Submitted to: Proceedings of Southern Weed Science Society
Publication Type: Abstract Only
Publication Acceptance Date: December 2, 2001
Publication Date: January 23, 2002
Citation: Johnson, W.C. 2002. Herbicide placement of cantaloupe and watermelon transplanted on polyethylene covered beds - weed control efficacy and injury [abstract]. Proceedings of Southern Weed Science Society. 55:208. Technical Abstract: Field trials were conducted at the Coastal Plain Experiment Station Ponder Farm in 2000 and 2001 to study the effects of herbicide placement on weed control and transplanted cucurbit crop injury in the "narrow" polyethylene tarp production system. Herbicides evaluated were halosulfuron (36 g ai/ha), clomazone (0.56 kg ai/ha), sulfentrazone (0.14 kg ai/ha and 0.28 kg ai/ha), and a nontreated control. Herbicide placements evaluated were preplant incorporated under the polyethylene tarp before transplanting, over-the-top after transplanting, and semi-directed after transplanting. Semi-directed after transplanting applications were made using TeeJet OC-03 spray tips onto the shoulders of polyethylene covered seedbeds and into the row middles, without direct contact with 'Vienna' cantaloupe and 'Stargazer' watermelon transplants. Across all herbicide treatments, preplant incorporated under the polyethylene tarp and semi-directed applications were the least injurious, with over-the-top applications the most injurious. In general, sulfentrazone (0.25 lb ai/A) was the most injurious herbicide and halosulfuron the least injurious, regardless of herbicide placement. Halosulfuron effectively controlled many broadleaf weeds and yellow nutsedge, with minimal phytotoxicity to cantaloupe and watermelon, regardless of placement.