How to Grow Square Watermelons? A Detailed Guide to the Latest Cultivation Techniques

How to grow square watermelons? Compared with traditional round watermelons, square watermelons are pressed in molds, so their internal tissue is denser, their sweetness is also higher than that of round watermelons, and they also have advantages such as being convenient to transport. In addition, words and patterns of any kind can be written on the watermelon.

Square Watermelon Cultivation Methods

1. Variety selection: For square watermelon cultivation, choose large-fruited, strongly disease-resistant, thick-skinned varieties suited to wide spacing. In our area, varieties such as Xinong No. 8, Xincheng, and Zhengza No. 5 are mainly chosen.

2. Seedling raising methods

① Preparation of nutrient soil: Use 7 parts vegetable garden soil that has not grown melons within 3 years, 1 part fully decomposed human, livestock, and poultry manure, and 2 parts plant ash. For each cubic meter of mixed soil, add 100 grams of 50% carbendazim wettable powder, 3 kilograms of superphosphate, and 500 grams of 3% phoxim granules, and mix thoroughly.

② Seed treatment: Sun-dry the seeds for 1 day, remove deformed, mixed, and shriveled seeds, soak the seeds in a 100-fold formalin solution for 1 hour, then rinse with clean water, rub by hand, wash off the mucilage, then transfer to normal-temperature water and soak for 6-8 hours, stirring once every 3-4 hours, then remove the seeds, air-dry the moisture, spread the seeds on a towel or gauze wrung dry, and cover with another 1-2 layers of gauze to make a germination bed. After 2-3 days, 70%-80% of the seeds germinate. Pick out the sprouted seeds in batches and sow them in batches.

③ Sowing and seedling management: Use nutrient pots for seedling raising. Fill the nutrient pots with nutrient soil, leaving 1-1.5 cm at the top, press lightly, water thoroughly, place the germinated seeds inside, 1 seed per hole, cover with nutrient soil, cover with plastic film, and set up an arched shed. After emergence, remove the plastic film promptly to prevent seedling scorch. Ventilate on sunny days, keep the temperature at 28-32°C, maintain humidity at about 75%, and water preferably in the morning on sunny days, following the principle of neither dry nor wet. Pest and disease control during the seedling stage can be carried out together with watering. Harden the seedlings 1 week before transplanting.

3. Timely transplanting

① Land preparation and fertilization: Choose a field with high terrain, smooth drainage, and shelter from the wind and facing the sun, deep plow, harrow finely, make beds, open fertilizer trenches, and apply per mu 3000 kilograms of decomposed farmyard manure, 25 kilograms of ternary compound fertilizer, 10 kilograms of superphosphate, and 50 kilograms of decomposed rapeseed cake as base fertilizer, then make beds 3 meters wide.

② Transplanting: Seedlings can be transplanted when they grow to 2 true leaves and 1 heart leaf. Single-row transplanting should be used, with a plant spacing and row spacing of 3 m × 0.4 m. Water thoroughly to settle the roots, and at the same time add a certain amount of fungicide.

Field Management of Square Watermelons

1. Timely topdressing: Inspect seedlings and replant missing ones. Replanted watermelon seedlings should preferably be close in age to the field seedlings, and attention should be paid to controlling underground pests such as cutworms and root maggots. When the vines grow to 30 cm, apply fruit-setting fertilizer before vine pressing, with 10 kilograms of urea, 5 kilograms of ternary compound fertilizer, and 50 kilograms of rapeseed cake per mu.

2. Pruning and vine pressing: Use two-vine pruning, that is, keep the main vine and the vigorous side vine growing from the base of the main vine, and retain the fruit on the main vine. Generally carry out 3-5 vine pressings, and stop vine pressing after the fruit sets firmly.

3. Water management: Promote growth during the vine extension stage and fruit swelling stage, and control water during the flowering and fruit-setting stage.

4. Fruit retention and mold placement: Artificial pollination can be carried out. Select and retain the fruit on the 2nd and 3rd female flowers at the 12th-20th nodes on the main vine. If fruit cannot set on the main vine, select and retain fruit on the 2nd and 3rd female flowers on a backup side vine. When the fruit grows to the size of a fist, mold placement can be carried out. The mold is a square glass container, 40 cm long and 25 cm wide, and its size can be adjusted. Under the pressure of the mold, after the watermelon becomes square, appropriately widen the mold again. Carry out this 2-3 times, and a square watermelon with uniform color and regular shape can be grown. Remove the mold when the watermelon is 70% ripe, and harvest when it is 80% ripe.

5. Pest and disease control: Thiophanate-methyl and carbendazim can be used to control anthracnose, fusarium head blight, and powdery mildew; Xiaobingling can be used to control fusarium wilt; and Yisaoguang and decamethrin can be used to control aphids.