Abstract
Two-year field trials were conducted at two winegrowing districts (Kavadarci and Skopje in 2016 and 2017) to evaluate wheather oxyfluorfen, pendimethalin and flazasulfuron can replace early post-emergence (EPOST) application of glyphosate in established vineyard until its application in early summer period. The weed vegetation in vineyards in both years was consisted mainly of Chenopodium album L., Setaria viridis (L). Beauv., Papaver rhoeas L., Xanthium strumarium L., Lolium multiflorum Lam., Sorghum halepense (L.) Pers. and Cynodon dactylon (L.) Pers. Pendimethalin, oxyfluorfen and flazasulfuron efficiently reduced predominant annual weeds and S. halepense seedlings in 2017, but not in 2016. PRE herbicides, regardless year, had no significant effect on C. dactylon. Opposite, the efficacy of EPOST applied glyphosate was significantly lower in 2017 compared to 2016. LPOST glyphosate applied at 2.0 l ha-1 provided at least 94 % control of dominant annual broadleaf and grass weeds. LPOST application of glyphosate at 2.0 l ha-1 and glyphosate at 2.0 and 4.0 l ha-1 resulted in unsatisfactory weed control of predominant perennial S. halepense, and C. dactylon, respectively. LPOST glyphosate applied at 4.0 l ha-1 provided control of S. halepense by 84 % or more. LPOST glyphosate applied at 8.0 l ha-1 reduced the amount of S. halepense and C. dactylon at least 97 %. Grapevine yield of both varieties was not lower in all herbicide treatments in 2016 compared with 2017. However, yield in the PRE herbicide treatments fb 2.0 and 4.0 l ha-1 glyphosate was collectively 15-19 % and 17-19 % lower compare to PRE herbicide treatments fb 8.0 l ha-1 glyphosate and standard two applications of glyphosate, respectively for both years and districts. No impacts to grapevine growth were observed from PRE herbicide treatments at either district
Highlights
In Republic of North Macedonia weeds management system in established vineyard based on multiple applications of glyphosate, which is required to maintain effective weed control throughout the season
It was concluded that PRE herbicide treatments followed by different efficacy of late post-emergence (LPOST) glyphosate applications, was the most effective for controlling C. album in both 2016 and 2017
Results of this research demonstrate that the efficacy of PRE herbicides pendimethalin, oxyfluorfen and flazasulfuron in established vineyards are strongly depended by the amount of precipitation and weed population
Summary
In Republic of North Macedonia weeds management system in established vineyard based on multiple applications of glyphosate, which is required to maintain effective weed control throughout the season. Another approach that may improve weed control and aid in the stewardship of glyphosate use is to apply a pre-emergence (PRE) herbicides prior to a single late post-emergence (LPOST) application of glyphosate. To prevent yield loss due to competition with weeds is required a high efficacy of herbicides against weeds during the critical weed control period of different crops (Knežević et al, 2002) This is an important component of an Integrated Weed management (IWM) system and is a major factor in deciding the optimal timing of herbicide application (Swanton et al, 1999; Boerboom, 2000). Studies have shown that full-season competition due to unmanaged weeds could cause reductions in grapevine yield of up to 37 %, cane mass of up to 68 %, in number of clusters per vine of up to 28 %, and in berry mass of up to 3 % (Byrne and Howell, 1978 cit. by Sanguankeo et al, 2009)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
