In the winter wheat varieties tested at the Uvalde center, the top two ‘picks’ were ‘TAM 305’ and ‘TAM 304’ out of 10 varieties evaluated. Two of the varieties: ‘TAM 112’ and ‘Fannin’ yielded the lowest, due to susceptibility to leaf rust infection. In relatively wet years, planting winter wheat under deficit irrigation or dry-land would not cause a significant yield loss in southwest Texas. Based on field tests conducted in Uvalde and Amarillo, we found a better way to predict leaf water use efficiency. Rather than evaluating the bulk leaf carbon isotopes, the team found leaf wax alkane concentration and compound-specific carbon and hydrogen isotopes best for predicting water use.
Our studies on corn and sorghum found after a two-year field study focused on the leaf and canopy traits that some of the modern corn genotypes achieved a water use efficiency that is 30% higher than sorghum genotypes when planted in the same field in southwest Texas.
Recently, in a study, we did on cotton we found in a field performance test of 12 commercial cotton varieties in Uvalde that a 35% reduction in the amount of irrigation did not affect seed cotton yields, but reduced fiber quality, such as fiber strength, fiber length, and elongation. The diminished fiber quality was prevalent with increased leaf dry matter content rather than leaf osmotic potential.
