Watermelon

Common name: Watermelon

Scientific Name: Citrullus lanatus

The watermelon is a common summer crop. It is generally grown for its ripe and well mature fruit the fruits are delicious and sweet when ripe.Watermelon rinds, usually a light green or white color, are also edible and contain many hidden nutrients, but most people avoid eating them due to their unappealing flavor. They are sometimes used as a vegetable. A watermelon contains about 6% sugar and 92% water by weight. As with many other fruits, it is a source of vitamin C. Watermelon also contains large amounts of beta carotene.

Production Technology of Watermelon:

Climate: Watermelon needs a long growing season with a relatively high temperature. It cannot withstand frost. The seed does not germinate satisfactorily below 21⁰C.  Dry weather during ripening with high temperature, enough sunshine and dry winds favor the development of flavor and high sugar content. 

Soil and its Preparation: Deep sandy loam soil is best suited for water melon crop. It is generally cultivated on river beds. The optimum soil pH is 5.5 to 7.0. The land is thoroughly prepared by giving 5 to 6 ploughings.

Seed Sowing Time: The seed is generally sown from November to March in the plains and from middle of February to end or March in the hills. The seed is soaked overnight before sowing.

Seed Rate: The seed rate is 3 to 4 kg/ha.

Method of Planting:

 1) Shallow Pit Method: In this method, pits of 60 x 60 x 45 cm. are dug at a distance of 1.5 to 2.5 meter. Each pit is filled with a mixture of soil and 4 to 5 kg of FYM or compost, 30 to 40 gm. Urea, 40 to 50 gm. Single Super phosphate and 80 to 100 gm of muriate of Potash. After filling the pit circular basin are made and five to six seeds are sown per basin at 2 to 3 cm. deep and covered with fine soil, F.Y.M. or compost.

2) Deep Pit Method: This method is followed in case of river bed cultivation. Circular pits of 60 to 75 cm. diameter and 1.0 to 1.5 m. depth are dug at a distance of 1.5 to 2.5 meter distance both ways.

3) Ridge Method:  The seeds are sown on the side of raised beds.

4) Mound Beds: Seeds are sown on the mounds. The seed rate is 1.6 kg per acre. The normal spacing is row to row 300 cm and plant to plant 90 cm. The germination percent and the storage life of seeds can be improved by treating freshly extracted seeds with 2 percent HCl or NaOH. 

Manuring: Apply 30-50 kg Cart loads FYM at the time of soil preparation. 80 kg N, 40 kg P & K is recommended. ¹/₂ dose N, full dose of P and K should be applied at the time sowing. Remaining half Nitrogen applied one month after transplanting.

Intel-cultural Operation: Two or three hoeing may be done during the early stage of growth to keep down the weeds and to conserve soil moisture. Two or three plants are kept at one place in the hills or beds by thinning the extra plant Herbicides (e.g. Chloroxuron and Prometryne @ 3 & 2 kg. a,i. per ha, respectively may be useful for controlling weeds).

Irrigation: The crop is watered by pitcher or water can after sowing.   The Crop is watered sparingly once every seven to ten days.

Harvesting: The plant bears fruits in 4 to 5 months after sowing. The watermelon should be harvested at the proper stage of maturity. The following points give an indication or ripeness:

1)      Withering of Tendrils: The tendril that subtends the peduncle of the fruit, usually wither when the fruits ripes and watermelon is seldom ripe if the tendril is still green. But it may be unripe even if the tendril is dried in some varieties.

2)       Thumping: Ripe fruit, when thumped with the finger, gives out a muffled dull or dead sound, whereas the immature fruits give out a metallic and ringing sound.

3)      Colour of the Ground Spot: It is white when fruits are green and they rest over it. When the fruits are ripe they change to yellow.

4)      Preserve on the Fro it: A ripe melon emits a crisp cracking noise on being pressed with the flat of the hand. Moreover, the rind of a ripe melon yields little under the pressure of the thumb. In some varieties even sunlight pressure will crack the fruit.

If the fruits are allowed to over ripen, the pulp loses the sweetness and soon develops an off flavor and rot. It is, therefore, very necessary that they should be harvested at the full ripe stage, because they ripen very little on their way to the
market.

Yield: The average yield is 200 to 300 quintal/ha.

Special Care for Water Melon: Watermelon plants are very susceptible to Fusarium wilt and cold weather. These problems could be overcome by approach grafting of 15 days old watermelon seedlings on 12 days old bottle gourd seedling using as root stock.

Pests: The important pests are Red Pumpkin Beetle and Epilachna Beetle.

Diseases: Downy Mildew and Powdery Mildew are important diseases affecting water melon.