TY JOUR TI PRODUCTIVITY OF POTATO OF DIFFERENT RIPENING DEPENDING ON NUTRITION AREA AND USE OF CALCULATED DOSES OF FERTILIZERS IN THE KAMA REGION OF THE REPUBLIC OF TATARSTAN KW potato KW variety KW planned yield KW calculated doses of fertilizers KW leaf area KW quality indicators KW starch KW vitamin C KW nitrates. JO Vestnik of Kazan State Agrarian University AU Gareev , I.. PY 2015 IS 10 PB Kazan state agrarian University