Effect of nitrogen on the yield and nitrate content of early potato grown under greenhouse conditions

Abstract

A major reason for early potato production under greenhouse conditions is the fact that this type of potato ensures early marketable yields, high prices and cost-effectiveness of production. Fertilization is an essential cultural operation in early potato production and therefore it should be given serious attention, as excessive fertilization during a short growing period can cause high nitrate accumulation in early potato tubers. An experiment involving five potato cultivars (Liseta, Adora, Cleopatra, Amorosa and Kondor) and four nitrogen rates (∅, 60, 120 and 180 kgN/ha) was conducted to identify the most suitable nitrogen rate that would facilitate high yields and simultaneous optimal nitrate accumulation in potato tubers. The average potato yields produced showed that mineral nutrition had a significant effect on yield, which ranged from 13.2 t/ha (cv. Kondor) to 18.2 t/ha (cv. Cleopatra). Nitrogen fertilization rates of up to 120 kg/ha did not pose a risk of increased nitrate accumulation in potato tubers, whereas the 180 kgN/ha rate resulted in higher-than-average nitrate levels in potato tubers.