High-Yield Cultivation Techniques for Luffa with a Yield of 50,000 Jin per Mu

AbstractSunlight greenhouse: seedling raising in plug trays can be done in late January, with a seedling age of about 35 days, then transplanting in early February, and harvesting begins 50-55 days after transplanting. Plastic tunnel: depending on seedling raising and planting facility conditions, seedling raising in plug trays can be done in mid-to-late February, with a seedling age of about 35 days, then transplanting at the end of March, and harvesting begins 50-55 days after transplanting. 3500-3700 plants can be transplanted per mu, and the average yield per mu can reach 50,000 jin.

I. Planting Season

1. Sunlight greenhouse planting 

The cropping pattern is one major crop per year; seedling raising in plug trays can be done in late January, with a seedling age of about 35 days, then transplanting in early February, harvesting begins 50-55 days after transplanting, and vines are pulled up at the end of October or in early November.

2. Plastic tunnel planting 

During this period, depending on seedling raising and planting facility conditions, seedling raising in plug trays can be done in mid-to-late February, with a seedling age of about 35 days, then transplanting at the end of March, harvesting begins 50-55 days after transplanting, and vines are pulled up at the end of October or in early November.

II. Planting Varieties

1. Through introduction and variety comparison, three excellent luffa varieties more suitable for local facility cultivation were selected: Bilu No. 1, Nongfu 801 and Huangguan No. 3.

2. Among them, Bilu No. 1 is mid-early maturing, has relatively strong adaptability, is cold tolerant, and has good disease resistance; Nongfu 801 is an early-maturing variety; Huangguan No. 3 is an early-maturing, heat-tolerant variety.

3. According to local production characteristics and cropping patterns, the planting area of early-maturing, mid-early maturing, and cold-tolerant and heat-tolerant varieties can be reasonably arranged to extend the market supply period and alleviate the contradiction of concentrated harvesting and marketing of a single variety and labor shortage.

III. Germination Promotion

Sun the seeds and soak them, then promote germination in an environment at 25°C; sow when 70%-80% of the seeds have broken white.

IV. Sowing

1. Suitable plug trays are 50-hole or 54-hole; the substrate should be a cucurbit seedling-raising substrate with good water permeability and not prone to loosening during transplanting. If fertilizer needs to be added to the substrate, dissolve the fertilizer in water first and then stir evenly; if fertilizer is added directly, it is easy to burn the tender shoots. Sprinkle water while stirring the substrate until the water content reaches 50%-60%.

2. Begin filling the trays when the substrate has evenly absorbed water thoroughly; during this process, note that the substrate should be consistent in tightness, scrape it level, use the bottom of another plug tray to press onto the filled tray so that the substrate sinks about 0.5 cm, then water thoroughly. Place the seeds flat in the seedling holes; if the seeds are placed upright, many will “wear caps” when emerging, and they can be covered with semi-moist vermiculite or mixed substrate and then scraped level.

3. For ground-level seedling raising in a greenhouse, it is necessary to prepare the seedling bed, level the bed, and water it thoroughly to ensure the healthy growth of luffa seedlings later. After sowing, arrange the plug trays on the seedling bed, fill the surrounding areas and gaps between trays with soil, cover with plastic film, and then set up a small arch tunnel inside the greenhouse, which is beneficial for heat preservation.

V. Seedling Stage Management

According to different seedling-raising conditions and stages, carry out protective measures well, as well as temperature and humidity management, pest and disease control, and hardening of seedlings. Luffa seedlings can be transplanted when they have 3 leaves and 1 heart.

VI. Reasonable Close Planting

Transplant in wide and narrow rows; the wide row spacing is 80 cm, with a furrow made in the middle of the wide row; the narrow row spacing is 60 cm, and the plant spacing is 25-28 cm, with 1 plant per hole; 3500-3700 plants can be transplanted per mu.

VII. Installation of Drip Irrigation Tape Equipment

Install drip irrigation tape; it is not advisable to use drip irrigation pipes, because drip irrigation pipes are easy to clog, relatively expensive, and labor-intensive to install and dismantle. For the main tape, choose 2-inch (1 inch = 3.33 cm) thickened non-perforated drip irrigation tape; for the branch tape, choose 1-inch 5-hole drip irrigation tape. After installing the main tape and tees, connect the branch tape laid in the middle of each ridge. Fold the tail ends of the main tape and branch tape 3 times, then cut a small amount of the corresponding tape and slip it over.

VIII. Full Greenhouse Coverage with Ground Film  

After fixing the drip irrigation tape, use 0.8 m wide black ground film to fully cover the greenhouse floor in a north-south direction. This helps reduce water evaporation, lower humidity inside the tunnel and the occurrence of diseases, increase soil temperature, maintain soil moisture, and avoid weeds. It is a necessary measure to ensure efficient and safe production of luffa and dense planting of luffa in facilities during the main crop.

IX. Temperature and Water-Fertilizer Management

1. After transplanting, the greenhouse needs to be closed to preserve heat and moisture, which helps increase temperature and promote seedling recovery. Keep the temperature no higher than 35°C, and appropriately adjust the uncovering and covering of the thermal insulation quilt, trying to extend the lighting time. Usually after 7 days of seedling recovery, the temperature should be appropriately lowered, with daytime temperature kept no higher than 30°C.

2. Densely planted luffa in facilities has strong fruiting ability, high yield, high fertilizer demand, and strong fertilizer uptake. Per mu, 1000 kg of decomposed organic fertilizer and 100 kg of 45% ternary compound fertilizer can be applied as base fertilizer. Use drip irrigation tape under the film for irrigation. After transplanting, water thoroughly for establishment; do not water during the seedling recovery period to promote root growth; after seedling recovery and before fruit setting, control water appropriately to promote steady growth of the seedlings.

3. After flowering and fruit setting, apply fertilizer with water. After entering the peak fruiting period, water promptly according to weather conditions and soil moisture. Usually, apply fertilizer with water once every 7-10 days, alternating per mu between 10 kg of urea or 30 kg of compound fertilizer.

X. Plant Adjustment

1. When the vine grows to 30 cm, hang the vines. Use hemp rope for vine hanging; tie one end tightly to a wooden stick about 10 cm long, insert the stick near the base into the soil to fix it, and gently wind it around the vine; tie the other end to the wire above the planting row with a slip knot to facilitate lowering the vines. As the stem elongates and fruits are continuously harvested, it is necessary to lower and coil the vines multiple times; the vine hanging height should preferably not exceed the wire.

2. Also, remove declining branches and old leaves in time to reduce mutual shading and ensure the plants receive uniform light. After the first fruit sets, pinch the top and cultivate 1 side branch to grow and bear fruit; thereafter, continuously pinch the top and lower the vines to promote fruit setting on side vines.

XI. Yield

In recent years, the dense planting technique for luffa in facilities during the main crop has been demonstrated and promoted. In 2015 and 2016, using this technique, the average yield of facility-grown luffa reached 50,000 jin per mu, effectively increasing the yield and quality of luffa in this region and increasing farmers' economic income.