Dry Pesticide Formulations
Part 2, Section 1: Pest Management
Pesticides and Their Application
Dry pesticide formulations
Granular (G) pesticides are formulated with a premixed carrier that has a low percentage of active ingredient. They are applied directly (dry) without further dilution. The carrier may be fertilizer, clay, lime, vermiculite, or ground corn cobs. The performance of granulated herbicides, compared to that of sprayable formulations, varies with the herbicide. Granular forms generally require more rainfall for activation than do sprayable formulations.
- water is not needed for application
- equipment required for application is relatively inexpensive
- selectivity may be improved because granular particles fall off leaves and sift through crop canopy to the ground
- heavy, bulky, and troublesome to store or ship
- small granules subject to drift
- application not as uniform as that of sprays
Pellets (P) are like granules but are compressed into larger cylinders about ¼ inch long. Herbicides formulated as pellets usually contain from 5% to 20% active material and are applied by hand to control clumps of brush. For brush control in forests or permanent pastures, they also may be applied with spinner spreaders mounted on helicopters or aircraft. Pellets gradually break down from rainfall and leach into the soil for root uptake.