Methods and Experience Sharing for Growing Zucchini in Greenhouses

Zucchini has the effects of relieving restlessness and quenching thirst, moistening the lungs and stopping cough, clearing heat and promoting diuresis, and reducing swelling and dissipating nodules; its fruit can be used as a vegetable. So, what are the methods for growing zucchini in greenhouses?

1. Cultivation techniques

1. Select excellent varieties

First, choose the Zaoying Yidai zucchini hybrid, which is early-maturing, high-yielding, fast-growing, and has trailing-vine characteristics.

2. Cultivate strong grafted seedlings. 1. Sowing time. For the autumn-winter crop of greenhouse zucchini, sowing is generally from early September to mid-September, with 500 grams of seed per mu; for the rootstock black-seeded squash, use 800-1000 grams of seed, sown at the same time as the zucchini. 2. Grafting methods: insertion grafting and approach grafting can be used. Insertion grafting: first lift out both kinds of seedlings, use a bamboo stick to remove the true leaves of the black-seeded squash, then make a hole between the two cotyledons, then remove the roots of the scion zucchini seedling, cut 0.5-0.8 cm below the hypocotyl into a wedge shape, water thoroughly, and cover the shed well. 3. Grafting time. Use sand-bed seedling raising, raising zucchini and black-seeded squash separately in two sand beds, and begin grafting when the true leaves of the young seedlings appear. Generally it takes about 5 days from sowing to grafting.

2. Planting techniques

1. Sowing time

Sowing time should be determined according to the local climate and the planting crop rotation. For the autumn delayed crop in a greenhouse, sowing in mid-September is suitable; for the overwintering crop in a winter-warm greenhouse, sowing in late October is generally suitable; for winter-spring crop cultivation (following autumn-delayed tomatoes or other vegetable crop rotations), early to mid-November is suitable; for the early spring crop, sowing around New Year's Day is suitable.

2. Careful seedling raising

Place nutrient pots into the seedling bed and water them (32-cell plug trays can also be used for seedling raising), watering the nutrient soil thoroughly; after the water in the pots has completely seeped down, it is best to dig a small hole 2.0 cm in diameter and 1.0 cm deep in the center of the nutrient soil, place the seed flat in the hole, and be sure not to insert the seed, so as to avoid seed rot caused by lack of oxygen. For the late-winter crop and winter-spring crop, it is recommended to water in the morning and first arch the film to raise the ground temperature, then sow in the afternoon; the covering soil thickness for sowing should preferably be 1.0 cm, as covering too deep or too shallow will affect the uniformity and vigor of emergence. After covering with soil, cover with an arched film to help raise the ground temperature. After emergence, remove the arched film to harden the seedlings and cultivate strong seedlings.

3. Planting density

Large row 100 cm, small row 80 cm, plant spacing 70-80 cm, planting 800-1000 plants per mu.

3. Fertilization techniques

1. Growth characteristics: Zucchini has a strong root system; it has a strong tolerance for low temperature and weak light, has strong water absorption and drought resistance, and also has relatively low requirements for soil, growing well on sandy soil, loam, or clay, with high yield, relatively light disease, a long melon-picking period, and high benefit.

2. Fertilizer requirement pattern: The fertilizer requirement is relatively large; to produce 1000 kg of marketable melons, the fertilizer requirement is equivalent to nitrogen 3.9-5.5 kg, phosphorus pentoxide 2.1-2.3 kg, and potassium oxide 4-7.3 kg.

3. Key points of fertilization: Zucchini fertilization should be mainly organic fertilizer, and in fertilizer combination, attention must be paid to the supply of phosphorus and potassium fertilizer, especially during the melon-setting period, where sufficient phosphorus and potassium fertilizer is necessary. Apply base fertilizer heavily. For zucchini crop cultivation, to prevent fertilizer shortage due to untimely topdressing under low winter temperatures, sufficient base fertilizer should be applied; when there is no previous crop occupying the land, water thoroughly before land preparation. When the soil is suitable for tillage, broadcast per mu 5000—7000 kg of high-quality decomposed organic fertilizer, 30—40 kg of diammonium phosphate, 30 kg of urea, and 20—30 kg of potassium sulfate or potassium nitrate, deep-plow 30 cm, after fertilizing close the shed to raise the temperature and bake the soil for 5—7 days before planting; fumigation with sulfur or chlorothalonil smoke fumigant also has a very good sterilization effect.

