Nematodes have been discovered in a field where crop plants are actively growing. Which nematicide application is most effective at this site?

• A. Chemigation of nematicides
• B. Soil drench
• C. Seed treatment
• D. Foliar spray

Answer: (A)

Targeting soil-dwelling nematodes in a field with active crop growth is best done by delivering the nematicide through irrigation, so it moves with the water into the root zone where nematodes feed. Chemigation distributes the product across the root zone as part of regular irrigation, providing uniform exposure to the nematodes throughout the field and aligning with active root activity. A soil drench can reach roots but often results in uneven distribution and may not cover the entire root zone as effectively, seed treatment protects only the seed or very young plants and won’t control established nematodes in a growing field, and foliar spray acts on aboveground pests and does not reach subterranean nematodes.