YIELD-WATER-NITROGEN RESPONSE ANALYSIS IN CORIANDER

A field study on the response of coriander (Coriandrum sativum L.) to irrigation and nitrogen was made for two years at the Central Arid Zon e Research Institute, Jodhpur. A 2-factor central composite rotatable design with water and N each at predetermined values -1.414, -1, 0, 1 and 1.414 was used. The actual values, in order of their predetermined levels were 120, 180, 340, 490 and 550 mm of water and 0, 18, 60, 102 and 120 kg N ha(-1). However, interactive effects of water and N were examined at their equispaced levels. The higher water supplies impose d greater demand on applied N. The nitrogen optima were 36, 62, 88, 11 4 and 140 kg ha(-1) for the 120, 240, 360, 480 and 600 mm of water sup plies, respectively. Nitrogen at 140 kg ha(-1) and water level at 600 mm were beyond the experimental range, and therefore the treatment com bining 480 mm of irrigation water and 114 kg N ha(-1) emerged as the o ptimal package to produce the seed yield of 2366 kg ha(-1). However, t he combination of 490 mm of water and 93 kg.N ha(-1) would cost least to the farmer for a yield goal set to 2300 kg ha(-1), which was identi cal to optimal yield.