Search

Bottle gourd [Lagenaria siceraria(Molina) Standly] is a neglected underutilized species that is available only as a landrace in sub-Saharan Africa. The objective of this study was to evaluate responses of bottle gourd landraces to water stress compared with pumpkin (Cucurbita maxima) and cucumber (Cucurbita pepo), the closest relatives. For this purpose, two bottle gourd landraces and one green pumpkin cultivar and a cucumber cultivar were grown under controlled conditions at three levels of water stress. Landraces had longer vines than hybrids while hybrid varieties produced more leaves than landraces at all levels of water treatments. The responses of landraces and hybrids to water stress were similar in that they all showed lower chlorophyll content index, stomatal conductance and plant growth in response to decreasing water availability. However, the landraces showed better stomatal regulation indicating better acclimation to water stress. The comparable performance of landraces to the exotic pumpkin and cucumber varieties and their water stress tolerance suggests that bottle gourd could be promoted as an alternative food security crop in rural communities. [ABSTRACT FROM PUBLISHER]

Lack of cereal nutritional water productivity (NWP) information disadvantages linkages of nutrition to water–food nexus as staple food crops in Sub-Saharan Africa (SSA). This study determined the suitability of sorghum (Sorghum bicolor L. Moench) genotypes to alleviate protein, Zn and Fe deficiency under water-scarce dryland conditions through evaluation of NWP. Sorghum genotypes (Macia, Ujiba, PAN8816, IsiZulu) NWP was quantified from three planting seasons for various sorghum seed nutrients under dryland semi-arid conditions. Seasons by genotypes interaction highly and significantly affected NWPStarch, Ca, Cu, Fe, and significantly affected NWPMg, K, Na, P, Zn. Genotypic variations highly and significantly affected sorghum NWPProtein, Mn. Macia exhibited statistically superior NWPprotein (13.2–14.6 kg·m−3) and NWPZn (2.0–2.6 g·m−3) compared to other tested genotypes, while Macia NWPFe (2.6–2.7 g·m−3) was considerably inferior to that of Ujiba and IsiZulu landraces under increased water scarcity. Excellent overall NWPprotein, Fe and Zn under water scarcity make Macia a well-rounded genotype suitable to alleviating food and nutritional insecurity challenges in semi-arid SSA; however, landraces are viable alternatives with limited NWPprotein and Zn penalty under water-limited conditions. These results underline genotype selection as a vital tool in improving "nutrition per drop" in semi-arid regions. [ABSTRACT FROM AUTHOR]

Water productivity (WP) is becoming a key issue in understanding the relationship between water availability and rainfed sorghum (Sorghum bicolor L. Moench) yields in agricultural systems across sub–Saharan Africa. The objective of this study was to determine water productivity of three sorghum genotypes under different environmental conditions. Three sorghum genotypes, a hybrid (PAN8816), a commercial open-pollinated variety (Macia) and a landrace (Ujiba) were planted at two sites (Ukulinga and Mbumbulu) in South Africa during 2013/2014 and 2014/2015. High clay content in Mbumbulu lowered plant available water in the soil compared to Ukulinga. Sorghum adapted to low water availability by significantly (P < 0.05) lowering plant growth (green leaf number, plant height and canopy cover), crop physiology (chlorophyll content index and stomatal conductance), biomass and grain yield. Ujiba and PAN8816 genotypes hastened phenological development, whilst Macia delayed phenological development in response to low water availability. Total and grain WP were lower at Mbumbulu (14.93 and 7.49 kg/ha/mm) relative to Ukulinga (21.49 and 11.01 kg/ha/mm), respectively. Results showed that Macia had significantly higher (P < 0.05) WP (10.51 kg/ha/mm) relative to PAN8816 (9.34 kg/ha/mm) and Ujiba (7.90 kg/ha/mm). Lack of significant genotypic differences in grain WP highlights that all three genotypes are equally suitable for production under sub–optimal and dryland conditions. [ABSTRACT FROM AUTHOR]