dry bean production - nda.agric.za · dry beans (phaseolus spp.) originated in central and south...
TRANSCRIPT
Editor DR A.J. LIEBENBERG
Dry bean production
2009 2002 Second print 2001 First print
Compiled by Directorate Agricultural Information Services Department of Agriculture, Forestry and Fisheries
In cooperation with ARC-Grain Crops Institute
Printed and published by Department of Agriculture, Forestry and Fisheries
Obtainable from Resource Centre, Directorate Agricultural Information Services Private Bag X144, Pretoria, 0001 South Africa
Also available on the web at www.nda.agric.za/publications
Contributions
M.J. du PlessisD. FourieA.J. LiebenbergM.M. LiebenbergC.J. van Zyl
Information provided by
ARC-Grain Crops Institute (ARC-GCI) Private Bag X1251, Potchefstroom, 2520 Tel: 018 299 6100
1
Dry beans is at present regarded as one of the most im portant field crops in South Africa on account of its high protein content and dietary benefits.
Of all the annual leguminous food crops that are harvested for dry seeds, the ordinary bean is by far the most important. Dry beans (Phaseolus spp.) originated in Central and South America. Within the genus Phaseolus there are three species which are agronomically important in South Africa.
z Phaseolus vulgaris
Many different types and colours, the most im-portant of which are: small white, red speckled or sugar beans, carioca and green beans
z Phaseolus acutifolius Tepary beans
z Phaseolus coccineus Large white kidney beans
Within each species there are many seed types which differ in size, shape and colour. Within each type there are different cultivars and the seeds of these cultivars differ very little from one another. However, considerable differences may occur in adaptability, growth habit, disease resistance and many other characteristics. In this publication, only P. vulgaris is discussed, except where mentioned otherwise.
Climatic requirements
The dry bean is an annual crop which thrives in a warm climate. It grows optimally at temperatures
2
of 18 to 24 °C. The maximum temperature during flowering should not exceed 30 °C for P. vulgaris and 26 °C for P. coccineus. High temperatures during the flowering stage lead to abscission of flowers and a low pod set, resulting in yield loss. Day temperatures below 20 °C will delay maturity and cause empty mature pods to develop. Cultivated under rainfed conditions the crop requires a minimum of 400 to 500 mm of rain during the growing season, but an annual total of 600 to 650 mm is considered ideal.
Soil requirementsBeans have to be planted in warm soils (minimum temperatures preferably above 13 °C) after all danger of frost has passed.
They grow well in soils with a depth of at least 90 cm, that have no deficiencies, and are well drained. Sandy loam, sandy clay loam or clay loam with a clay content of between 15 and 35 % is suitable. With sandy soils, problems of low fertility or nematode damage may occur.
Beans prefer an optimum soil pH (H2O) of 5,8 to 6,5, and are very sensitive to acidic (pH (H2O) < 5,2) soils (acid saturation above 10 %). They will also not grow well in soils that are compacted, too alkaline or poorly drained.
Cultivar choiceThe National Dry Bean Cultivar Trials are conducted by the ARC–GCI annually and the information is published by the DPO in SA Dry Beans. Dry beans are classified into types according to:
3
Colour and seed size
z Small white beans (15–25 g/100 seeds), used mainly for canning purposes; 10 to 20 % of local production.
z Red speckled or speckled sugar beans (red speckles on a beige background) (40–55 g/100 seeds); 65 to 75 % of local production.
z Large white kidney beans (80–100 g/100 seeds); 5 to 10 % of local production.
z Carioca beans (khaki stripes on a beige background) 20 to 25 g/100 seeds); 3 to 5 % of local production.
z Alubia beans (large white) (45–55 g/100 seeds); 1 to 5 % of local production.
Growth habit
z Type 1: determinate or bush type
z Type 2: indeterminate compact upright
z Type 3: indeterminate runner type (short runners).
Growing season
Temperatures, especially during the night, determine the length of the growing season of a cultivar: z Short (85–94 days) z Medium (95–104 days) z Long (105–115 days).
A cultivar can have any combination of these characteristics. Further information on cultivars can be obtained from the ARC-GCI.
4
Seed is produced by Dry Bean Seed (Pty Ltd), tel: 012 325 1850 and PANNAR tel: 033 413 1131.
Seed quality
For successful production, it is important that high-quality (certified) seed with a high germination percentage (80 % or higher) be used. This production cost factor is slight when compared to probable yield losses due to disease or poor stand. Low-quality seed can cause a poor and an uneven stand, resulting in uneven maturity, harvesting problems and yield losses. Using disease-free seed will reduce the incidence of seed-borne diseases such as bean common mosaic virus (BCMV), bacterial diseases (common blight, halo blight and bacterial brown spot) and the fungal disease, anthracnose. Other benefits of disease-free seed are that it is: z Labelled to indicate germination percentage. z Guaranteed true to type and ensures
homogeneity. z Guaranteed free of weed seeds and foreign
matter.
