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Sweetpotato (Ipomoea batatas Lam) is a staple food globally, but it has remained underutilised resource in Ghana due to lack of consumer preferred cultivars. There is the need to develop staple-type sweetpotato cultivars which are preferred by consumers to increase sweetpotato use as a food security, health and industrial crop commodity in Ghana. This study was conducted to evaluate the breeding potential of sweetpotato germplasm for the development of farmer and consumer preferred varieties in Ghana. A total of 115 sweetpotato accessions were evaluated for genetic variability. Significant (P<0.01) differences were observed indicating genetic diversity. G x E was significant for all traits, except dry matter, sucrose, total sugar, and starch content. Phenotypic Coefficient of Variation (PCV) ranged from 4.78% for starch content to 63.40% for marketable root weight. Genotypic Coefficient of Variation (GCV) ranged from 4.07% for starch content to 55.35% for marketable root weight. Broad-sense heritability estimates varied from medium (0.61) to high (0.90) for all the traits, except for sucrose content. Predicted improvement over the means is 10 up to 105% for all traits, except starch (7.13%). This indicates sufficient useful genetic variation prospect which could be used to provide substantial improvement through selection of superior genotypes. The strong positive genetic association between dry matter and starch (r = 0.71), and strong negative relationship for sugar and dry matter (r = -0.77) and starch content (r = -0.99) indicates the possibility of developing non-sweet high dry matter sweetpotatoes, which are the preferred varieties in Ghana. [ABSTRACT FROM AUTHOR]

Abstract: Growth and fruit yield of scarlet eggplant were examined under intercropping with an erect and semi-spreading early maturing cultivars of cowpea in an additive intercropping model with scarlet eggplant as the main crop, in two dry seasons, under irrigation. Cowpea was planted simultaneously with scarlet eggplant, 2 and 4 weeks ahead of scarlet eggplant. Land equivalent ratio (LER) of the intercrops ranged from 1.38 to 1.94, indicating that the intercrops were more productive than the pure crops. Reduction in fruit yield of the main crop, when intercropped with the semi-spreading cowpea cultivar was significantly (p &#60;0.01) greater than with the erect cowpea cultivar. Simultaneous planting of cowpea and scarlet eggplant produced 90–99% the fruit yield of sole scarlet eggplant, while planting cowpea 2 and 4 weeks ahead produced 65–80% and 58–60% of sole crop yield, respectively. Competition between component crops was however most favourable for both cultivars of cowpea when planted 2 weeks ahead of scarlet eggplant. Planting cowpea 2 weeks ahead of the main crop also produced the highest LER most likely due to more efficient utilization of sunlight, water and soil nutrients. Simultaneously planting cowpea and transplanting scarlet eggplant, is recommended for such additive intercropping system, aimed at full yield of scarlet eggplant with additional cowpea for food, income or fodder. [Copyright &y& Elsevier]

Background: Drought is a major constraint affecting the seed yield of common bean in smallholder farmers' fields in Malawi. Therefore, there is a need to develop genotypes that can perform well under drought conditions. The study was conducted to assess the variability of common bean genotypes under stressed and optimum soil moisture conditions. Methods: Forty-three common bean genotypes were evaluated under low and optimum soil moisture in a split-plot pot experiment in 2017. Data were collected at flowering stage on five root traits and seed weight. Result: Highly significant (P<0.01) differences were observed among the genotypes and the genotype × water treatment interactions for the root traits and seed weight. Water stress increased hypocotyl root number, basal root number and basal root growth angle by 127.1, 11.3 and 46.1% respectively, while hypocotyl root length, basal root whorl number and seed weight were reduced by 7.1, 1.9 and 9.4% respectively. Broad sense heritability and genetic advance (%) was highest for hypocotyl root length. Genotypes CER-78, SAB-560 and SER-125 were considered tolerant to soil moisture stress and should therefore be tested in various drought conditions for release and used for genetic enhancement focusing on root traits and seed yield. [ABSTRACT FROM AUTHOR]

