Research: Effects of a Low Rate of Aldicarb on Soybean and Associated Pest Interactions in Fields Infested with


  • S. R. Koenning
  • H. D. Coble
  • J. R. Bradley
  • K. R. Barker
  • D. P. Schmitt


Aldicarb, Corn Earworm, Glycine Max, Green Clover Worm, Helicoverpa zea, Herbicides, Heterodera glycines, Pest Interactions, Plathypena scabrra, Soybean Cyst Nematode, Weeds


Field experiments conducted from 1989 to 1991 focused on potential interactions of insects and weeds, as influenced by a low rate of aldicarb (0.84 kg a.i./ha in-furrow application) in the presence of Heterodera glycines (SCN). A split-split-plot experimental design was used with whole plots as aldicarb treatments, sub plots designed to manage weed densities and sub-sub plots to manage insects. The sites were planted without pre-emergence herbicides, and post-emergence herbicides were utilized to maintain weed densities as desired. Numbers of SCN females per 3-plant-root systems were less in aldicarb-treated plots in 1989 and 1991, but not in 1990. Aldicarb treatment resulted in increased plant height, canopy width, and number of nodes per soybean plant. The increased canopy growth tended to result in lower weed and lower corn earworm population densities in aldicarb-treated plots. Numbers of corn earworm larvae were greater (P = 0.05) in untreated plots in 1989 and 1991. Weed densit