Past research has shown that removal of upper-canopy squares at nodes above white flower five plus 350 heat units (NAWF=5+350
H.U.) may divert carbohydrates to developing bolls with a resulting yield advantage. To test this hypothesis, a square removal project was performed in northeast Arkansas on an early-maturing Deltapine DP20B cultivar under irrigated conditions. This study evaluated 11 chemical and 2 physical methods of removing late-season upper-canopy squares. By removing this unwanted fruit, yields could potentially be increased from the translocation of additional carbohydrates to harvestable bolls still developing below the area of square removal. Results from the 2000 field study indicated that Roundup Ultra, when combined with Chlormequat (CCC), removed the most upper-canopy fruit of all treatments tested. However, the highest lint yields occurred in the control plots where no fruit was removed. The hand-square-removal and mechanical topping treatments, where all upper-canopy fruit was removed, represented the lowest lint yields and some of the smallest first position bolls at NAWF=5. Favorable late-season weather patterns in 2000, which extended the cotton growing season, may be the reason why fruit removal treatments yielded the lowest and control yields were the highest. More research is needed to determine if end-of-season fruit removal is a viable practice for enhancing lint yields in cotton.