EVALUATION OF AGRISURE CORN ROOTWORM TRAITED CORN HYBRIDS IN COMBINATION WITH SOIL INSECTICIDES AT PLANTING FOR LARVAL CORN ROOTWORM CONTROL, 2013

Agrisure corn rootworm (CRW) traited corn hybrids, in combination with soil insecticides, were evaluated for effectiveness of larval WCR control near Clay Center, NE during 2013. Trial site was late-planted corn and pumpkins (insecticide free) during 2012. Experimental design was a RCB with 4 replicates. Plot size was 2 rows x 70 ft length in 30inch row spacing. Soil type was a Crete silt loam. ‘Golden Harvest H8969 3122’ (Agrisure 3122; contains 95% Agrisure CB/LL, Agrisure RW, Herculex I, and Herculex RW insect traited seed and 5% non-insect traited seed) and ‘Golden Harvest H8969 3111’ (Agrisure 3111; contains 100% Agrisure 3000GT and Agrisure Viptera insect traited seed) corn hybrids were planted on 7 May with a 2-row JD 7100 Maximerge planter with finger pickup seed units. Each hybrid received a seed-applied treatment of CruiserMaxx 250 (thiamethoxam @ 0.25 mg ai/kernel). A south wind @ 5-12 mph coincided with planting. Liquid insecticides were applied in-furrow (IF) in 5 GPA water solution via a CO2 pressurized system. Plant populations were evaluated on 10 Jun. The total number of plants per plot was recorded and converted to plants per acre. Extended leaf height (ELH) of twenty plants per plot was recorded to the nearest half-inch on 18 Jun. Larval feeding damage was evaluated on 25 Jul. Six randomly selected plants were dug from each plot, washed, and rated using the Iowa State 0-3 scale (0 = no feeding, 1 = one node of roots pruned to within 1.5 inches of the stalk, 2 = two nodes of roots pruned to within 1.5 inches of the stalk, 3 = 3 or more nodes of roots pruned to within 1.5 inches of the stalk). A significant weather event occurred on 01 Aug. A northeast wind of 65 mph was accompanied by pea to nickel-sized hail. The total number of lodged plants, and plants broken at or above, or below the ear per plot, were recorded on 7 Aug. Plots were machine harvested on 10 Oct. Percent moisture and lbs of grain was recorded and corrected to 56 lbs/bu @ 15.5% moisture. Data were analyzed by PROC MIXED with mean separation using differences of least square means (P = 0.05).