Influence of soil type and water content on release of triticonazole from coated maize seed

The release of [C-14]triticonazole from coated maize seeds into soil, and i ts incorporation in maize, were studied under laboratory conditions over se ven days in two soils at two different water contents (equivalent to a matr ix potential of -3kPa and -1580kPa). The behaviour of a commercial coating formulation was compared to that of the same formulation supplemented with a pellicle to improve coated seed handling. Triticonazole released into soi l, remaining in the integument and incorporated in different parts of the p lant (stem, root, albumen) was measured. The triticonazole released into th e soil corresponded to 25% of the initial applied amount on the seed under the best conditions (sandy soil, matrix potential of-3kPa, set without pell icle). In these conditions, 13% of applied triticonazole was incorporated i nto roots and stems after seven days. The presence of an additional pellicl e to improve the coating decreased the quantity of triticonazole released i nto soil and consequently the quantity of triticonazole incorporated into t he plant. In all cases, the diffusion of triticonazole from the seed to the soil was not limited by the water solubility of triticonazole. Instead, th e sorption of triticonazole on soil appears to be the key process governing its fate in soil. (C) 2000 Society of Chemical Industry.