Optimizing of sulfosulfuron and sulfosulfuron plus metsulfuron-methyl herbicides efficiency against Japanese downy brome Bromus japonicus L. by adjuvants application

Efficiency of many herbicides can be increased by adding adjuvants to the spray solution. So, the addition of an appropriate adjuvant to foliar herbicides is important in weed control researches. To identify an appropriate adjuvant for sulfosulfuron and sulfosulfuron + metsulfuron-methyl herbicides against Japanese downy brome Bromus japonicus, two experiments were conducted in randomized complete block design with two factors under field condition separately in Zabol and Zahedan, Iran. Factor A was different doses of herbicide namely 0, 50, 75 and 100% of their recommended dose and factor B was adjuvants including: sweet almond oil, olive oil, sesame seed oil and D-Octil. Results showed that efficiency of sulfosulfuron and sulfosulfuron + metsulfuron-methyl herbicides increased by increasing their doses and adjuvant addition. The addition of sesame seed oil (followed by D-octil) had the highest effect on sulfosulfuron efficacy against Japanese downy brome control. In general, sulfosulfuron at 100% of its recommended dose (26.5 g ha-1) plus sesame seed oil was the best formulation to control of Japanese downy brome. In addition, this formulation significantly improved wheat grain and biological yield. Adding of D-Octil had the highest influence on sulfosulfuron plus metsulfuron-methyl performance in Japanese downy brome control. The highest wheat grain and biological yield were mainly obtained at 100% recommended dose (40 g ha-1) of sulfosulfuron + metsulfuron-methyl plus D-Octil followed by sesame oil.