Hydrophobicity of Buprofezin and Flutolanil in Relation to Their Soil Adsorption and Mobility in Rice Plants

Compound behavior such as adsorption with soil and mobility in rice plants of 2-tertbutylimino-3-isopropyl-5-phenyl-3, 4, 5, 6-tetrahydro-2H-1, 3, 5-thiadiazin-4-one (buprof ezin) and 3'-isopropoxy-2-(trifluoromethyl)benzanilide(flutolanil) were determined and compared with results reported previously for a set of fungicidal compounds. Highly hydrophobic buprofezin was strongly adsorbed with the soil and was hardly mobile in rice plants. Flutolanil, which was not highly hydrophobic, was not strongly adsorbed with the soil and considerably mobile in the plants. These types of behavior may be contributing characteristics in their effectiveness as pesticides. Relationship between behavior and hydrophobicity (log P) of the fungicides were found to be extendible to structurally unrelated compounds such as buprof ezin and flutolanil. This in turn means that compound behavior can be generally predictable from a measure of the hydrophobicity, log P-