Agroeconomic justification of technologies of distributed application of the herbicide corum in soybean agrocenoses

Abstract

Aim. The article analyses the feasibility of using a system of distributed application of insurance herbicides in intensive soybean cultivation technologies. Methods. The aim of the research was to establish the biological and economic performance of two-time consecutive sprayings of soybean crops with reduced norms of Corum herbicide. The three-year (2018–2020) field experiments were conducted in a stationary crop rotation at the separate subdivision of the National University of Life and Environmental Sciences "Agronomic Research Station". The effectiveness of the insurance herbicide Corum (l. c., 48% bentazon + 2.24% imazamox) was studied at application rates (1.5; 2.0 and 2.5 l/ha) and two consecutive sprayings of 0.75 l/ha in tank mixtures with the surfactant Metolat (1.0 l/ha). The insurance herbicides Bazagran (a. s., 48% bentazon) and Pulsar (w. s. c., 4% imazamox) were used as reference ones at the recommended application rates of 2.5 and 1.0 l/ha, respectively. Results. The results of the research established that the herbicide Corum together with the surfactant Metolat provided effective control of the dominant segetal vegetation in soybean crops at all rates and methods of application with a biological efficiency of more than 85%, which is by 5–10% higher than the indexes of reference insurance herbicides. A two-time sequential spraying with the herbicide at a rate of 0.75 l/ha was the most effective, which ensured almost complete elimination of dicotyledonous juveniles and 75–92% of cereal annuals, which is equal to the effectiveness of the maximum single rate (2.5 l/ha). The high biological efficiency of Corum herbicide in tank mixtures with surfactant Metolat with two consecutive applications provided the largest increase in the marketable crop of soybeans — 1.46 t/ha or 77% compared to the level of an untreated control in the absence of quantitative changes in the protein and oil content in seeds. Conclusions. A significant increase in crop and low additional investment in the system ensured obtaining a maximum net profit per 1 ha (UAH 12155). At the same time, the profitability of growing the crop reached 49.0% with a six-fold return on the funds invested in the technology. Given the combination of household, economic and environmental factors of the innovative system of distributed application of the herbicide Corum, it is advisable to introduce it into production.