Study on the Effects of Fresh Shoot Biomass of Tithonia diversifolia on the Germination, Growth and Yield of Cowpea (Vigna unguiculata L.)

摘要

Studies on the effects of fresh shoot biomass of Tithonia diversifolia on the germination, growth performance and yield of cowpea ( Vigna unguiculata L.) were carried out at the experimental site of the Department of plant science of Ekiti State University, Ado Ekiti in the 2011 and 2012 cropping seasons. Fresh shoots of Tithonia diversifolia were collected from the University environment and blended using pestle and mortar to make the fresh shoot biomass (FSB). The FSB was weighed into 50g, 100g, 150g and 200g and thoroughly mixed with collected soils in horticultural pots. The soil sample had already been autoclaved at 100oc for 24hr. The control experiment recorded the highest emergence percentage but similar to the 50g FSB of T. diversifolia recorded. Higher FSB resulted to lower emergence percentage. Growth parameters in terms of plant height stem girth, number of leaves per plant and leave area were highest in the 150g Tithonia diversifolia FSB but lowest in the control. The highest yield of cowpea was obtained in the 150g Tithonia diversifolia FSB applied pots which was similar to those of 100g FSB applied pots. The stimulatory growth factor and yield increase enhanced by FSB of Tithonia diversifolia is an indication that Tithonia diversifolia possesses no negative allelopathic effect on cowpea growth. The poor seedling emergence observed suggests that the land be left for some time to allow proper degrading of the Tithonia diversifolia before planting cowpea. This study further revealed that fallowed land occupied by Tithonia diversifolia could be successfully used to produce optimum cowpea yield.