Zucchini has a strong root system and is highly resistant to low temperatures and low light, making it suitable for cultivation in warm-winter greenhouses. Overwintering stubble cultivation has a long melon picking period and high efficiency. It can not only increase the variety of fresh vegetables in winter and spring, but also solve the problem of a single variety of overwintering stubble vegetables in warm-winter greenhouses.
At present, most of the early-green generation zucchinis are used in production. The suitable sowing period is early to mid-October, and the seedling age is about 30 days. If the sowing date is too early, before late September, the temperature will be high and it is easy to be infected with viral diseases, which is not conducive to the differentiation of flower buds and may even cause leggy growth. If the sowing date is too late, there will be little nutrient accumulation and poor adaptability, and it is easy to form rigid seedlings. If black seed pumpkin seedlings are grafted, the sowing period is 3 to 5 days earlier than that of self-rooted seedlings, and the rootstock and scion can be soaked and germinated at the same time. When sowing and raising seedlings in early October, the seedlings should generally be raised outside the shed; when sowing in mid-October and the outside temperature is low, the seedlings should be raised inside the shed. When there are cracks in the pot soil or between the pots, sprinkle dry fine soil or plant ash to fill the gaps to preserve moisture. Generally, there is no need for watering during this period. If watering is needed, spraying should be done in the morning on a sunny day. In order to increase the nutrition of the seedlings, two extra-root top dressings can be carried out in conjunction with the prevention and control of pests and diseases. Spray 0.2% to 0.3% nitrogen, phosphorus, and potassium. It is best to use ternary compound fertilizer or 0.2% urea plus 0.2% potassium dihydrogen phosphate alternately. To prevent and control whiteflies in the seedling stage, you can use 1000 times liquid of Aphids. To control mites, you can use 1000 times liquid of Mite Cleaner and spray. To prevent viral diseases, you can spray twice in a row 7 days after the first true leaf unfolds. 83 Antiagent 100 times solution.
Generally, planting is carried out in early to mid-November. If the weather changes, conditions for planting should be created. Before planting, the soil should be prepared to create moisture. If the moisture is insufficient, trenches should be dug 8 to 10 days in advance to allow water to be irrigated to create moisture. After irrigation, ventilation should be strengthened to disperse moisture. After the ground is dry, the trenches should be leveled and plowed 30 centimeters deep. Base fertilizer should be reapplied in conjunction with soil preparation. Apply 5,000 kilograms of ring fertilizer, 1,000 kilograms of chicken manure, 50 kilograms of superphosphate (or 20 kilograms of diammonium phosphate), and 30 kilograms of potassium sulfate per 667 square meters. Mix the ring fertilizer with superphosphate and add wheat bran and crushed grass for sealing and fermentation one month in advance, mash it finely and then spread it. Decomposed chicken manure, diammonium phosphate and potassium sulfate are concentrated in ditches when making borders.
The planting method is large and small row planting, with a density of 22,000 to 2,500 plants per 667 meters. When planting large and small rows to make a border, the border width is 1.2 meters, the large rows are 70 cm, and the small rows are 50 cm. Double high ridges are made on the small rows. The bottom width of the small ridges is 30 cm, and the height is 12 to 15 cm. The distance between the two small ridges is 20 cm. , the top spacing is 50 cm, the plant spacing is 50 cm, and the two rows are planted staggered with each other. Before planting seedlings, first open a small trench with a depth of 10 to 12 cm on the ridge, apply chicken manure, diammonium phosphate, and potassium sulfate into the trench, mix well, then water along the trench, and plant the seedlings according to the spacing between plants to stabilize the water. After water seepage, the soil from the outside of the ditch is sealed into small ridges, and then raked and covered with mulch. It is better to use double-width mulching film, that is, one covers small rows and one covers large rows. There is no need to bury the film, so as to facilitate the removal of the film for cultivating and fertilizing.
On the day of planting, grass thatch should be covered early to increase night temperature. Before slowing down the seedlings, the greenhouse temperature should be maintained at 25-30°C during the day, 16-20°C at night, and the ground temperature should be above 16°C. Management after slowing the seedlings to before late winter: 3 days after planting, ventilate and dispel moisture around noon, then increase from small to large. After slowing the seedlings, keep the greenhouse temperature at 20-26℃ during the day, and harden the seedlings at 10-12℃ at night. After 34 days Properly increase the shed temperature to 24-28°C during the day and 12-14°C at night. The grass thatch should be uncovered early and covered late to try to increase the exposure time to light. After slowing down the seedlings, cultivating and loosening the soil should be carried out 2 to 3 times.
Zucchini is a cross-pollinated crop. Since there is no insect pollination in overwintering cultivation, and there are few male flowers due to light and temperature, artificial pollination and hormone treatment are required. Hormone treatment should be done around 9 a.m. , paint with 2,4-D at a concentration of 20 to 30 mg/kg.
From mid-to-late December to mid-to-late February of the following year, management focuses on increasing light, preserving heat, and promoting seedlings. The maximum temperature during the day on a sunny day shall not exceed 30°C, and the lowest temperature at night shall not be lower than 10°C, and shall not be lower than 8°C for a short period of time; on a cloudy day, the lowest temperature at night shall not be lower than 8°C, and shall not be lower than 6°C for a short period of time. The temperature difference between day and night should preferably be maintained at 8 ℃ or above. During this period, the light is poor. In order to promote plant growth and obtain the highest yield, photosynthetic micro-fertilizer should be sprayed twice and sugar-added foliar fertilizer 2 to 3 times from mid-December to January of the following year. Water once in early to mid-January, and top-dress fertilizer once in early-to-mid February in combination with watering. Top-dress fertilizer on one side of the ditch, uncover the mulch film, open the ditch and apply it. Apply 200-250 kg of fermented bean cake and urea every 667 m2. 15 kilograms, 30 kilograms of superphosphate, and 10 kilograms of potassium sulfate. Mix it with soil and spread it, then water it along the ditch. Watering and topdressing should be done on a sunny day. In addition, carbon dioxide fertilization can be carried out from early to mid-December if conditions permit. When 8 leaves have grown, hang the vines. The iron wire hanging the hanging rope should be movable. The hanging rope buckle should be a loose buckle of more than 30 centimeters. Hang or tie the plant in a circle. Through hanging vines, the height of the plants should be consistent and gradually increase from south to north to improve the overall light reception. Old and diseased leaves that have turned yellow should be removed promptly. When the empty leaf vines at the lower part reach more than 30 cm, the vines should be dropped in time to make the entire plant and leaves evenly distributed.
From late February to pulling out the seedlings, the main purpose is to prevent diseases, protect the seedlings and increase yield. To prevent viral diseases and powdery mildew, you can spray 800 times of phytopathogen and 500 times of triadimefon respectively. In order to increase the yield, the second top dressing was carried out in mid-March, applying 20 kg of urea and 10 kg of potassium sulfate per 667 m2, combined with watering.
In the future, after every watering, 500 kilograms of decomposed human feces or 10 kilograms of urea should be flushed every 667 m2, and the two fertilizers should be used alternately.
The commercial characteristics of this crop of zucchini require small, fresh and tender melons, uniform and correct melon shapes, so they must be harvested in batches at the right time to achieve the highest efficiency. Harvesting at the right time is also beneficial to the development of the upper melons and the growth of the plant.