Soil preparation
Seedbed preparation for the planting of dry beans follows the same pattern as that for any row crop planted in the spring. The seedbed must be deep, level and firm because this ensures better surface contact between the seed and the soil, increasing the absorption of moisture. A level seedbed also facilitates planting to a uniform depth.
5
Fertilisation
It is recommended that beans be planted on soils which have been previously well fertilised. General fertility is more advantageous than direct fertilisation, because beans are sensitive to high concentrations of mineral salts.
Macronutrients
The total withdrawal figure per 1 ton of dry bean seed produced is about 36 kg N, 8 kg P and 18 kg K.
NitrogeN (N)
Inoculation of dry bean seed is regarded as ineffective. Consequently, dry beans should be considered as incapable of satisfying all of their nitrogen requirements through N-fixation. The application of all the nitrogen at planting time is recommended, particularly where undecomposed material has been ploughed in before planting.
Deficiency symptoms
Lower leaves become light green and then yellow and eventually die. Young leaves may be lighter green than normal.
Guidelines for nitrogen application
Yield potential (t/ha) 1,5 2,0 2,5
N fertilisation (kg/ha) 15,0 30,0 45,0
6
PhosPhorus (P)
Under commercial production the yield responses to phosphorus fertilisation are not dramatic in dry beans and P is not normally a yield-restrictive factor. Under subsistence production, where small quantities of fertiliser are applied P can be a yield-limiting factor. Where the P content of the soil is lower than 20 ppm (Bray 1) it is recommended that superphosphate be broadcasted and ploughed into the soil to a depth of 15 to 20 cm before planting.
Phosphorus fertiliser must still be band placed at the time of planting. In low pH soils, phosphorus can be utilised efficiently by bandplacing 3,5 cm to the side and 5 cm below the seed.
Deficiency symptoms
Young leaves are small and dark green, older leaves senesce prematurely. Plants have short internodes and reduced branching.
Guidelines for phosphorus fertilisation
Soil analysis P application for potential (t/ha)
Ambic Bray 1 1,5 2,0 2,5
P (mg/kg) P fertilisation (kg/ha)
10 13 16 22 28
15 20 12 16 20
20 27 10 13 16
25 34 9 12 15
>45 >55 5 5 5
7
Potassium (K)
When dry beans are grown on soils with a high clay content, potassium is not normally a limiting factor. Deficiencies are most likely to occur on sandy soils with an analysis of less than 50 ppm K. The optimum leaf content is 2 % potassium.
Deficiency symptoms
Bright yellow chlorosis of older leaves, appearing from the margins and then extending rapidly to the centre of leaflets.
Guidelines for potassium fertilisation
Soil analysis K fertilisation for potential (t/ha)
Ambic 1 NH4OAc 1,5 2,0 2,5
K (mg/kg) K fertilisation (kg/ha)
40 40 22 27 32
60 59 19 24 29
80 78 17 21 26
100 98 15 19 24
>100 >98 0 0 0
Micronutrients
molybdeNum (mo)
If the soil has a pH (H2O) of less than 6, a seed treatment of 100 g sodium molybdate per 50 kg seed and/or a foliar spray of 100 g sodium molybdate per hectare should be given. If the pH
8
(H2O) is below 5,3 and there are no Rhizobia in the soil, no results will be achieved by applying molybdenum.
Deficiency symptoms are similar to those of nitrogen because it is important for N metabolism.
ZiNc (ZN)
The critical level of zinc in bean tissue is 15 to 20 ppm. Levels higher than 120 ppm can decrease yields. The availability of zinc is highest in slightly acid soils (pH 6,0–6,8) and lowest at pH(H2O) above 7,4.
Deficiency symptoms
Pale, yellow leaves, especially between veins and near the tips. The plants become deformed and dwarfed and may die. Pod formation is hampered and the plants are slow to mature.
maNgaNese (mN)
Deficiencies only occur on soils with a high pH value. Symptoms include small leaves with a mosaic yellowing in the interveinal areas while the veins remain prominently green. Deficiencies can be corrected by applying manganese sulphate (MnSO4) at 15 to 20 kg/ha.
boroN (b)
Boron toxicity is a more frequent problem than deficiency and symptoms include chlorosis and dwarfing. With time, the chlorosis increases and resembles burn, with the leaf margins curling in.
9
Beans should not follow a sunflower crop which has received boron fertiliser.
iroN (Fe)
Deficiency occurs on calcareous or saline soils where pH (H2O) values are above 7,4. Symptoms are characterised by bright yellow leaves and green veins. Deficiencies can be rectified by a 1 % FeSO4 solution or chelate applied as a foliar spray.
Soil acidity (pH)
The optimum soil pH levels for dry beans are: z pH (H2O): 5,8–6,5 z pH (KCl): 4,8–5,5.
The percentage of acid saturation has to be lower than 10 % for the cultivation of dry beans. The soluble aluminium content has to be less than 25 to 30 %.
