Stability and Adaptation of New Tobacco Varieties to Three Growing Areas under Rain Fed Conditions in Zimbabwe

Abstract

Background: Variety development is a continuous process that caters for the ever changing farmer crop growing conditions. Changing climatic conditions, soil fertility conditions, crop disease and pest regimes as well as farmer agronomic practices require that new varieties adapted to new practices be availed to growers so that they continue to get high yields. Initial variety development processes are carried out by the breeder, usually on station and usually involves aggregation of traits of interest into a genotype with little or no information about the response of the genotype to different farmer cropping situations. However, before the varieties can be recommended to growers, they need to be evaluated in multi-environment trials (MET) in order to identify varieties with broad adaptation for general recommendation and those with specific adaptation for targeted environment production. Methods: In order to evaluate the adaptation and stability of newly developed tobacco varieties to three growing locations in Zimbabwe, seven varieties were evaluated in a randomised complete block design with three replicates at Kutsaga Research Station near Harare, Trelawney and Tengwe over three seasons ranging from 2013 to 2015. Result: The study results showed significant differences among the varieties and locations tested for saleable yield (P less than 0.05). Of all the varieties tested, T76 was the most stable showing consistently high performance across the seasons and locations tested followed by T75. However, ETH03 was the least stable variety of them all. Unlike what is currently believed in the tobacco industry in Zimbabwe, the variety K RK26 is no longer the most broadly adapted. Based on the study results, the varieties, T76, T75 and ETH06 are stable and, therefore, recommended for growing across the whole of the tobacco farming belt in Zimbabwe.