options for managing striped cucumber beetle and bacterial wilt on organic farms abby seaman, nys...
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Options for Managing Striped Cucumber Beetle and Bacterial
Wilt on Organic Farms
Abby Seaman, NYS IPM ProgramWith information from Ruth Hazzard, Meg
McGrath, and Mike Hoffmann
Bloodnick Farm
Blue Heron Farm
Blue Heron Farm
Porter Farm
Slack Hollow Farm
Squash Pests
Striped cucumber beetle (AUDPC)
26.95 7.48 *
Squash bug (AUDPC) 18.69 12.91 ns
Aphids (AUDPC) 8.04 12.88 ns
Powdery mildew (AUDPC)
(top leaf surface)7.60 10.15 ns
Powdery mildew (AUDPC)
(bottom leaf surface)6.41 10.45 ns
Organic Conv. Sig.
Striped Cucumber Beetle Parasitism
Species Management Early Late Average
Syrrhizus diabrotica
Organic 16.2(±8.9)
11.6(±7.8)
13.9 (±8.5)
Conventional 4.4(±6.8)
7.7(±8.9)
6.2 (±7.8)
Celatoria setosa Organic 5.1(±4.8)
5.0(±6.2)
5.0(±5.5)
Conventional 5.5(±5.9)
2.6(±5.3)
3.9 (±5.5)
Courtesy Michael Hoffmann, Cornell University
Striped cucumber beetle life cycle
Overwinters as adult in field borders
Adults migrate to fields
Eggs laid at base of plants - larvae feed
on rootsSummer adults emerge in
early August
Courtesy Michael Hoffmann, Cornell University
Management Options
• Transplanting
• Trap Cropping
• Row Covers
• Chemical
Attractiveness to beetles varies with crop type and variety
Susceptibility to wilt varies with crop type and variety
Plants past the five-leaf stage are less susceptible to bacterial wilt
Induced Resistance
• Zhender et al. have found reduced SCB feeding and wilt incidence on plants treated with PGPR
• BioYield and other approved products may be able to cause induced resistance
• Do microbially active soils elicit an induced resistance response?
Transplanting
Reduces direct plant loss from beetle feeding
Reduces time plants are in susceptible stage
Cost of Transplants vs Direct Seed(winter squash or pumpkins at 2x6 spacing)
• Direct seeded $260/A• Transplanted $1630/A*
*@ $0.45/plant to produce and establish
http://www.nysaes.cornell.edu/recommends/
Harvest Moon
Howden
MagicLantern
Merlin
# Beetles/10 plants Feeding Damage (%)Wilt on 25 Aug (%)
Cucumber Beetle Density, Feeding Injury, and Cucumber Beetle Density, Feeding Injury, and Bacterial Wilt Incidence for Pumpkin, 1999Bacterial Wilt Incidence for Pumpkin, 1999
77
22 b22 b99
44
3 b3 b
44
44
22
89 a89 a
13 b13 b
88
88
Harvest Moon
Howden
Magic Lantern
Merlin
# Beetles/plant Feeding DamageWilt on 22 Aug (%)
Cucumber Beetle Density, Feeding Injury, and Cucumber Beetle Density, Feeding Injury, and Bacterial Wilt Incidence for Pumpkin, 2000Bacterial Wilt Incidence for Pumpkin, 2000
66
98 a98 a55
33
33
22
58 b58 b
53 b53 b
97 a97 a
33
66
66
on 3 July (%)
Cucumber (Cucumber (Cucumis sativusCucumis sativus))Calypso, Dasher II, County Fair (wilt resistant)Calypso, Dasher II, County Fair (wilt resistant)
Muskmelon (Muskmelon (Cucumis meloCucumis melo))Eclipse, Saticoy, AthenaEclipse, Saticoy, Athena
Watermelon (Watermelon (Citrullus lanatusCitrullus lanatus))Crimson SweetCrimson Sweet
Gourd (Gourd (Cucurbita maxima Cucurbita maxima andand C. pepo C. pepo))Turk's Turban, Pear BicoloredTurk's Turban, Pear Bicolored
Pumpkin (Pumpkin (Cucurbita pepoCucurbita pepo))Magic Lantern, Merlin, Howden, Harvest MoonMagic Lantern, Merlin, Howden, Harvest Moon
