µm from H. licarsisalis. Capsule size was 433 ± 15.4 nm long and 242.7 ± 17.4 nm wide in M. frugalis, and 412.9 ± 31.4 nm long and 234.1 ± 17.4 nm wide in C. medinalis.

Light and electron micrographs showing the following: nuclear polyhedra isolated from M. separata (1a), S. litura (1b), and H. licarsisalis (1c); granular capsules of C. medinalis (1d) and M. frugalis (1e), with some abnormal forms (arrow); and virions of S. litura polyhedra after treatment with weak alkali for 30 min (1f).

or artificial diets to determine incidence of virus diseases. Specimens were examined under the light and phase contrast microscope. Virus particles were examined with the electron microscope.

Three species of nuclear polyhedrosis viruses (NPV) and two species of granulosis viruses (GV) were found (see table). The behavior of infected larvae was characteristic of most virus-infected insects: they become sluggish and cease

feeding a few days after infection. As the diseases progressed, a watery

fluid exuding from the mouth of the larvae S. fitura changed from colorless to a pale tint to pink. Most larvae infected with NPV hung from their host plant by attaching the second abdominal legs to the plants. In late stages of the disease, the cuticle ruptured, releasing a milky white fluid. Mocis frugalis larvae infected with GV were yellow with shrunken abdominal segments. The

Weed hosts of rice hispa Dicladispa armigera Olivier (Coleoptera: Hispidae)

Q. M. A. Razzaque and A. N. M. R. Karim, Entomology Division, Bangladesh Rice Research Institute (BRRI), Gazipur, Bangladesh

Rice hispa beetles sometimes infest weeds and wheat. We studied the suitability of some common weeds as hosts of rice hispa in 1985-86.

36 IRRN 14:2 (April 1989)

Table 1. Rice hispa beetle feeding and development on some common weeds. BRRI, Gazipur, Bang- ladesh, 1985.

Feeding Eggs Grub Host damage a deposited development

(%)

Cyperus rotundus 3 Few 0 Digitaria ciliaris 9 Few 0 Digitaria setigera 9 Few 0 Echinochloa colona 9 Few 0 Echinochloa crus-galli 9 Few 0 Eleusine indica 9 Few 0 Leersia hexandra 9 Few 0 Rice (BR3) 9 Many >50%

a 0 to 9 scale: 0 = no damage, 9 = more than 50% leaves damaged.

Seven weed species and rice variety BR3 (30-d-old plants) were grown in 15- cm clay pots. Each pot was infested with 4 greenhouse-reared, mated, hispa females and enclosed in mylar film cages for 7 d. Exposed plants were sprinkled with water daily for grub development. Feeding damage was graded on a 0 to 9 scale.

The beetles laid numerous eggs on rice, but few on weeds (Table 1). Grubs died at the 1st- or 2d-instar stage on weeds, but more than 50% developed into pupae on rice. Feeding damage on

Cyperus rotundus was minimal (damage grade 3) and no grubs developed. All other weeds and rice were heavily damaged.

It appears that, while rice hispa may use weeds as alternate food sources, it cannot complete its life cycle on them.

In a separate experiment, 30-d-old plants of rice (BR3), wheat (Barkat), maize (JC-2), and 9 species of weeds were grown separately in 15-cm clay pots enclosed in fine mesh wire net rectangular cages, with 4 replications. Greenhouse-reared hispa beetles were

Effect of parasitization on The hatch was reared individually in food consumption of rice tubes with cut leaves from 60-d-old rice leaffolder (LF) Marasmia variety IR64. Leaves were changed every patnalis 24 h until LF larvae ceased feeding and

mummified. The area of leaf consumed G. S. Arida, B. M. Shepard, and L. P. was measured on graph paper. Almazan, IRRI In another experiment, 20 newly

hatched LF larvae were reared The amount of food the LF, an individually in tubes with cut leaves of important defoliator of the rice plant, rice variety IR64. Leaves were changed consumes during feeding affects yields. daily. When the larvae reached the 4th But when LF is parasitized, the amount instar, 10 were placed individually in of leaf tissue consumed changes. tubes containing pairs of G. triangulifer.

