Open Agriculture (Nov 2024)
Yield stability of ten common bean (Phaseolus vulgaris L.) genotypes at different sowing dates in Lubumbashi, South-East of DR Congo
Abstract
The common bean is one of the most widely used sources of plant protein in the human diet in developing countries. Despite its importance, production remains relatively low and is likely to worsen as a result of climatic disturbances. In sub-Saharan Africa, rainfall is the most limiting climatic variable for bean production. Using the best genotypes and sowing dates has proven to be the best solution to overcome these constraints. Then, the aim of this study was to evaluate the performance and stability of common bean genotypes under different sowing dates in Lubumbashi agro-ecological conditions. The trial was carried out during two consecutive years using a split-plot design consisting of sowing date ‘main plot’ and genotype ‘sub-plots’, replicated three times. The results showed that 2020 had less rainfall than 2019 (774.2 and 812.6 mm, respectively). Significant interactions were observed between genotype and sowing date (E × G), year and genotype (G × Y), sowing date and year (E × Y), and genotype, sowing date and year (E × G × Y). Higher phenotypic variation for yield (184313.5) than genotypic variation (95524.2) as well as for the other observed traits. High heritability for the trait day at flowering (JFL) (0.7) and low heritability (0.1) for plant height (HP.28.JAS) and 0.5 for yield, highlighting the influence of environmental factors (sowing date). The GGE biplot identified genotypes V8 (1,178 kg ha−1) and V9 (985 kg ha−1) as the best performing and most stable genotypes, compared to genotypes V2 (650.4 kg−1) and V5 (646.3 kg ha−1), which were stable but less successful. The most favorable environments were identified as E8, E4, and E5. Despite the climatic disturbances, some common bean genotypes show good plasticity, and using them would increase production, which depends not only on the potential of the genotype but also on the time of sowing.
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