Utilization of the potentials of selected microorganisms as biocontrol and biofertilizer for enhanced crop improvement

Abstract

Some selected microorganisms isolated from rhizosphere of crops, were screened for their abilities to enhance crop growth and suppress plant parasitic nematodes; in screenhouse experiments. Two promising hybrids of soybean genotypes: TGx 1448-2E (medium duration) and TGx 1485-1D (early maturing) and a high yielding hybrid of maize genotype Oba Super 1 were used. Microorganisms assessed included the fungi: Trichoderma pseudokoningii, Trichoderma viride, Paecilomyces lilacinus, Aspergillus niger, Glomus mosseae and the rhizobacteria Pseudomonas fluorescens and Pseudomonas putida. One thousand juveniles of Meloidogyne incognita were applied to soybean, while five thousand Pratylenchus zeae (juveniles and adults) were applied to maize. Fungal spores and rhizobacteria cells approximately 2.5x106 mL-1 concentration were applied per plant, for maize experiment. For soybean experiment, Bradyrhizobium japonicum (106 cells), Trichoderma pseudokoningii (6.8x106 spores) and G. mosseae (200 spores) were inoculated per plant. The effect of microorganism`s application was compared with a nematicide (carbofuran) treatment, untreated control and a nematode only control. The parameters measured were nematode density, root damage due to plant parasitic nematode infection, relative leaf chlorophyll content and plant growth parameters. The inoculated beneficial microorganisms in most cases significantly (p≤0.05) reduced the nematode density across the treatments in test crops by up to 79.6% and improved plant growth by up to 46.0%, when treatments performances were compared across treatments. Most of the beneficial microorganisms assessed have prospects of enhancing nematode management through nematode density reduction and improving crop production.