The effectiveness of herbicides in soybean cultivation

Abstract

The necessity to improve systems of soybean crop protection from weeds as a critical factor in further increasing of crop yields and improving of food quality conditioned the topicality of a problem raised in this publication. In this regard, we directed this article on the determination of biological activity of individual post-emergence herbicides in relation to the most common and harmful weed species and establishing of their technical and economic efficiency under growing of soybeans in the Right-Bank Forest-Steppe of Ukraine. The effectiveness of chemical weeding of crops with preparations bentazone, imazamox and bentazone+imazamox in two-year field experiments in a stationary crop rotation at the Agronomic Research Station of the National University of Life and Environmental Sciences of Ukraine was analysed. It is established that the application of post-emergence herbicide bentazone+imazamox, which at the expense of high biological activity significantly reduced density of widespread and relatively chemicalresistant weeds at a mixed type of soybean crop weediness, is effective enough. Twofold application of 0.75 l ha^–1 of the herbicide in a tank mixture with 1.0 l ha^–1 of the surfactant Metolat with a two-week interval in the phase of two or three true leaves on soybeans was more effective. It resulted in a loss of 89% of gray bristle (Setaria glauca (Poir.) Roem. & Schult), 65% of common chicken millet (Echinochloa crus-galli (L.) P. Beauv.) and almost full destruction of broadleaf species (99%) with 97% reduction of raw weed biomass. However, the soybean yield averaged 3.82 t ha^–1 over 2 years that is by 34% higher than in the control option without chemical weeding. Application of the herbicide did not reduce protein and oil content.