Comparison of cotton (Gossypium hirsutum L.) yield and fibre properties over locations and seasons

Abstract

The cotton breeding program in the Republic of South Africa is conducted at the localities Loskop, Upington and Vaalharts. Preliminary results from breeding trials indicated that a finer but more mature fibre could be produced at Vaalharts as compared to the other two localities. This might be advantageous to the rotor spinning industry. In analyses of variance over seasons and localities, the order of magnitude of the GxE interaction variances was G×L < G×Y×L < G×Y where G = genotypes, Y = years and L= localities. This suggested that localities were contributing less strongly to G×E interactions than seasons and that limited possibilities may exist for the development of specifically adapted varieties. More benefit is likely to be derived from expanded testing over seasons rather than sites.