The pH can be raised (acid saturation reduced) by applications of agricultural lime. These applications to acid (low pH) soils can make certain micronutrients, such as molybdenum, more available to the plant. The availability of phosphorus is influenced by the pH. It is readily available at a pH (H2O) of 6 to 7.
Calcium and magnesium deficiencies can be alleviated with agricultural lime. High pH soils are often associated with an excess of sodium salts which reduce nutrient uptake. Beans will tolerate a sodium saturation percentage of up to 8 or 10 and an electrical conductivity of up to 1 mmho/cm.
10
Planting date
The most suitable planting date is determined by the following factors: z Correct soil temperature z Probability of heavy rain which may lead to soil
crusting and restrict seedling emergence z Possibility of high temperatures later in the
season which may cause blossom drop z Length of the growing season (high
temperatures during flowering, rain during harvest and frost damage should be avoided)
z Crop rotation programmes (position of the bean crop in the total crop setup, i.e. planted after another crop, such as maize).
Planting dates are mainly restricted by the possible occurrence of frost (planting too late), and rain at harvesting, resulting in poor quality (planting too early). Planting dates in South Africa range from November to mid-January in areas where frost occurs. In frost-free areas, March and April are the best months for planting beans. The large white kidney bean (P. coccineus) is an exception and is planted from mid-November to mid-December and is not adapted to winter production.
Spacing, plant population and planting depth
The between-row spacing for all types of beans under commercial production is 900 mm because dry beans are usually cultivated in rotation with maize. For early maturing cultivars, especially those with a determinate growth habit, a row spacing of 750 mm is recommended if mechanisation is practical (see table).
11
Spacing and plant population
Type Spacing within rows (mm)
Spacing between rows (mm)
Plant population seeds/ha
Early maturing, determinate
75 750 177 000
Medium and late maturing
75 900 150 000
Large white kidney
100–150 900 115 000
Planting depth is determined by the soil texture and its moisture content. Generally the seeds are placed 2,5 to 5,0 cm below the soil surface.
Irrigation
Irrigation offers the potential for increasing yields and enabling production in otherwise unsuitable soils. Sprinkler irrigation is the most frequent means of irrigation for dry beans. The system used is determined by the size and shape of the lands, as well as available labour and capital. In areas where water is unrestricted (not merely supplementary irrigation), the soil should be wet to field capacity to the depth of the 1 m root zone before planting. As soon as the soil is sufficiently dry, the seedbed should be prepared and planted and thereafter the field should not be irrigated until the seedlings have emerged.
Irrigation scheduling is essential for optimum yield per unit of water. The critical, moisture-sensitive growth stages are flowering and early pod set which occur at 40 to 50 % and 50 to 60 % of the growing season. It is important that irrigation cycles be correctly scheduled, because
12
excess moisture can create conditions conducive to root rot and Sclerotinia. Moisture stress can also aggravate some root rots such as Fusarium oxysporum. Irrigation should cease when a quarter of the bean pods have turned yellow. For the correct irrigation scheduling, expert advice must be obtained.
Harvesting
Dry beans have a moisture content of about 50 % at physiological maturity. The beans, however, are only ready for harvesting when the moisture content drops to 16 %, the ideal being 15 %. Seeds may split during threshing when the moisture content is less than 12 % and such seeds are rejected by canners and seed companies. It is difficult to clean without further seed split or broken seed coats. Dry beans should be harvested when all the pods have turned yellow, but before they have become so dry that the pods begin to shatter.
Dry beans can be harvested as follows: z Handpulling and threshing by driving a tractor
over them on a threshing floor. Smaller volumes can be threshed by hand by beating with a stick covered in a hessian sack. The wind can be used to separate the seed from the chaff.
z Partially mechanised systems, where the plants are pulled up by hand, placed in windrows and threshed with a harvester or stacked, whereafter they are threshed with a stationary threshing machine.
z Fully automated system with mechanical pulling. The beans are raked into wind rows and threshed by means of an automated combine.
13
Tips z Pulling of beans should start when the
moisture content of the pods is temporarily high (to prevent shattering), i.e. early in the morning before the dew has evaporated.
z Mechanised harvesting must be done when there is no danger of crop damage by rain.
z To prevent cracking and splitting beans should be threshed at slow cylinder speeds with a machine equipped with an axial flow threshing mechanism.
Weed control
Effective weed control is a prerequisite for high dry-bean yields. Dry beans, being low-growing plants, struggle to compete with or overshadow weeds. Early control is extremely important, because the root system of the plant develops at this stage and some weeds secrete chemical inhibitors which limit plant growth. At a later stage weeds hamper the harvesting and threshing processes, adversely affecting the quality of the crop.
Mechanical weed control
Mechanical weed control should begin during seedbed preparation (remove all weeds) and be repeated with a tiller between the rows when necessary up to the flowering stage. Care should be taken that implements do not damage the crop by using row spacings which permit easy access and taking care that roots
14
are not damaged. Cultivation between the rows is also advantageous because it loosens the soil and improves aeration and water penetration. Weeds in the row have to be handpulled.
