SOYBEAN PEST ASSESSMENT METHODS

Defoliation Assessment: To estimate defoliation collect at random 30 or more trifoliates and estimate average level of defoliation (see examples on next page). Avoid samples from field perimeter.

Maximum levels of defoliation tolerated by soybeans without significant loss in yield.

From To % Defoliation
Seedling Bloom 30 to 40
Bloom Pod Fill 10 to 15
Pod Fill Maturation 20 to 25

Pod Injury Assessment: To evaluate pod injury inspect 10 or more whole plants, selected at random. Pod injury is highest in the upper canopy. When 8% or more of pods exhibit injury seed damage is evident, especially if high moisture infection periods trigger mold development.

Sweep Net Sampling of Insect Pests: Trends of increasing or decreasing pest activity on soybeans can be determined by periodically taking 10 sweeps from 3 or more locations in a field.


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Corn, Soybean, Wheat, and Alfalfa Field GuideBulletin 827