The Interrelation of Fruit Development and Leaf Senescence in 'Anoka' Soybeans

Abstract

In order to study the relationship between fruit development and monocarpic senescence in soybeans (Glycine max [L.] Merrill ''Anoka''), rapid, nondestructive methods were developed for measuring these processes. Both senescence (leaf chlorosis) and fruit development stages are given numerical designations and described quantitatively. Senescence is measured as the percentage of leaves .ltoreq. .5 yellow, and this method is checked for reliability against 2 photometric methods that measure chlorophyll content. The fruit maturity stages are designated 1-5, depending on fruit size and color, and are also correlated with the growth of individual parts of the fruit. The onset of chlorosis coincides with mid pod fill when the seeds undergo their maximum growth. The developing fruit cause, at least in part, the slowdown of vegetative growth, a decrease in the number of fruit initiated, and an increase in the number aborted.