Examination of Leaf Removal or Root Cut Treatment for Suppression of Green Stem Disorder in the Black Soybean ‘Tambaguro’

Abstract

The black soybean ‘Tambaguro’ is a specialty product in Kyoto Prefecture, Japan. Recently, it is often reported that the stem and leaf of Tambaguro remain green compared to the ripening progress of pod and the maturation of entire plant is delayed, called green stem disorder. Therefore, we investigated the effect of leaf removal or root cut treatment after the R7 stage on suppressing green stem disorder, yield and grain quality. Depending on the year, the leaf removal and the root cut treatments promoted fading of the color of stem and leaf and decreased the degree of green stem disorder in the R8 stage. Because damaged and wrinkled grains tended to be decreased and increased, respectively by the leaf removal treatment, decrease in the water content of plant and the source to sink in the period of R7-R8 might affect grain quality.