Physiological and Growth Responses of Tomato Plants to Different Delivery Methods of Biocontrol Agent Chaetomium globosum

Chaetomium globosum is a cosmopolitan fungus which has great potential as a biocontrol agent. Apart from being an effective biocontrol agent, C. globosum is reported to have promising effects on plant growth and development. In this study, we evaluated effect of five delivery methods of C. globosum Cg-2 (seed treatment, drenching of rhizosphere and various combination of seed treatment and drenching) on growth and physiological parameters of tomato plants. Seed treatment supplemented with double drenching with suspension and seed treatment supplemented with single drenching with suspension showed highest increase in plant growth among five treatments, 36.70 per cent and 36.79 per cent increase in plant height; 65 per cent and 53 per cent increase in root length, respectively. The physiological parameters like photosynthesis, stomatal conductance and transpiration increased in Cg-2 treated plants and were found highest in seed treatment supplemented with double drenching with suspension which was 9.72 μmol m^-2s^-1, 0.216 mol m^-2s^-1and 0.03 mol m^-2 s^-1 respectively whereas internal CO₂ concentration decreased in Cg-2 treated plants. The combination of treatments performed better over single treatment (either seed treatment or drenching) for plant growth promotion and enhancement of physiological parameters. Among these combinations, the seed treatment supplemented with single drenching is recommended for use at field level as it is economically sound and best in performance.