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 per plant (13.67 and 1.11 in full and 1/2 strengths respectively), larger average leaf length (17.53cm and17.35 cm),more leaf area index (LAI) per plant (234.85 cm2 and 200.59 cm2) more number of roots per plant (225.3 and 208.8), longer average root length (227.3cm and 206.2cm per plant), more average leaf yield per plant (53.89 g and 45.45 g), more leaf yield per pot (323.4g and 272.7g), more average leaf yield per container (970.10 g and 818.40 g), more utilization of nutrients solution (17.48 litres and 20.93 litres ),more average total cost per container (Rs.56.89 and Rs.42.09), more average crop revenues per container (Rs.48.51 and Rs.40.90 in full and 1/2 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 Rs.1.86: 1.00 for full and 1/2 strengths grown plants respectively). While, the BCR on the basis of average total cost per container 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 pl ants on nutrients solution cost basis.