Assessment of the Biological Efficacy of Biopesticides (Plantsain and Fertisain) Against Dieback of Mango in Burkina Faso

Dieback of Mango, primarily caused by Lasiodiplodia theobromae, poses a significant threat to mango production in Burkina Faso. This study evaluated the efficacy of biological and chemical treatments in controlling dieback and promoting tree recovery. Field trials were conducted in Koloko and Léo provinces across three mango orchards exhibiting varying disease incidences. Symptomatic tissues were collected for pathogen isolation and molecular confirmation via PCR, validating the presence of L. theobromae. Three biopesticide treatments (Plantsain, Fertisain, and their combination) were compared with a chemical reference (Azox + Manga Plus) and an untreated control, using a randomized complete block design with six replicates per treatment. Results indicated that Plantsain achieved the highest branch regeneration, with rates of 72.72% in Koloko and 60.49% in Léo, compared to 7.03% and 8.92% in untreated controls. Both disease incidence and severity decreased significantly with treatment, displaying a dose-dependent response. The combined Plantsain + Fertisain treatment at dose of 2 L/ha each also demonstrated high efficacy, comparable to the chemical Azox. These outcomes suggest that biopesticides not only significantly reduce the incidence and severity of the disease, the infection rate of L. theobromae, but can also promote the physiological regeneration of affected tissues. In conclusion, biological control strategies, taken individually or in combination, constitute sustainable and effective alternatives to chemical fungicides for the management of dieback in Burkina Faso.