Chemical weed control
Chemical weed control can be implemented before planting or before and/or after emergence. A sufficient number of herbicides have been registered to control all weeds throughout the entire growing period of dry beans. Information in this regard is obtainable from the different agrochemical companies.
DISEASES AND PESTS
Diseases and pests may have been partially responsible for the unstable production that has been experienced in the past. Incidence and severity vary between seasons because of environmental and management practices. Integrated disease and pest management, using all suitable control measures, is recommended.
15
Cau
sal o
rgan
ism
, sym
ptom
s, id
eal c
ondi
tions
, pre
vent
ion
and
trea
tmen
t of i
mpo
rtan
t dry
-bea
n di
seas
es (c
ont.)
Dis
ease
Cau
sal o
rgan
ism
Sym
ptom
sId
eal c
ondi
tions
Prev
entio
n/tr
eatm
ent
Ang
ular
leaf
sp
otPh
aeoi
sario
psis
gr
iseo
laD
ark
grey
to b
row
n an
gula
r les
ions
on
leav
es. S
mal
l sp
ore-
carr
ying
org
ans
rese
mbl
ing
bear
d st
ubbl
e on
un
ders
ide
of le
sion
s. S
ever
e in
fect
ion
lead
s to
leaf
ye
llow
ing
and
defo
liatio
n. L
arge
, rou
nd, f
lat,
redd
ish
lesi
ons
on p
ods
and
elon
gate
d da
rk b
row
n le
sion
s
on s
tem
s
Mod
erat
e to
hot
, pr
olon
ged
perio
ds
of h
igh
hum
idity
Plan
t res
ista
nt c
ultiv
ars;
es
peci
ally
sm
all s
eede
d; w
ork
bean
deb
ris in
to th
e so
il af
ter
harv
estin
g
Anth
racn
ose
Col
leto
trich
um
linde
mut
hian
umB
rick-
red
to p
urpl
ish
dark
enin
g of
vei
ns o
n lo
wer
le
af s
urfa
ce. B
row
n le
sion
s, b
ecom
ing
sunk
en w
ith a
re
ddis
h-br
own
bord
er, o
n po
ds. D
ark
lesi
ons
(var
ious
si
zes)
on
seed
s
Coo
l and
hum
idP
lant
dis
ease
-free
see
d; w
ork
bean
deb
ris in
to th
e so
il af
ter
harv
estin
g; re
stric
t mov
emen
t in
fiel
d; a
pply
sui
tabl
e fu
ngic
ides
; cr
op ro
tatio
n w
ith n
onho
sts
(bea
ns e
very
3-4
yea
rs)
Asc
ochy
taP
hom
a ex
igua
Dar
k br
own
to b
lack
con
cent
ric le
sion
s on
leav
es a
nd
pods
. Can
cau
se ra
gged
leav
es a
nd d
efol
iatio
nC
ool t
o m
oder
ate
an
d hu
mid
Wor
k be
an d
ebris
into
the
soil
afte
r har
vest
ing;
app
ly s
uita
ble
fung
icid
es
Bac
teria
l br
own
spot
Pse
udom
onas
sy
ringa
e pv
. sy
ringa
e
Leaf
sym
ptom
s ar
e sm
all,
irreg
ular
bro
wn
spot
s w
hich
ar
e so
met
imes
sur
roun
ded
by a
light
-gre
en z
one.
Old
er
leav
es h
ave
a ta
ttere
d ap
pear
ance
. Pod
sym
ptom
s ar
e sm
all,
dark
-bro
wn
sunk
en le
sion
s. In
fect
ion
of p
ods
at
an e
arly
sta
ge, i
nhib
its g
row
th a
t the
poi
nt o
f inf
ectio
n,
whi
ch re
sults
in m
alfo
rmat
ion
and
twis
ting
of p
ods.
B
eans
with
out v
isib
le s
ympt
oms
can
harb
our s
ubst
antia
l po
pula
tions
of t
he p
atho
gen
Mod
erat
e te
mpe
ratu
res,
hu
mid
Pla
nt d
isea
se-fr
ee w
ork
bean
deb
ris in
to th
e so
il af
ter
harv
estin
g: a
pply
cop
per-b
ased
ba
cter
icid
es a
s a
pre v
entiv
e m
easu
re; c
ontro
l wee
ds a
nd
volu
ntee
r bea
ns
16
Cau
sal o
rgan
ism
, sym
ptom
s, id
eal c
ondi
tions
, pre
vent
ion
and
trea
tmen
t of i
mpo
rtan
t dry
-bea
n di
seas
es (c
ont.)
Dis
ease
Cau
sal o
rgan
ism
Sym
ptom
sId
eal c
ondi
tions
Prev
entio
n/tr
eatm
ent
BC
M(N
)VB
ean
com
mon
m
osai
c (n
e cro
tic)
viru
s
Bot
h di
seas
es c
ause
dar
k-gr
een
vein
ban
ding
, dow
n-w
ard
curl
of th
e le
aves
and
leaf
mal
form
atio
n. L
eave
s ha
ve a
n ar
ched
, puc
kere
d an
d bl
iste
red
appe
aran
ce
and
look
thin
ner.
