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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.

Genotype assessment across various environments is a basic condition for developing stable and superior genotypes for sustainable maize production in the South-East of the DR Congo. Therefore, this research’s objectives were to identify the performance of newly developed provitamin A maize genotypes in various environments, and to recommend high-performing and stable genotypes for broader adaptation. Eight provitamin A maize genotypes, including one commercial variety, were planted at three sites during two consecutive cropping seasons (2020/2021 and 2021/2022) forming six environments. All genotypes in six environments were planted in a randomized complete block design containing three replications. Two stability analysis approaches, GGE biplot and Eberhart and Russell method are widely used to identify high yielding and stable genotypes. The combined analysis of variance revealed that G and E as well as their interaction (GEI) have significantly affected the emergence rate, cob’s insertion height, days to anthesis and silking, cob length, cob grain weight and grain yield. Average grain yield varied from 8.30 t/ha for PVAH-7L to 9.41 t/ha for PVAH-1L. The Eberhart and Russell method and the CV identified PVAH-1L, PVAH-4L, PVAH-7L and PVAH-6L as the most stable genotypes, but could not reliably identify the high yielding genotypes. On the other hand, the GGE biplot reliably and graphically showed the stable and high-yielding genotypes (PVAH-1L > PVAH-6L) as well as the low-yielding genotypes (PVAH-7 > PVAH-4L). In additional, the GGE biplot showed that L’shi21 was the best test environment for selecting high performing and stable provitamin A maize genotype. The results of this study indicate that PVAH-1L and PVAH-6L are the stable, high-yielding provitamin A maize genotypes in the South-East of the Democratic Republic of the Congo and should be disseminated in this region.

Small-holder banana fields are often intercropped with various annual crops to optimize land-use in East and Central Africa, a practice severely constrained by light availability under the banana canopy. Light availability is not a major constraint in newly established banana fields, giving a window of opportunity to target light-demanding annual crops before shifting to more shade-tolerant crops. This study investigated the performance of climbing and bush beans and the vegetable amaranth in banana fields with varying shade levels across three sites in the South Kivu province, DR Congo. These crops were selected for their highly nutritious and good market value and the added benefit of nitrogen fixation for the legumes. We show that both grain legumes and vegetable amaranth can achieve reasonable yields during a first annual cropping season in newly established banana fields, irrespective of the plant density. Declines in yield occurred during a second cropping season in more densely spaced banana fields (2 × 2 m and 2 × 3 m). A greater decline occurred in amaranth and its cultivation should be limited to the first annual cropping season or to less dense banana fields. The legumes could be extended to a second cropping season with reasonable yield. Significant variability in amaranth and legumes performance was observed across sites, with rapid yield declines occurring under more fertile soil conditions due to fast banana growth/canopy formation and under more vigorous cultivars. The choice of banana spacing will need to be tailored to the banana cultivar, soil conditions and the farmers' objectives. [ABSTRACT FROM AUTHOR]