TY JOUR TI REACTION OF POTATO VARIETIES FOR TERMS AND LOOSE OF LANDING IN THE CONDITIONS OF THE MIDDLE URAL KW potato KW variety KW term and density of planting KW productivity KW quality JO Agricultural education and science AU Tyutenov, E.S. AU Mingalev, S.K. PY 2017 IS 2017 PB Ural State Agrarian University