Pre-emergence and postemergence application of herbicide Adengo in corn crops

Abstract

The trials of herbicide Adengo were conducted under vegetation (2016, 2017) and field conditions (2016-2018) in corn crops of the hybrid population P 8521 for grain. The experimental plot had brown meadow podzolized soil, containing 3.5% percent of humus in the arable horizon. Agricultural technology used was based on non-moldboard soil tillage system. The predecessor was soya. Susceptibility to Adengo herbicide was studied in 15 weed species with pre-emergence application and 13 species with the treatment of vegetative plants. The research identified weeds that were highly susceptible to Adengo herbicide under vegetation conditions (biological efficiency of the preparation over 90%): barnyard grass, yellow-foxtail grass, velvet leaf, lamb’s quarters, common amaranth, St. Paul's wort, smartweed, hibiscus trostisy, field sow thistle and bristle thistle; moderately susceptible (70-90%): bristle grass, hairy cup grass, common ragweed and Asian copperleaf; and weakly susceptible (less than 70%): dayflower. In post-emergence application of Adengo, dayflower proved to be a susceptible weed, while Asian copperleaf - weakly susceptible. Weed infestation of experimental plots in the field experiment amounted to 542 pieces of weeds per m 2 on average, with the total above-ground mass of 4427 g/m 2 . Herbicide Adengo (0.4 and 0.5 l/ha) applied before the crop and weeds emerged, and in phases 2-3 and 5-6 of corn leaves reduced the number of weeds to 134-199 pieces/m 2 (or by 63-75%). In all periods of application, the herbicide was actively restraining the growth and development of annual grasses by 77-91%, and annual dicotyledons - by 95-99%. Dayflower was effectively eliminated when using Adengo in the phase of 2-3 leaves (86%), and bristle thistle - when spraying in the phase of 5-6 leaves (81-88%). High biological efficiency of the post-emergence herbicide application made it possible to save 4.75-5.26 t/ha of corn grain, while the yield in the control was 0.72 t/ha. Pre-emergence application of the herbicide resulted in a lower yield of corn grain by 0.49-1.0 t/ha than post-emergence application.