Cotton water-deficit stress, age, and cultivars as moderating factors of cotton fleahopper abundance and yield loss

Field experiments were conducted in 2012 and 2013 during drought conditions in South Texas and the Texas High Plains to test whether cotton water-deficit stress, age, and cultivars are moderating and interacting factors that affect cotton fleahopper, Pseudatomoscelis seriatus (Reuter) (Hemiptera: Miridae), abundance and yield loss. Irrigation and sequential plantings of several cultivars were used to simulate a range of water stress, plant ages, and cultivar variability. Cotton grown under these experimental conditions were exposed to cotton fleahopper using natural and artificial infestation. Cotton cultivars had a strong influence on cotton fleahopper abundance, with higher densities on Stoneville cultivar 5458 B2RF, which is relatively pubescent, than on the Phytogen cultivar 367 WRF, which is relatively glabrous, in South Texas (p < 0.04). But the strong cultivar effects on cotton fleahopper abundance did not correspond to yield reduction. No water stress effects on cotton fleahopper densities were observed in 2012 (p > 0.05), whereas cotton fleahopper densities increased on older cotton grown under no water stress in 2013 in South Texas (p < 0.05). In contrast, yield response was primarily sensitive to soil moisture conditions (up to 50% yield reduction when grown in dryland mimic conditions below 75% crop ET replacement, p < 0.0009). Water and cotton fleahopper stress synergies were detected but variable, with greatest lint yield loss attributable to cotton fleahopper seen in cotton grown in high water stress conditions in the High Plains (p < 0.05). Yield trends were consistent across cultivars (no interaction with cultivar), even though cotton fleahopper populations varied significantly across cultivars and exceeded regional economic thresholds beginning the second week of squaring (p < 0.05). © 2016 Elsevier Ltd. All rights reserved.