ABSTRACT

West Texas has historically relied on an aggressive management approach to early square feeding insects such as the cotton fleahopper and the western tarnished plant bug. This weather-limited production area purportedly does not have enough end-of-season heat units for the cotton plant to compensate for this early square loss. This study was initiated to evaluate the cotton plant's capacity to compensate for pre-bloom square loss in the Texas High Plains area and to determine if this value is the same as that currently utilized by the cotton management expert system, COTMAN. Four first position square retention treatments were evaluated ranging from 0-100%. Squares were removed manually from the first 9 fruiting nodes when they reached a diameter of 3/16 inch. The COTMAN computer model was used to track the plant's growth and development from first square to first flower and then to cutout, and to determine the timing for crop termination. Each of 100 plants per plot were mapped and each boll was removed from the plant and sorted according to main stem node number and position. Early square removal ranging from 20-40% resulted compensation. This compensation for early square removal was not primarily by adding fruiting nodes but rather by increasing boll retention at the 2nd and 3rd positions. This data suggests that the current early season threshold for western tarnished plant bug and fleahopper could be too aggressive when weather and high yield potential favor compensation.