A clear understanding of the genetic mechanism that controls the expression of the agronomic traits is imperative to define appropriate selection methods in bean breeding. The objective of this study was to assess the level of variability and genetic gain within iron and zinc biofortified common bean genotypes in eastern Democratic Republic of Congo. A field study was conducted involving 164 Fe and Zn dense bean genotypes and five local (non-biofortified) varieties. Data was collected on the number of days to flowering, number of days to 75 and 90% of maturity, number of pods per plant and seeds per pod, total grain yield and 100 seed-weight. There were significant differences among genotypes for all the traits monitored except for number of pods per plant and grain yield. The yield for genotypes RW298, BF08-16-36A, BF08-1-77, RWV2359 and MV-14 was more than 2000 kg ha-1. These records make these genotypes the most competitive for this specific trait. The variance components showed moderate broad-sense heritability for the number of days to flowering and low for all the other parameters. Also, genotypic coefficient of variation was moderate only for grain yield but low for all other characters. The genetic gain was low (<10%) for all the traits, suggesting a non-additive gene action controlling the traits considering the study genotypes. Clustering showed that genotypes could be grouped into four important clusters (Cluster 1 = 49 genotypes, Cluster 2 = 30 genotypes, Cluster 3 = 42 genotypes and Cluster 4 = 48 genotypes). It is recommended that selections should be effected within the Cluster 2 (blue part of the dendrogram) which comprised the most promising genotypes for grain yield or to subject the study genotypes to heterosis breeding method. [ABSTRACT FROM AUTHOR]

Background: Bean is an important nutritious food and cash crop. Bean productivity is low mostly due to various abiotic, biotic and socio-economic constraints. The aims of this study were to assess constraints to high bean seed yield productivity, determine farmers' perceptions on drought and low soil fertility, strategies farmers are practicing to adapt to the constraints and preferred bean traits. Methods: A Participatory rural appraisal approach was applied by administering a questionnaire to 139 household representatives from Bazale, Phalula and Utale areas in 2017. Result: Farmers (68.4%) cultivated beans under irrigation in winter (dry) season and most of them practiced sole cropping. Constraints to high bean seed yield productivity include drought and low soil fertility (31.7%) and deforestation (81.3%) contributed a lot. Farmers (44.6%) implemented afforestation, 32.4% grew early maturing bean varieties, while 20.9% practiced conservation agriculture. Farmers were not involved in variety development as indicated by 91.4% of the respondents. However, farmers preferred determinate plant type (95.7%), creamy taste (61.2%) and high number of pods per plant (47.4%). These farmers' preferred traits need to be considered in the ongoing bean improvement program(s) to increase adoption rate of improved varieties. [ABSTRACT FROM AUTHOR]

Aflatoxins are carcinogenic secondary metabolites produced mainly by two species of Aspergillus fungi, (A. flavus and A. parasiticus). The toxin contaminates maize grains during the developmental stage as well as in storage. Grains with contamination levels above 20 ng/g are usually destroyed in the USA while the European Union and Japan allow 2–4 ng/g and nil respectively. Ghana lacks regulatory infrastructure for monitoring fungal contamination and detection of aflatoxin in grains prior to market. Therefore, this study assessed the extent of A. flavus contamination together with other mould on maize and total aflatoxin accumulation among stored maize grains across 34 towns and villages under three agro-ecologies in Ghana during the minor crop season of 2015–2016. A. flavus, was identified as the most predominant contaminant and recorded average percentage contamination of 56.7%, 30.6%, 53.5% and 45.6% on grains sampled across four communities (Fumesua, Wenchi, Ejura and Akomadan), respectively. Total aflatoxins recorded in the samples per community were in the range of below limit of detection (LOD) to 692 ng/g, 23 ng/g, 945 ng/g and 112 ng/g for Fumesua, Wenchi, Ejura and Akomadan, respectively. These dangerous upper limits demand urgent attention in the area of aflatoxin resistance breeding in maize to help address the aflatoxin menace in Ghana. • Aflatoxin contamination of maize grains is wide-spread in Ghana. • Wide adaptation of Aspergillus flavus across different agro-ecologies in Ghana. • Aspergillus flavus is the leading mould contaminant of stored maize across three agro-ecologies in Ghana. • Aflatoxin levels in stored grains are highly varied per district. • Low corroboration between Aspergillus flavus contamination and aflatoxin levels. [ABSTRACT FROM AUTHOR]