LF parasitoids are abundant in After parasitization, the larvae were ricefields. Copidomopsis nacoleiae, a returned to their original tube parasitoid of egg and larvae, and containing cut rice leaf until they Goniozus triangulifer, a parasitoid of stopped feeding. LF larvae, are important mortality The leaf area consumed was measured factors for LF in the Philippines. on graph paper. LF parasitized by C.

We studied the influence of parasitism nacoleiae consumed more food than by C. nacoleiae on LF food unparasitized LF. The lowest food consumption. Ten newly laid LF eggs consumption was by larvae parasitized were exposed for 24 h in tubes by G. triangulifer (see figure). C. containing colonies of the parasitoid. nacoleiae -parasitized larvae fed for 16.4

Table 2. Preference of rice hispa beetles for rice, wheat, maize, and some common weeds. BRRI, Gazipur, Bangladesh, 1986.

Host

Beetles settling on plants

(%)

Rice (BR3) Echinochloa colona Eleusine indica Scirpus maritimus Digitaria ciliaris Leersia hexandra Paspalum distichum Monochoria vaginalis Maize (JC-2) Commelina benghalensis Cyperus rotundus Wheat (Barkat)

24.2 a 19.2 ab 14.2 bc 9.0 cd 8.3 d 8.0 d 7.2 d 2.7 e 2.7 e 2.4 e 1.3 e 0.7 e

starved for 3 h and released at 100 beetles/cage. Beetles that settled on plants were counted 48 h after infestation.

Rice was the most preferred site (24% beetles settled), followed by Echinochloa colona (19%) and Eleusine indica (14%) (Table 2). Wheat was least preferred. Hispa beetles probably disperse to other plants when the available rice canopy is inadequate to support their numbers.

d; G. triangulifer -parasitized larvae fed 13.9 d; and unparasitized larvae fed 15.2 d.

The number of live larvae and the percentage of damaged leaves are the bases for deciding to spray LF with insecticide. Presence or absence of either parasitoid might influence an integrated control program.

Influence of parasitization by C. nacoleiae and G. triangulifer on leaf consumption by LF.

IRRN 14:2 (April 1989) 37

White stem borer (WSB) effect on upland yield

M. S. Pabbage, Entomology Department, Maros Research Institute for Food Crops, P. O. Box 173, Ujung Pandang, South Sulawesi, Indonesia

We studied the effect of WSB Scirpophaga innotata on upland rice with seven levels of protection in an experiment at the Makariki Experimental Farm, Seram Island, May-Aug 1982. IR36 was planted in a 5 × 5 m plot at 25 × 25 cm plant spacing in a randomized complete block design with 4 replications. Fertilizers as urea, TSP, and KCl were applied at 120 kg N, 40 kg P, and 50 kg K/ha. Half the N and all the P and K were applied in the row at the side of the plants 7 d after planting (DP). Half the N was applied 40 DP.

Yield loss caused by WSB S. innotata under upland conditions. Makariki, Seram Island, Indonesia, 1982.

WSB damage b (%) Grain Yield Treatment a

3 WP 5 WP 7 WP 9 WP (t/ha) (%) yield loss c

1. Complete protection 7.2 1.2 1.5 1.9 2.4 – 2. Complete protection minus a 11.4 1.5 2.0 2.3 3. Complete protection minus b 21.9 7.9 4.4

2.4 1.7 3.3 1.8 25.6

4. Complete protection minus c 24.2 8.9 2.7 3.3 5. Complete protection minus d 14.4

1.8 2.1 3.4

25.6

6. Recommended d protection 12.5 3.3

2.2 2.3

2.3 2.6 5.8

7. No protection (control) 2.2

39.2 15.5 8.6 9.7 1.8 26.9 9.1

LSD (0.05) 2.7 1.2 0.6 0.6 0.4 9.7 14.6 11.2 9.9 14.6 – CV (%)

