Spring Lettuce: sowing seedlings in the fall, early winter or early spring colonization, spring harvest. When the seedlings are colonized with 5-6 true leaves, the growth is robust and the roots are well developed. Seeding early or late, when the winter is over, the seedlings are too large or too small, and they are susceptible to freezing. The wet sowing method should be adopted, and the seedlings should be 1-2 times after emergence. Appropriate control of irrigation at the seedling stage leaves the leaves thick and flat. In winter, the open areas can be planted in winter, as early as possible before the winter planting, such as before the harvest for the late or for the stages listed, can also be planted in the spring. In regions where winter is difficult, the soil is thawed in early spring and planted as soon as possible. We chose clay loam and sandy loam with rich organic matter, water retention and fertility. Apply organic fertilizer as base fertilizer. The form of 畦 varies from place to place. Line spacing is about 40cm. Pre-winter control irrigation, careful cultivator, shallow soil, protect the root and neck from frost damage. After returning green in the early spring, many times of cultivating and maintaining the temperature increase the leaf area rapidly. When the fleshy stem begins to hypertrophy, nitrogen and potassium fertilizers are combined with irrigation. After the irrigation should be uniform, top dressing can not be too late, the amount of fertilizer each time can not be too large to prevent cracking of fleshy stems. The tip of the main stem and the tip of the tallest leaf are usually suitable for harvesting. The harvest is too late, the stems elongate, the fibers increase, the fleshy stems become hard and even hollow, and the quality is poor. Autumn Lettuce: sowing in summer and harvesting in late autumn. High temperature during sowing, seed germination is difficult, not easy to seedlings, seedlings are easy to grow long, flower buds differentiate early, and twitching quickly. Cultivating strong seedlings and preventing premature bolting is the key. Choose the appropriate sowing time for mid-late and late-maturing varieties that have a slow response to high temperature and long days. Seeds were soaked in cold water for 5-6 hours. Seeds were germinated under light conditions at 15-18°C. Seeds were sowed in wet sowing method, and the soil was covered with a shallow cover to cool the shade. 4-5 true leaf colonies. After the mast begins to hypertrophy, available nitrogen and potassium fertilizers are applied. More use of spring lettuce leave seed. Select plants with cultivar characteristics, late bolting, dense internodes, no collaterals, few leaves, long fleshy stems without cracking and disease-free plants, available nitrogen fertilizers and phosphate fertilizers before flowering, and no water shortage after flowering. Reduce irrigation after flowering, prevent sprouting at the late stage, and consume nutrients. Take a white umbrella-like crown on the achene. The main pests and diseases are downy mildew, sclerotia, mosaic disease, aphids, thrips, and ground tigers. Shower Commode,Stainless Steel Commode,Steel Stacking Commode ,Mobility Wheeled Commode Chair Active Life Healthcare Co.,Ltd , https://www.alh-med.com
Mainly divided into spring and autumn. Suburbs of major cities such as Nanjing, Shanghai, Beijing, Chengdu and Xi’an have basically started to be sown and listed in stages.