How to grow loofah in greenhouse

Luffa likes sunlight and is slightly shade-tolerant. It is a short-day plant with an optimum temperature of 20-30°C. It will be damaged by frost when the temperature is below 5°C. The plant will first produce male flowers, and then both male and female flowers will be produced at each node. Luffa has high requirements for soil, requiring soil that is rich in organic matter and has strong water retention capacity, and is mostly cultivated in low-lying areas. Let’s learn about the planting method of loofah in a greenhouse .

1. Cultivation of strong seedlings

1. Suitable for sowing

(1) Select the variety

For greenhouse cultivation, you should choose fleshy loofah varieties with thick flesh, less fiber and good taste;

(2) Sowing time

The suitable seedling age of loofah is about 50 days. Usually in a single-layer greenhouse for wintering, the planting time is from late April to early May; in a multi-layer covered greenhouse for wintering, it is in late April. Depending on the planting period and seedling age, sowing and raising seedlings can be started in a heated greenhouse about 2 months in advance;

(3) Seed soaking and germination

Use warm water at about 55℃ to blanch the seeds for 10 minutes, stirring constantly. After blanching the seeds, soak them in room temperature water for about 10 hours, wash them, wrap them in wet gauze or wet towels with good air permeability, and place them in a place with 28℃ to 30℃ for germination;

(4) Sowing techniques

It can be sown in a seedling tray and transplanted after the cotyledons unfold. If there is enough space for seedlings, it is best to sow them directly into nutrient pots or paper pots to reduce labor. Sow one sprouted seed in each pot, cover with 2.0 to 2.5 cm of soil (the same nutrient soil as cucumber ), water thoroughly, and place in a warm place to promote germination. Luffa likes warmth, so it is best to place it on an electric hotbed or a raised bed, or build a small arch shed for insulation.

2. Seedling management

Pre-emergence management. High temperature management before emergence helps with emergence. The daytime temperature is about 30℃, the night temperature is above 15℃, and the ground temperature is around 30℃; management after emergence. After the seedlings emerge from the soil, lower the temperature appropriately to prevent the hypocotyl from growing too long. The daytime temperature remains at 20℃~25℃, the night temperature at 10℃~13℃, and the ground temperature at 20℃~25℃. Increase indoor light and do not water unless the soil is dry. After the true leaves appear, the temperature gradually increases, with the daytime temperature at 25℃~28℃, the night temperature at 13℃~15℃, and the ground temperature around 25℃. Keep the soil moderately moist. If the leaf color becomes lighter, spray 0.246 mg/kg potassium dihydrogen phosphate solution. Weed and prevent aphids in time. One week before transplanting, gradually increase ventilation and cool down, control water to train the seedlings, and enhance their adaptability.

2. Planting at the right time

1. Plastic film greenhouse preparation

It is best to replace the new film in the autumn of the previous year. The frozen soil layer in the wintering shed is shallow and thaws quickly, which is suitable for early planting. For multi-layer covering greenhouses, prepare multi-layer covering materials such as second-layer curtains, small arch sheds, and ground film half a month before planting.

2. Land preparation and fertilization

Deeply plow the soil to 20 cm. The loofah has a long growing period, so you can apply more base fertilizer, 2/3 of which can be applied by broadcasting throughout the garden and 1/3 by applying in ditches. Make beds at intervals of 1.2 meters, dig trenches in the middle of the beds for fertilizer application, with a trench depth of one shovel and fertilizer spread to a thickness of about 10 centimeters. Then close the ridges, which should be about 10 cm high. Scrape the bed surface level and cover it with soil film one week in advance.

3. Planting period

In single-layer or multi-layer covered greenhouses, the suitable planting period for loofah is slightly later than that for cucumber, and the earliest is the same period as cucumber. Luffa likes warmth, so you can't plant it ahead of time blindly to avoid low temperature damage.

4. Planting method

Loofah grows vigorously in greenhouses, and the planting density should be smaller than that in the open field. Plant in two rows in a 1.2-meter-wide ridge, with a row spacing of about 50 cm and a plant spacing of about 50 cm. Choose a sunny morning at the end of cold and the beginning of warm season, dig holes for planting, select high-quality seedlings of the right age, plant them in wet soil, and apply 5 grams of diammonium phosphate per soil as fertilizer. Mix the fertilizer with the soil evenly to avoid burning the roots. The top of the seedling ball should be at the same height as or slightly higher than the bed surface. The gap between the seedling ball and the soil around the planting hole should be filled with soil so that the roots of the seedlings are closely connected to the surrounding soil. Water the plants shallowly and seal the soil after the water has completely sunk to keep them warm and moist.

