Planting of lemon trees: 1. Temperature management: When the temperature drops below 10℃, lemon should enter the room. The indoor temperature should be kept at 25℃, and the lowest temperature should not be lower than 9 ~ 10℃. If it appears below 2 ~ 3℃, it will shed leaves and freeze to death for a long time. However, judging from the Lisbon lemons planted in recent years, there will be a little defoliation at-1 ~-3℃ in the short term, but it will not affect the flowering and fruit setting rate. 2. Pruning, if the temperature is suitable, lemons can bloom all year round, young trees grow vigorously, the tree looks open, the backbone branches and bends are easy to grow long branches, which disturbs the tree shape, and new shoots are rarely produced after long branches bear fruit, which is easy to form large and small years. Buds usually grow on 2-3-year-old branches, and branches that bloom in summer and autumn are mostly spring shoots of that year. The tree shape is a happy natural round head, and the main branch and the trunk extend straight up at an angle of about 30 degrees, which can reduce the appearance of long branches. Branchlets should be spaced apart and slightly open, and the crown should be light and astigmatism to prevent prickly varieties from stabbing the fruit. When pruning, you should always wipe the buds of the backbone branches and pull out the long branches as soon as possible to form fruiting branches. In summer and autumn, 5 ~ 6 leaves should be picked from the shoots, and the main branches and auxiliary branches should be updated in time if they are prone to drooping after fruiting. 3. Pest control. In addition to scabbing and ulceration, we should also pay attention to chapped skin and gummosis (black spot disease). Chapped dermatosis is a virus-like disease. After the onset of the disease, the bark splits longitudinally, the outer skin falls off, the new shoots are few and weak, the leaves turn yellow, and the zinc-deficient branchlets die. Therefore, it is very necessary to choose disease-free trees for planting. After suffering from melasma, the cuticle is necrotic, the xylem turns grayish brown, and the diseased and healthy parts produce yellowish brown bacterial bands, and the diseased parts are covered with black spots. In addition to the initial scraping and disinfection of diseased spots, 1% bordeaux mixture was sprayed before germination, and 1 50% bactericide and 600 times 50% thiophanate methyl were sprayed at flowering stage and young fruit stage respectively. Soot disease is related to whiteflies, scale insects and aphids. When spawning in groups in the first ten days of July every year, 50% chlorfenapyr 1000 times or 40% omethoate 1000 times can be sprayed 2-3 times. During May-June or from late August to early September, the scale insects were sprayed with 1000 ~ 2,000 times or phoxim1000 times.

4. Fertilizer and water management. Lemons are generally fertilized 3-4 times a year, namely, accelerating germination fertilizer, stabilizing fruit fertilizer, strengthening fruit fertilizer and picking fruit fertilizer. That is, when the temperature drops to 10 ~ 12℃, apply some decomposed organic fertilizer, add some phosphorus and potassium fertilizer, generally use manure or cake fertilizer, and add a small amount of urea and potassium dihydrogen phosphate. From mid-February to early March, germination accelerating fertilizer, mainly nitrogen fertilizer, can be used as cake fertilizer or human and animal manure. In the late stage of physiological fruit drop, stable fruit fertilizer was applied, mainly nitrogen and potassium fertilizer, and the fruit-bearing period of lemon was long. For trees with many fruits, apply NPK compound fertilizer from July to 65438+10. Water potted lemons as little as possible during flowering and flower bud differentiation. The temperature is high in summer, which is the growing period of summer shoots, so water more. Generally, water every 2 ~ 3 days in spring and autumn, and 1 ~ 2 times a day in summer.