Estimation of efficiency and phytotoxicity of Adengo herbicide in corn crops

Abstract

The study was conducted in the Primorsky Territory in 2017-2018 in the corn crops of the hybrid population P 8521 for grain. The soil of the experimental plots was meadow-brown podzolized, containing 3.5% humus in the arable horizon. Agricultural technology used was based on non-moldboard soil tillage system. The predecessor was soya. Adengo herbicide was used before seedling, in phases of 2-3 and 5-6 leaves in corn. The experiment was carried out in two plots: the first grown with weeds, at a consumption rate of 0.5 l/ha, the second – clean from weeds with regular manual weeding, at a consumption rate of 0.5 and 1.0 l/ha (twice the recommended rate). The infestation of the first plot averaged 272–626 plants per 1 m 2 with a total above-ground mass of 4181–4305 g/m2 . About 80% of weeds were annual grasses and common ragweed. Adengo herbicide, applied after sowing and before seedlings of corn and weeds, prevented the germination of St. Paul’s wort, velvet leaf, lamb’s quarters and smartweed. Common ragweed, Asian copperleaf and annual grasses sprouted 96, 65 and 78%, respectively, less than in the control. When applying treatment in the phase of 2–3 leaves in corn, the herbicidal activity of the preparation increased compared to its preemergence application from 46 to 71%. When applied during these periods, Adengo did not affect perennial dicotyledonous weeds. The main advantage of the studied preparation, applied in the 5–6 leaf phase, was herbicidal activity against perennial dicotyledonous weeds – the creeping thistle and field sowthistle. When using Adengo in phases 2–3 and 5–6 leaves, 5.34 and 5.46 tons of grain/ha were saved, respectively, which was more than when it was applied before germination at 4.76 t/ha (in the control 0.76 t/ha). In the second weed-free experiment, the phytotoxic effect of the herbicide on corn plants, regardless of the timing of application during the growing season, reduced grain yield. In all variants with the use of the preparation, 0.08–0.78 t/ha less grain was received than in the control (without herbicides – 8.64 t/ ha). When Adengo was applied in the phase of 5–6 leaves at a consumption rate of 1.0 l/ha (twice the recommended value), corn plants significantly lagged in growth and development; the obtained yield was by 0.78 t/ha lower than the control variant. In practically all variants of the experiment, the weight, length of the ear and the number of grains from it, and the mass of 1000 grains were recorded significantly less than in the control.