The Influence of Glomus mosseae and Trichoderma harzianum on Phytohormone Production in Soybeans (Glycine max L. Merr) Planted in Sterilized and Unsterilized Soils

This study was carried out to investigate the effect of the mycorrhizae; Glomus mosseae and Trichoderma harzianum; singly and in combination on the level of phytohormones (auxin, gibberrelin and abscisic acid) of soybean (Glycine max L. Merr) planted in sterilized and unsterilized soils. The experimental design adopted was completely randomized with four treatments i.e. Glomus mosseae (G), Trichoderma harzianum (T) and combination of G. mosseae and T. harzianum (GT) and an uninoculated (control (C)). There were four replications harvested at maturity after a growth period of 15 weeks. The experiment was carried out in the Department of Microbiology, University of Agriculture, Abeokuta, Ogun State, Nigeria between March 2009 to April 2010. Phytohormone levels before and after treatments were determined using documented method. The volume of phytohormones obtained were significantly (P>0.05) higher (7.05-70.43mg/100ml) in sterilized than unsterilized (6.27-52.73mg/100ml) soil. In all the treatments, auxin volume was highest (63.64mg/100ml) followed by abscisic acid (60.55mg/100ml) and gibberrellin (7.75mg/100ml). Treatment of soil with combined mycorrhizae G. mosseae and T. harzianum enhanced phytohormone production in soybean compared to soil treatment with single mycorrhiza and trichodermal inoculations.