Greenhouse cultivation technology

(1) Sowing and seedlings. The resistance to stress is strong, and the range of the sowing period is relatively wide. The appropriate sowing period can be determined according to local climatic conditions and cultivation requirements to ensure that the stems and leaves of the plant grow robustly, and can pass through the vernalization stage at a low temperature after an appropriate size. The formation of flower buds and the flower bud differentiation and flower ball development are in the most suitable environment. This is the key to the success of cultivation. Generally speaking, the suitable seeding period in the south is from July to March of the following year. When growing in a greenhouse in summer, shading and seedlings are combined with shading nets to cool down the cultivation to achieve annual production. 1/15 hectares (1 acre) of seedlings are seeded with a volume of 20-30 grams and the seedling age is 25-30 days (short in summer and autumn and long in winter and spring). When the true leaves are expanded about 5 pieces, they are colonized at the right age. Strong seedling standards: larger plants, thick stems with short internodes, large leaf area, and no pests.

(2) Tricky planting. Before plowing, the land was deepened and sun-baked earlier, and 1000 kg of manure and 30 kg of compound fertilizer were used as base fertilizer in the middle of the plow. After plowing and leveling, the rake was thinned to make a plow with a width of 1.2-1.3 meters. Plant two rows with a distance of 0.4-0.5 meters. The seedbed was scratched 3 hours before planting, and healthy seedlings were selected for planting. Planting should not be too deep, so as not to affect growth. After planting, you should water enough roots to facilitate survival. The planting time is generally cloudy or after 3:30 pm.

(3) Management of fertilizer and water. After broccoli is planted, it is usually watered every 5-7 days. If the dry soil has poor water retention during growth, it can be watered every 3-4 days. It is necessary to keep the soil moist to promote plant growth, so that it has a sufficient number of leaves (usually not less than 15-17 leaves) and a large leaf area before the present ball, which lays the foundation for the formation of high-quality flower balls and high yield.

The plant size of broccoli is directly proportional to the size of the flower ball. In addition to applying sufficient base fertilizer, attention should be paid to timely topdressing to promote the full development of the plant. Especially for early maturing varieties, we must do a good job of topdressing. There were 3 times of topdressing for broccoli, the first time was about 7 days after the planting and survival, and the water was irrigated with 10 kg of urea per 1/15 hectare (1 acre); the second time was 15 days after the first time. Topdressing with 20 kg of compound fertilizer every 1/15 hectare (1 acre). When the top flower ball has been formed for the third time, in order to promote the increase in weight of the top flower ball, 5 kg of urea can be applied every 1/15 hectare (1 acre), but the amount should not be excessive. At the same time, special attention should be paid to increasing the application of boron and potassium fertilizers to prevent yellowing and browning of the surface of flower buds and cracks in the base of flower stems. Therefore, foliar fertilization can be performed at the seedling and bud stage, and external root topdressing with 0.5% borax or boric acid can be applied 2-3 times, supplemented with 0.3% potassium dihydrogen phosphate spraying 1-2 times. This has a significant effect on preventing flower bud yellowing and cracking at the base of the flower stem. After the main ball is harvested, it is necessary to continue watering and fertilizing the varieties that are prone to side branches to promote the growth of side flower balls and increase yield.

(4) Temperature and humidity control. Broccoli is cold and cold, and it belongs to semi-cold-tolerant vegetables. The suitable temperature for plant growth is 20-22 ℃, and the suitable temperature for flower bud development is 15-18 ℃. Growth is higher than 25 ° C and susceptible to disease, while growth is slower than 5 ° C. Therefore, when using broth to cultivate broccoli, the temperature must be controlled first. When the broccoli enters the growing season, the temperature in the shed should be controlled at 25-20 ℃, and the temperature should be properly ventilated above 25 ℃ to prevent the stems and leaves from growing too long and the flower bulbs becoming smaller. The temperature during the flower ball formation period should be controlled at 20-15 ℃, and above 20 ℃ should be ventilated. Due to the large temperature difference between the interior and exterior of the shed, there will be more dew condensation on the film covering the shed. Therefore, polyethylene or polyvinyl chloride-free film should be used, and ventilation and humidity should be appropriately and timely at the same time.

Broccoli should not be dry and afraid of waterlogging. In rainy days, water should be removed in time. The water demand during the flower ball development period * should ensure the water supply. Soil must be kept moist throughout the growing period. Pay attention to weeding and soil cultivation.

(5) Pest control. The main diseases of broccoli include black rot, soft rot, and sclerotinia. The main pests are aphids, cabbage worms, and diamondback moth worms. Pay attention to early control.

(6) Harvesting. The flower ball of broccoli consists of small flower buds, and does not stop developing after the differentiation is completed. After growing into large flower buds, if the temperature is higher, it will bloom to reveal yellow petals, making the flower ball "yellow" and losing edible value. Therefore, when the flower ball reaches the commodity maturity standard, it should be harvested in time. If the harvest is too early, the flower ball is not fully grown, and the yield is low; if the harvest is too late, the flower ball is loose, the spherical surface is uneven, and the buds are loose, and even the yellow petals are exposed, which will reduce the quality and commercial value of broccoli. . After the main flower ball is harvested, the varieties with strong side branch generation can also receive some side flower balls after strengthening the fertilizer and water management.

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