BC
MN
V c
ause
s sy
stem
ic n
ecro
sis
(bla
ck ro
ot) i
n pl
ants
con
tain
ing
the
I-gen
e
Pre
senc
e of
in
fect
ed s
ourc
es,
aphi
ds a
nd
susc
eptib
le
culti
var
Pla
nt re
sist
ant c
ultiv
ars/
dise
ase-
free
seed
; pla
nt
early
to a
void
larg
e ap
hid
popu
latio
ns; c
ontro
l aph
ids
w
ith s
uita
ble
pest
icid
e
Cha
rcoa
l ro
ot ro
t (A
shy
stem
bl
ight
)
Mac
roph
omin
a ph
aseo
lina
Sm
all,
sunk
en b
lack
lesi
ons
on s
tem
s at
soi
l lev
el,
spre
adin
g up
war
d to
bla
cken
low
er s
tem
s. F
olia
ge
may
yel
low
, wilt
and
die
off.
Min
ute
blac
k do
ts (p
ycni
dia)
ba
rely
vis
ible
on
blac
kene
d st
ems.
Mor
e co
nspi
cuou
s on
mat
ure
plan
ts
Hot
and
dry
See
d tre
atm
ent w
ith s
uita
ble
fung
icid
es (o
nly
effe
ctiv
e at
an
ear
ly s
tage
); flo
odin
g or
ve
ry w
et c
ondi
tions
for a
few
w
eeks
bef
ore
plan
ting;
goo
d irr
igat
ion;
wor
k in
bea
n de
bris
af
ter h
arve
stin
g. C
rop
rota
tion
has
limite
d va
lue
beca
use
mai
ze,
sorg
hum
and
sm
all-g
rain
cro
ps
are
also
hos
ts
Com
mon
bl
ight
Xan
thom
onas
ax
onop
odis
pv
phas
eoli
Leaf
sym
ptom
s ap
pear
as
larg
e, b
row
n ne
crot
ic le
sion
s su
rrou
nded
by
a na
rrow
, brig
ht y
ello
w m
argi
n. P
od
sym
ptom
s ar
e ci
rcul
ar, s
light
ly s
unke
n, d
ark
redd
ish-
brow
n le
sion
s. S
eeds
dire
ctly
con
nect
ed w
ith p
od le
sion
s m
ay b
e di
scol
oure
d
Hot
and
hum
idP
lant
dis
ease
-free
see
d; w
ork
bean
deb
ris in
to th
e so
il af
ter
harv
estin
g; a
pply
cop
per-
base
d ba
cter
icid
es a
s a
prev
entiv
e m
easu
re; c
ontro
l wee
ds a
nd
volu
ntee
r bea
ns
17
Cau
sal o
rgan
ism
, sym
ptom
s, id
eal c
ondi
tions
, pre
vent
ion
and
trea
tmen
t of i
mpo
rtan
t dry
-bea
n di
seas
es (c
ont.)
Dis
ease
Cau
sal o
rgan
ism
Sym
ptom
sId
eal c
ondi
tions
Prev
entio
n/tr
eatm
ent
*Fus
ariu
m
root
rot (
dry
root
rot)
Fusa
rium
sol
ani
f. sp
pha
seol
iE
long
ated
redd
ish
disc
olor
atio
n of
the
tapr
oot,
(roo
t m
ay ro
t com
plet
ely)
, Pla
nts
may
bec
ome
stun
ted,
sho
w
prem
atur
e de
folia
tion
and
even
ually
die
. Sec
onda
ry
root
s ne
ar th
e so
il su
rface
. Inf
ectio
n m
ost s
ever
e w
hen
the
root
sys
tem
is u
nder
stre
ss
Stre
ss c
ondi
tions
, es
peci
ally
dro
ught
. Pa
th og
en o
ccur
s in
mos
t soi
ls a
nd
may
be
spre
ad in
so
il dus
t (w
ind)
or
on
seed
s)
Cro
p ro
tatio
n w
ith m
aize
or
oth
er g
rain
cro
p; d
eep
plou
ghin
g; a
void
stre
ss, p
oor
nutri
tion
and
dam
age
to
stem
s (b
y fo
r exa
mpl
e be
an
fly, h
oein
g, m
achi
nery
); us
e til
lage
whi
ch m
inim
ises
soi
l co
mpa
ctio
n
Fusa
rium
ye
llow
s (F
. wilt
)
Fusa
rium
ox
yspo
rum
f.
sp. p
hase
oli
Visi
ble
in fi
eld
as g
roup
s of
yel
low
ing
plan
ts. L
eave
s be
com
e ye
llow
and
die
off.
