Agricultural Plant Pest Control
Scouting and thresholds
Management starts with correct identification and monitoring (sweep nets, pheromone traps, weed counts, disease forecasting). Act on an economic or action threshold, not on the first insect seen. Integrate cultural, mechanical, biological, and chemical tactics - crop rotation, resistant varieties, planting date, cultivation, beneficials, and seed treatments all reduce reliance on sprays.
Timing is the exam's favorite theme
Weed control is timing: burndown before planting, preemergence herbicides before weeds emerge (they rarely control established weeds), and postemergence products matched to weed size and crop stage. Soil-applied herbicides depend on moisture for activation, and persistence creates rotational-crop carryover - always check plant-back intervals. Insecticides work best against young, susceptible stages; fungicides are preventive and require mode-of-action rotation (FRAC groups) to slow resistance.
Application mechanics
Watch formulation and mixing order: partly fill the tank, add water conditioners/antifoam, then dry formulations (WP, WDG), then liquid flowables, then emulsifiable concentrates, and adjuvants last, agitating throughout. Calibrate to deliver labeled gallons per acre; nozzle type, pressure, and boom height set drift risk. Keep spray out of sensitive adjacent crops, and mind volatility (ester vs. amine formulations, high temperatures, inversions).
Traps
Assuming a preemergence product will rescue an already-emerged weed; ignoring plant-back restrictions; treating at the wrong growth stage; forgetting that repeated use of one mode of action selects for resistance. Rule of thumb: scout, identify, then choose the product and timing - never the reverse.