Performance and response to web blight and angular leaf spot of tropical black bean genotypes

ar leaf spot, with yield significantly superior to that of the Negro Jamapa variety. Design/methodology/approach: Eleven genotypes were evaluated using a randomized complete block design with three replications. Their reactions to both diseases were rated using the 1 to 9 scale of the International Center for Tropical Agriculture (CIAT). Grain yield was estimated in kilograms per hectare. Analyses of variance were performed on the quantified variables, and a combined analysis was conducted for grain yield. Mean separation was carried out using the Least Significant Difference test at a 0.05 significance level. Results: With mean disease severity values ranging from 2.0 to 3.33, five lines and the Verdín variety demonstrated resistance to web blight. Nine lines, along with Verdín, also exhibited resistance to angular leaf spot. Among these two groups of outstanding genotypes for disease resistance, Jamapa Plus/XRAV-187-3-4-4 and Jamapa Plus/XRAV-187-3-4-1 were the most productive, with average yields exceeding 2100 kg ha⁻¹, statistically similar to those of Verdín and Jamapa Plus/XRAV-187-3-1-2. Limitations on study/implications: Although angular leaf spot did not significantly affect bean yield, the disease incidence and the severity in the regional control were sufficient to evaluate and classify the genotypes’ reaction to this disease under natural infection conditions. Findings/conclusions: The three lines derived from the Jamapa Plus/XRAV-187-3 cross and the Verdín variety exhibited resistance to both diseases and achieved an average yield significantly higher than that of the Negro Jamapa variety.