|Mesbah, Abdel - UNIVERSITY OF WYOMING|
|Miller, Stephen - UNIVERSITY OF WYOMING|
Submitted to: Crop Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 14, 2004
Publication Date: August 26, 2004
Citation: Mesbah, A.O., Miller, S.D., Stevens, W.B. 2004. Redstem filaree control in sugarbeets with micro-rate herbicide treatments. Online. Crop Management. doi: 10.1094/CM-2004-0826-01-RS. Interpretive Summary: Redstem filaree (Erodium cicutarium L.) is becoming a serious weed problem for sugarbeet (Beta vulgaris L.) growers in northern Wyoming and southern Montana. This weed species originated in the Mediterranean region of Europe and has spread to many areas of the world including Africa (14), Australia (12), and North and South America (6,7,10). Redstem filaree, a winter annual or biennial broadleaf, is a prolific seed producer (3) and can quickly develop into dense infestations under non-competitive conditions. Blackshaw (2) reported that under controlled environmental conditions, redstem filaree seeds germinated at soil temperatures of 5 to 20°C and produced optimal vegetative growth at 15 to 2o0c. Little information is available on redstem filaree's ability to compete with row crops. Studies have shown that redstem filaree has the potential to compete and cause major economic losses in perennial pasture and forage crops such as alfalfa (Medicago sativa L.) (6,9) and in annual cereals and oilseed crops (4). In a zerotillage cropping system study, Blackshaw et al. (5) found that an increase in wheat (Triticum aestivum L.) seeding rate from 50 to 300 kg/ha reduced redstem filaree biomass and seed production by 53 to 95%. Limited data are available on the competitive effect and control of redstem filaree in sugarbeets (8). This study was conducted to determine (a) the effect of preplant and postemergence herbicides on redstem filaree control, and (b) the effect of herbicide rate, number of applications, and timing of applications required to control redstem filaree without reducing sugarbeet root yield.
Technical Abstract: Field experiments were conducted at the University of Wyoming Powell Research and Extension Center to evaluate redstem filaree control and sugarbeet response to several herbicide treatments. Preplant herbicides used were ethofumesate and pyrazon applied alone or in combination. Postemergence herbicides included desmedipham-phenmedipham-ethofumesate plus triflusulfuron plus clopyralid at various application rates and timings. A standard postemergence treatment was compared with a micro-rate system, which included 1.5O/0 methylated seed oil. Redstem filaree control was influenced by number and time of applications. Treatments applied at cotyledon stage provided better control than those applied at 2-leaf sugarbeet stage. Redstem filaree control increased as the number of applications increased. With or without preplant herbicides, four sequential applications using micro-rate provided more than 90% redstem filaree control. Micro-rate treatments with methylated seed oil adjuvant were significantly superior to standard treatments in controlling redstem filaree. There was no significant difference in redstem filaree control between treatments containing preplant herbicides and those without, suggesting that preplant herbicides may not be necessary. Preplant herbicides followed by standard rate postemergence treatments showed more injury than those followed by micro-rate treatments. Sugarbeet root yield was higher in treated plots than in the untreated check and was closely related to both redstem filaree control and sugarbeet injury. Sugar content was not affected by any of the herbicide treatments. With or without preplant herbicides, four sequential micro-rate applications provided significantly higher yields than standard postemergence treatments.