EFFECT OF ORGANIC ISOLATES FROM NON-EDIBLE OILSEED CAKES IN ENHANCING UREA-NITROGEN USE EFFICIENCY IN TOMATO

摘要

Pot experiment was conducted during February to April, 1998 under greenhouse condition with tomato (Lycopersicon esculentum) variety Pusa Gaurav at Indian Agricultural Research Institute, New Delhi. The soil having sand 68.8 per cent, silt 16.1 per cent, clay 15.1 per cent, (textural class sandy loam), pH (1:2.5,:: soil: water) 7.90, EC (1 : 2.5, :: soil : water) 0.42 dS m~(-1), organic carbon 0.41 per cent, CEC 10.30 cmol (p~+) kg~(-1), total nitrogen 0.065 per cent, available nitrogen 252.00 kg ha~(-1), ammonical nitrogen 20.16 mg kg~(-1), nitrate nitrogen 16.12 mg kg~(-1) available P 11.9 kg ha~(-1), and available K 129.0 kg ha~(-1). The treatments ocnsituted with 44.5 mg urea-N kg~(-1) soil and organic isolated from each of the four non-edible oilseed cakes viz., neem, sal, kusum and undi @ 15 per cent and 30 per cent of applied urea (weight basis). The treatments received basal application of 31.25 mg kg~(-1) soil for each of phosphorus (P_2O_5) and potassium (K_2O). The defatted oilseed cakeswere extracted with aqueous solutions of ethanol, acetone, methanol and mixture of acetone and ethanol, respectively for neem, sal, kusum and undi with cake to extractant ratio of 1 : 5. The extracts were dried on water bath and used as organic isolates. Experiment was replicated four times in completely randomized design. The sources of nitrogen, phosphorus and potassium were urea, SSP and muriate of potash, respectively and were applied before to transplanting of the seedlings as per recommended forthe crop. The tomato seedlings were raised in the same soil in a nursery bed with the application of FYM only. Healthy and disease free seedlings of 35 days old were selected and transplanted in the pots. One plant was maintained in each pot. The fruitsper pot were first picked up and fresh weight were recorded. The plants were harvested after 75 days of transplanting and these plants were washed with tap water followed by distilled water. The plants were then air dried followed by oven drying. The dry matter yield was recorded. Fruits and plant samples were further processed for chemical analysis. Total nitrogen in plants (stalk & fruits) were determined by modified micro-kjeldahl method (Jackson, 1973).