Performance and uptake of some carbendazim‐producing fungicides applied as seed treatments to spring barley, in relation to their physicochemical properties

摘要

AbstractThe performance of carbendazim and its chemical precursors benomyl, thiophanatemethyl and methyl 4‐(2‐aminophenyl)‐3‐thioallophanate (I) ( “NF48” ) as systemic fungicidal seed treatments on barley was investigated. In field trials all treatments significantly decreased smut (Ustilago nuda) at 3.2 g kg‐1of seed; the order of effectiveness wasI>benomyl>thiophanate‐methyl>carbendazim. Control of barley mildew (Erysiphe graminis) followed a similar pattern but results were less clear‐cut. Measurements of uptake and translocation from seeds, treated with radiolabelled fungicide and planted in pots of Woburn soil in a controlled environment room, showed that seedlings accumulated much moreIthan the other compounds over 28 days. This substantial early uptake into leaves could explain whyIwas particularly effective against smut in the field trials. Comparisons of amounts taken up. with solubility in water, octanol/water partition coefficient, extent of adsorption on soil and pKavalues suggested that the effects of these properties on availability in the soil solution may be more important than their influence on penetration into the root in determining relative uptake and disease control in the case of localised applications such a