ISHS Acta Horticulturae 563: International Conference on Environmental Problems Associated with Nitrogen Fertilisation of Field Grown Vegetable Crops
EFFECTS OF NITROGEN FERTIGATION ON GROWTH, YIELD, QUALITY AND LEAF NUTRIENT COMPOSITION OF MELON (CUCUMIS MELO L.) |
| Author: | L. Panagiotopoulos |
| Keywords: | trickle irrigation, fertigation, nitrogen, melon |
| Abstract:
Two field experiments were conducted in southern Greece on a sandy loam soil with 1.2% organic matter and small amounts of residual nitrogen, to study the effects of nitrogen applied with the trickle irrigation system on 'Dichty' melon (Cucumis melo L.). In 1991, two different watering regimes, namely 'wet' and 'dry', were applied to the main plots of a split-plot experiment, with 80, 160 and 240 mg l-1 N applied by trickle fertigation to the subplots. In the irrigation treatments, water was applied to return the soil to field capacity whenever water depletion reached 8 mm and 30 mm in the 'wet' and 'dry' treatments, respectively. In 1992, concentrations of 50, 125 and 200 mg l-1 N were applied in a factorial combination with 100 and 200 mg l-1 K2O in the irrigation water. In 1991, no significant differences between treatments were detected in stem diameter. Irrigation treatments and nitrogen and potassium levels did not alter significantly the fruit yields produced from the first flush of fruit set in both years. Soluble solids content of fruit juice were not affected significantly by the nitrogen and irrigation treatments. Fertigation with 100 mg l-1 K2O was sufficient to produce soluble solids above 12.0 %. In 1992, mineral nitrogen in the root zone increased significantly from 17 mg kg-1 NO3-N in the low N treatment to 50 NO3-N mg kg-1 in the highest N treatment, at fruit swelling. In both years, nitrogen concentration of the recently matured leaves at the initial fruit stage reached high levels ranging between 5.0 and 5.3% in 1991 and 4.8-4.9% in 1992, while decreasing to 2.5-3.6% at harvest time. The same trend was found for leaf P, K and Mg, but the opposite trend for Ca. Petiole NO3-N at fruit set ranged between 19,800 and 20,100 mg l-1, in 1992. | |
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