CULTIVATION OF LETTUCE IN DIFFERENT STRENGTHS OF THE TWO NUTRIENTS SOLUTION RECIPES IN A NON-CIRCULATING HYDROPONICS SYSTEM

Plants of lettuce cultivar Dutch were grown in 13 litres plastic tubs using two strengths (1/2 and Full) of Cooper’s 1988 and Imai’s1987 recipes on a RCBD in the green house facility of Institute of Biotechnology and Genetic Engineering (IBGE) NWFP Agricultural University, Peshawar during the fall 2006. Cooper’s solution recipe (mg L-1 ) of N-236, P 60.0, K 300, Ca 85, Mg 50, S 68, Fe (EDTA) 12, Mn 2.0, Zn 0.1, Cu 0.1, B 0.3, Mo 0.2) proved better with regards to the number of days to first harvest (35.67,37.33 days after seeding), more number of leaves plant-1(13.67 and 1.11 in full and ½ strengths respectively), larger average leaf length (17.53cm and17.35 cm),more leaf area index(LAI) plant-1 (234.85 cm2 and 200.59 cm2)more number of roots plant-1 (225.3 and 208.8),longer average root length (227.3cm and 206.2cm plant-1), more average leaf yield plant-1 ( 53.89 g and 45.45 g) ,more leaf yield pot-1 (323.4g and 272.7g),more average leaf yield container-1 (970.10 g and 818.40 g), more utilization of nutrients solution (17.48 litres and 20.93 litres ),more average total cost container-1( Rs 56.89 and Rs 42.09), more average crop revenues contsainer-1 (Rs 48.51 and Rs 40.90 in full and ½ strengths grown plants respectively) as compared to the corresponding strengths of the Imai’s solution recipe (mg L-1 ), NO3-N 140.0, P 35.05, K 360.22, Ca 160.16, Mg 48.60, Fe (EDTA) 3.0, Mn 0.5, Cu 0.02, Zn 0.05, B 0.5, Mo 0.01).. The benefit cost ratio (BCR) based on solution chemicals costs was also good for Cooper’s recipe (Rs 1.32: 1.00 and Rs1.86: 1.00 for full and 1/2 strengths grown plants respectively). While, the BCR on the basis of average total cost container-1 was with in the acceptable range (Rs 0.85: 1.00 and Rs 0.98: 1.00 respectively, in full and 1/2 strength solutions of Cooper’s recipe). However, the BCR values for Imai’s solution recipe were much better than the Cooper’s recipe grown plants on nutrients solution cost basis