Effects of Depodding and Light Intensity on Soybean (Glycine Max (L.) Merrill) In South West Nigeria

Abstract

A study was undertaken to obtain information on the performance of depodded soybean under reduced light intensity prevalent in South West Nigeria during the season of soybean cultivation. Soybean plants were subjected to 0, 10, 20 and 40% depodding at the R5 stage of growth and grown simultaneously under 75, 50 and 100% daylight regimes for two weeks. The 100% light regime served as control. Depodding engendered a greater accumulation of chlorophyll in the leaves of depodded plants. Yield was reduced in depodded plants and the magnitude of reduction increased with increasing severity of pod removal. Depodding interacted with light intensity such that the effect of reduced Sight intensity on soybean was made more pronounced. Depodded plants grown under subdued light intensities had higher chlorophyll concentration than plants depodded and grown under the 100% Sight regime. Similarly, field grown plants (which received lower photon flux) had a higher chlorophyll level than pot grown plants. It is likely that several factors in addition to light interacted to determine the magnitude of chlorophyll production in soyabean. The lower light regimes had relatively little impact on the vegetative growth of soyabean apparently because of the advanced stage of growth in which the treatments (depodding and light regimes) were imposed on the plants.