3. Management after planting

1. Management during the seedling stage

After planting, a small arch shed should be immediately covered for multi-layer cultivation. The key during this period is to keep the greenhouse tightly sealed to raise the temperature and promote the growth of seedlings. No ventilation is required unless the temperature reaches 38℃. Under conditions of high temperature and high humidity, the seedlings will grow in about 5 days. In case of cold waves, surround the greenhouse with straw mats to keep it warm.

2. Management from seedling acclimatization to root melon settling

When the heart leaves begin to grow, the seedlings have resumed growth and should be immediately watered with an appropriate amount of water to promote growth and development. During this period, the main focus is on cold protection and heat preservation, with the temperature not exceeding 35℃ and no ventilation. Control water appropriately and stun the seedlings to promote rooting. Multi-layer covering, opened during the day to increase light transmission. After watering to help the seedlings grow, when the surface soil is dry, immediately use bamboo poles to insert an upright frame, and then tie the vines to the frame in an "8" shape. Generally, all the side branches under the root melon are removed.

3. Result period management

The environmental conditions in the greenhouse in spring are not conducive to the fruiting of loofah. Unlike cucumber, which has strong parthenocarpic ability, loofah needs the assistance of artificial pollination . If there are few people, you can also use 2.4-D solution with a concentration of 15-20 mg/kg to spray flowers or apply on fruit stalks to increase the fruit setting rate. During the fruiting period, the water and fertilizer requirements increase sharply, so fertilizer and water management should be strengthened. After the root melon is established, the seedling squatting is stopped and topdressing with fertilizer and watering is started. In the early stage, water is irrigated once a day, and in the later stage, water is irrigated once a week. Apply 224 kg of potassium dihydrogen phosphate or ammonium nitrate per hectare, apply it in pits or follow the water, and water in time after fertilization. Top dressing should be done about 4 times during the entire growing period of loofah. As the fruit-bearing period begins, the outside temperature gradually rises. When the temperature inside the shed is no less than 13°C at night, the small shed can be removed. When the temperature in the greenhouse exceeds 30℃, start ventilation. First open the door or make gaps on both sides of the greenhouse to let in a small amount of air. Gradually increase the ventilation volume, roll up the film around the greenhouse, and close the air when the temperature in the greenhouse drops to around 25℃ in the afternoon. When the outside temperature is not lower than 13℃, ventilate day and night. Starting from September, the vents will be gradually reduced, and finally completely blocked to keep the air out. As the plant grows, continue to tie the vines to the rack, select the strong side branches on the upper part of the root melon and keep about 5 to 7, pinch off the top after the fruit is formed, and pinch off the main vine about 15 cm away from the greenhouse film. If the large greenhouse rack can hang vines, then the main and side vines can grow freely without pinching.

4. Pest and disease control

The main diseases of loofah include brown spot disease, downy mildew, and vine blight. Among them, brown spot disease is the most harmful. Brown spot disease mainly harms leaves and is a fungal disease. The lesions initially appear water-soaked, then turn yellow-brown or gray with green-yellow-brown edges. In severe cases, the entire leaf dies. The main insect pest is melon aphid, which is prone to occur in hot and rainy seasons. We should strengthen crop rotation, pay attention to garden and field cleanliness, reduce the sources of overwintering aphids, and take timely prevention and control measures when aphids are discovered.

5. Harvest and Seed Collection

Harvest: Harvest two weeks after flowering, usually when the fruit top is full and the skin is shiny. Do not pull hard when harvesting, it is best to use scissors . Greenhouses produce 45,000 to 60,000 kilograms per hectare;

Seed collection: Isolation measures should be taken to preserve seeds, or artificial pollination should be carried out by bunching flowers. Select the middle fruit with the characteristics of this variety as seed melons, pick them more than 40 days after flowering and let them ripen. Then cut the melons open to remove the seeds, dry them and store them.

The above is an introduction to the planting methods and key points of greenhouse loofah. If you adopt the greenhouse planting method, you can choose marketable loofah varieties to cultivate according to local conditions.