WATERMELON CULTURAL PRACTICES

Scientific name: Citrullus lanatus

Telugu name: Puchakaya

Introduction:

        Watermelon belongs to the family Cucurbitaceae (gourd family) which includes pumpkin, squash and cucumber. It is a warm weather crop. Watermelons vary in shape; from globular to oblong. External rind colour varies from light to dark green and may be solid, striped or marbled. The pulp colour of most commercial varieties is red. The fruit is generally eaten raw. Fruit size varies from 2-15kgs depending on variety. 

     Watermelon has very high-water content (93ml/100g edible portion). It contains carbohydrates (5mg), calcium (8mg), phosphorous (9 mg), ascorbic acid (8 mg) and vitamins (0.64 g) per 100 g of edible portion. Water melon can be successfully grown in fields, greenhouse and poly houses. Farmers can make good profits from cultivation of watermelon, if proper cultivation methods and farm management practices are followed.

Climate:

• Watermelon belongs to the warm season crop and common in tropical and sub-tropical areas.
• Abundant sunshine is essential.
• Dry weather and long day suits to the cultivation.
• Excessive humid condition is harmful as it can cause disease like viruses, insects and mildew.
• At least 20°C temperature is required at the stage of germination.
• Temperature for early growth: 25-30°C
• During fruit development: 30-35°C

Soil:

• Soil for the cultivation of watermelon should be fertile. Sandy or sandy loam soil is preferred for the cultivation of watermelon.
• Soil pH: 6-7.
• Soil of poor drainage does not suit the cultivation of Watermelon.

Field preparation: 

     Prepare the land by clearing all the vegetation covers and plant debris. Avoid using same field which other cucurbits were planted. A fine tilth is required for the cultivation. Normally seeds are directly applied in the farm. It can also be seeded in nurseries or greenhouses (to prevent frosts). 

Seed rate:

Seed rate ranges from 3.5-5.0 Kg per hectare.

Seed spacing:

There are different systems of sowing seeds depending on the season and system of cultivation.

• Furrow method: 2-3m apart
• Pit method: 2-3.5m apart
• Hill method: 1-1.5m apart

Varieties:

• Sugar Baby: Weight of each fruit 3-5 Kg,Deep pink flesh,Small seeds.
• Improved shipper: Dark green outer skin,Average in sweetness,Large in size.
• Special No.1: Red colored flesh,Early maturity feature,Small in size.
• Arka Manik: Very sweet in taste, Deep red flesh,Oval-shaped fruit.

Nursery management:

Select seeds of high yielding variety. Watermelon seeds need special care during germination, as the embryo is enclosed in hard seed coat. Temperature and moisture control is important to success, and too much moisture during germination can kill the seed. Direct seedling in the garden has very low success because outside climate is difficult to control or predict. Therefore, seedling has to be raised under protected condition.

      For one acre of land about 1500 watermelon seeds are required. In one acre of land about 1300 seedlings density are required. Seeds in group of 2-3 are sown 2-4 cm deep in container (Poly pot); seedlings are later thinned to 1 per pot and later transplanted when 10-14 cm height. Watermelon seed germinate in about 7-8 days. Seedlings must be transplanted and watered as soon as possible after they have been obtained from the nursery. Seedlings should be kept cool and moist in shade before transplanting. Nursery seeding is done during first week February and transplanted in mid March through early April. The crop can be harvested between first week of June and early July.

Transplanting/planting:

For seedling transplants; dig holes of 30cm wide, 30cm length and 10cm deep (do not plant too deep). Use of transplants not only reduces seed cost but also ensure 100% seedling density. After transplanting keep the soil moist. It is best to have a watering schedule because the fruits become stressed when pattern changes and this affects the fruit development and the spray program. When transplanting, remove the seedlings from the plastic pots with the soil without damaging the roots. It is recommended to irrigate the nursery seedlings a day before actual transplanting.

Irrigation:

• Watermelon requires less repeated irrigation as it has deep tap roots.
• 10-14 days of interval in irrigation is needed.
• Fruit cracking can occur on excessive irrigation.
• Irrigation in the evening and at night should be avoided to protect crop from foliar diseases.

Varieties:

There are many varieties of watermelon. Some of them are mentioned below:

Sugar Baby: Weight of each fruit 3-5 Kg, Deep pink flesh, Small seeds.

Improved shipper: Dark green outer skin, Average in sweetness, Large in size.

Special No.1: Red colored flesh, Early maturity feature, Small in size.

Arka Manik: Very sweet in taste, Deep red flesh,Oval-shaped fruit.

Weeding:

Weeding is important during the seedling stage, as young plants are very sensitive to weed growth which competes with water, nutrients and sunlight. Therefore, three to four hands weeding cum earthing up may be necessary depending upon the weed pressure. While doing hand weeding, care must be taken to avoid damage to the roots. A weed free condition is necessary till the plants have reached the root or bulb formation stage. Watermelon vines should be mulched to keep down the weeds and conserve moisture, but the mulch should not be applied until the soil is thoroughly warm in the initial stage. Straw, sawdust, crop residues are the best mulching materials.

Nutrient Management:

Watermelon require a lot of  Nitrogen,Phosphorous,Potassium.They should be fertilized every 2-3 weeks with Balanced fertilizer. Required quantity of fertilizers for N:P:K is 100:60:60 kg/ha. During the time of land preparation, 25 tones of FYM should be applied in field.

Harvesting:

• Harvesting can take place after 95-120 days from the time of sowing.
• It is harvested when the fruit is fully matured.
• Maturity of watermelon can be seen when the rind becomes hard and cannot be separated with the help of thumbnail.

Yield:

Yield of watermelon ranges from 150-220 quintals per hectare (depending upon the climatic conditions and variety).

Storage:

• Watermelon requires to be cooled in temperature of 12-15°C within 24 hours of harvesting in case of long period of storage.
• Watermelon can be stored up to two weeks if they are in the atmosphere of 7°C and relative humidity.

Long period of storage can cause lose of crispiness and color.