How to determine the watermelon seedling-raising period? A detailed explanation of the judgment methods

(Agricultural Wealth Network) 1. For direct sowing or transplanting of watermelon under plastic film mulching cultivation, the time is when the soil temperature at a depth of 10 cm steadily passes 15°C and the daily average temperature steadily passes 18°C. The sowing time is 25 to 30 days earlier than transplanting. The seedling-raising and sowing times for single-layer greenhouses, greenhouses plus small arched tunnels, and greenhouses plus small arched tunnels plus straw mat protected ground are respectively 40 days, 50 days, and 60 days earlier than seedling raising under plastic film mulching. 2. Determine the sowing period according to the weather forecast, especially the 1-week weather forecast, which is very important. For seedbeds without heating facilities, sowing should be chosen when there is about 1 week of clear and good weather; for seedbeds with heating conditions, choosing a sunny day for the best emergence is advisable.