–

a a = seed treatment with carbaryl 85 S, b = carbofuran 3G (10 DP) + diazinon 60 EC (21 DP), c =

planting. c Compared with complete protection. Carbofuran 3G (10 DP) + diazinon 60 EC (when carbofuran 3G (42 DP) + diazinon 60 EC (63 DP), d = monocrotophos 15 WSC. b WP = weeks after

deadhearts exceeded 10%).

WSB damage at active tillering 3 wk significantly higher than control, no after planting was high, an average protection during active tillering 39.2% in control (see table). As plants (treatment 3), and no protection at grew, damage decreased. booting (treatment 4).

Complete protection yielded 2.4 t/ha,

Weed management Effect of different herbicide treatments on shoot dry weight and height of I. rugosum 6 wk after seeding under simulated dry seeded and wetland conditions. a

Effect of herbicides on Ischaemum rugosum Herbicide and

application rate (kg ai/ha)

Time of Shoot weight Plant application (mg/plant) height

(mm) R. T. Lubigan and K. Moody, IRRI

Ischaemum rugosum Salisb., reported to be a major weed of partially irrigated and rainfed lowland rice in Thailand, Sri Lanka, and the Philippines, is very competitive against rice.

We designed a greenhouse experiment to study the effect of some herbicides on growth of I. rugosum under dry seeded and wet seeded conditions. There were 12 treatments in the dry seeded trial and 9 treatments in the wet seeded (see table). The experiment was laid out in a randomized complete block design with six replications.

Plant height and shoot dry weight were measured 6 wk after seeding. Under dry seeded conditions, both plant height and shoot dry weight were reduced by all the herbicides at all application times (see table). Even though propanil applied at the two- and

Dry seeded Butachlor (2.0) Preemergence 0.6 b 5 ab

l-leaf 2.9 d 22 c 2-leaf 5.0 f 48 d

Thiobencarb (3.0) Preemergence 1.2 c 7 ab 1-leaf 3.3 de 24 c 2-leaf 4.3 ef 46 d

l-leaf 3.0 d 22 c 2-leaf 5.6 b 44 d

Propanil (2.0) 2-leaf 1.4 c 43 d

Untreated – 21.6 g 247 d Wetland

Butachlor (1.0) Preemergence 0 a – 1-leaf 119.9 c 42 a 2-leaf 119.6 c 54 b

Pendimethalin (2.0) Preemergence 0.4 a 3 a

3-leaf 0.5 ab 18 bc

Thiobencarb (1.0) Preemergence 0 a 1-leaf 112.7 bc 44 a 2-leaf 67.2 b 52 b

–

Propanil (2.0) 2-leaf 0 a

Untreated – 124.6 c 156 c

a In a column under each condition, means followed by the same letter are not significantly different at the 5% level by DMRT.

3-leaf –

0 a –

38 IRRN 14:2 (April 1989)

R. P. Singh, J. P. Singh, Y. Singh, A. K. Singh, and R. A. Singh, Dryland Research Project, Agronomy Department, Institute of Agricultural Sciences, Banaras Hindu University (BHU), Varanasi 221005, India

Weed, management in rainfed rice - lentil crop sequence

three-leaf stages killed all weeds, some seedlings emerged after its application. Repeated applications may be needed to achieve complete weed kill. Preemergence applications of butachlor, thiobencarb, and pendimethalin were superior to postemergence applications.

preemergence applications of butachlor and thiobencarb, and propanil

Under wet seeded conditions,

application at the two- and three-leaf stages killed I. rugosum. Flooding a few days after treatment increased the effect of the preemergence treatments and, with propanil, prevented further weed seedling emergence. Butachlor and thiobencarb applied at the one- and two-leaf stages were not as effective as under dry seeded conditions. Herbicide uptake by the plant seems to be more

effective under dry seeded conditions because the herbicide is more easily leached down into the root zone.

