Productivity of potato cultivars under the use of bioactive preparations on irrigated soils of the North-Western Caspian region

Agroclimatic conditions of the Lower Volga region are favorable for realizing the productive potential of potato varieties cultivated using intensive resource-saving technologies. The aim of the study was to assess the agronomic effectiveness of bioactive preparations Forsage and Biostim Start when growing various potato cultivars in drip irrigation on light chestnut soils of the Astrakhan region (North-Western Caspian region). The studies were carried out in 2022–2024 in a field experiment on an experimental irrigated area. The objects of the research were the cultivars ‘Koroleva Anna’, ‘Gala’ (Germany) and ‘Azhur’ (Russia). The ‘Azhur’ potato cultivar used water more efficiently in irrigated conditions (water consumption factors – 63.0–85.5 m 3 /t) compared to the ‘Koroleva Anna’ (113.7–180.1 m 3 /t) and ‘Gala’ (115.4–164.7 m 3 /t) cultivars. The use of Forsage preparation in the treatment of tubers and plants reduced the water consumption of the cultivars, the most noticeable result was obtained for the ‘Azhur’ variety (63.0 m 3 /t). In terms of the increase in the biological yield of potatoes relative to the control variants (without treatment), the Forsage preparation showed the highest results – 8.2–10 t/ha from tuber treatment before sowing and 4.9–17.3 t/ha from leaf treatments in the budding phase. The effect of the biostimulator Biostim Start was significantly lower – 2.2–7.7 and 3.7–11.2 t/ha, respectively. The results showed that the maximum yield of ‘Azhur’ potato tubers (94.3 t/ha) was obtained with the following combination of methods and techniques of using the Forsage and mineral fertilizers: pre-planting treatment of tubers with Forsage (2 l/t, working solution consumption 10 l/t); application of N 60 P 60 K 60 to soil before sowing + N 60 fractionally during fertigation; leaf treatment with Forsage (200 l/ha) in the budding phase. The ‘Azhur’ potato cultivar, according to this variant, exceeded the ‘Koroleva Anna’ and ‘Gala’ varieties – by 40.3 and 44.6 t/ha in terms of commodity yield and by 192.0 –212.8 % in the level of profitability.