|Richard Jr, Edward|
Submitted to: Proceedings of Southern Weed Science Society
Publication Type: Abstract Only
Publication Acceptance Date: 1/23/2008
Publication Date: 1/28/2008
Citation: Dalley, C.D., Richard Jr, E.P. 2008. Doveweed Control with Preemergence and Postemergence Herbicides in Fallowed Sugarcane. Proceedings of Southern Weed Science Society. 61:20. Available: http://www.weedscience.msstate.edu/swss Interpretive Summary:
Technical Abstract: Doveweed infestation of fallowed sugarcane is becoming a management concern for Louisiana’s sugarcane growers. Doveweed is poorly controlled with glyphosate and this allows it to establish dense infestations across formed rows which can impede planting practices. The objectives of this research were to compare herbicide treatments that could be applied preemergence (PRE) to prevent establishment of doveweed and to evaluate postemergence (POST) activity of herbicide treatments on established doveweed that could be applied as a burndown prior to planting. In the PRE experiment, atrazine (1, 2, and 3 lbs ai/A), metribuzin (1 and 2 lbs ai/A), sulfentrazone (0.19, 0.25, and 0.31 lbs ai/A), flumioxazin (0.064, 0.13, and 0.26 lbs ai/A), diuron (1.6 and 3.2 lbs ai/A), diuron plus hexazinone (1.2 plus 0.35 and 1.9 plus 0.53 lbs ai/A), mesotrione (0.19 and 0.25 lbs ai/A), terbacil (0.8 lbs ai/A), and pendimethalin (0.95 and 1.4 lbs ai/A) were evaluated for their PRE activity on doveweed at two locations. Prior to their application, 0.75 lbs ai/A of paraquat was applied to all plots to control any emerged doveweed. At one location, treatments were evaluated only at 4 and 5 weeks after treatment (WAT) as the field was planted at 6 WAT, while at the other location treatments were evaluated weekly starting at 4 WAT and continuing until 10 WAT. At 4 WAT, doveweed control was greater than 90% with the application of metribuzin, diuron plus hexazinone, flumioxazin, and mesotrione, regardless of rate used. Control was 77% with diuron at 3.2 lbs/A and 73% with terbacil. All other treatments gave poor or no control of doveweed. At 7 WAT, doveweed control continued to be greater than 90% when metribuzin, diuron plus hexazinone, flumioxazin at 0.26 lbs/A, or terbacil were applied with mesotrione at both rates providing 83 to 86% control. At 10 WAT, the only treatments that controlled doveweed 80% or more were metribuzin (85 to 90%), diuron plus hexazinone (91 to 95%), flumioxazin at 0.26 lbs/A (83%), and terbacil (84%). For fields with a known history of doveweed, these herbicides could be applied PRE following row formation to prevent doveweed infestation.