Weed Control with Liquid Carbon Dioxide in Established Turfgrass

• Published in: Weed technology 2014-09, Vol.28 (3), p.560-568
• Main Authors: Mahoney, Denis J, Jeffries, Matthew D, Gannon, Travis W
• Format: Article
• Language: English
• Subjects: annuals; Carbon dioxide; Clover; corn; Cynodon dactylon; Cynodon transvaalensis; Digitaria ischaemum; Digitaria sanguinalis; Eleusine indica; exposure duration; Festuca arundinacea subsp. arundinacea; Freezing; frost; greenhouse experimentation; Herbicides; hybrids; Liquids; Nonchemical weed control; Nozzles; Perennials; Plants; Poa pratensis; Prototypes; Stellaria media; Trifolium repens; turf; Turf grasses; Veronica; Weed control; Weeds; Zoysia japonica
• ISSN: 0890-037X; 1550-2740
• DOI: 10.1614/WT-D-14-00003.1

In recent years, increasing implementation of biological, cultural, and mechanical weed-control methods is desired; however, many of these techniques are not viable in established turfgrass systems. The use of freezing or frost for weed control has previously been researched; however, is not well elucidated. Field and greenhouse experiments were conducted to evaluate liquid carbon dioxide (LCD) for weed control in established turfgrass systems. LCD was applied with handheld prototypes that were modified to reduce the amount of LCD required for weed control. Common annual and perennial turfgrass weeds included common chickweed, corn speedwell, goosegrass, large crabgrass, smooth crabgrass, Virginia buttonweed, and white clover. Turfgrass tolerance was evaluated on the following species: hybrid bermudagrass, Kentucky bluegrass, tall fescue, and zoysiagrass. The final modification allowed for lower output (0.5 kg LCD min−1) when compared with the initial prototype (3 kg LCD min−1). In general, weed control increased as LCD increased. When comparing weed species life cycles, annuals were controlled more than perennials (P  90%) was greater than in the one- to two-tiller stage ( 30%) on all species, but declined to 0% by 28 DAT. These data suggest that LCD has the potential to provide an alternative for weed control of select species where synthetic herbicides are not allowed or desired. Nomenclature: Common chickweed; Stellaria media (L.) Vill.; corn speedwell; Veronica arvensis L.; goosegrass; Eleusine indica (L.) Gaertn.; large crabgrass; Digitaria sanguinalis (L.) Scop.; smooth crabgrass; Digitaria ischaemum (Schreb.) Schreb. ex Muhl.; Virginia buttonweed; Diodia virginiana L.; white clover; Trifolium repens L.; hybrid bermudagrass; Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt-Davey; cv. ‘Tifway 419′; Kentucky bluegrass; Poa pratensis L. ‘Unique'; tall fescue; Lolium arundinaceum (Schreb.) S.J. Darbyshire ‘Confederate'; zoysiagrass; Zoysia japonica Steud. ‘El Tor