The Latest Watermelon Cultivation Techniques and Methods Tutorial

Watermelon is a major summer fruit for beating the heat, with crisp and tender flesh, sweet and juicy, containing rich mineral salts and various vitamins, and is the largest fruit sold in China in summer and autumn. To improve yield and quality, the watermelon cultivation techniques are introduced as follows:

Biological characteristics

1. Morphological characteristics

① Root: The root of watermelon is a deep root system, with the main root reaching more than 1 m deep, lateral roots extending horizontally up to 4-6 m, and the main root mass distributed within the 10-40 cm soil layer, with strong ability to absorb fertilizer and water. The regeneration ability of the roots is weak, and it is not easy to recover after injury, so direct sowing is often used in production; if raising seedlings for transplanting, be sure to pay attention to protecting the roots.

② Stem and leaves: The watermelon stem is also called the vine. The main vine grows upright before 5-6 leaves, and when it continues to grow to a certain length beyond 30 cm, because the mechanical tissue is not well developed and cannot support its own weight, it grows prostrate on the ground. The branching ability of the stem is very strong, and it can sprout 3-4 levels of lateral branches, but the lateral branches sent out from the leaf axils of the 3rd-5th leaves of the main vine are relatively robust. Adventitious roots are very easily produced at the stem nodes of watermelon. By adopting the method of pressing the vine, the formation of adventitious roots can be promoted, the absorption area increased, the plant fixed, and the vine prevented from rolling. The leaves are alternate, with types such as deeply lobed, shallowly lobed and entire.

③ Flowers, fruits, seeds: Watermelon flowers are small and yellow, monoecious with unisexual flowers, borne singly in leaf axils. Early-maturing varieties bear the first female flower at the 6th and 7th nodes of the main vine, while mid- and late-maturing varieties produce the first female flower after the 10th node. The interval between female flowers is 7-9 nodes. A few bisexual flowers may appear during the peak flowering period, and the flowers open in the early morning and close in the afternoon. The fruit is oval or spherical, and the color may be dark green, light green, or with dark green stripes or markings. The flesh may be red, yellow, white, etc. The seeds may be black, white, or red, etc. Watermelons can also be divided according to seed size into large-seeded watermelons, small-seeded watermelons and seedless watermelons, with a 1000-seed weight of 100 g-150 g for the large-seeded type, 40 g-60 g for the medium-seeded type, and 20 g-25 g for the small-seeded type.

2. Growth cycle

The whole growth period can be divided into four stages: the germination stage, the seedling stage, the vine-running stage and the fruiting stage.

① Germination stage: From seed germination to cotyledon unfolding and true leaf emergence is the germination stage. After the seedlings emerge, excessive growth should be prevented in order to promote the development of roots and leaves.

② Seedling stage: From the emergence of true leaves to 5-6 leaves is the seedling stage. The growth amount in this period is small, and good conditions should be provided in cultivation to promote the differentiation of the seedling root system and organs.

③ Vine-running stage: From the beginning of vine running at 5-6 leaves to the opening of the female flower at the fruit-setting node is the vine-running stage. The growth speed in this period is fast and the growth amount is large. In cultivation, it is necessary to promote stem and leaf growth to form a certain vegetative body system, and at the same time control excessive growth to ensure the formation of floral organs.

④ Fruiting stage: From the opening of the female flower at the fruit-setting node to the beginning of vigorous fruit growth. It can further be divided into 3 periods: the fruit-setting period, the vigorous fruit growth period, and the flesh-changing period.

⑤ Fruit-setting period: From the opening of the female flower at the fruit-setting node to the beginning of vigorous fruit growth. Photosynthetic products begin to be transported into the fruit. In cultivation, the main task is to regulate the balance between vegetative growth and fruit development to ensure fruit set.

⑥ Vigorous fruit growth period: From rapid fruit growth to the point when fruit size is basically fixed. In this period the fruit grows greatly and absorbs the most nutrients, and it is the key period for yield formation. In cultivation, heavy fertilizer and heavy water should be applied to promote rapid fruit growth.

⑦ Flesh-changing period: From the point when fruit size is basically fixed to the mature stage. In this period sugar is rapidly transformed, and the appearance takes on the inherent color of the variety. In cultivation, premature senescence of stems and leaves should be prevented to ensure yield and quality.

3. Requirements for environmental conditions

① Temperature: Watermelon likes a warm, dry climate and is not cold-tolerant. The optimum temperature for growth and development is 24-30°C, the optimum temperature for root growth and development is 30-32°C, and the minimum temperature for root hair occurrence is 14°C. During growth and development, watermelon needs a relatively large diurnal temperature difference, and a relatively large diurnal temperature difference can produce high-quality watermelons.

② Moisture: Watermelon is drought-tolerant and not moisture-tolerant. When there are many rainy days, humidity is too high, it is susceptible to disease, yield is low, and quality is poor.

③ Light: Watermelon likes light. Under conditions of sufficient sunshine, yield is high and quality is good.

④ Nutrients: Watermelon has a long growth period and high yield, so it requires large amounts of nutrients. For every 100 kg of watermelon produced, about 0.19 kg of nitrogen, 0.092 kg of phosphorus, and 0.136 kg of potassium need to be absorbed. However, there are obvious differences in nutrient uptake at different growth stages: 0.01% at the germination stage, 0.54% at the seedling stage, 14.6% at the vine-running stage, and the fruiting stage is the period of most vigorous nutrient uptake by watermelon, accounting for 84.8% of the total nutrient amount. Therefore, as the plant grows, the fertilizer requirement of watermelon gradually increases, reaching its maximum when the fruit grows vigorously.

⑤ Soil: Watermelon has strong adaptability, and sandy soil with loose texture, deep soil layer and good drainage is best. It likes weak acidity, pH 5-7.