Butachlor applied at the one- and two-leaf stages did not reduce shoot weight. Thiobencarb applied at the two- leaf stage reduced shoot weight. All plants that survived butachlor and thiobencarb treatments were stunted.

Rice - lentil is a widely adopted rainfed crop sequence in eastern Uttar Pradesh. Weed control affects yields.

We conducted a field trial 1985-86 and 1987-88 cropping years. Seven treatments were laid out in a randomized block design with four replications. Soil was sandy loam with

19.86% field capacity, 5.18% wilting point, 0.32% organic C, 160 kg available N/ha, 15 kg available P/ha, 166 kg available K/ha, and pH 7.7. EC was 0.104 dS/m at 25 °C, bulk density 1.47 g/cc, and water-holding capacity 33.1%. Akashi rice and Pant 209 lentil were the test varieties.

Table 1. Effect of weed control method on weed dry weight and yield of rice and lentil at B.H.U., Varanasi, India.

Rice Lentil

Treatment Weed dry weight (g/m 2 )

Weed dry weight Yield (t/ha) (g/m 2 ) Yield (t/ha)

1985-86 1987-88 Grain Straw 1985-86 1987-88 Grain Straw

1985-86 198788 1985-86 1987-88 1985-86 1987-88 1985-86 1987-88

T1 Sowing of both crops with 403 280 0.4 0.4 2.6 3.5 113 163 0.7 1.0 1.1 1.5 normal tillage and no weed control in either

weedings in both crops)

dryland weeder in both crops

intrarow hand weeding each time

T2 Farmer's method (2 hand 253 149 2.1 3.0 3.4 5.4 63 89 1.0 1.3 1.5 1.9

T3 Interculture twice by 325 241 0.9 1.6 3.0 4.3 82 101 0.8 1.1 1.0 1.6

T4 Interculture as in T3 + 262 169 2.8 3.6 4.2 5.5 36 40 1.0 1.4 1.3 1.6

T5 Butachlor at 2.0 kg ai/ha 178 140 3.0 2.8 4.0 4.2 112 159 0.7 1.0 at preemergence in rice and no weeding in lentil

preemergence in rice, normal tillage for lentil sowing, and preemergence application of prometryn at 0.75 kg ai/ha in lentil

1.0 1.2

T6 Butachlor at 2.0 kg ai/ha at 189 135 3.0 2.9 4.2 4.2 92 90 1.0 1.6 1.4 1.7

T7 Butachlor at 2.0 kg ai/ha 116 146 3.0 2.9 4.2 4.2 93 90 1.0 at preemergence in rice,

1.7 1.9 2.8

paraquat application at l.0 ai/ha after rice harvest, no tillage for lentil sowing, and prometryn at 0.75 kg ai/ha at preemergence in lentil

LSD (0.05) 156 99 0.5 0.2 0.8 0.9 21 35 0.2 0.3 0.6 0.8

IRRN 14:2 (April 1989) 39

The rice crop received 861.9 mm total rainfall in 1985-86 and 1,050.1 mm in 1987-88; lentil received 51.8 mm in 1985- 86 and 74.1 mm in 1987-88.

Application of butachlor in wet season and prometryn in dry season, with and without paraquat, reduced weed dry weight in rice the most (Table 1). In lentil, interculture with intrarow hand weeding reduced weed dry weight the most.

Highest rice grain and straw yields were with interculture twice plus intrarow hand weeding, followed by hand weeding and chemical control. Highest lentil yield was with preemergence application of butachlor in wet season and prometryn in dry season. Interculture was least effective in both crops.