Inte
rnal
dis
colo
ratio
n of
lo
wer
ste
m (v
ascu
lar t
issu
e). Y
oung
er p
lant
s st
unte
d,
may
wilt
and
die
Hot
and
dry
, st
ress
con
ditio
nsC
rop
rota
tion
with
gra
in c
rops
(m
aize
, whe
at, e
tc);
deep
pl
ough
ing;
avo
id s
tress
and
da
mag
e to
ste
ms
(by
for
exam
ple
bean
fly,
hoe
ing,
m
achi
nery
)
Hal
o bl
ight
Pse
udom
onas
sa
vast
anoi
pv
phas
eolic
ola
Leaf
sym
ptom
s in
itial
ly a
ppea
r as
smal
l, w
ater
-soa
ked
lesi
ons
on th
e un
ders
ide.
Les
ions
turn
redd
ish
brow
n an
d be
com
e ne
crot
ic w
ith a
ge. T
he m
ost c
hara
cter
istic
sy
mpt
om is
a li
ght-g
reen
zon
e (h
alo)
sur
roun
ding
the
necr
otic
spo
t. P
od s
ympt
oms
are
grea
sy, w
ater
-soa
ked
spot
s of
var
ious
siz
es. L
esio
n m
argi
ns m
ay tu
rn b
row
n as
they
mat
ure.
Les
ions
nor
mal
ly s
tay
gree
n on
dry
po
ds. P
lant
s w
ith in
fect
ed v
ascu
lar s
yste
ms
(sys
tem
ic
infe
ctio
n) a
ppea
r stu
nted
, gen
eral
ly s
how
ing
a lim
e-gr
een
colo
ur a
nd a
redd
ish
disc
olor
atio
n at
the
node
s
Coo
l and
hum
id
Pla
nt d
isea
se-fr
ee s
eed;
wor
k be
an d
ebris
into
the
soil
afte
r ha
rves
ting;
app
ly c
oppe
r-ba
sed
bact
eric
ides
as
a pr
even
tive
mea
sure
; con
trol w
eeds
and
vo
lunt
eer b
eans
18
Cau
sal o
rgan
ism
, sym
ptom
s, id
eal c
ondi
tions
, pre
vent
ion
and
trea
tmen
t of i
mpo
rtan
t dry
-bea
n di
seas
es (c
ont.)
Dis
ease
Cau
sal o
rgan
ism
Sym
ptom
sId
eal c
ondi
tions
Prev
entio
n/tr
eatm
ent
Pow
dery
m
ildew
Ery
siph
e po
lygo
niO
rigin
ally
fain
t bla
cken
ed s
uper
ficia
l sta
rlike
blo
tche
s,
beco
min
g w
hite
, coa
lesc
ing
to c
over
aer
ial p
arts
in a
dry
po
wde
ry fi
lm.
Pla
nts
may
dry
out
and
bec
ome
defo
liate
d
Hot
and
m
oder
atel
y hu
mid
Res
ista
nt c
ultiv
ars,
sui
tabl
e fu
ngic
ides
*Pyt
hium
Pyt
hium
spp
Poo
r em
erge
nce,
wilt
ing
and
dyin
g of
f of y
oung
se
edlin
gs. W
ater
-soa
ked,
then
gre
y to
bro
wn
lesi
ons
near
soi
l sur
face
, spr
eadi
ng to
ste
ms
and
root
s an
d le
adin
g to
sof
t rot
. Are
as in
row
s w
ith d
ead
plan
ts
bord
ered
by
stun
ted
plan
ts. I
n se
vere
cas
es, l
arge
are
as
may
be
affe
cted
Coo
l and
wet
co
nditi
ons
See
d tre
atm
ent w
ith s
uita
ble
fung
icid
es; g
ood
drai
nage
; cro
p ro
tatio
n
*Rhi
zoct
o-ni
a ro
ot ro
tR
hizo
cton
ia s
olan
iR
eddi
sh-b
row
n le
sion
s on
low
er s
tem
s, b
ecom
ing
sunk
en a
nd s
prea
ding
to c
ause
wilt
ing
and
dyin
g of
f of
pla
nt. O
ften
mor
e se
vere
at s
eedl
ing
stag
e bu
t may
ca
use
stun
ting
and
unev
en m
atur
atio
n in
old
er p
lant
s
Mod
erat
e to
hig
h so
il m
oist
ure
and
tem
pera
ture
s
See
d tre
atm
ent w
ith s
uita
ble
fung
icid
es; g
ood
drai
nage
; de
ep p
loug
hing
; sha
llow
pl
antin
g; c
rop
rota
tion
Rus
tU
rom
yces
ap
pend
icul
atus
Smal
l, w
hite
spo
ts d
evel
op o
n le
aves
, (so
met
imes
onl
y on
und
ersi
de),
lesi
ons
enla
rge
and
burs
t ope
n to
form
ra
ised
, rus
t-col
oure
d pu
stul
es re
leas
ing
a re
ddis
h-br
own
dust
(spo
res)
whe
n ru
bbed
. Spo
res
may
bec
ome
blac
k at
end
of s
easo
n. P
ustu
les
som
etim
es s
urro
unde
d by
ye
llow
hal
o or
nec
rotic
(dea
d) ti
ssue
. Lea
ves
may
yel
low
an
d di
e of
f. P
ustu
les
on p
ods
elon
gate
d
Mod
erat
e te
mpe
ratu
res,
al
tern
ate
wet
and
dr
y pe
riods
, win
dy
Res
ista
nt c
ultiv
ars;
sui
tabl
e fu
ngic
ides
; wor
k in
pla
nt d
ebris
af
ter h
arve
stin
g; re
-mov
e vo
lunt
eer b
eans
19
Cau
sal o
rgan
ism
, sym
ptom
s, id
eal c
ondi
tions
, pre
vent
ion
and
trea
tmen
t of i
mpo
rtan
t dry
-bea
n di
seas
es (c
ont.)
