How to grow Indian lettuce for high yields? Cultivation techniques for high-quality fish forage grass

Indian lettuce is an annual or perennial herbaceous plant in the Asteraceae family, genus Lactuca. It is rich in nutrients, and its crude protein content is 35%-40% higher than that of Sudan grass, which enjoys the title of "king of forage grasses." The tender leaves of Indian lettuce contain a lot of carbohydrates, have good palatability, and a utilization rate of nearly 100%, making it a superior green feed for fish. Indian lettuce is the best "green forage" for "filling the gap between seasons and bridging to the peak season" between the off-season of ryegrass and the coming peak season of Sudan grass. It can serve both as the "staple food" for herbivorous fish and as a "delicacy" for cultivating fish species such as black carp, grass carp, and bream.

Cultivation characteristics: Indian lettuce likes warm and humid climates, and is also heat-tolerant and cold-resistant. It is not strict about soil fertility, but yields are higher when planted in soil with good drainage or slightly sandy soil. It has strong regeneration ability and tolerates cutting, and can be cut 7-8 times per year. Cultivation and management are simple, and it has relatively high productivity. Under ordinary conditions, the yield per mu is about 4,000 kg, and can reach more than 5,000 kg at high levels.

Sowing techniques: Indian lettuce can be direct-sown or transplanted, but in production, direct sowing is mainly used. Indian lettuce can generally be sown when the daily average temperature stabilizes at 12°C. Because Indian lettuce seeds are small and the cotyledons of the seedlings are small and thin, the land should be carefully leveled before sowing, and enough base fertilizer mainly composed of organic fertilizer should be applied. Direct sowing has three methods: drilling, dibbling, and broadcasting, but drilling is better. Drilling: the sowing furrow is about 15 cm wide and 2 cm-3 cm deep, with a row spacing of about 25 cm. Dibbling: plant and row spacing are generally 20 cm x 25 cm. Broadcasting: sowing over the entire bed. Whether drilling, dibbling, or broadcasting, the seeds must first be mixed into stove ash or fine soil mixed with calcium magnesium phosphate fertilizer, then sown evenly. After sowing, except that broadcasting requires appropriate covering with fine crushed fertilized soil, drilling and dibbling do not need covering. Generally, about 0.5 kg of seed is used per mu. When the soil is moist and the temperature is normal, most seedlings can emerge from the soil in about 7 days.

Cutting management: Indian lettuce grows quickly, has strong regeneration ability, and has a high demand for fertilizer. Therefore, in addition to applying enough base fertilizer at sowing, during the seedling stage, a quick-acting fertilizer mainly composed of human and livestock manure water should also be applied as a top dressing in combination with intertillage, loosening the soil, and weeding, to promote early and rapid growth of the seedlings and shorten the cutting cycle. The vigorous growth period of Indian lettuce is from April to July. In early May, when Indian lettuce has grown to about 40 cm, it can be cut for the first time. When cutting, leave a stubble of about 3 cm, and afterward it can be cut again about every 20 days. After each cutting, intertillage and top dressing should be carried out immediately. Generally, 5 kg-8 kg of urea per mu plus 150 kg of human and livestock manure water are diluted with water and poured on. During the growth period of Indian lettuce, aphid damage mainly occurs. To control aphids, pesticides are generally applied on sunny afternoons. Per mu, 50 kg-60 kg of a 1500-fold to 2000-fold solution of 80% dichlorvos emulsifiable concentrate, or a 1000-fold solution of 25% diflubenzuron No. 3 suspension concentrate, can be sprayed. Note: stop applying pesticides 10 days before cutting.

Seed-saving method: For saving seed of Indian lettuce, choose a plot with above-average fertility. Generally speaking, the seed-saving plot stops cutting in late July (that is, after 4-5 cuttings), and a fertilizer mainly composed of phosphorus and potassium is applied as a top dressing to promote robust plant growth and lay the foundation for flower bud differentiation and more flowering and seed setting. Because Indian lettuce has the characteristics of a long flowering period and seeds maturing at different times, attention should be paid in the later stage to preventing early-maturing seeds from falling off naturally, and doing a good job of harvesting seeds in batches, that is, "harvest as they mature," to strive for high seed yield and a bumper harvest.