PRE herbicides and POST halosulfuron for purple nutsedge control in tomato grown in plasticulture systems
Yu, J., Sharpe, S.S., Boyd, N.S. (2020). PRE herbicides and POST halosulfuron for purple nutsedge control in tomato grown in plasticulture systems. Weed Technology, [online] 34(5), 642-646. http://dx.doi.org/10.1017/wet.2020.24
Plain language summary
Purple nutsedge is among the worst weeds in Florida plasticulture. It is capable of surviving most fumigation techniques, pierces the plastic mulch, and grows aggressively when uncontrolled. Various herbicide programs were developed and tested to control purple nutsedge in tomato production. Combining a pre-emergence application of sulfentrazone or S-metolachlor under the plastic mulch followed by halosulfuron post-emergence provided the best control. Halosulfuron is an important component to provide season-long nutsedge control within tomato plasticulture.
Purple nutsedge is a troublesome weed in tomato grown in plasticulture systems. Field trials were conducted in the fall of 2017 and spring of 2018 at Balm, FL, to evaluate multiple herbicide programs applied pretransplanting (pre-T), post-transplanting (post-T), and pre-T followed by (fb) post-T for purple nutsedge control in plasticulture tomato. Pre-T treatment of sulfentrazone or S-metolachlor alone were ineffective and did not decrease purple nutsedge density compared with the nontreated control. Post-T application of halosulfuron did not reduce purple nutsedge density at 12 wk after initial treatment (WAIT) in fall 2017 but reduced the purple nutsedge density at 17 WAIT in both seasons. Pre-T sulfentrazone or S-metolachlor application fb halosulfuron applied post-T were the most effective treatments and consistently reduced purple nutsedge population in both seasons. Herbicide treatments did not injure or reduce tomato height or yield. Overall, these results suggest sequential herbicide programs, including pre-T application of sulfentrazone or S-metolachlor fb post-T application of halosulfuron generally resulted in greater purple nutsedge control compared with pre-T or post-T application only. Halosulfuron applied post-T is critical to provide season-long purple nutsedge control in plasticulture tomato.