Abstract:
Going through a process of withering, rolling, fermenting, drying and grading the finest black
tea is collected whereas the left over brown tea is rejected as refused tea. The total annual tea
production of the country is recorded as 326 million kilograms and 10 % of it is declared as
‘Refuse Tea’ (Sri Lanka Tea Board, 2012). But refused tea has more beneficial physical and
chemical characteristics. Good aeration, good drainage and physical stability are some of those
physical characteristics. Refused tea is also rich in important plant nutrients such as Nitrogen,
Calcium and Potassium (Mohotti, 1999). Therefore, refused tea is used as a fertilizer, mulching
material, dry litter material and a growing medium in mushroom production (Atapattu and
Wickramasinghe, 2007; Rupasinghe and Nandasena, 2006; Dayananda and Wahundeniya,
2002). Refused tea is readily available in up country regions, where there is also a high potential
for growing plants under hydroponics. Coir dust is the common growing medium used for
hydroponics production in Sri Lanka and it is not abundantly available in up country areas. In
this regard, refused tea would be an alternative hydroponics growing medium which can be used
in up country area easily with low cost. Therefore, this research was conducted to assess the
performances of refused tea as a hydroponics growing medium for lettuce (Lactuca sativa).
Methodology
The study was conducted during May to July 2013 in a protected house at the university
premises. Different combinations of two growing media (coir dust and refused tea) were tested
under five treatment levels (Table 1) replicating each three times and arranging them according
to the Complete Randomized Design.
