How to grow seedless watermelon?

Watermelon is a very popular fruit , known as the "king of fruits", and has the highest water content of all fruits. There are many varieties of watermelon, and seedless watermelon has been very popular in recent years. So how are seedless watermelons grown? Let’s learn more about it below.

How to grow seedless watermelon?

Seedless watermelon is obtained by artificially inducing polyploidy. For example, the seeds or seedlings of diploid watermelon are treated with colchicine (a plant alkaloid) to hinder the formation of spindle fibers and primary walls in the metaphase of cell division, so that the replicated chromosome sets cannot separate to the two poles and form a secondary wall in the middle. As a result, cells with doubled chromosome sets are formed, and tetraploid watermelon plants are obtained. Then they are hybridized with diploid watermelon plants to obtain triploid seeds, that is, seedless watermelon seeds . The watermelons cultivated with triploid watermelon seeds are seedless watermelons.

Cultivation technology of seedless watermelon

1. Seed cultivation

Seedless watermelons are grown using the method of artificially inducing polyploidy. The seeds of diploid ordinary watermelon are soaked in 0.2-0.4% colchicine liquid for 12-24 hours, or 0.2-0.4% colchicine liquid is dripped on the stem tips of seedlings at 6-7 pm every day for 4 consecutive days. The treated seeds were washed and placed under diffuse light. Using tetraploid watermelon as the mother plant and combining it with diploid pollen can produce triploid watermelon seeds.

2. Seed treatment

Carry out seed selection, pick out tetraploid and diploid as watermelon seeds, and eliminate hybrids and inferior varieties. Then, a few days before soaking the seeds, dry the seeds in the sun for 1 to 2 days. Then put the triploid seeds into 55°C warm water, stir, let the water cool, and soak the seeds for 6 to 8 hours. The seeds are placed at a constant temperature of 33-35℃ for germination, and the buds within 0.5cm long are picked out for sowing.

3. Land preparation and cultivation

Choose a windless and sunny day for planting, plant 500 to 700 plants per mu, and water them after planting. Practice three-vine pruning, and it is best to keep the third female flower on the main vine for fruit setting, and avoid fruit setting at low nodes.

4. Water and fertilizer management

During the seedling stage of seedless watermelon, apply 5 kg of urea per mu to promote seedling growth. During the flowering and fruiting period, generally no watering or fertilizer is applied. When the watermelon is the size of a duck egg , apply fertilizer to make it grow larger once, with 15 to 20 kg of urea and 15 kg of potassium sulfate per mu. Spraying 0.2% potassium dihydrogen phosphate on the leaves in the late growth stage can increase yield and quality.

5. Artificial pollination

Seedless watermelons are pollinated with artificial assistance. Around 8 o'clock in the morning, the male flowers of the pollination variety that are open that day are used to pollinate the female flowers of the seedless watermelon. The earlier the flowering and pollination time, the better, no later than 10 o'clock. One male flower can pollinate 3 to 4 female flowers. Pollination should be even and the action should be gentle to avoid damaging the stigma.

That’s it