TY JOUR TI THE PRODUCTIVITY AND QUALITY OF SEED TUBERS OF EARLY RIPE POTATOES VARIETY SEVERNY AT DIFFERENT TERMS AND WAYS OF PLANTING IN THE NORTHERN FOREST-STEPPE ZONE OF TYUMEN REGION KW potatoes KW variety KW seed tubers KW term KW the way of planting KW productivity KW quality JO Bulletin of KSAU AU Loginov, Y.P. AU Kazak, A.A. AU Yakubyshina, L.I. PY 2019 IS PB Krasnoyarsk State Agrarian University