EFFECT OF NITROGEN AND POTASH APPLICATION ON YIELD AND QUALITY OF CHINA HYBRID TEA (CAMELLIA-SINENSIS) GROWN IN KANGRA VALLEY OF HIMACHAL-PRADESH

A 140-year-old dark leaf china hybrid tea [Camellia sinensis (L.) O.Ku ntze] section was fertilized with 4 levels of nitrogen (0, 60, 120, 18 0 kg/ha) and 4 levels of potash (37.5, 75.0, 112.5, 150 kg/ha) at cons tant level of phosphate (39 kg/ha) since 1988. Yield responses have be en presented for 6 years from 1988-93 averaged over 2-3 years pruning cycles. Nitrogen application up to 60 kg/ha increased the yield and de clined thereafter. Application of potash responded up to 75 kg/ha and had a decreasing effect thereafter in a regular fashion. The synergist ic effect of N-60 with K-75 was significantly achieved over a period o f 6 years and the largest crop to the extent of 1 722 kg made tea/ha w as harvested at N60P39K75 fertilization level. As regards quality of m ade tea in terms of total colour and per cent brightness, the highest values were found in no-nitrogen application, whereas the same charact er was improved with the application of potash.