Break down seed treatment combinations: Insecticides

Published on: 14:39PM Nov 13, 2009
David Long
Because of the benefits of soybean seed treatments, growers have more choices available to protect their crops. Many of these options combine several active ingredients into one package. The best way to figure out the option that makes the most sense for your crop is to compare individual active ingredients in a combination. 

For example, thiamethoxam and imidacloprid are two common insecticide active ingredients used in seed treatment combinations. Thiamethoxam requires less soil moisture for activation, so it ensures plant protection even in dry soil conditions. 

The longer thiamethoxam remains in the soil, the more tightly it binds to the soil, making it less likely to leach. This indicates that thiamethoxam is readily available to be absorbed by plant roots, but shortly after application it binds to the soil profile thereby reducing leaching potential. However, it does not bind so tightly that it is not available for plant uptake. 
In bioassays conducted for determination of soil absorption, imidacloprid showed stronger binding on each of the analyzed soil types than thiamethoxam. High levels of soil absorption or binding can render the pesticide unavailable for plant uptake and biological activity.