Tropical and subtropical vegetables (2+1)

Preparation of field

• Land should be thoroughly prepared to get fine tilth for seed bed.

Sowing
Watermelon is a seed propagated crop and insitu sowing is practised. In some cases where early crop is desired seeds can be sown in polyethylene bags (10X15 cm) of 100-200 gauge and germinated under cover to protect them from low temperature and then could be transplanted at 2 true leaf stage. The recommended seed rate for watermelon is 750-1125 g/ha.
Various system of sowing are followed, such as furrow, bed, pit (deep or shallow) and mounds. In case of furrow sowing the furrows are made at 2.5 to 3 meter and sowing is done at 1 metre spacing between plant to plant. The other methods of sowing are described under muskmelon.The seeds of watermelon should be soaked in water overnight and then should be kept in moist cloth or gunny bag near a warm place before planting. Germination would start within 3 to4 days. Soaking of seeds in ethephon at 480 mg/litre for 24 hrs improves the germination. Seed dressing with Thiram controlled fungi effectively and also enhanced seed germination.

Training and pruning
Yield and fruit quality are improred with pruning in watermelon. Retaining 3-4 main shoots per plant and keeping 30cm between two hills give highest yield.

Nutrition

Watermelon responds well to manuring. The quantity of ferlizers depends upon the availability of nutrients present in the soil.

Fertilizer recommendations for various states of India.

States	N (kg/ha)	P (kg/ha)	K (kg/ha)
Punjab	62	40	40
Haryana	50	25	25
Karnataka	100	88	100
Madhya Pradesh	100	50	50
Tamil Nadu	55	55	55
Rajasthan	80	40	40
Assam	68	68	130

Irrigation
• Frequent irrigation is very important in summer to spring crop, while in rainy season crop, irrigation may not be necessary at all. If rainfall in well distributed between July-September. Other aspects of irrigation requirements are discussed under musk melon.

Weeding
• At the time of top dressing with nitrogenous fertilizers, weeding and earthing up are done when the vines start spreading; weeding in between the rows or ridges becomes unnecessary since vine growth can smother the weeds. For successful growing of watermelon, plots kept tree from weeds. During early stage of crops, beds, ridges etc need to be kept free from weeds.

Use of Growth regulators
• In watermelon to increase the fruiting and the fruit yield exogenous application of chemicals such as TIBA (25-250 PPM), boron (3-4ppm), Molybdenum (3-4 ppm) and calcium (20-25PPM) is recommended. These chemicals/plant growth regulators must be applied at 2-true leaf stage, repeat the spray at 4- true leaf stage. Foliar spray of GA at 25-50 ppm, ethrel 500 ppm, MH 100 ppm and NAA 200 ppm increases fruit yield.