Biopesticide Effect of Potential Microorganisms in Bioformulation Against Phytophthora infestans (mildew) and Alternaria spp. (alternariosis) on Capsicum annuum L. in Field

The production of pepper, a staple food of millions of people in the world is facing a severe parasitic pressure of pests and diseases. The objective of this work aimed at developing a biopesticide formulation (T1) using potential microorganisms as Trichoderma harzianum and Metharizium anisopliae and test it performance against the virulence of Alternaria solani and Phytophthora infestans isolated from two pepper varieties V1 (Safi) and V2 (Burkina yellow) in two agroecological areas. The previous formulation was made up with rice bran fermentation and potential microorganisms specifically selected. The two-factor split-plot design consisted of 06 basic plots per block for each pepper variety. A significant difference (p = 0.05) was revealed between the formulation (T1), chemical pesticide as positif control (T2) made up with Mandipropamid and the control (T0) in the field on disease incidence and severity in all stage of pepper growth. Mildew incidence ranged from 12.72% to 53% for the V1 and 10.01% to 49% for the V2 in agro-ecological area III. Similarly, 8.99% to 60.9% for variety V1 and 7.12% to 55% for variety V2 in agro-ecological area V between 4 and 12 weeks. The incidence of alternariosis varied from 7.12% to 77.12% for variety V1 and 7.01% to 69.15% for variety V2 in agro-ecological area III. Also 4.32% to 71.9% for variety V1 and 5.12% to 67.08% for variety V2 in agro-ecological area V between 4 and 12 weeks. Gas chromatography combined with mass spectrometry revealed an overproduction of bioactive molecules in the hydro-methanolic extracts of pepper leaves treated with the formulation T1, which are responsible for its phytoprotection in the two agroecological areas. In conclusion, the use of the Trichoderma harzianum and Metharizium anisopliae formulation significantly induced systemic resistance of Capsicum annuum L plants against alternariosis and mildew agents.