Dis
ease
Cau
sal o
rgan
ism
Sym
ptom
sId
eal c
ondi
tions
Prev
entio
n/tr
eatm
ent
Sca
bEl
sino
ë ph
aseo
liN
ew le
aves
and
sho
ots
curl
upw
ards
. On
olde
r lea
ves,
gr
ey to
ligh
t-bro
wn
circ
ular
sca
b-lik
e le
sion
s, u
sual
ly
conc
entra
ted
near
the
vein
s. S
imila
r les
ions
, dar
keni
ng
with
age
, on
the
pods
Hot
and
hum
idP
lant
dis
ease
-free
see
d;
plan
t res
ista
nt c
ultiv
ars;
app
ly
suita
ble
fung
icid
es
Scl
erot
inia
(w
hite
m
ould
)
Scl
erot
inia
sc
lero
tioru
mEa
rly s
ympt
oms
smal
l, w
ater
-soa
ked
spot
s on
leav
es a
nd
stem
, fol
low
ed b
y w
hite
mas
ses
of m
ycel
ium
. Scl
erot
ia
form
on
this
mas
s an
d tu
rn b
lack
afte
r 7–1
0 da
ys.
Drie
d ou
t inf
ecte
d tis
sue
have
a c
hara
cter
istic
ble
ache
d ap
pear
ance
Hum
id, d
ense
le
af c
anop
yC
rop
rota
tion
with
mai
ze; u
se
dise
ase-
free
seed
; sch
edul
e irr
igat
ion
cycl
es s
o th
at p
lant
s do
not
rem
ain
wet
for l
ong
perio
ds; a
void
ove
r irrig
atio
n;
appl
y su
itabl
e fu
ngic
ides
*Scl
erot
ium
ro
ot ro
t (s
outh
ern
blig
ht)
Scl
erot
ium
rolfs
iiG
rey
wat
er-s
oake
d le
sions
, bec
omin
g br
own,
nea
r th
e so
il su
rface
, spr
eadi
ng to
the
tapr
oot a
nd le
adin
g to
w
iltin
g an
d de
ath
of th
e pl
ant.
Low
er le
aves
may
als
o be
af
fect
ed. C
hara
cter
istic
sm
all r
ound
ligh
t-yel
low
to b
row
n sc
lero
tia a
nd w
hite
fung
us g
row
th
visi
ble
on e
stab
lishe
d le
sion
s
Dry
wea
ther
fo
llow
ed b
y ho
t an
d hu
mid
Goo
d dr
aina
ge; c
rop
rota
tion;
w
ork
in b
ean
stub
ble
afte
r ha
rves
ting;
dee
p pl
ough
ing
* D
isea
ses
of th
e ro
ots
and
stem
, kno
wn
as “r
oot r
ot”,
ofte
n oc
cur i
n a
com
plex
and
can
incl
ude
any
of th
e fo
llow
ing:
fusa
rium
, pyt
hium
, rhi
zoct
onia
, ch
arco
al ro
t and
scl
erot
ium
root
rot (
Sou
ther
n bl
ight
), th
e fir
st th
ree
bein
g th
e m
ost f
requ
ent.
The
latte
r fou
r can
als
o ca
use
rotti
ng o
f see
d an
d da
mpi
ng
off.
To s
ome
exte
nt ro
ot ro
t can
be
prev
ente
d, b
ut n
ot tr
eate
d. F
ungi
cide
s ca
n on
ly b
e ap
plie
d to
see
d as
a p
reve
ntiv
e m
easu
re a
gain
st P
ythi
um a
nd
Rhi
zoct
onia
root
rot
20
Pes
ts (c
ont.)
