Abstract Summer and fall irrigation treatments increased pecan yield, trunk diameter, and percent kernel over nonirrigated trees. Sticktights and viviparous nuts were reduced by late-season irrigation in a dry year (1984). All irrigation treatments increased pecan size; the most frequently irrigated plots had the largest pecans and least tree water stress as measured by a pressure bomb in 1984. The less water was applied in Sept, and Oct. 1984, the more sticktights resulted. Late-season water stress in all treatments indicated that water was needed just before shuck opening.