Comparison of two nutrient solution recipes for growing spinach crop in a non-circulating hydroponic system

Plants of spinach cv. Local double were grown in nutrient solutions of two different strengths (Full and 1/2) of Cooper's 1988 and Imai's1987 recipes (using 13 litres plastic tubs) on a Randomized Complete Block Design (RCBD) in the green house facility of Institute of Biotechnology and Genetic Engineering (IBGE), NWFP Agricultural University, Peshawar Pakistan during the fall 2006. Cooper's solution recipe comprising (mg L-1) N- 236, P 60.0, K 300, Ca 185, 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 many of the parameters studied. The crop grown in Cooper's recipe (full and 1/2 strengths respectively) took significantly less number of days to first harvest (32.44 and 35.56 days after seeding), produced more number of leaves per plant (12.33 and 12.44), larger average leaf length (34.43cm and 31.90 cm), significantly larger leaf size / leaf area (LA) per plant (104.90 cm2 and 78.45 cm2), sign ificantly more average number of roots per plant (118.45 and 107.67), longer average root length (82.42 cm and 70.95 cm per plant), significantly more average leaf yield per plant (25.87 g and 21.50 g of single harvest), significantly higher leaf yield per pot (794.40g and 645.21g), as well as higher average leaf yield per container (2.383 kg and 1.941 kg respectively), as compared to the corresponding (full and 1/2 strengths) solutions of the Imai'1987 recipe. The amounts of nutrient solution consumed (17.03 litres and 17.27 litres) were almost statistically the same for full strengths grown plants in both the recipes, the average cost of nutrient solution consumed was significantly higher (Rs.35.94 and Rs.20.86), the average total cost of growing spinach per container was also significantly higher (Rs.56.94 and Rs.40.86), the crop revenues obtained per container were also significantly higher (Rs.28.60 and Rs. 23.29) for Cooper's recipe grown crop as compared to the crop gr own in corresponding strengths of the Imai's 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). However, the BCR values either on solution chemicals cost bases (1.25: 1.00 and 2.76:1.00) or on total cost per container bases (0.58: 1.00 and 0.76: 1.00) were significantly higher for Imai's recipe grown crop.