The Effect of Different Doses of Tank-mixed Herbicides on Antioxidant Enzymes Activity of Soybean

Herbicide plays the main role in guaranteeing the quantity and quality of food. Soybean reactive oxygen species scavenging system eliminates the herbicides’ side effects on the plant by activating antioxidant enzymes, which affects the yield. So, we investigated this procedure to reveal the effect of herbicides on food production. Methods: Experiments were carried out in two locations of Alborz province in 2014 during the growing seasons. Seven different tank-mixed herbicides were produced by mixing one triple mixture of imazethapyr+bentazon+sethoxydim active ingredient, three double mixture of imazethapyr+bentazon, imazethapyr+sethoxydim, and bentazon+sethoxydim, as well as single usage of imazethapyr, bentazon, and sethoxydim. Reduced herbicide rates were 100, 60, and 30% of the recommended dosage inducing soybean plots through leaf expanding phase. Results: Both herbicides and their reduced rates changed soybean yields through antioxidant enzymes’ activity. Maximum soybean yield was registered at tank-mixed imazethapyr+bentazom+ sethoxydim which were induced at 33, 320, and 125 g active ingredient/hectare, respectively. The minimum activity of enzymes (superoxide dismutase 3.9 international unit) was also demonstrated in this research. Our data showed that when the herbicide rate was reduced from 100% to 30%, as a result, the label recommended soybean yield was reduced by just 17%, while superoxide dismutase activity was reduced too. The minimum yield was 1.2 ton/hectare of sethoxydim with 225 g active ingredient/hectare. Conclusion: Antioxidant enzymes were promoted to maximum activity by increasing the herbicide rate for scavenging the herbicide side effects. Tank-mixed herbicides, with reduced herbicide rates can eliminate poison residue in the environment and food chain while increasing weed control.