ABSTRACT
Pesticide use has become an integral part of modern agricultural production systems for cereals. This chapter addresses the dissipation of pesticides following deposition on both soil and plants. Spray application can result in pesticide inputs to the atmosphere in the form of spray drift. Vapor losses may originate from both soil and plant surfaces; however, vapor losses from soil depend upon the availability of soil surface moisture. Soil surface factors affecting pesticide vapor loss are better understood. Ambient temperature, wind, precipitation, and dew formation also play a role in affecting the rate and magnitude of pesticide vapor losses from treated targets. In higher plants, biotransformations of organic pesticides have involved nonsynthetic processes such as oxidations, reductions, and hydrolyses, conjugation of the pesticide with endogenous plant substrates, and binding of the pesticide to structural components of plant tissues. Movement of pesticides from the soil surface into the soil matrix by leaching has been well established with field leaching studies.
