How to grow seedless watermelon?

Seedless watermelon is a carefully bred variety that is popular among consumers because it has no seeds and is easy to eat. So how are seedless watermelons grown? Let’s learn more about it below.

Principles of Seedless Watermelon Cultivation

Seedless watermelon is not a naturally occurring variety, but is bred through artificial hybridization and chromosome doubling technology. The steps are as follows:

1. Cultivation of triploid watermelon plants: Select diploid watermelon as the mother plant, use chemical agents such as colchicine to treat its seeds, so as to double the number of chromosomes of the plant after seed germination, and successfully cultivate tetraploid watermelon plants.

2. Hybridization produces triploid watermelon: Tetraploid watermelon plants are hybridized with normal diploid watermelon plants, and the resulting offspring are triploid watermelon plants. Due to abnormal chromosome pairing during meiosis in triploids, the pollen is sterile, resulting in seedless watermelons.

How to grow seedless watermelon

1. Melon field selection

Seedless watermelon can adapt to a wide range of soil conditions, but the most suitable one is sandy loam with loose texture and certain water and fertilizer retention capacity. The melon field should generally be selected on a plot with higher terrain, convenient drainage and irrigation, sufficient sunlight, fertile soil, and no repeated cropping within 3-5 years.

2. Seed treatment

The seed shell of seedless watermelon is thicker and needs to be broken to increase the germination rate. After seed treatment, germination is usually carried out at 32-35℃.

3. Sowing and seedling raising

Use nutrient pots to grow seedlings in a cold bed. Fill the pots with nutrient soil and place them in the seedbed. Water the bottom of the pots sufficiently, wait for them to fully penetrate before sowing the seeds. Then cover them with a 1-cm thick layer of nutrient soil, then cover with ground film and add a small arch shed. When the seedlings are above the soil, the ground film should be removed in time to avoid scalding the tender shoots.

4. Configure pollination

Seedless watermelons are highly sterile when self-pollinated with this variety, so they need to receive pollen from ordinary watermelons to set fruit. Therefore, a certain amount of ordinary watermelons should be interplanted as pollination plants during cultivation. Generally speaking, when planting 3-4 rows of seedless watermelons, one row of ordinary watermelons should be interplanted.

5. Transplant at the right time

When the seedlings have three leaves and one bud, choose a sunny day to transplant them. Compared with ordinary watermelons, seedless watermelon seedlings require higher temperatures for growth and development and are not resistant to low temperatures. Therefore, whether it is double-cover cultivation in a small arch shed or plastic greenhouse cultivation, the planting time is 5-10 days later than that of ordinary watermelons.

In general, seedless watermelons are mainly produced by hybridizing natural diploid watermelons with tetraploid watermelons produced by mutation. The triploid seeds obtained can produce seedless watermelons after proper sowing.