Sensitivity of Red Raspberry to Several Herbicides with Potential to Aid in the Control of Perennial Weeds

摘要

Two studies were conducted in northwestern Washington, USA, testing several herbicides known to aid in the control of perennial weed species often infesting red raspberries in the Pacific Northwest. These species include Canada thistle (Cirsium arvense), horsetail (Equisetum spp.), broadleaf dock (Rumex obtusifolius), creeping buttercup (Ranunculus repens), field bindweed (Convolvulus arvensis), quackgrass (Elymus repens), and yellow nutsedge (Cyperus esculentus). Trial 1 examined effects of clopyralid and granular or liquid diclobenil applied postemergence (POST) in 2007 and 2008; Trial 2 examined effects of halosulfuron and rimsulfuron applied POST in 2009 and 2010. By applying these products after weeds are visible, growers can treat portions of fields where infestations are heaviest, resulting in cost savings compared to broadcast preemergence applications, and perhaps with greater efficacy to weeds. In Trial 1, primocane injury was noted both years. The greatest injury in 2007 resulted from diclobenil, ranging from 18 to 36%. Liquid diclobenil caused a similar level of injury from early postemergence (EPOST) application as did granular diclobenil applied either EPOST or late postemergence (LPOST), but injury from LPOST liquid diclobenil was only half as severe. In 2008, LPOST diclobenil caused the greatest primocane injury, with the liquid diclobenil at either timing caused a similar level of primocane injury as granular diclobenil, ranging from 11 to 19%. Clopyralid applied EPOST or LPOST caused only slight injury to primocanes, ranging from 0 to 8% in 2007 and 10 to 13% in 2008, statistically similar to non-treated raspberry. Floricanes were not significantly injured by either herbicide either year, and berry yield was also not significantly affected. In Trial 2, neither rimsulfuron nor halosulfuron caused a reduction in berry yield in 2009, nor significant injury to primocanes or floricanes. In 2010, however, rimsulfuron and halosulfuron caused 63 and 55% primocane injury, respectively. Berry yield that year was reduced by rimsulfuron compared to nontreated raspberries, although yield in this older planting was low.