Environmental safety assessment of Stallar herbicide application

Abstract

There was studied the efficiency of Stellar herbicide in sowing grain maize, tolerance for it, and aftereffect to buckwheat and soybean. Experiments were carried out in Primorsky Territory in 2014 and 2015 against two backgrounds: weedy, and hand weeding during the growing season. It was shown that Stellar herbicide at consumption rates of 1.5 and 2.0 liters per hectare reduced weed infestation of the maize sowings by 64-68% and buildup of weed tops by 90%. This made it possible to yield 5.08-5.70 tonnes of maize grain per hectare (10.4 t/ha in the control). Hand weeding against the background of herbicide applied earlier allowed eliminating a negative impact of remained weeds. It was found that Stellar herbicide had a growth-promoting impact on the maize plants, when used at consumption rates of 1.5 and 2.0 liters per hectare, and inhibited the growth and development of plants at 3.0 liters per ha (twice as big as recommended dose). The tolerance indices were 1.04 and 0.98, respectively. This gives reason to think that the crop is not tolerant to Stellar herbicide at a consumption rate of 3 liters per ha. When sown buckwheat and soybean in the experimental plot treated with Stellar herbicide next year, aftereffects for plants and yields of these crops were not observed. The soybean seed yield made up 1.81-1.86 tonnes per hectare that was at a level of the control (1.84 t/ha), and the green mass yield of buckwheat 5.64-5.86 t/ha that was 0.32-0.54 t/ha more than in the herbicide-free variant (5.32 t/ha).