Key Points for Watermelon Cultivation and Management

I. Fertilization Management: Base fertilizer should primarily consist of organic fertilizers, supplemented appropriately with compound fertilizers and micronutrient‑rich fertilizers. When the young melons reach the size of an egg, apply a fruit‑expansion fertilizer according to plant vigor; typically, apply 15–20 kg per 667 m² of a 45% nitrate‑sulfur or potassium sulfate‑based controlled‑release fertilizer. II. Water Management: During the seedling stage, minimize watering—or even withhold it—to encourage the development of a robust root system. Before flowering and fruit set, maintain water restriction to prevent excessive vegetative growth. After fruit set, ensure adequate moisture to promote fruit enlargement and increase yield. In the 7–10 days prior to harvest, avoid watering to allow the fruits to accumulate sugars. When water is limited, irrigate during the cooler hours of early morning or late evening.

Watermelon cultivation period

In northern China, year-round watermelon production still must take into account the market impact of transporting “pumpkins” northward; at present, Hainan Province exerts the greatest influence on the northern market. Watermelon production in Hainan is concentrated in two main seasons: one is autumn sowing with winter harvest, with peak market availability in January; the other is winter sowing with spring harvest, peaking in April. Based on these circumstances, the following outlines the primary cultivation cycles currently employed for watermelons. I. Open-field cultivation 1. Spring crop: This is planted after the last frost, and can be established through seedling transplanting, sprout‑transplanting, or direct seeding. 2. Summer crop: In the Huanghuaihai region, it is sown from late May to early June and harvested in mid- to late August. 3. Autumn crop: In the Huanghuai…