A field experiment was conducted at the research farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur, Bangladesh during 15 March to 6 July 2010. The experiment was arranged in a RCBD with six treatment combinations replicated thrice. Plot size was 2.4 m x 2 m. Okra (BARI Dherosh-1) was used as the test crop. The row to row and plant to plant distances were 60 cm and 50 cm, respectively accommodating 16 plants in each plot. The treatment combinations comprised of three levels of nutrient solution (1000, 3000, 5000 times dilution concentration ukisinki solution) together with full or partial (75 and 50%) recommended doses of fertilizers (RDF). The detailed treatment combinations were T1. Control (100% RDF), T2. 1000 times diluted nutrient solution (TDNS) + 100% RDF T3. 3000 TDNS + l00%, RDF, T4. 5000 TDNS + 100% RDF, T5. 1000 TDNS +75% RDF and T6. 1000 TDNS + 50% RDF. All treatments received full doses of recommended nitrogen. The total amounts of P, K, S, B, Zn and cow-dung (10 ton/ha) were applied as basal dose. Nitrogen was applied in four equal installments at 15, 30, 45 and 60 days after sowing as top dressing.
Preparation and application of 1000, 3000 and 5000 times diluted nutrient solution
Twelve liters of nutrient solution was applied as irrigation water in each plot at seedling, maximum growth, and flowering stages and 3 days before the final harvest of fruit. Intercultural operations were done when necessary.
Mature fruits of okra were harvested from 10 randomly selected plants of each plot. The fruits were air-dried and then oven-dried (at 65oC for 72 hrs.) for dry weights of fruits and finally grounded for analysis.
Total soluble solids (TSS) by Abbe Refractometer (Rangana 1979), total ash content (AOAC 2000), nitrogen content in pod (Black 1965), reducing and non-reducing sugar (Somogyi 1952; using Bertrand-A, Bertrand-B, and Bcrlrand-C solutions) ascorbic acid (Purseglove 1987) and β-carotene by spectrophotometer (Model 200-20, Hitachi, Japan) at 663, 645, 505 and 453 nm were determined. Calculation was done by the following formula of Nagata et aI. (1992). β-carotene content = 0.216 [663] + 0.452 [453J - 1.22 [645] — 0.304 [505] Where, Bold figures indicate optimal density.
Statistical ana I ys is was done following DMRT (Gomez and Gomez 1984).