In order to overcome the difficulties of watermelon rotation and enhance watermelon resistance to wilt disease, agricultural technicians and melon farmers of Qingyuan County, Hebei Province, after years of continuous practice and practice, have summed up grafting techniques suitable for watermelons in early spring greenhouses. The technology has certain guidance and reference value for the grafting cultivation of watermelon in Hebei province, especially in Baoding city. The main technical measures are as follows.
I. Variety selection
There are many varieties used for grafting rootstocks of watermelons. According to grafting affinity, disease resistance and quality traits, the order of goodness and inferiority are pod melons, pumpkins and melons, and there are great differences among different varieties or varieties within the same species. After many years of practice, we believe that the local farm varieties gourd is ideal for watermelon rootstocks, of which the largest calabash gourd is the best. Sowing time is mid-January. The scion is Jingxin No. 1 series variety, Jinzhong Guanlong, Zhengza No. 7 and so on.
Second, the preparation of nutritious soil
Six fertile soils containing no disease-free bacteria, no eggs, and no weed seeds without cucurbitaceae vegetables were mixed with 4 parts of fully decomposed organic fertilizer, and nitrogen, phosphorus, and potassium were added to each cubic meter of soil. % compound fertilizer 1.5 kg, 200 grams of carbendazim, 200 grams of trichlorfon, the fertilizer, soil smashed after screening and chemical fertilizers, pesticides mixed evenly, sealed with plastic film 10 days of decomposition and sterilization. After disinfection, it shall be packed in a plastic nutrient bowl or plastic bucket with a height of 10 cm and a diameter of 10 cm above the mouth, depending on the cultivated variety. Such as the cultivation of Jing Xin No. 1 and other early varieties with 850 to 1000.
Third, seed processing
Select good weather, the selected rootstock (cucurbit) seeds drying 3 to 4 days, 250 ~ 500 grams of acres. Slowly pour the seeds into 55°C warm water (two portions of boiled water on a portion of cold water) and stir while stirring. When the water temperature drops to 20°C, stop stirring and continue soaking for 12 to 14 hours. Repeatedly rub the seeds, then soak for 12 to 14 hours and remove them in the shade until the seed coat is not slippery. Use a pair of pliers to pry the mouth apart to facilitate budding. Take an appropriate amount of enamel plate in the amount of seeds, and spread the sterile towel, spread the seeds of the seed coat evenly on the towel, and then cover with a wet towel, set the germination in a constant temperature box at 34-35°C ( Until the bud grows to 0.3-0.5 cm, it can be sown.)
Seedlings of watermelon scion are 10 to 15 days later than gourd rootstock seedlings. The specific time depends on the weather and the growth of gourd seedlings. The amount of mu is generally 50 to 100 grams. Specific approach: Select a sunny weather for 1 day, and then use hot water at 55°C for 5 minutes. Wait for the water temperature to drop to 30°C. Continue soaking seeds for 3 hours and then remove the seeds. Wash again several times, then remove seed coat and mucus. Remove moisture from the epidermis, wrap it in a wet cloth after breaking it, germinate for 18-24 hours under the condition of 30°C, and sow when more than 60% of the seed is white.
Fourth, sowing and post-cast management
The rootstock seeds are sown 2 to 3 days before sowing, the seedlings are soaked, the fire is warmed, and the soil temperature in the middle of the Yuzhong is stable at 10 to 12°C. A thin 1 cm deep ditch is drawn with bamboo in each of the Yongzheng and the seeds after budding are sown. Place the ditch flat, the buds down, and then cover 0.5 to 1 cm thick wet fine soil. In order to speed up the emergence of seedlings, cover the film after sowing. During the day, the room temperature is stable at 30-35°C and nighttime at 20-25°C. When more than 50% of budding soil is used, the mulch film shall be peeled off to prevent roast buds. After the seedlings are kept at 25°C during the day, the night temperature is 20°C, and the air is ventilated in the upper part at noon for 5 to 8 minutes to facilitate ventilation. When the first two true leaves of rootstock seedlings overlap, true leaves should be removed in time to reduce nutrient consumption and prevent the increase of medullary cavity.
