The response of clone BBK 35 tea to nitrogen fertilizer rates and harvesting intervals in the lake Victoria basin of Kenya.

Abstract

Tea is an economic crop in the Lake Victoria basin of East Africa, earning high foreign exchange and creating employment opportunities especially in the rural poor regions. It is grown under varying environments causing differences in yields and quality. However, agronomic recommendations are uniform throughout the region despite these differences. It is necessary to develop region specific agronomic recommendations to realise economic returns from tea enterprises. Nitrogenous fertiliser use and harvesting are the most costly agronomic inputs and their incorrect use reduces yields and black tea quality. Trials using clone BBK 35 were conducted at Timbilil, Changoi, Kipkebe and Sotik Highlands within the Lake Victoria basin in Kenya to determine yields and black tea quality responses of the cultivar to locations of growth, nitrogenous fertiliser rates and plucking intervals. Yields and black tea quality significantly (P<0.05) varied with the environment. Similarly, rates and extents of yields and quality responses varied with locality, demonstrating that despite uniform agronomic inputs, different locations need different levels of inputs for optimal economic returns. Black tea quality declined with high rates of nitrogenous fertiliser and long plucking intervals. There was yield increase at Changoi and decrease at Sotik Highlands with long plucking intervals. It is concluded that region specific agronomic recommendations are necessary to realise high yields and quality black teas. However, low rates of nitrogenous fertilisers of about 100 kg N ha-1 year-1 and short plucking intervals produced high quality black teas.