Productivity of Drought-Tolerant Alternative Crops Subjected to Water-Limiting Conditions in West Texas.

The declining water supply for irrigation from the Ogallala aquifer and erratic droughts are posing serious threats to agricultural productivity in West Texas. Emphasis is growing in exploring alternative, drought hardy crops as a strategy to extend the life of limited water resources and to optimize farm profit in the region. A field study is planned at Lubbock, TX during 2017 and 2018 to compare the growth, yield, water use and economics of six alternative crops (sesame, guar, safflower, sunflower, pearl millet and grain sorghum) with cotton under limited irrigation. The experiment units are randomized into split plot design with irrigation levels as main plots and crops as subplots. The target irrigation amounts for in-season irrigation levels are 51 mm (I₁), 127 mm (I₂), 203 mm (I₃) and 279 mm (I₄). A preliminary study was conducted in summer 2016 where sesame, pearl millet and cotton were evaluated under three irrigation levels (I₁, I₂ and I₃). In response to irrigation treatments, no significant difference in harvest index (HI) was observed among crops except for pearl millet, where the highest HI was observed in I₂, which was comparable to I₁. In contrast, significant difference in yield was observed in cotton and sesame, but not in pearl millet. The highest yield was recorded in I₃ in cotton and sesame, but yield was statistically similar to I₂ in sesame. These preliminary results showed that unlike cotton, sesame and pearl millet do not need higher in-season irrigation after a certain level to produce potential yields. In 2017 and 2018, further evaluation of seven crops including cotton under limited irrigation will be helpful in identifying profitable and water efficient crops for the region.