Bio-control Effect of Trichoderma asperellum (Samuels) Lieckf. and Glomus intraradices Schenk on Okra Seedlings Infected with Pythium aphanidermatum (Edson) Fitzp and Erwinia carotovora (Jones)

Abstract

Biological control agents are known to reduce the effect of plant pathogens and also reduce the environmental hazard caused by the persistent use of synthetic chemicals. In this study the effect of Trichoderma asperellum and the arbuscular mycorrhizal fungus Glomus intraradices were observed on young okra seedlings infected with the same concentration of disease causing microorganisms; Pythium aphanidermatum and Erwinia carotovora. This study was designed to evaluate the effect of biocontrol agents against okra seedlings infected with Erwinia carotovora and Pythium aphanidermatum. The experiment was conducted in the green house of the faculty of Agriculture, Ile- Ife, Nigeria. Different combinations of these microorganisms were observed on the growth performance of Okra seedlings. Okra seedlings were planted in the nursery for 2 weeks and 3 weeks respectively before they were transplanted into pot of 17 cm by 17 cm filled with sterilized soil. Inoculums concentration of 10-8CFU/ml of each micro- organism and 30 g of AM were introduced to the root zone of the young seedlings during transplanting from nursery tray to the growing pots according to the designated treatments and each treatment was replicated thrice. The same procedures were used for 3 weeks okra seedlings. The effects of micro-organisms were observed using plant growth parameters such as; stem girth, number of leaf, stem height and leaf area.  The result shows that the bio-control agents reduced the negative effect of the pathogen on the young seedlings and Glomus intraradices enhanced the development of plant parameters. The organisms had a lesser synergistic effect on each other due to their high requirements for metabolic product of plant but produced more antagonistic effect on the pathogenic micro-organisms. In conclusion, Glomus intraradices and Trichoderma asperellum could be effectively used as bio-control agents to reduce the effect of Erwinia carotovora and Pythium aphanidermatum on young Okra seedlings