How to grow Cucurbitaceae melon seedlings? Detailed explanation of spraying, watering during the seedling stage, and fruiting time
Melon is also known as gangua, xiangua, Hami melon, bailan melon, and Wallace melon, and is widely cultivated throughout China. It is also widely cultivated in temperate to tropical regions of the world.So how do you grow melon seedlings? What pesticide is sprayed during the seedling stage? When should you water? How long after flowering does it set fruit? According to Mr. He, a melon grower in Shandong, 3--4 days after the xiangua flowers, the melon platform shows new growth and increases in size, with the melon platform doubling in size. Thin-skinned xiangua matures in 25---30 days, while some thick-skinned xiangua varieties can take more than 40 days to mature.
How do you grow melon seedlings?
1. Melons grown in greenhouses should use the method of growing seedlings and transplanting. You can use conventional nutrient soil for growing seedlings, or use plug trays. The nutrient soil is prepared by mixing poultry and livestock manure (already decomposed) with furnace ash and slag at a ratio of 2:3, stirring evenly and crushing it, making sure there are no clumps, preferably sifting it, and then disinfecting the nutrient soil with a fungicide. You can use drugs such as carbendazim according to the instructions for the mixing ratio. Nutrient soil after disinfection treatment can greatly prevent the occurrence of downy mildew and damping-off disease.
2. Two days before sowing, expose the seeds to sunlight for 1-2 days, then scald and wash them with 50°C warm water, stirring slowly for 15-20 minutes. After cooling, soak the seeds in a 200-fold potassium permanganate solution for 20-30 minutes, then wash off the residual chemicals on the seeds. Wrap them in a damp cloth once each morning and evening, and keep them at 28-30°C for budding and sprouting until white appears. Once sprouted, they can be sown.
3. Before sowing, water the seedbed thoroughly with bottom water, cover with 1.5cm of soil, place on the seedbed, then cover with plastic film and arch up a greenhouse. Under normal conditions, seedlings emerge in 5 days. When the emergence rate reaches 70%, the plastic film should be uncovered to lower the temperature and ensure the seedlings receive sufficient sunlight, ensuring strong and good growth.
4. During the 4-5 days after the seedlings emerge completely, carry out hardening. Keep the daytime temperature at 20-25°C, and lower the nighttime temperature to 8-10°C. Uncover the film early and cover it late, promptly remove dust on the film, and extend the light duration and intensity,
5. During the 7-10 days before planting, prevent and control the occurrence of damping-off and Rhizoctonia rot during the seedling stage. If found, pull them out immediately and promptly spray pesticides for treatment. You can use a 400-fold copper-ammonium mixture solution (copper-ammonium ratio = 2:11) or a 300-fold thiophanate-methyl solution for root drenching.
6. After sowing and before emergence, use high temperature to promote early emergence. The suitable temperature is between 22°C-26°C. At this time, note that no watering is needed for 4-5 days to avoid spindly growth, and 7 days before planting, carry out low-temperature hardening treatment so they adapt to open-field climate conditions.
What pesticide is sprayed during the melon seedling stage?
1. Strengthen seedbed management
(1) Choose a sunny plot with higher terrain and good drainage as the seedbed.
(2) Use disease-free new soil for the bed soil, and the fertilizer must be decomposed. If using an old bed, it should be disinfected.
(3) Sowing should not be too dense, and the soil cover should not be too thick, to facilitate emergence.
(4) Do a good job of keeping the seedbed warm, ventilate appropriately, do not water on cloudy and rainy days, and keep the seedbed neither dry nor wet.
2. Bed soil disinfection
(1) Formalin: 2-3 weeks before sowing, rake the bed soil loose, use 1.5mL per square meter, add an appropriate amount of water and pour it on the bed surface, cover with plastic film for 4-5d, then uncover the film and rake the bed soil loose so the solution fully volatilizes. Sow only after two weeks.
(2) Quintozene: Mix 70% quintozene with an equal amount of zineb, use 10g of the mixed powder per square meter, or 10g of 32% miaojundi wettable powder, mix with 10-15kg of dry fine soil, drench the seedbed thoroughly with water, spread about 1/3 of the prepared medicated soil on the seedbed, and reserve the remaining 2/3 to cover on top after the seeds are sown.
3. Seed disinfection
Soak the seeds in 50-55°C warm water for 10-15min, or use 50% thiram wettable powder, or 65% zineb wettable powder, at 0.3% of seed weight for seed dressing disinfection, killing pathogens carried inside and outside the seeds.
4. Chemical control
If a small number of diseased seedlings have been found in the seedbed, after pulling out the diseased seedlings, you can use 72.2% propamocarb aqueous solution at 600-fold dilution, 72% propamocarb aqueous solution at 600-fold dilution, 15% lüheng No. 1 at 600-fold dilution, 30% miaojundi, 15% hymexazol (hymexazol) aqueous solution and other pesticides, spraying once every 7-10d, for 1-2 treatments. If the seedbed humidity is relatively high, a small amount of plant ash or dry fine soil can be scattered to adjust it.
When should melons be watered?
1. Ensure watering in the greenhouse is done on sunny days, and make sure the 2-3 days after the watering day are sunny weather, avoiding continuous cloudy days, strong winds, rainstorms and other severe weather after watering, which would increase humidity in the greenhouse and lower the ground temperature. In the first 2 days after a sudden clearing following many consecutive rainy days, watering is also not suitable. You should first raise the greenhouse temperature and ground temperature, so that the plants basically return to normal growth before watering.
It is best to choose to water in the morning on a sunny day, preferably around 10:00. At this time, the water temperature and ground temperature are relatively close. After watering, the roots are less stimulated, and at the same time the ground temperature recovers quickly, allowing enough time to remove moisture from the greenhouse. If watering after noon, the temperature difference between the ground temperature and water temperature is greatest at this time. After watering, the ground temperature will change abruptly, affecting the growth and development of the root system. Never water in the early morning or evening, to prevent too great a difference between the water temperature and the greenhouse temperature, causing root damage. According to measurements, when the difference between water temperature and greenhouse air temperature reaches more than 5°C, root damage is likely to occur, and plant roots should be protected from damage.
2. Under early spring low-temperature conditions, greenhouse melons have relatively low water demand. When watering, follow the principle of not watering if not lacking, and preferring dry over wet, keeping the soil moisture in the melon root zone at about 60%. Therefore, the amount of watering should be small rather than large, and the interval between two waterings should be appropriately extended. Do not use flood irrigation. It is best to use small amounts of frequent watering, or use a watering can to spot-water each plant, which can effectively prevent a significant drop in greenhouse temperature and a significant increase in humidity, and avoid root rot or epidemic diseases in greenhouse melons caused by low temperature and high humidity.
After watering, promptly raise the temperature and reduce humidity. On the day of watering, in order to restore the ground temperature as quickly as possible, keep the greenhouse closed so the temperature inside rises rapidly, using air temperature to promote ground temperature. After the ground temperature rises, ventilate appropriately to remove moisture, bringing indoor air humidity down to a suitable range, which is conducive to healthy plant growth. Ventilation is best carried out near noon when the temperature is relatively high.