Planting techniques of watermelon

Watermelon is the main summer fruit in summer, the flesh is crisp and tender, sweet and juicy, rich in mineral salts and a variety of vitamins, is the largest fruit sold in summer and autumn in China. In order to improve the yield and quality, the cultivation techniques of watermelon are introduced as follows:

Biological characteristics

1. Morphological characteristics.

① root: the root of watermelon belongs to deep root, the main root is more than 1 meter deep, and the lateral root extends 4-6 meters laterally. The main root group is distributed in 10-40 cm soil layer and has strong ability to absorb fertilizer and water. The ability of root regeneration is weak, and it is not easy to recover after injury. Direct seeding is often used in production. If seedlings are transplanted, we must pay attention to the protection of roots.

② stem, leaf: watermelon stem, also known as vine, the main vine grows upright in front of 5-6 leaves, and when it grows more than 30 cm to a certain length, it grows on the ground because the mechanical tissue is underdeveloped and cannot support its own weight. The branching ability of the stem is very strong, and it can germinate 3-4 grade lateral branches, but the lateral branches from 3-5 leaf axils of the main vine are more strong. Adventitious roots are easily produced on the stem nodes of watermelons. The method of pressing vines can promote the formation of adventitious roots, increase the absorption area, fix plants and prevent seedling rolling. The leaves are alternate, and there are deep, lobed, entire and other types.

③ flowers, fruits, seeds: watermelon flowers small yellow, monoecious, solitary in leaf axils. The early-maturing varieties gave birth to the first female flower at the sixth and seventh nodes of the main vine, while the middle and late-maturing varieties produced the first female flower after the tenth section. The number of internodes of female flowers is 7-9 nodes. A small number of bisexual flowers can appear in the peak flowering period, and the flowers open in the morning and close in the afternoon. The fruit is oval, spherical, dark green, light green, or with black-green stripes or markings. The flesh of melon is red, yellow, white and so on. The seeds are black, white, or red. Watermelon can also be divided into big-seed watermelon, small-seed watermelon and seedless watermelon according to the size of its seeds. the 1000-seed type is 100g ~ 150g, the medium seed type is 40g ~ 60g, and the small seed type is 20g ~ 25g.

2. Birth cycle

The whole growth period can be divided into four stages: germination stage, seedling stage, vine stage and fruit stage.

① germination stage: from seed germination to cotyledon expansion, true leaf exposure is the germination stage. After the seedlings are unearthed, it is necessary to prevent overgrowth in order to promote the development of roots and leaves.

② seedling stage: from true leaves to 5-6 leaves are seedling stage. The growth in this period is small, and good conditions should be given in cultivation to promote the differentiation of seedling roots and organs.

③ trailing stage: from the beginning of 5-6 leaves to the opening of female flowers with melon nodes. In this period, the growth rate is fast and the growth rate is large. In cultivation, it is necessary to promote the growth of stems and leaves and form certain nutrients. at the same time, it is necessary to control overgrowth and ensure the formation of flower organs.

④ fruiting stage: from the flowering node of the female flower to the exuberant growth of the fruit. It can be divided into three periods: fruit setting period, fruit growth peak period and fruit changing period.

⑤ fruit setting period: from the opening of female flowers to the beginning of exuberant fruit growth. Photosynthate begins to be fed into the fruit. In cultivation, it mainly regulates the balance between vegetative growth and fruit development to ensure melon setting.

The vigorous growth period of ⑥ fruit: from the rapid growth of the fruit to the time when the size of the fruit is basically fixed. In this period, the fruit has a large growth and absorbs the most nutrients, which is the key period for the formation of yield. Large fertilizer and water should be given in cultivation to promote the rapid growth of fruit.

⑦ ripening period: the fruit size is basically fixed to the mature stage. In this period, the sugar content is transformed rapidly, and the appearance has the inherent color of the variety. In cultivation, premature senescence of stems and leaves should be prevented in order to ensure yield and quality.

3. Requirements for environmental conditions

① temperature: watermelon likes warm, dry climate, not cold-resistant, the optimum temperature for growth and development of watermelon is 24-30 degrees, the optimum temperature for root growth and development is 30-32 degrees, and the lowest temperature for root hair generation is 14 degrees. Watermelon needs a large day-night temperature difference in the process of growth and development, and a large day-night temperature difference can cultivate high-quality watermelon.

② moisture: watermelon is drought-tolerant, not moisture-tolerant, overcast and rainy days, excessive humidity, susceptible to disease, low yield and poor quality.

③ light: watermelon likes light. Under the condition of sufficient sunshine, the yield is high and the quality is good.

④ nutrients: watermelon has a long growth period and high yield, so it needs a lot of nutrients. Every 100kg watermelon needs to absorb 0.19kg of nitrogen, 0.092 kg of phosphorus and 0.136 kg of potassium. However, there are obvious differences in the amount of nutrients absorbed by different growth stages, accounting for 0.01% in the germination stage, 0.54% in the seedling stage and 14.6% in the vine stage. The fruiting period is the most vigorous period for watermelon to absorb nutrients, accounting for 84.8% of the total nutrient content. Therefore, with the growth of the plant, the fertilizer requirement of watermelon gradually increased, and reached the maximum value when the fruit grew vigorously.

⑤ soil: watermelon has strong adaptability, and the sandy soil with loose soil, deep soil layer and good drainage is the best. Like weak acid, PH5-7.

Suitable sowing time

The open field cultivation of watermelon is the cultivation without protective equipment. Generally speaking, the local final frost has passed, and the suitable time for sowing in the open field is when the ground temperature is stable at about 15 ℃. The best time for sowing should also be determined according to the variety, cultivation season, cultivation mode and consumption season. Generally sowing and raising seedlings in mid-and late-March, planting in mid-and late-April, harvesting and listing in late June; sowing in the first and middle of July and harvesting in late September.

Apply sufficient base fertilizer for soil preparation