Identifying high-yielding dryland wheat cultivars for the summer rainfall area of South Africa

Abstract

Drought is a major challenge to dryland wheat (Triticum aestivum L.) production in the summer rainfall area (SRA) of South Africa. Dryland wheat farming in the SRA is unique in that the crop is dry-planted on high-water-table soils in winter, relying on stored moisture for germination and vegetative growth. Drought risk is high as only 260–300 mm rainfall is received during the growth period of the wheat from May to December. A number of new, improved dryland wheat cultivars released for the SRA during the recent period from 2003 to 2012 were evaluated for yield over several seasons under the National Wheat Cultivar Evaluation Program. As preliminary work for improving drought tolerance of wheat in the SRA, yield data of this genetic pool was re-analysed to identify the best-adapted cultivars based on means and coefficients of variation across years and geographic regions. Cultivars SST 347, PAN 3120, SST 356, PAN 3377, Matlabas, PAN 3161, PAN 3368, PAN 3379, PAN 3144, PAN 3355 and PAN 3118 had above-average yield and stability. These are recommended for adoption by farmers, as well as possible utilisation by researchers in improving drought tolerance of wheat.

Keywords: breeding, cultivar adaptation, cultivar evaluation, drought tolerance, wheat yield, yield improvement