Interactive effect of Jatropha curcas leaf extract and Trichoderma reesei for the management of Sclerotium rolfsii disease on pepper (Capsicum annuum) in Calabar

Sclerotium rolfsii is a destructive soil-borne disease limiting pepper production in tropical regions. Research into the control of Sclerotium rolfsii was conducted in the Screenhouse within the Botanical Garden of University of Calabar. The objective was to evaluate the efficacy of Trichoderma reesei in combination with leaf extract of Jatropha curcas to control Sclerotium rolfsii. Two weeks old pepper plants were inoculated with three (Sclerotia g-3) in a heat sterilized soil. Trichoderma reesei at various spore load of 3.90×107, 2.40×107, 1.70×107 and 6.0×106 spores/mL were applied singly and in combination with various concentration of Jatropha curcas at 0.20, 0.40 and 0.60 g/mL at 3 weeks after planting. The experiment was laid out in a completely randomized design with twenty treatments replicated three times. Results obtained showed that pepper plant was highly susceptible to S. rolfsii infection as the rate of root colonization index was rated (RCI= 5.00) on pots without Jatropha curcas and Trichoderma reesei. Increase in J. curcas application and T. reesei applied singly significantly reduced Sclerotium rolfsii infection in pepper plant. The combination of different concentrations of J. curcas with Trichoderma at various spore loads significantly (p<0.05) inhibited S. rolfsii infection more than single application. Inoculation of Trichoderma reesei at 3.90×107 spores/mL with J. curcas at 0.60g/mL significantly decrease the susceptibility of pepper plants to (RCI = 1.00). Similarly, the combined inoculation of T. reesei with leaf extract of J. curcas significantly (p<0.05) lowered S. rolfsii disease incidence from (58.41 to 10.28%) and also enhanced the growth attributes, number of pods, fresh pod weight. The highest fresh fruit yield (108.40g/plant) was obtained with Trichoderma reesei at 3.90×107 spores/mL in combination with 0.60g/mL of J. curcas.