Managing other pests

Effect of bund dimensions on rodent infestation in irrigated ricefields

V. K. Sharma and A. M. K. M. Rao, Central Plant Protection Training Institute, Rajendranagar, Hyderabad 500030, India

We surveyed 83 transplanted irrigated ricefields 1987-88 to examine the relationship between rodent infestation and the width and height of bunds. Rodent infestation was measured as the

Table 2. Economics a of weed control treatments in rice - lentil sequence at BHU, Varanasi, India, 1985-88.

Mean yield (t/ha) Total cost of Return to Value of land land Benefit

Treatment Rice Lentil produce preparation and preparation and to-cost ($/ha) weed control weed control ratio

Grain Straw Grain Straw ($/ha) ($/ha)

T1 0.4 3.0 0.8 1.3 406.35 250.00 156.35 0.63 T2 2.6 4.4 1.2 1.7 831.07 367.65 463.42 T3 1.3 3.7 0.9 1.3 551.72 279.41 272.31

1.26

T4 3.2 4.8 1.2 1.4 927.93 308.82 0.97

T5 619.11

2.9 4.1 0.8 1.1 749.00 280.88 2.01

468.12 T6 3.0 4.2 1.3 1.6 926.41 295.66

1.67

T7 630.75

2.9 4.2 1.3 2.3 940.29 306.29 634.00 2.13 2.07

a Price of produce: Rice: grain - $132.35/t, straw - $14.71/t; lentil: grain - 330.88/t, straw - 21.74/t. Cost of treatments: Land Preparation (1) $8.82/ha, hand weeding (1) $29.41/ha, interculture by dryland weeder (1) $7.35/ha, intrarow hand weeding (1) $7.35/ha, spraying of herbicide (1) $4.41/

of cultivation: $214.72/ha. ha, butachlor at $13.23/kg ai, prometryn at $13.78/kg ai, and paraquat at $23.85/kg ai. General cost

On a pooled mean basis, highest net prometryn following paraquat in lentil return was with preemergence (Table 2). application of butachlor in rice and

Correlation between rodent infestation and bund dimensions. a Hyderabad, India.

Bund variable Crop stage b ( r value)

Seedling (13) Tillering (19) Booting (17) Flowering (21) Maturity (13)

Width (W) 0.87** 0.79** 0.44* 0.77** Height (H)

0.82** 0.83** 0.57

W × H 0.78**

0.80** 0.78** 0.63**

0.63** 0.78** 0.64** 0.61**

a Significance at the 5% (*) and 1% (**) levels. b Numbers in parentheses indicate sample size.

number of live burrows/ 10 m. bund height was significant at all stages The correlation between rodent except tillering (see table) when rodents

infestation and bund width was establish themselves. Bund volume significant at all stages of the crop (height × width) and infestation were growth; that between infestation and directly related.

Farming systems

Rice-based cropping sequences for rainfed conditions in midhills of Uttar Pradesh

V. Prakash, P. Singh, and V. K. Bhatnagar, Vivekananda Parvatiya Krishi Anusandhan Shala, Almora 263601, U. P., India

Spring rice (Mar-Sep) is the predominant upland crop in the midhills

of Uttar Pradesh. Because currently available spring rice varieties have long duration, cropping cereals and legumes in rotation is not feasible. The most popular 2-yr cropping sequence is upland rice (Mar-Sep) - wheat (Oct- May) - finger millet (Jun-Oct) - fallow (Nov-Mar), for a 150% cropping intensity.

upland rice variety VL Dhan 163 was released, we evaluated 5 intensive cropping sequences for production and return 1985-86 at the Hawalbagh

After shortduration (110 d Jun-Oct)

40 IRRN 14:2 (April 1989)

experiment farm (1,250 m, 29 °36'N, 79º 40%). The split-plot design had crop sequence as the main plot and organic and inorganic fertilization as subplots, with four replications. Soil was a sandy loam with medium fertility.

seeded in the wet season, followed by wheat variety VL 421, barley VLB 1, pea VL Matar 1, lentil VL Masur 1, and rapeseed T9 in the dry season. Rice was sown the first week of Jun, the winter crops were planted the third week of Oct. Organic fertilizer treatment was

Rainfed short-duration rice was direct

Grain yield and net return of rice-based cropping systems under rainfed upland conditions. a Almora, India, 1985-86.

