Role of Copper on Physiological Parameters and Salt Tolerance in Sweet Sorghum (Sorghum bicolor L.) Cultivars

This research was carried out to determine effect of sorghum cultivars and copper foliar spray on physiological traits under saline water situation via split plot experiment based on randomized complete blocks design with four replications during 2015 and 2016 year. The main plot consisted sorghum cultivars at three level (Kimia, KGS10, KGS4) and Copper foliar spray (C1: 0 or control, C2: 0.20, C3: 0.30 and C4: 0.40 kg Cu ha-1) by source of CuSO4 at stem elongation stage (55 days after planting date) belonged to sub plot. Result of combined analysis of variance revealed effect of different sorghum cultivar, Cu foliar application and interaction effect of treatment on all measured traits was significant at 1% probability level. Foliar application of copper had effective role on salt tolerant and physiological parameters of the studied sorghum cultivars were significantly affected by the exposure to well water and copper. The cultivar Kimia was observed as more salt tolerant and cultivar KGS4 was more salt sensitive on the basis of starch, amylose and amylopectin rates. Cultivar Kimia was also observed to produce high rates of amylose and amylopectin compared with the other cultivars. Results of this experiment showed that effect of copper on physiological contents is a useful tool for measuring the salt tolerance among sorghum cultivars to identify possible donors for future sorghum quality enhancement and breeding and be useful to the local sorghum growing farmers under salt stress. According to result of current research Kimia cultivar with foliar application of 0.4 kg Cu ha-1 it can suggested to farmers to decrease negative effect of salinity situation.