Search Results (3)

The instability between water demand and availability is making it challenging to cultivate viable, sustainable crops. To address this, improved irrigation scheduling regimes need to be adopted, focusing on full crop water requirements to determine optimal water allocation. This study aimed to identify suitable intercropping combinations of leguminous dry bean plants with indigenous African leafy vegetables (specifically cleome gynandra and cucumis myriocarpus) that could enhance interactions with regulated deficit irrigation. The experiment was designed in 3 (irrigation levels: 100%, 75%, and 50%) × 5 (three monocrops and two intercrops) split plot arrangement within a randomized complete block design (RCBD), replicated three times across four growth stages. The study was designed to rigorously assess the effectiveness of two intercrops compared to three monocrops, each cultivated under varying irrigation levels of 100%, 75%, and 50%. There was an increase in selected gaseous parameters, such as stomatal conductance and photosynthesis rates when dry beans were intercropped with cucumis myriocarpus and subjected to 75% deficit irrigation during the mid-pod stage of the dry bean. In contrast, decreased gaseous parameters were noted under a 50% deficit irrigation across all dry bean growth stages, which also negatively affected the growth of African leafy crops. Regarding yield, an inverse relationship was observed between the crops. The yield of dry beans significantly increased under 75% irrigation during the mid-pod stage. Meanwhile, yields of cucumis myriocarpus increased under both 75% and 100% irrigation levels during the early-pod stage of the dry beans, which corresponded to the vegetative stage of the two African leafy crops. In conclusion, regulating irrigation under 75% deficit irrigation during the mid-growth stage is recommended as an ideal irrigation level for intercropping dry beans with cucumis myriocarpus, and this can potentially save 25% of water. Full article

The Cucurbitaceae is a monophyletic family with close to 1000 species of climbers, including important agronomic species and varieties characterized by tendrils and pepo fruits. The seed’s morphology is varied, and the development and structure of the seed coat have been described in detail on some species. Overall description of the seed shape is based on terms comparing it with geometric figures, but quantitative methods are lacking in the literature. Here we apply a general morphological analysis to seeds of representative genera of the Cucurbitaceae, followed by curvature analysis in the poles and symmetry analysis. These methods are useful for the quantitative description of seed shape and the comparison between species and varieties. Differences between species were found for most morphological measurements, as well as for symmetry and curvature values. The comparison between three species of Cucumis (Cucumis sativus, C. myriocarpus and C. melo) and two varieties of C. melo reveals differences between species and varieties both in curvature and symmetry. The results obtained from both methods, curvature and symmetry analysis, form similar groupings in a cluster analysis. The methods described here were applied for the identification of agronomic varieties and the quantitative description of seed shape in taxonomy. Full article

Cucumber green mottle mosaic virus (CGMMV) is a severe threat to melon production worldwide. At present, there are no cultivars available on the market which show an effective resistance or tolerance to CGMMV infection; only wild Cucumis species were reported as resistant. Germplasm accessions of Cucumis melo, as well as C. anguria, C. ficifolius, C. myriocarpus and C. metuliferus, were mechanically infected with isolates belonging to the European and Asian strain of CGMMV and screened for resistance by scoring symptom severity and comparing the accumulation of virus by qRT-PCR. The wild species C. anguria and C. ficifolius showed no symptoms and did not accumulate CGGMV following inoculation, while C. metuliferus was highly susceptible to the isolates of both strains of CGMMV. The virus accumulated also in C. myriocarpus and the European isolate produced symptoms, but the Asian isolate did not. Thirty C. melo accessions were susceptible to CGMMV. An isolate-dependent expression of symptoms was observed in 16 melon accessions: they showed mild and severe symptoms at 14 and 21 days after inoculation with the European and Asian isolate, respectively. Freeman’s Cucumber showed few or no symptoms following inoculation with the isolate of either CGMMV strain. This particular accession also showed reduced virus accumulation, whereas most other tested germplasm accessions showed significantly higher viral loads and, therefore, may well be a candidate for breeding programs aiming to reduce the losses produced by CGMMV with resistant commercial melon cultivars. Full article