Evaluation of Insecticides for Control of Insect Pests in an MG VII Soybean Beaumont, TX 2009 Soybean Nursery North No. 4

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1 Beaumont, TX 2009 Soybean Nursery North No. 4 North PLOT PLAN I II III IV Guard tier on North and South, 4 row buffers on east and west Plot size = 8 rows, 30 inch row spacing, trimmed to 20 ft long Variety = S78-G6 TREATMENTS AND RATES No. Description 1 Untreated Orthene 90S Belt 480SC 3 oz/a 4 Belt 480SC + 5 Tenchu 20SG 8 oz/a Agronomic and Cultural Information Experimental design: Randomized complete block with 6 treatments and 4 replications Planting: Beds were pulled on Morey silt loam soil (30 inch row width) on Apr 16. On May 21 beds were cultivated and planted with S78-G6 (MG VII). Plot size: Herbicide: 8 rows, 30 inch row width, trimmed to 20 ft after emergence 0.75 oz/a First and 2.5 pt/a Dual Magnum were applied pre-emergence on May 29 at 29 gpa. s: s 2 6 applied with a 2-person hand-held spray boom (13, No. 2 cone nozzles, 50 mesh screens 18 gpa) on Sep 25 (lots of defoliation) 83

2 Sampling: V7 on Jun 29 R2 on Jul days after treatment (DAT) on Sep 28 R5/6) 8 7 DAT on Oct 2 R5/6) 8 11 DAT on Oct 6 R5/6), very few leps, more stink bugs) 8 17 DAT on Oct 12 R6) Harvest: Harvested on Nov 19 Size harvested plot = 2 middle rows, 20 ft long Data analysis: Insect counts transformed using x ; yields adjusted to bu/a at 13% moisture; all data analyzed by ANOVA and means separated by LSD. Discussion Only statistically or biologically significant results are discussed. yields were not significantly greater than the untreated and ranged from bu/a (Table 1). All treatments, including the untreated, produced seed of the same quality, a rating of 3.0. The most abundant insect was the redbanded stink bug (RBSB) (Tables 2-13). Basically, at 17 days after treatment (DAT), the Tenchu and Orthene + Discipline treatments provided the best control (67%) of stink bugs (mainly RBSB) (Table 11). At 7 DAT, the Tenchu, Orthene and Orthene + Discipline treatments provided good control of stink bugs, again primarily RBSB (Table 5). Pest Lepidoptera populations were relatively low; nevertheless, at 3 DAT, the Belt + (non-ionic surfactant) treatment provided the best control (73%) (Table 3). Data suggest the addition of the improved control of Lepidoptera. At 3 and 11 DAT, the Belt treatments did not control threecornered alfalfa hopper, but the other treatments did (Tables 4 and 10). Assassin bugs were numerically lower in all treatments compared to the untreated at 3 DAT. At 17 DAT, big-eyed bug numbers were reduced significantly in the Tenchu and Orthene + Discipline treatments. 84

3 Table 1. Mean yield data for maturity group VII soybean insecticide screening. Beaumont, TX Yield (bu/a) Seed Quality (1 5) Untreated a 3.0 Orthene 90S a 3.0 Belt 480SC 3 oz/a 32.3 b 3.0 Belt 480SC % v/v 39.0 a 3.0 Tenchu 20SG 8 oz/a 42.3 a 3.0 Discipline 2EC a 3.0 a Yield adjusted to 13% moisture b Seed Quality: 1 = excellent, 5 = poor Table 2. Mean stink bug data 3 days after treatment for maturity group VII soybean insecticide Southern green Redbanded Brown A a N a T a A N T A N T Total Untreated a a 2.0 ab a Orthene 90S b b 0.3 c c Belt 480SC 3 oz/a b a Belt 480SC + Tenchu 20SG 8 oz/a b ab ab ab a 3.3 a a 0.8 ab 1.0 bc bc b b 0.3 c c a A = adults; N = nymphs; T = total 0.05, ANOVA and LSD) 85