Skillful topdressing: After seedling revival, water promptly once; together with watering, apply 10 kg of urea per mu as a flush application. Then control water to promote seedling squatting. Entering the melon-setting period, which is also a period of lower winter temperatures unfavorable for vine growth, during this period vegetative growth and reproductive growth proceed simultaneously; to coordinate the relationship between the two, balanced fertilization is key. When the root melon begins to expand, carry out the second topdressing together with watering, applying 15—20 kg of diammonium phosphate or 10—15 kg of nitrogen-phosphorus-potassium compound fertilizer per mu. When topdressing, first dissolve the fertilizer in water and then irrigate it along with the water into the dark ditch under the plastic film. After irrigation, seal the plastic film tightly and strengthen ventilation to remove moisture. Entering the full fruiting period, fertilizer and water management is very important. Zucchini has a high harvesting frequency, and each plant can harvest 7—9 fruits. Topdress about once every 15 days, each time applying per mu as a flush application with water 20—30 kg of urea or ammonium sulfate, or 35 kg of nitrogen-phosphorus-potassium compound fertilizer, or cake fertilizer composted liquid, or 400—500 kg of fully decomposed human manure diluted 10 times. Alternating application of chemical fertilizer and organic fertilizer is best. At the same time, alternately spray foliar fertilizer such as 0.1% urea plus 0.2% monopotassium phosphate plus 100-fold sugar water, or Aiduoshuo, Yemianbao, etc., to make up for the deficiency in nutrient absorption by the roots. In the late melon-setting period, the plant ages, so appropriately reduce the amount of fertilizer.

4. Growth period management

1. Temperature management

After planting, zucchini grows rapidly; after entering November, light watering should be done appropriately, then the shed should be closed and weeds removed in time, and the regenerated leaves of the squash should be removed. After winter begins, heat preservation should be covered in time to ensure normal growth of zucchini.

2. Fertilizer and water management

Before zucchini flowers and sets fruit, watering should be minimized as much as possible. After the fruit is set, water lightly as appropriate; after winter begins, basically no watering is needed, and only foliar topdressing is done together with pesticide spraying.

3. Vine hanging and pruning

Zaoying Yidai zucchini has trailing-vine characteristics; vine-hanging cultivation can increase planting density, prolong the growth period, set fruit early, and increase yield. Vine hanging is an important measure for high yield and high efficiency of zucchini. In early November, vines should be hung in time, and at the same time excess side branches should be removed to reduce nutrient consumption.

4. Increase fruit-setting rate

To increase the fruit-setting rate of zucchini, carry out artificial pollination in time, then apply 10-15 mg/L 2,4-D solution to the fruit stalk, or dip flowers in Shennong No. 2 water solution, to prevent flower and fruit drop and promote uniform fruit expansion. 7-10 days after planting, water once again to promote seedlings, so as to favor vigorous plants and strong seedlings and lay a foundation for later high yield; generally no more watering before fruit setting. When the plant grows to 10 leaves, spray zucchini regulator (this variety is sprayed 2-4 leaves later than other varieties) for chemical regulation to prevent excessive growth. Because this variety sets fruit early and has dense fruit nodes, it is recommended not to keep fruit before 8 leaves for spring and autumn crops, and not to keep fruit before 10 leaves for overwintering crops. Before keeping fruit, the plant should be cultivated to reach the standard of thick stems, short internodes, large leaves, thick leaves, and both strong and vigorous; otherwise, weak plant growth will seriously affect mid-to-late yield. When the plant grows to about 15 leaves, depending on plant vigor, spray zucchini balance agent once more. Make the plant strong but not excessively growing at the early fruit stage, with vegetative growth and reproductive growth coordinated; after fruit setting is complete, water once for fruit expansion.

5. Disease control

In recent years, the area of zucchini cultivation in solar greenhouses has been relatively large, and the occurrence of zucchini gray mold often causes tender melons to rot, affecting yield and benefit. Therefore, measures should be taken for integrated control.

Grafting to prevent disease. Using Yunnan black-seeded squash as rootstock and zucchini as scion for grafting can increase zucchini's resistance to gray mold.

Vine-hanging cultivation. When zucchini grows to 8 leaves, begin hanging vines; above each row of plants, connect a wire in the north-south direction, and according to the position of each zucchini plant, tie a nylon rope on the wire hanging vertically to the root, then tie the rope end at the root of the zucchini, so that the hanging rope and the stem vine intertwine with each other. Chemical flower dipping. After zucchini blooms, when dipping flowers every morning, add 0.1% procymidone to 2,4-D, which can effectively control zucchini gray mold.

Chemical control. You can spray with 50% procymidone wettable powder 1500-2000 times solution, or 50% iprodione wettable powder 1000-1500 times solution, 70% zineb wettable powder 400 times solution, or 50% carbendazim wettable powder 500 times solution, spraying once every 6-7 days, 2-3 times continuously, 45-60 kg of spray solution per mu each time. Strengthen field management. Clean up diseased residues thoroughly, keep the field sanitary, and prevent the spread of pathogens,

Control temperature. Use dark irrigation under film or drip irrigation for watering, and nighttime humidity should be less than 80%. When humidity is high, measures should be taken to reduce humidity. In the late production period, clean up old leaves in time, increase ventilation and light transmission, make the plants grow robustly, and increase disease resistance.