Yield (t/ha)

Rainy season Dry season

OF IOF OF IOF

Total cost ($/ha) Net return ($/ha) Benifit-cost Protein (t/ha) Carbohydrate (t/ha)

OF IOF

Crop sequence

OF IOF OF IOF OF IOF

OF IOF

Rice - wheat 2.1 2.4 2.5 2.8 377.4 368.4 205.2 290.2 1.5 1.8 0.46 0.50 3.39 3.83 Rice - barley 2.2 2.4 2.2 2.4 373.3 357.8 152.3 215.4 1.4 1.6 0.42 0.46 3.22 3.51 Rice - pea 2.4 2.7 1.9 2.0 337.8 341.8 615.4 682.4 2.8 3.0 0.55 0.59 2.92 3.22 Rice - lentil 2.5 2.7 1.7 1.8 329.5 324.6 527.5 589.1 2.6 2.8 0.60 0.64 2.90 3.10 Rice - rapeseed 2.3 2.5 0.8 1.0 341.6 340.0 207.5 301.7 1.6 1.9 0.33 0.39 1.94 2.16

a OF = organic fertilizer, IOF = inorganic fertilizer.

12 t farmyard manure (FYM)/ ha. (see table). Highest average net return 0.21 t/ha lower than with inorganic Inorganic fertilizer treatment was was from rice - pea, followed by rice - fertilizers. Net return, benefit-cost ratio, recommended NPK for each rainfed lentil; lowest was from rice - barley. and protein and carbohydrate crop. Rice received 60-18-25 kg Benefit-cost ratios were highest (above production were higher with inorganic NPK/ ha. 2.0) for rice - legume and lowest for fertilizers.

All dry season crops grew successfully rice - barley. Yields with FYM averaged

Vegetables for high return Gross returns of rice - vegetable cropping systems in coastal Maharashtra, India. and water use efficiency in irrigated rice- based systems Cropping system

Yield (t/ha) Gross return ($) Increase (%) Wet season Dry season a Wet season Dry season b Total

B. P. Patil and C. S. Pulekar, Irrigation Research Scheme, Central Experiment Station, Wakawdi 415711, Dapoli, Ratnagiri District, Maharashtra, India

Opportunities for vegetable cultivation on rice fallows are increasing with new facilities for irrigation in coastal Maharashtra (Konkan). Rainfall is high (2,500-3,500 mm) Jun to Sep with a rain-free postrice season. We evaluated rice - rice (Ratna), rice - tomato (Sonali), rice - chili (DPL-C-1), and rice - watermelon (Sugarbaby) for gross return and water use.

Soil is lateritic with 1.65% organic C, 2.3 kg available P/ ha, 242 kg available K/ha, and pH 6.0. Wet season rice was entirely rainfed, planted the first week Jul at 20- × 15cm spacing and harvested the second week Oct. Watermelon was planted at 2 × 1 m the first week of Nov, tomato at 60 × 60 cm and chili at 60 × 45 cm were transplanted the first week of Dec, dry season rice was transplanted the second week of Jan. Dry season irrigation was scheduled at 25 mm crop potential evapotranspiration (CPE) for rice, 30

Rice - rice 3.7 4.5 711.5 865.3 1576.8 –

Rice - tomato 3.7 49.0 711.5 3769.2 4480.7 184 (150.0) a (5.8)

(75.0) (50.3) Rice - chili 3.7 10.0 711.5 3846.2 4557.7 189

(115.0) (33.4)