4 Table 3. Mean lepidopterous larvae data 3 days after treatment for maturity group VII soybean insecticide Soybean looper Green cloverworm Velvetbean caterpillar Total Untreated a 3.0 ab Orthene 90S b 1.5 bc Belt 480SC 3 oz/a b 1.5 bc Belt 480SC % v/v b 0.8 c Tenchu 20SG 8 oz/a b 3.3 a b 1.8 bc Table 4. Mean misc. insect data 3 days after treatment for maturity group VII soybean insecticide Banded Threecornered alfalfa hopper cucumber beetle Big-eyed bug Spiders Assassin bugs Untreated a a Orthene 90S bc b Belt 480SC 3 oz/a 1.5 ab b Belt 480SC a ab Tenchu 20SG 8 oz/a 0.3 bc b c b 86

5 Table 5. Mean stink bug data 7 days after treatment for maturity group VII soybean insecticide Southern green Redbanded Brown A a N a T a A N T A N T Total Untreated a 1.8 bc 3.3 a a Orthene 90S b 0.3 c 0.5 b b Belt 480SC 3 oz/a ab 4.5 a 5.3 a a a 4.0 ab 5.3 a a Tenchu 20SG 8 oz/a b 0.5 c 0.5 b b b 0.3 c 0.3 b b a A = adults; N = nymphs; T = total 0.05, ANOVA and LSD) Table 6. Mean lepidopterous larvae data 7 days after treatment for maturity group VII soybean insecticide Soybean looper Green cloverworm Velvetbean caterpillar Total Untreated Orthene 90S Belt 480SC 3 oz/a Tenchu 20SG 8 oz/a

6 Table 7. Mean misc. insect data 7 days after treatment for maturity group VII soybean insecticide Banded Threecornered alfalfa hopper cucumber beetle Big-eyed bug Spiders Assassin bugs Untreated a Orthene 90S b Belt 480SC 3 oz/a b Belt 480SC b Tenchu 20SG 8 oz/a b b Table 8. Mean stink bug data 11 days after treatment for maturity group VII soybean insecticide Southern green Redbanded Brown A a N a T a A N T A N T Total Untreated a Orthene 90S ab Belt 480SC 3 oz/a a ab Tenchu 20SG 8 oz/a b b a A = adults; N = nymphs; T = total 0.05, ANOVA and LSD) 88

7 Table 9. Mean lepidopterous larvae data 11 days after treatment for maturity group VII soybean insecticide Soybean looper Green cloverworm Velvetbean caterpillar Total Untreated Orthene 90S Belt 480SC 3 oz/a Tenchu 20SG 8 oz/a Table 10. Mean misc. insect data 11 days after treatment for maturity group VII soybean insecticide Banded Threecornered alfalfa hopper cucumber beetle Big-eyed bug Spiders Assassin bugs Untreated ab Orthene 90S b Belt 480SC 3 oz/a 1.0 ab Belt 480SC a Tenchu 20SG 8 oz/a 0 b b

8 Table 11. Mean stink bug data 17 days after treatment for maturity group VII soybean insecticide Southern green Redbanded Brown A a N a T a A N T A N T Total Untreated a bc 2.3 ab a Orthene 90S b ab 2.3 ab ab Belt 480SC 3 oz/a b a 4.5 a a ab cd 1.8 bc a Tenchu 20SG 8 oz/a b d 0.3 c b b cd 1.5 bc b a A = adults; N = nymphs; T = total 0.05, ANOVA and LSD) Table 12. Mean lepidopterous larvae data 17 days after treatment for maturity group VII soybean insecticide Soybean looper Green cloverworm Velvetbean caterpillar Total Untreated b 0 b Orthene 90S b 0 b Belt 480SC 3 oz/a b 0 b b 0 b Tenchu 20SG 8 oz/a a 1.0 a b 0.3 b 90

9 Table 13. Mean misc. insect data 17 days after treatment for maturity group VII soybean insecticide Banded Threecornered alfalfa hopper cucumber beetle Big-eyed bug Spiders Assassin bugs Untreated c a Orthene 90S bc ab Belt 480SC 3 oz/a 2.5 a a Belt 480SC b a Tenchu 20SG 8 oz/a 0.3 c b c b