Watermelon seeding uses a rectangular seedling tray 80 cm long, 40 cm wide, and 10 cm deep. The plate is packed with clean, large-grained river sand, 5 to 6 cm thick, and then poured into 55°C warm water to soak the river sand. When the buds are 0.1-0.5 cm long, they can be broadcast on demand, densely distributed. The spacing of the plants is not more than 1 cm 1 cm, and the buds are laid flat. With the damp sandy soil covered with the points, a thickness of 1 cm prevents the seed from “wearing a cap†unearthed. After sowing, the plastic film covers the heat preservation and humidification, and the seedling plate can be placed on a fire pot in the home or in an electric hotbed for raising seedlings, keeping the temperature at 30-35° C., and accelerating the excavation. When the watermelon seedlings had just arched the soil, the seedling trays were moved to the fire lanes in the greenhouse under the condition of insulation, and the bricks were covered and the plastic film was placed on the cover. Before emergence, daytime temperature is maintained at 30-35°C, nighttime temperature is 20°C, and relative humidity is 95%. When 70% of the top soil is seeded, the plastic film is peeled off in time. After Qimiao pay attention to spraying and disease prevention, especially Jingxin No. 1 and other varieties, it can spray 2500 times of streptomycin for agricultural use to prevent bacterial leaf spot disease and epidemic disease, spray or mix with 72% Kelu wettable powder 700 times liquid. Plant ash spread to prevent devastating disease.
V. Grafting
Using oblique plug-in method, the required tool is an ordinary double-edged shave blade, bamboo sticks made from old bamboo pieces.
For proper grafting time, rootstock (cucurbit) requirements are less stringent, giving birth to 2 to 4 true leaves. Before grafting, the seedbeds were sprayed with permeable water first and sprayed with 500 times chlorothalonil to prevent disease. When grafting in the greenhouse, in order to prevent wilting, we must put grass and weeds to achieve partial shade. Cut the gourd head (tips and needles) first with a blade, but leave 5 to 8 mm high stems. It requires two people to cooperate with each other when they are grafted. One person holds the gourd with his left hand, and the right hand uses a special bamboo stick inserted in the direction parallel to the gourd cotyledium from the root of one cotyledon obliquely to the other side until the left index finger has a touch. The bamboo stick is not pulled out. The other person will pull the watermelon seedlings 5 ​​to 6 centimeters high. The left hand holds 1 to 1.5 centimeters below the cotyledon, and uses the new blade to cut the length down to 0.8 to 1 in the direction perpendicular to the two cotyledons. The incline of centimeters is 30 to 40 degrees, and then the first person's right index finger and thumb take the cut melon seedlings, the little finger and ring finger pull out the bamboo sticks, and quickly insert the melon seedlings (scouts) into the rootstock holes until they are inserted. Move so far. To make watermelon and gourd cotyledons "10" shape. After grafting, the grafted seedlings should be placed in a small shed as soon as possible, watered (avoid watering at the interface), and covered with moisture.
Sixth, grafted seedlings management
Nursery and grafting period should pay attention to warming, insulation and temperature control. The seedbed is covered with straw and grass, and a small arch shed is placed on the seedbed. Also heat the fire. During the day, the room temperature is controlled at 20 to 25°C, and at night 17 to 20°C. The relative humidity in the small arch shed is kept above 95%. After 3 to 4 days, shading time is gradually reduced and light is increased. After 7 days, the small shed was removed (depending on the weather). After 10 days, the wounds basically healed, and the true leaves sprouted in time were removed, and the leaves were sprayed with 1000-fold thiophanate-methyl for prevention. At the same time, spray sweet vinegar once every 10 days to increase nutrition. After 20 days, the room temperature is controlled at 27-28°C during the day, 14-15°C at night, and the highest temperature is 17-18°C. The relative humidity of the air is controlled at 70%. Pay attention to the wind at noon on sunny days to prevent high temperature roasted seedlings. When the grafted seedlings have 3 to 4 true leaves, the soil temperature within 10 cm of the shed is stable at a minimum of 13°C, and the average temperature is above 18°C. The minimum temperature in the shed is set at 5°C or above.
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