Vegetos

Abstract

The objective of the study was to evaluate 38 new genotypes of Gossypium hirsutum L. for their productivity and drought tolerance ability under rainfed situation during 2014–15 and 2015- 16 at ARS Dharwad Farm. The genotypes were evaluated under moisture stress in polythene bags at seedling stage and for their performance in the field, later. Physiological parameters like excised leaf water loss, SPAD chlorophyll meter readings were recorded in the field while, root-shoot length, weight and root volume were examined in seedling studies. The field performance was correlated to the reaction of the seedlings to moisture stress. The genotypes G h AM-46 (1577.41 kg/ha), G h AM-9 (1433.73 kg/ha), EC560413 (1328.69 kg/ha) and G h AM-78 (1315.00 kg/ha) were found to be high yielding across the years. The productivity was attributed to the desirable root-shoot characteristics, higher SPAD chlorophyll meter readings and low to moderate excised leaf water loss. Contrastingly, genotype MAP-20-4, even though having higher yield was considered drought susceptible as evidenced by poor adjustment to moisture stress situation coupled with higher excised leaf water loss rate. The experimental results indicated that genotypes having higher productivity under rainfed conditions were associated with desirable physiological characters that made them to adapt to moisture stress. The correlation among root-shoot traits was significantly positive under water stress condition and such genotypes may be suitable genetic resources and the traits can be used as water stress tolerance indices in drought resistance breeding of cotton.