Fungal mycotoxins are important contaminants of agricultural commodities that pose serious concerns to producers, consumers and exporters. Aflatoxin is a carcinogenic metabolite produced by the fungi Aspergillus flavus and A. parasiticus. These fungi and other mould species living in the soil contaminate several crops including maize. This study was undertaken with the following objectives: (i) to assess the presence of A. flavus and other moulds in Ghanaian soil; (ii) to determine the distribution and density of A. flavus under three agro‐ecologies noted for major maize production; and (iii) to assess the effect of percentage of carbon (C) and nitrogen (N) and soil pH on A. flavus population densities and diversity in the isolates found across the agro‐ecologies. The data showed seven moulds that were common across the agro‐ecologies. Significant differences (P < 0.05) were observed in the A. flavus density and distribution within and across these agro‐ecologies. Fumesua soils recorded the highest levels of A. flavus (1.185 × 103 cfu g−1) while Akomadan recorded the least (9.76 × 102 cfu g−1). Percentage available C, N and soil pH did not significantly influence A. flavus density. The A. flavus isolates identified in this study varied in genetic sequence within the aflatoxin gene cluster, but these differences were not distinguishable by origin. [ABSTRACT FROM AUTHOR]

Iron and zinc are important minerals in humans in sub Saharan Africa, whose deficiency is known as "hidden hunger" due to the lack of recognised symptoms in the early stages. Although iron deficiency is the most prevalent, zinc is also involved in inhibition of replication of viruses, including the corona virus (COVID-19). In North Kivu and South Kivu provinces where more than 50% of common bean is produced and consumed in Democratic Republic of Congo, 36% and 47% of preschool children are anemic due to iron deficiency. This paradox is mainly due to insufficiency of iron-rich foods. The aim of this study is to characterise 59 iron and zinc biofortified varieties together with six local varieties of common bean for a potential selection programme in Butembo town in the Democratic Republic of Congo. We focused on 15 qualitative and five quantitative parameters. The qualitative parameters were helpful to distinguish the different morphotypes and for cluster analysis. In addition to the descriptive statistics, the quantitative data were used for Pearson correlation and for principal component analysis, PCA. Qualitative parameters enabled grouping of the study genotypes into 14 morphotypes according to the aspect and colour of the seed coat, the colour around the hilum and the size of seeds. Clustering grouped the 65 genotypes into 12 clusters with the most similar genotypes grouped in the same cluster. Quantitative parameters showed that the study genotypes were dissimilar (P=0.00). A positive correlation was obtained between the days to flowering and the days to maturity (P<0.05) and between the number of pods per plant and the days to flowering. A strong correlation was found between the number of pods per plant and seeds per pod (P<0.01). In contrast, a negative correlation was observed between the 100 seed weight and the number of seeds per pod. The PCA represented on two perpendicular axes showed 64.1% of the total variance of which the 42.3% is explained by the first axis and 21.8% by the second axis. Overall, the study genotypes are morphologically and quantitatively different and thus can be used in a selection programme. [ABSTRACT FROM AUTHOR]

The parasitic weed, Striga gesnerioides, is a major constraint to cowpea production in sub-Saharan Africa. It causes significant yield reductions of cowpea, especially in dry areas. The objective of this study was to evaluate the response of 80 genotypes to Striga gesnerioides under natural infestation. The results showed significant variations in the resistance of cowpea lines to Striga; lines IT93K-693- 2, IT99K-573-1-1 and IT98K-205-8 being free from Striga infestation; while lines 2491-171, 2472-154 and Suvita-2 supported few Striga shoots. The other lines supported more and varied numbers of emerged Striga shoots. The reduction of yield due to Striga infestation was more pronounced for the susceptible genotypes as compared to the resistant and tolerant lines. The high level of resistance observed in some breeding lines can be exploited in breeding cowpea for resistance to Striga. Principal Component Analysis (PCA) and clustering grouped the genotypes in three main clusters as follow: (i) high yielding and tolerant to Striga (ii) moderate yielding and resistant (iii) low-yielding and susceptible. [ABSTRACT FROM AUTHOR]