Identification of Yield Potential of Different Corn and Sorghum Genotypes in Southwest Texas.

Grain yield is a parameter of economic importance for farmers and other agriculturists. Several factors affect grain yield in crops such as corn and sorghum, one being drought. Not only abiotic factor such as drought, but leaf and canopy architecture, and transpiration, etc., also affect grain yield of crops. 15 entries each of corn and sorghum were planted in southwest Texas in 2016 and 2017. They were planted in two different irrigation regimes – full irrigation and deficit irrigation, with three replications per irrigation regime. Among corn genotypes were one tropical derived, one mostly temperate derived, ten tropical-temperate derived experimental hybrids and three temperate derived commercial checks. Sorghum consisted of eight hybrids and seven inbred lines. Commercial checks performed better than experimental hybrids in corn. Among experimental hybrids, GP7169GT/Tx777, NP2643GT/Tx777, and Tx781/Tx777 were high yielding and better performers. Sorghum hybrid ATx2752/RTx430 and ATx645/RTx437 produced higher yields, whereas, among inbred lines B.Tx623 and B.Tx645 performed and yielded better. LAI showed weak negative correlation with grain yield (r = -0.179) in corn whereas almost no correlation (r = -0.094 and r = -0.062) among Leaf area index (LAI) and grain yield in sorghum hybrids and inbred lines. Grain yield in corn showed weak negative correlation with grain starch and grain protein (r = -0.103 and r = -0.115), whereas, in sorghum positive correlations can be seen between grain yield and grain starch content (in hybrids r = 0.485 and in inbred lines r = 0.535). Correlation between grain protein content and grain yield in sorghum hybrids as well as inbred lines is negative (r = -0.422 and r = -0.559). Higher accumulation of protein in grains usually occurs in genotypes exposed to drought and high temperature. Genotypes showing higher yield in response to protein accumulation in grains should have drought tolerance characteristic.