Affinity and mobility of fungicidal dialkyl dithiolanylidenemalonates in rice plants

The affinity of certain fungicide analogs to rice plant varied progressively, showing a linear decrease with decreasing length of, or branching of, the alkyl chains, and correlated well with the hydrophobic parameter, log P. The more hydrophobic the compound was, the higher was the affinity to rice plant. Compound mobility in rice plant also varied regularly. The resulting relationship between hydrophobicity and mobility of these fungicide analogs suggested that the situation in rice plant is quite analogous to rice-plant column chromatography, by which the affinity to rice plant was determined. The major factor preventing movement within the plants seems to be interaction with sites in the rice plant leading to partition or binding and the resulting loss from the transpiration stream.