Agronomic performance of new cream to yellow-orange sweetpotato cultivars in diverse environments across South Africa

Abstract

Sweetpotato is grown in diverse environments of South Africa by both commercial and subsistence farmers. The aim of the present study was to assess the stability, agronomic performance and palatability of new ARC cultivars bred for the informal market, and to make cultivar recommendations. Eight new cultivars with cream to yelloworange flesh were evaluated in multi-environment trials using a randomised complete block design in six provinces. Data were recorded on root yield, percentage dry mass, palatability and vine vigour. An additive main effects and multiplicative interactions model was employed for data analysis. New cultivars with high potential were Ndou, Letlhabula and Monate, with root yields similar to or slightly lower than the commercial control cultivar Blesbok. Ndou and Monate had vigorous vine growth, high dry mass and good end-user acceptability and offered the best combination of important traits for the informal market. Letlhabula seemed more suitable for the commercial market to lower dry mass. The new improved cultivars will be advantageous, firstly, to farmers as a result of high yield and, secondly, to consumers owing to better palatibility.

Keywords: additive main effects and multiplicative interaction, end-user acceptability, genotype by environment interaction, multi-environment trials, sweet potato