Nitrogen Treatments for Greenhouse Galia Muskmelon (Cucumis melo L.) Grown in Soilless Media

Galia muskmelons, produced in Spain, Turkey, Morocco and Israel and exported to Europe, have been a high priced staple in Europe for 25 years. Extensive research has been carried out on the nitrogen requirements for growing Galia melons in soil and protected culture systems, but very little research has been conducted for growing Galia under soilless culture in the greenhouse. Galia melon production in soil relies on the technique of alternating nitrogen levels (increasing then decreasing) throughout the season. The present experiment evaluated yield and fruit quality from plants grown at 4 different nitrogen levels (120 ppm, 160 ppm, and 200 ppm) supplied continuously throughout the growing season each time the plants were irrigated and the standard recommended practice of altering N at 120 ppm (14 days; from transplant), 200 ppm N (60 days; vegetative stage to fruit maturation), and a reduction to 160 ppm N (45 days; maturation to harvest) during the growing season. Plants were grown in polyethylene bags filled with a medium grade of perlite (3 plants per bag). Early and total yields as fruit per plant and fruit quality (as soluble solids) were similar regardless of N treatment. Total fruit weight per plant was greater in the 200 ppm treatment than those from the other three N treatments. Using a constant fertility level (120, 160 or 200 ppm N) may be a more favorable type of system for growing Galia melons in soilless media, instead of the standard recommended practice of alternating N throughout the season, by eliminating changes in management practices during the growing season.

Means of early yield (Oct. 15-Nov. 19) for fruit yield and fruit quality of Galia melon grown in soilless protected culture with 4 different nitrogen treatments (Fall 2000).

Treatment Number of fruits/plant Total fruit wt./plant (kg/plant) Weight per fruit (kg) Width (mm) Length (mm) Soluble solids

120 ppm N 0.52 0.72 1.38 137.8 145.8 9.7
160 ppm N 0.45 0.57 1.25 135.0 140.3 10.3
200 ppm N 0.59 0.84 1.48 133.0 140.3 10.8
120-200-1601 0.40 0.52 1.30 130.8 148.8 10.8
Nitrogen NS NS NS NS NS NS
LSD (5%) - - - - - -

 

Means for entire season of total marketable yields for Galia melon grown in soilless protected culture with 4 different nitrogen treatments (Fall 2000).

Treatment Number of fruits/plant Total fruit wt./plant (kg/plant) Individual fruit wt./plant (kg) Width (mm) Length (mm)

120 ppm N 1.02 1.51 1.48 137.0 148.5
160 ppm N 1.13 1.60 1.43 134.3 147.5
200 ppm N 1.50 2.23* 1.50 137.0 149.8
120-200-1601 0.90 1.26 1.40 136.0 148.5
Nitrogen NS * NS NS NS
LSD (5%) - 0.512 - - -

 

Percentages of total fruit per plant for Galia melon grown in soilless protected culture with 4 different nitrogen treatments (Fall 2000).

% of plants
Treatment 1 fruit 2 fruits 3 fruits 4 fruits 5 fruits 0 fruits

120 ppm N 42.8 18.3 5.8 1.5 3.0 32.0
160 ppm N 39.0 26.5 7.0 0.0 0.0 27.5
200 ppm N 36.0 20.8 15.3* 3.0 0.0 22.3
120-200-1601 43.0 19.5 3.0 0.0 0.0 34.5
Nitrogen NS NS * NS * NS
LSD (5%) - - 6.765 - 2.770 -

1120-200-160 is the combination of 3 nitrogen concentrations by lowering and decreasing throughout the season (standard recommended practice).