Influence of Time and Depth of Planting on Yield and Quality of Potato Tubers
The influence of the term and depth of potato planting on the yield and quality of tubers in the forest-steppe zone of the southern Urals, depending on agricultural techniques. During the study period (2014–2017), the potato yield varied depending on the level of mineral nutrition (factor contribution – 59%), density (20%) and planting period (7.5%), genotype (10.5%); the depth of seed tuber embedding had a significant, but significantly less impact (0.5%). An optimal agrotechnical term planting potatoes – 12–15 may. Planting may 25–29, without affecting the yield, reduced the quality of tubers. The content of dry matter in potato tubers of Rosara varieties (early) decreased by 1.8, Kuzovok (medium-ripe) – by 1.3%, starch by 1.6 and 1.3%, nitrate – increased by 1.26 and 1.52 times, respectively. Late planting (5–12 June) reduced the yield of the studied varieties by 11.3 and 15.1%, the marketability of the crop – by 1.1 and 1.4%, the starch of tubers – by 1.9 and 2.1%, the dry matter content – by 2.7 and 2.9% and increased the accumulation of nitrates in 2.05 and 2.19 times compared with planting in the 2<sup>nd</sup> decade of may. The optimum depth of seed tuber embedding depended on the planting period. When planting potatoes in the first decade of may, a significant advantage was the sealing of tubers to a depth of 5–6 cm, when planting in late may and early June – to a depth of 10–12 cm.