Evaluation of cowpea varietal response to bacterial blight in Burkina Faso: Implications for breeding and integrated disease management

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Résumé

Cowpea bacterial blight, caused by Xanthomonas citri pv. vignicola (Burkh.), is increasingly becoming a major constraint to cowpea productivity worldwide. The use of genotypes that are resistant and/or tolerant to the pathogen is an effective means of controlling the disease. In this study, we evaluated the response of 12 cowpea genotypes of Burkina Faso to three strains (CFBP 7111, CFBP 7112, and CFBP 7113) of X. citri pv. vignicola under greenhouse conditions. For each strain, an inoculum of 1 × 10? CFU/mL?¹ was used to inoculate two-week-old trifoliate leaves. Parameters assessed included symptom percentage, bacterial population size, yield components, and leaf chlorophyll content. The results revealed that genotype Yiisyandé was the most affected by all strains, with approximately 50% leaf symptom coverage. In contrast, genotype KVx745-11P showed no symptoms for any of the strains. Strain CFBP 7113 generally reached the highest bacterial populations (7.17 log CFU/cm² for genotype Komcallé). KVx745-11P also exhibited the best yield, with an average per plant of 8.83 pods, 14.56 g pod weight, 90.92 seeds, and 13.37 g seed weight. These observations provide a solid basis for incorporating KVx745-11P into breeding programs aimed at developing broad-spectrum, durable resistant cowpea cultivars.

Mots-clés

Cowpea, Xanthomonas citri pv. vignicola, resistance, Burkina Faso.