Squash, Summer (Squash, Summer (Cucurbita pepoCucurbita pepo))Multipik, Goldbar, SunrayMultipik, Goldbar, Sunray
Squash, Winter (Squash, Winter (Cucurbita pepo Cucurbita pepo andand C. moschata C. moschata))Golden Delicious, Blue Hubbard, Burgess Golden Delicious, Blue Hubbard, Burgess Buttercup, Waltham Butternut, Table AceButtercup, Waltham Butternut, Table Ace
Squash, Zucchini (Squash, Zucchini (Cucurbita pepoCucurbita pepo))Seneca, AmbassadorSeneca, Ambassador
Cucurbit Crop Types and CultivarsCucurbit Crop Types and Cultivars
Number Cucumber Beetles/10 Plants, 1999Number Cucumber Beetles/10 Plants, 1999
Winter squashWinter squash
PumpkinPumpkin
GourdGourd
WatermelonWatermelon
MuskmelonMuskmelon
CucumberCucumber
Zucchini Zucchini squashsquash
Yellow squashYellow squash
9 bc9 bc
6 cd6 cd
20 a20 a
4 de4 de
6 cde6 cde
2 e2 e
12 b12 b
5 de5 de
Incidence of Bacterial Wilt on 3 Aug 1999Incidence of Bacterial Wilt on 3 Aug 1999
Winter squashWinter squash
PumpkinPumpkin
GourdGourd
WatermelonWatermelon
MuskmelonMuskmelon
CucumberCucumber
Zucchini squashZucchini squash
Yellow squashYellow squash
14 c14 c
12 c12 c
48 b48 b
7 c7 c
0 c0 c
68 a68 a
13 c13 c
33 b33 b
Winter squashWinter squash
PumpkinPumpkin
GourdGourd
WatermelonWatermelon
MuskmelonMuskmelon
CucumberCucumber
Zucchini squashZucchini squash
Yellow squashYellow squash
29 b29 b
26 bc26 bc
21 cd21 cd
20 d20 d
10 e10 e
15 de15 de
39 a39 a
20 d20 d
Number Cucumber Beetles/10 Plants, 2000Number Cucumber Beetles/10 Plants, 2000
Incidence of Bacterial Wilt on 2 Aug 2000Incidence of Bacterial Wilt on 2 Aug 2000
Winter squashWinter squash
PumpkinPumpkin
GourdGourd
WatermelonWatermelon
MuskmelonMuskmelon
CucumberCucumber
Zucchini squashZucchini squash
Yellow squashYellow squash
11 d11 d
40 bc40 bc
50 b50 b
12 d12 d
6 d6 d
97 a97 a
32 c32 c
38 bc38 bc
Trap Cropping
• Choose attractive, wilt tolerant variety for trap crop
• Surround entire planting, two rows are better than one
• Arrange main crop such that attractive or susceptible varieties are surrounded by less attractive/susceptible
• Reduce attractiveness of main crop– Surround, BioYield
Trap Cropping
• Reducing second generation beetle production in trap crop– Disc up?– Apply nematodes to roots?
• Steinernema riobravis (Ellers-Kirk et al., PA)• Heterorhabditis bacteriophora strain GPS-11 (Miller and
Welty, OH)
– Nothing?
Costs for Trap Cropping
To produce and establish transplants– One row - $185 for a square 1A field
– Two rows - $370
Plus any cost of managing beetles on trap crop
Row Cover
Must be removed at flowering
Provides excellent control plus growth enhancement
But:
Interferes with cultivation
Cost: ~ $415/A hoop system
~ $435/A entire field system
Insecticide Options
Per application - cost of materials only
Pyganic 5.0 @4.5-18 oz/A - $23.75-95.00/AReliable kill or just knockdown?
Surround @ 6.25-25 lb./A - $6.25-25.00/AGreatly reduced if transplants treated in flats
Surround-treated transplants
Scouting and Thresholds?
Twice weekly scouting during invasion season, keep an eye on maturing fruit later
Depends on crop susceptibility to wilt and reliability of control (0.5-2 beetles/plant)
Current approved insecticides do not provide reliable control
Relying on insecticides alone will not work for organic farmers
Integrate a variety of approaches.