Effect of Combine Application of Urea, Urease, Nitrification Inhibitors and Plant Growth Regulators on Spinach Productivity

An experiment was conducted to assess the effect of applying different rates of urea treated with nBTPT (N-(n-butyl) thiophosphoric triamide) alone, or a combination of both nBTPT and DCD (Dicyandiamide) and DMPP (3, 4-Dimethylpyrazol-phosphate), on spinach productivity at experimental area of Faculty of Agriculture, Gomal University, Dera Ismail Khan during 2012-13. The experiment was arranged in a Complete Randomized Design (CRD) with nine treatments and four replications. Composite soil samples were collected before the experiment for various physico-chemical analysis viz soil texture, soil pH, organic matter, bulk density, NH4-N, NO3-N, extractable P and exchangeable K. The results showed that treatment (T6) with dose of Urea@150 kg/ha + GA3 @60 gram/ha was more effective than agrotain alone i.e tallest plant height (11.54 cm), maximum number of leaves (69), highest fresh weight (22.37g), highest dry weight (4.64 g), maximum biological yield (227 g pot-1) and highest net return (13.42 million). Such findings may be due to availability of nitrogen for longer period and reduced loss on nitrogen by volatilization. The results further suggested that applying urea treated with Gibberellic acid (GA3) or Agrotain significantly increased the spinach growth. However, combine application of Urea, Urease, Nitrification Inhibitors and Plant Growth Regulators on Spinach productivity was better than urease inhibitor alone (agrotain).