Sequential postemergence/preemergence treatments for crabgrass control in bermudagrass turf

• Published in: Journal of environmental horticulture 1999-09, Vol.17 (3), p.103-107
• Main Authors: Wiecko, G, Couillard, A.A
• Format: Article
• Language: English
• Subjects: application rate; application timing; Cynodon dactylon; Digitaria; dithiopyr; golf courses; herbicides; MSMA (herbicide); oxadiazon; pendimethalin; seasonal variation; split application; weed control
• ISSN: 0738-2898; 2573-5586
• DOI: 10.24266/0738-2898-17.3.103

Crabgrass (Digitaria spp.) was controlled in common bermudagrass [Cynodon dactylon (L.) Pers.] with postemergence (POST) and preemergence (PRE) herbicides on a tropical island of Guam. The recommended label rates of PRE herbicides oxadiazon at 3.4 kg/ha (3.0 lb/A), pendimethalin at 3.4 kg/ha (3.0 lb/A), and dithiopyr at 0.6 kg/ha (0.5 lb/A) were applied initially and one-half recommended rates were applied to one-half of the plots 8 weeks later. MSMA was applied as the POST herbicide treatment in 1, 2, or 3 applications. The first MSMA treatment was applied in sequence with the PRE herbicides and followed by either 1 or 2 additional MSMA applications at 1 or 1 and 2 weeks after the initial MSMA application. Two weekly applications of MSMA assured complete control of existing crabgrass. Single applications of pendimethalin, oxadiazon, and dithiopyr at full rates assured ≥90% control for a period of 20 to 26 weeks during the rainy season and for 6 to 12 weeks during the dry season. There was no advantage of the second PRE treatments at a reduced rate. On fairways where crabgrass infestation was 95%, an application of MSMA resulted in severe turf discoloration lasting 5–6 weeks.