Inse
ctSc
ient
ific
nam
eD
amag
eTr
eatm
ent
Bla
ck b
ean
aphi
d
Gro
undn
ut a
phid
Aph
is fa
bae
Aph
is c
racc
ivor
a
Vect
ors
of v
ario
us v
iruse
s
Vect
ors
of v
ario
us v
iruse
s
App
ly s
uita
ble
inse
ctic
ide
App
ly s
uita
ble
inse
ctic
ide
Toba
cco
whi
tefly
Bem
isia
taba
ciP
oten
tial v
ecto
r of b
ean
gold
en
mos
aic
viru
sN
o in
sect
icid
e cu
rren
tly
regi
ster
ed
Toba
cco
leaf
hopp
erJa
cobi
ella
fasc
ialis
Suc
k sa
p fro
m le
aves
No
treat
men
t nec
essa
ry
Bea
n se
ed m
aggo
t
Bea
n st
em m
aggo
t
Del
ia p
latu
ra
Oph
iom
yia
spen
cere
llaO
phio
myi
a ph
aseo
li
Mag
gots
atta
ck c
otyl
edon
s, m
ine
into
ste
ms
belo
w s
oil l
evel
and
pup
ate
Mag
gots
min
e in
to s
tem
s an
d pu
pate
Cont
rol w
ith a
see
d dr
essin
g in
sect
icid
e
No
inse
ctic
ide
curr
ently
re
gist
ered
Spo
tted
mai
ze b
eetle
CM
R b
eetle
Ast
ylus
atro
mac
ulat
us
Myl
abris
ocu
lata
Feed
on
polle
n, d
estro
y flo
wer
s
Des
troy
flow
ers
No
inse
ctic
ide
curr
ently
re
gist
ered
App
ly s
uita
ble
inse
ctic
ide
Bla
ck m
aize
bee
tle
Cha
fer b
eetle
Het
eron
ycus
ara
tor
Ado
retu
s cr
ibro
sus
Ado
retu
s te
ssul
atus
Dam
age
stem
s on
or b
enea
th s
oil s
urfa
ce
Feed
on
youn
g le
aves
, pet
als
and
polle
n
App
ly s
uita
ble
inse
ctic
ide
App
ly s
uita
ble
inse
ctic
ide
Bea
n bu
gC
lavi
gral
la to
men
tosi
colli
sS
uck
sap
from
leav
es, s
tem
s an
d po
ds—
caus
e w
iltin
g of
dev
elop
ing
pods
No
inse
ctic
ide
curr
ently
re
gist
ered
21
Pes
ts (c
ont.)
Inse
ctSc
ient
ific
nam
eD
amag
eTr
eatm
ent
Tip
wilt
er
Gre
en v
eget
able
bug
Ano
ploc
nem
is c
urvi
pes
Nez
ara
virid
ula
Suc
k sa
p fro
m s
tem
s—ca
use
wilt
ing
and
dyin
g of
tips
of s
hoot
s
Suc
k sa
p fro
m p
ods—
caus
e br
owin
g of
se
eds
insi
de
No
inse
ctic
ide
curr
ently
re
gist
ered
No
inse
ctic
ide
curr
ently
re
gist
ered
Com
mon
cut
wor
mA
grot
is s
eget
umD
amag
e st
ems
on o
r ben
eath
soi
l sur
face
App
ly s
uita
ble
inse
ctic
ide
Afri
can
bollw
urm
Hel
icov
erpa
arm
iger
aFe
ed in
to p
ods
and
dam
age
seed
sA
pply
sui
tabl
e in
sect
icid
e
Cab
bage
sem
i-loo
per
Tric
hopl
usia
oric
halc
eaFe
ed in
to p
ods
and
dam
age
seed
sA
pply
sui
tabl
e in
sect
icid
e
Am
eric
an le
afm
iner
Sou
th A
mer
ican
leaf
-m
iner
/Pot
ato
leaf
min
er
Lirio
myz
a tri
folii
Lirio
myz
a hu
idob
rens
is
Larv
ae tu
nnel
into
leav
es
Larv
ae tu
nnel
into
leav
es
App
ly s
uita
ble
inse
ctic
ide
No
inse
ctic
ide
curr
ently
re
gist
ered
Bea
n flo
wer
thrip
s
Bea
n th
rips
Meg
alur
othr
ips
sjös
tedt
i
Ser
icot
hrip
s oc
cipi
talis
Feed
in fl
ower
s, c
ausi
ng a
roug
hene
d,
silv
ery
text
ure
on p
ods
Feed
in fl
ower
s, c
ausi
ng a
roug
hene
d,
silv
ery
text
ure
on p
ods
App
ly s
uita
ble
inse
ctic
ide
App
ly s
uita
ble
inse
ctic
ide
Bea
n w
eevi
l
Bea
n ga
ll w
eevi
l
Aca
ntho
scel
ides
obt
ectu
s
Alc
idod
es e
ryth
ropt
erus
Larv
ae e
nter
see
d an
d ho
llow
it o
ut b
y fe
edin
g
Larv
ae e
nter
ste
ms,
pup
ate
in th
e ga
lls
form
ed
App
ly s
uita
ble
inse
ctic
ide
App
ly s
uita
ble
inse
ctic
ide
22
ENQUIRIES
For futher information on bean production contact:
z ARC-Grain Crops Institute (ARC–GCI) Private Bag X1251 Potchefstroom 2520 Tel: 018 299 6100
z Dry Bean Producers’ Organisation (DPO) P.O. Box 26269 Arcadia 0007 Tel: 012 325 1850 and subscribe to SA Dry Beans, a quarterly magazine. The Dry Bean Production Manual can also be ordered from the same address.