Yield assessment of advanced wheat breeding lines the Winter Rainfall Region of South Africa. I. Homogeneity of the region

Abstract

The major wheat-producing areas in the Winter Rainfall Region are geographically divided into the Rûens and Swartland. The question whether the Rûens and Swartland should be regarded as non-similar areas, each meriting its own wheat-breeding programme, is considered. Correlations between cultivar means obtained in the two regions, interaction variance components, the nature of patterns regarding yield at different flowering dates and the similarity in choice of cultivars by farmers in the two areas, all sėem to point to a high degree of similarity. It is concluded that it may not be worth while to conduct separate breeding programmes.