Performance of Trichoderma harzianum and Bacillus amyloliquefaciens Bioformulation on Germination and Expression of Bioprotective Molecules against Cercosporiosis in Abelmoschus esculentus in the Field

The present study aimed at assessing the performance of the formulation combining Trichoderma harzianum and Bacillus amyloliquefaciens on germination and induction of the synthesis of bioprotective molecules against pathogens in Abelmoschus esculentus causing cercosporiosis. A significant difference (p = 0.05) was revealed between the formulation (T1) and the control (T0) in the field on the seed germination rate of okra varieties Clemson spineless (V1) (83.3 vs 94.4%; 88.8 vs 100%; 77.7 vs 88.8%) and Hire (V2) (77.7 vs 94.4%; 88.8 vs 100%; 83.3 vs 88.8%) in agroecological areas V, III and IV respectively. The same effect observed on plant health with bioformulation was significant compared with the control in terms of protection against cercosporiosis pathogens. The protection ranges according to treatment and control for the two okra varieties in agroecological areas V, III and IV were 79.24 vs. 86.48%; 100 vs. 100%; 77.76 vs. 91.82% for variety V1 and 88.88 vs. 94.44%; 94.44 vs. 100%; 83.33 vs. 94.44% for variety V2. Gas chromatography combined with mass spectrometry revealed an overproduction of bioactive molecules in the hydro-methanolic extracts of okra leaves treated with the formulation, which are responsible for its bioprotection in the three agroecological areas. In conclusion, the use of the Trichoderma harzianum and Bacillus amyloliquefaciens formulation on okra crops significantly induced germination and systemic resistance of Abelmoschus esculentus plants against cercosporiosis agents.