Agricultural Plant (1a) and Agricultural Animal (1b)
Agricultural Plant (1a)
Field crops and forages
Oklahoma's planted acreage is dominated by winter wheat, with canola, grain sorghum, corn, cotton, soybeans, peanuts, and bermudagrass or alfalfa hay filling out the picture. Questions in 1a blend agronomy with pesticide judgment: knowing the crop stage, the pest, and the label restriction all at once.
Key concepts. Scout and use economic thresholds rather than calendar sprays. Know preplant, preemergence, and postemergence timing, and how adjuvants and carrier volume change performance. Learn herbicide mode-of-action groups well enough to rotate away from repeated use (Group 1 grasses, Group 2 ALS, Group 4 synthetic auxins, Group 9 glyphosate, Group 14 PPO, Group 15 seedling growth inhibitors). Understand grazing, haying, and crop-rotation restrictions, not just the PHI for harvest.
Drift and volatility. Group 4 products are the classic off-target story. Applications made in a temperature inversion, at high temperature, or with a volatile ester move far beyond the field. Note wind speed, boom height, nozzle selection, and buffers to sensitive crops, gardens, and vineyards.
Chemigation. Fertilizer and pesticide injection requires approved anti-backflow equipment - check valve, vacuum relief, low-pressure drain, and an inspection port - and the state requires a chemigation permit in many situations.
Trap: a product labeled for wheat may restrict grazing or feeding straw; the harvest PHI does not cover forage use. Read the rotational crop and feeding sections.
Worked example. A postemergence broadleaf herbicide lists "do not graze or feed forage within 14 days" and a 30-day PHI. If cattle are on the field, the 14-day forage restriction controls your timing, not the 30-day harvest interval.
Agricultural Animal (1b)
Livestock and poultry pest control
This category covers pesticide use on and around cattle, horses, swine, sheep, goats, and poultry - feedlots, stocker operations, dairies, and confinement buildings. The pests are familiar: horn flies, stable flies, face flies, house flies, ticks, lice, grubs, mites, and rodents around feed.
Concepts to master. Distinguish animal-applied products (pour-ons, sprays, dusts, ear tags, oral larvicides) from premise products (space sprays, residual wall sprays, baits). Some products are labeled only for premises and must never contact the animal or feed. Fly control is an IPM problem: manure and moisture management, biological control, feed-through larvicides that stop development in manure, and rotated insecticide classes for ear tags. Continuous use of one pyrethroid class breeds resistant horn flies.
Withdrawal times are the highest-stakes item. Meat and milk withdrawal periods appear on the label and in the product literature; violating them leaves illegal residues. Some products are prohibited entirely on lactating dairy animals. Never treat a cull animal and sell it on the same schedule as a treated market animal.
Rodenticides and feed. Place baits where livestock, pets, and children cannot reach them and where baits cannot contaminate feed or forage. Record placement and check stations.
Trap: a premise spray labeled for feedlots may be applied to surfaces but not as a direct animal spray; the reverse is also true. Site on the label decides.
Worked example. A pour-on states 0 days slaughter withdrawal but "not for use on lactating dairy cattle." Treating a springer heifer close to calving can put residue in colostrum and milk - treat heifers well before calving or use a dairy-labeled product.