Yield responses of corn to simulated black cutworm (Lepidoptera: Noctuidae) damage
1998
Santos, L. | Shields, E.J.
A field trial was conducted to study the impact of 6 increasing levels of simulated black cutworm, Agrotis ipsilon (Hufnagel), damage on grain and silage yields. Plants were damaged at the V3 and V5 stages of corn development. The experiment was conducted on 2 corn hybrids, Pioneer 3921 and Pioneer 3733, planted at 6.0 and 8.0 plants per square meter, in 1993 and 1994. A significant year effect on both grain and silage yield was detected. In both years of study, hybrid had a significant effect on grain yield but not on silage yield, whereas plant density had no significant effect on grain and silage whole-crop yields. Significant linear and quadratic relationships between both grain and silage yields and damage level were detected. Grain yield losses, averaged across plant density, varied from 0 to 24% and 0 to 81% when plants were damaged at the V3 and V5 stages of corn development respectively, depending on hybrid, damage level, and year. For P3733, maximum grain loss exceeded silage loss by as much as 9 and 14% in 1993 and 1994, respectively. P3921 grain losses paralleled silage losses in both years. A phenological delay associated with the simulated damage was observed.
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