Abstract

Cotton, which is also known as ‘white gold’, is an important crop in many developing countries. The crop yield is dependent on the environment in which it is grown. One of the major challenges for cultivar recommendation is the genotype x environment interaction when the performance ranking of genotypes over environments is not constant. The identification of cultivars with high adaptability and stability to the growing conditions is an option to deal with this fact. The objective of the present study was to assess the yield stability and adaptability of commercial cotton cultivars (Gossypium hirsutum L. race latifolium H.) in Mozambique.  The experiments were set up over three years in Namialo, Montepuez and Morrumbala, in a total of seven environments. Plots were established in a randomized complete block design with four replications of nine treatments. The stability and adaptability were assessed using methodologies by Annicchiarico and Toler and Burrows. The joint analysis of variance showed that there were high environmental variation and high effect of cultivar x environment interaction. The cultivars ISA 205, STAM 42 and IRMA 12-43 showed greater phenotypic stability for cottonseed yield, according to the Annicchiarico method. Regarding the Toler and Burrows methodology, the cultivar STAM 42 presented specific adaptation to low quality environments, while the cultivar CA 324 presented specific adaptation to high quality environments.

Key words: confidence index, cottonseed productivity, genotype x environment interaction, non-linear regression.