Effect of potassium fertilization on processing grade tuber yield and quality parameters in potato (Solanum tuberosum)

The potassium requirements for 2 Indian cultivars of potato (Solanum tuberosum L.), viz 'Kufri Chipsona 1' and 'Kufri Chipsona 2', meant for processing, were studied during 2000-2001 and 2001-2002 in relation to their processing grade tuber yield and quality parameters. Potassium levels (0-166 kg K/ha) affected the yield of process grade tubers in both the cultivars; a maximum yield of process grade tubers (32.8 and 29.5 tonnes/ha in 'Kufri Chipsona 1' and 'Kufri Chipsona 2' respectively) was obtained at a fertilization dose of 124.5 kg K/ha. However, potassium did not influence quality parameters for processing, viz tuber dry matter, specific gravity, reducing sugars and chip colour significantly. The potassium requirements for 'Kufri Chipsona 1' and 'Kufri Chipsona 2'(124.5 kg K/ha) were 50% higher than that for table-purpose potato cultivar like 'Kufri Bahar'.