Effect of Rolling on the Lateral Spread of Khakiweed ( Alternanthera pungens Kunth)

The dark green color and abundant seed production of khakiweed ( Alternanthera pungens Kunth) interfere with playability and aesthetic quality of home lawns, golf courses, and athletic fields. In 2009 and 2010, the effect of rolling on lateral spread of khakiweed was investigated in Lubbock, TX. Rolling treatments were conducted using a ride‐on roller that applied a static pressure of 58 kPa at a speed of 1.55 m s −1 . Weekly rolling treatments were: nonrolled, low (4 passes × 3 events), moderate (8 passes × 3 events), and high (12 passes × 3 events). Khakiweed lateral plant diameters were recorded at trial initiation and every 2 wk over 12 wk. Statistical differences in khakiweed diameters were not observed until 10 wk after initial treatment (WAIT). Nonrolled plots exhibited 30.1 cm plant diameter, similar to low rolling (24.4 cm) but greater than moderate (23.3 cm) and high (20.4 cm) rolling 10 WAIT. A decrease in plant diameter was observed in response to high rolling (19.9 cm) 12 WAIT compared with nonrolled plots (28.8 cm). Although numerically less than the nonrolled check (28.8 cm), khakiweed plant diameters in response to low (23.5 cm) and moderate (23.1 cm) rolling were statistically similar. Although rolling treatments reduced khakiweed diameter compared with the nonrolled check, plants increased in size from initial trial diameters while hybrid bermudagrass [ Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] cover decreased over time in response to high rolling. Therefore, practices that reduce soil compaction may be important to increase bermudagrass competition with khakiweed.