(30.0) (76.9) Rice - watermelon 3.7 30.0 711.5 2307.7 3019.2 91

a Figures in parentheses = water use (cm). b Figures in parentheses = gross return ($)/cm water).

for tomato, 36 for chili, and 10 for Increase in gross income was 184% watermelon. Depth of irrigation per turn for rice - tomato, 189% for rice - chili, was 50 mm for rice, tomato, and chili, and 91% for rice - watermelon (see and 20 liters/basin for watermelon. Rice table). Gross returns/cm water used received 100-50-50 kg NPK/ha in both was 8 times higher for rice - tomato, 6 seasons; tomato, 150-75-50; chili, 150- times higher for rice - chili, and 13 times 50-50; and watermelon, 100-50-50. higher for rice - watermelon than for Protection from pests was need-based. rice - rice.

The International Rice Research Newsletter invites contributions of concise summaries of significant current rice research for publication. Contributions should be limited to no more than 2 pages typed double-spaced accompanied by no more than 2 figures, tables, or photographs. Contributions are reviewed by appropriate IRRI scientists and those accepted are subject to editing and abridgment to meet space limitations. Authors are identified by name and research organization. See inside front cover for more information about submissions.

IRRN 14:2 (April 1989) 41

Supplementary irrigation using shallow groundwater for soybean after wetland rice

A. Prabowo, B. Prastowo, and I. U. Firmansyah, Agricultural Engineering Division, Maros Research Institute for Food Crops, Maros, Indonesia

We evaluated methods of irrigation using shallow groundwater on soybean grown after rice. A soybean crop growth model (CRPSM) was used to improve irrigation management and phenology clock.

Irrigation methods tested were manual drip, spraying at 5- and 14-d intervals, furrow, and rainfall only. For furrow irrigation, 7.6-cm and 5.0-cm diameter pumps were used.

Jul 1985. Rainfall received during the Soybean cultivar Orba was sown 12

Rainfall, a irrigation, and grain yield of soybean under several irrigation methods. Maros, Indonesia, 1985.

Supplemental Effective Total Grain yield (t/ha) ET Water use Treatment irrigation irrigation water supply

actual b efficiency

(mm) mm % (mm) Observed Predicted (mm) (t/ha-mm)

Rainfed – 0 – 115 0.6 0.7 188 Manual drip 165 116 70 231 1.4 1.4 265 Sprayed every 233 156 67 271 1.4 266 6.02

8.62 1.4

Sprayed every 233 156 67 271 1.3 1.4 25 1 5.52

Furrow 7.6 cm 274 156 57 271 1.0 1.2 269 3.85

Furrow 5.0 cm 274 156 57 271 0.8 1.2 269 2.88

–

5 d

14 d

pump

pump

a Rainfall received was 144 mm. Effective rainfall (115 mm) = 80%. b Predicted from model.

cropping period totaled 115 mm. 5.0-cm pump the lowest (see table). The Minimum water consumption was results indicate that soybean yields can 116 mm. be doubled with supplementary

highest yield, furrow irrigation with the Manual drip irrigation produced the irrigation (see figure).

ERRATA Influence of P, K, micronutrients, and Effect of azolla green manure on rice Grain characteristics of traditional dolomite on azolla growth, 13:4 (Aug yield, 13:4 (Aug 1988), 29. Soil data in Basmati varieties of northwest India, by 1988), 23. Soil data in column 1, column 2, paragraph 2, lines 2-3 should V.P. Singh, E.A. Siddiq, F.U. Zaman, paragraph 2, lines 2-3 should read read “0.113% total P, 0.0155% Olsen and A.R. Sadananda. 13 (5) (Oct 88), “0.113% total P, 0.0155% Olsen P...” P...” 10-11.

Page 11: lines 2-3 should read: “represent group B. HBC-30, 34, 40, 45, 46, 95, 98, and 136; Mohabawali, Kanwali,”. . .

42 IRRN 14:2 (April 1989)