Efficiency of using tank mixtures of fungicides for the control of phytopathogens in potato agrocenoses

Abstract

Goal. To evaluate the level of effectiveness of phytopathogen control elements in agrocenoses of potatoes for different combinations of pesticides with biologically active substances, methods of application and the reaction of Aria potatoes to them. Methods. Field — for monitoring the main diseases of potatoes in field experiments, recording the harvest, determining the effectiveness of combinations of fungicides with plant growth regulators and microfertilizers; laboratory — for recording damage to tubers by diseases. Research was conducted in accordance with generally accepted methods. Results. In 2019—2021, the Laboratory of Plant Immunity and Protection of the Institute of Potato Breeding of the National Academy of Sciences conducted research on the improvement of elements of phytopathogen control technology in potato agrocenoses under various schemes of using tank mixtures of fungicides, growth regulating substances (RRS) and microfertilizers. The research used the Aria variety selected by the institute. The lowest level of development of Alternaria was in the version where tuber treatment was carried out (fungicide impregnant + microfertilizer + PPR) and two plant treatments (Kurzat R + microfertilizer + PPR). The development of the disease was 14.7% for the spread of 66.6%, and the technical efficiency of the protection elements was 68.8%. To effectively control the development of common scab, rhizoctoniosis and fusarium dry rot, it is advisable to treat tubers with a tank mixture of impurity-fungicide + PPR + microfertilizer and to treat plants with a mixture of Kurzat P + PPR + microfertilizer, which significantly reduces the level of tuber disease control and limits their spread compared to and chemical standards. The yield of potatoes in the variants was higher than in the control (25.4 t/ha) — 29.8—36.8 t/ha. The level of the preserved harvest compared to the control was in the range of 4.4—11.4 t/ha or 17.3—44.9%. The highest level of yield (36.8 t/ha) was in the variant: treatment of tubers — impregnation-fungicide + micro-fertilizer + PPR and two plant treatments — Cuproxate + micro-fertilizer + PPR. This indicator is 11.4 t/ha (44.9%) higher than the control and 4.7 t/ha (14.6%) higher than the standard. Conclusions. The use of tank mixtures of fungicides with a growth regulator and microfertilizer significantly reduces the level of potato diseases and increases the yield. It was established that the use of a mixture of impurity-fungicide + PPR + microfertilizer for treating potato tubers and Kurzat P + microfertilizer + PPR for treating plants significantly reduces the level of common scab, rhizoctoniosis and fusarium dry rot and limits their spread, compared to control and chemical standards.