Degradable in agriculture

Steinheimer, T.R. (1993). HPLC determination of atrazine and principal degradates in agricultural soils and associated surface and ground water. J. Agric. Food Chem., 41 588-595. 

Plant processes. In plants chemical substances enter, are transported, are absorbedinto organic matter andbioaccumulated, are metabolised and degraded. In agricultural areas, plant processes may therefore play a significant role in the fate of pesticides. 

Tetrahydrofurfuryl alcohol also has been cleared for use in California under Rule 66. It meets the rigid specifications for uv degradation in environmentally sensitive areas. In addition to domestic use, a substantial amount of tetrahydrofurfuryl alcohol is used as a solvent for agricultural chemicals in Europe. 

Synthetic pyrethroids now account for at least 30% of the world insecticide market and are rapidly replacing other agricultural chemicals for control of insect pests. Fenvalerate is one of the more widely used synthetic pyrethroid insecticides. It is derived from a combination of a-cyano-3-phenoxybenzyl alcohol and a-isopropyl phenylacetate ester. Technical fenvalerate is a mixture of four optical isomers, each occurring in equal amounts but with different efficacies against insect pests. Fenvalerate does not usually persist in the environment for >10 weeks, and it does not accumulate readily in the biosphere. Time for 50% loss (Tb 1/2) in fenvalerate-exposed amphibians, birds, and mammals was 6 to 14 h for reptiles, terrestrial insects, aquatic snails, and fish it was >14 h to <2 days and for various species of crop plants, it was 2 to 28 days. Fenvalerate degradation in water is due primarily to photoactivity, and in soils to microbial activity. Half-time persistence in nonbiological materials is variable, but may range up to 6 days in freshwater, 34 days in seawater, 6 weeks in estuarine sediments, and 9 weeks in soils. 

Weeds constitute one of the major problems in agriculture. They are an important constraint on yield in most crops across the world. These days, growers spend much money on weed control. About 6 million ton of herbicides was sold in the world in 2006 and herbicides are the most used pesticides they form approximately 38% of the total amount of pesticides (FAO 2006). Nowadays, an effort to tighten rules for authorization and application of pesticides, research and develop products that are target-specific, degrade quickly and do not accumulate in the food chain, exists in... 

The use of pesticides in agriculture does not inevitably mean that food residues will result. In many cases, pesticides are applied to non-food agricultural crops, while in other instances pesticides may be applied around, but not directly on, food crops, such as the case in which a broad-spectrum herbicide is used. Even when pesticides are applied directly to food crops, food residues are often not detected. In some cases, pesticides may be applied prior to the development of edible portions of the crop, while in others the rapid environmental degradation of the pesticide between the time of application and the time of harvest may also avoid food residues. 

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