Survival of sweetpotato (Ipomoea batatas [L] Lam) vines in cultivars subjected to long dry spells after the growing season in Mozambique

Abstract

Optimisation of sweetpotato production potential is not realized in sub-Saharan Africa where dry spells are common after the growing season. Lack of seed cultivars at the beginning of the rainy season is the challenge and identifying those cultivars with the ability to survive a 4 to 7-month dry spell is an important objective in these regions. To this end, the purpose of the present study was to estimate survival of vines of different cultivars under drought stress. Three harvesting times set as 5, 9 and 11 months after planting were established at Umbeluzi, Nwallate and Gurue in 2015. For each harvesting time, 37 clones were evaluated in a randomized complete block design with two replications. Data collected on yield, vine length and number of sprouts were analysed using SAS 1996. Resisto had long stems but no vines after 9 months at any of the sites. The ability of some clones to reach 9 months and 11 months with few vines at Umbeluzi and Nwallate offer sources of planting material for the subsequent season. Sprouting had broad sense heritability above 50%. Sprouting is known to be an important aspect of cultivar survival. While we show that vine length and thickness could be traits responsible for sweet potato drought tolerance

Keywords

• plant morphology
• photosynthates
• sweetpotato
• sprouting
• biomass