1 Variety selection In winter, the temperature is low, the light is weak, and the sunshine time is short. In order to make the green grow normally and obtain high yield, you should choose a variety with wide adaptability, strong cold resistance, compact plant type, compact flower bulbs, good quality, and high yield. When cultivating, the early-maturing varieties should be the main, and the middle-early maturing varieties should be matched according to the specific situation. 2 Cultivate strong seedlings The cultivation time of broccoli in the greenhouse after the winter delay depends on the climatic conditions and the growth period of the varieties. The specific sowing period can be determined according to market demand. In the delayed winter cultivation in the greenhouse, the seedlings can be sown in the seedbed first, and the seedlings should be divided once every 2-3 leaves, and then cultivated into strong and strong seedlings and then transplanted. Transplanting is suitable for calendar seedling age of 40-45 days and physiological seedling age of 4-5 true leaves. Because broccoli is afraid of waterlogging, and the season of high temperature and rain is during the nursery season, a well-drained plot should be selected for the nursery ground. After the land is leveled, a 10 cm high seed bed is made, and then 6-7 cm thick nutrient soil is spread on it. The nutrient soil can be prepared by mixing half of fully rotted pig manure and vermiculite with appropriate amount of nitrogen and phosphorus compound fertilizer. The seeds can be planted after the irrigation is submerged. In order to save the amount of seed, it is advisable to use thin seeding, sowing 4-5 grams per square meter, and 20-25 grams per mu of field. After sowing, cover nutrient soil 0.5-1.0 cm. Shade nets are erected above the seedbed to prevent rainstorms and sun exposure, and to reduce ground temperature. Pay attention to seedbed management after sowing. If the temperature reaches 20-22 ℃ during the day, the seedlings can emerge in 2-4 days. After emergence, the seedbed should be sprinkled with a thin layer of soil to facilitate moisture retention and rooting. The temperature should be maintained at 15-18 ° C during the day and not lower than 10 ° C at night; the relative humidity of the soil should be maintained at 70% -80%. If there is a drought, water should be sprayed in time, and attention should be paid to preventing the damage of cabbage worms and yellow bent strip jumpers. 20-25 days after emergence, when there are 2-3 true leaves, you should choose a cloudy day or evening to split seedlings, and fake seedlings are planted in a nutrient bowl or plastic nutrient bag, one plant per pot (bag). The nutrient soil can be prepared by fertilizing the top soil of the grain field and half of the rotten pig manure, and adding appropriate amounts of nitrogen, phosphorus and potassium compound fertilizers. The specification of the nutrition bowl (bag) is 9-10 cm high, and the diameter of the upper mouth is about 8 cm. After splitting the seedlings, discharge the nutrient bowl on the bed seedlings to keep them moist. The watering should be dry and wet, and do not suffer drought. The temperature should not be too high to prevent long legs and accept exercise. When the seedlings reach 40-45 days and the seedlings grow 4-5 true leaves, they can start colonization. 3 Soil preparation and fertilization After the previous crops are harvested, the fields are cleaned, the soil is ploughed, and the ground is dried for about 10 days. Then apply 52500 kg of organic fertilizer per hectare, 1125 kg of cake fertilizer, 750 kg of phosphate fertilizer, 300 kg of urea, and 150 kg of potassium fertilizer. Combine the land preparation to mix the fertilizer with the soil, rake thin and level, make a border of 1.12 meters wide, ditch 0.25 meters deep, and then cover the mulch. Soil preparation and fertilization should be completed 10 days before planting. 4 Reasonable close planting The planting density is 3000 plants per mu, that is, each row is planted with 3 rows, and the plant spacing is 0.45 meters. When planting, pour shovel water, pour rewatering once on the second day, and then seal the planting hole with soil fertilizer or fine soil. 5 Management after planting 5.1 Fertilizer and water management Plastic film mulch cultivation is generally not suitable for top dressing when sufficient base fertilizer is applied, but 0.3% -0.5% urea and potassium dihydrogen phosphate solution can be used for foliar top dressing to promote robust growth of stems and leaves. The soil should be kept moist. If it is too dry, ditch irrigation should be carried out. Shallow irrigation, rapid irrigation and rapid drainage should be used. Infiltrating the border soil is suitable. 5.2 Pest control The main diseases are black rot and black spot. The black rot fungus mainly damages the leaves, and begins to develop from the edge of the leaf, extending from the apex of the vein to the inside and both sides, forming a yellow-brown lesion in the shape of "V", and the vein necrosis becomes black. When the air is damp, the tissue of the diseased department rots, and when the air is dry, the diseased department is dry and brittle. The vascular bundles turn black when the stems and roots are damaged. The prevention and treatment can be sprayed with 50% Dysonamine 1000 times solution at the initial onset, sprayed once every 7-10 days and continuously sprayed 2-3 times, the effect is better. It should be noted that the medicine must be stopped 15 days before harvest. Black spot disease mainly damages the leaves and petioles. At the beginning of the disease, nearly round gray-white to light brown disease spots appeared on the leaves, gradually becoming dark brown, with obvious concentric circles on the disease spots, and often yellow halo around. The lesions on the petiole are long and fusiform, dark brown, slightly sunken, with a wheel pattern. When the humidity is high, black mold grows on the lesions. The prevention and treatment can be sprayed with 75% chlorothalonil wettable powder 500-600 times solution, or 50% thiophanate-methyl 500 times solution, or 0.25% Bordeaux solution or 50% carbendazim 1000 times solution, every 7 days. Spray once every -10 days, spray 2-3 times in total to control the development of the disease. Pests mainly include cabbage worms and aphids. Cabbage worms are controlled by Kung Fu, Yitaibao, Kazhike spray. Aphids are sprayed with 40% dimethoate emulsion 2000 times solution. 6 Harvest When the flower ball is fully grown, the flower bud particles are neat, and the ball and flower are not scattered, the quality and yield *. The broccoli varieties mainly producing top flower buds can be used to clear the garden after harvesting the top flower buds. Disclaimer: Some articles of this website are transferred from the Internet. If the legal rights of third parties are involved, please inform this website for processing. phone Anesthesia Medical Co., Ltd. , https://www.medicaldiverse.com