Environmental conditions suitable for growing lemons

It is suitable for cultivation in subtropical areas with warm winters and cool summers, areas with warm winters and small annual temperature differences.

Lemon likes warmth, tolerates shade, is intolerant of cold, and is afraid of heat. Therefore, it is suitable for an average annual temperature of 17 to 19°C, greater than or equal to 10°C, and an annual effective accumulated temperature of 5200 to 6500°C in January. It can be cultivated in areas with an average temperature of 6 to 8°C, extreme low temperatures of greater than -3°C, annual rainfall of 1200 to 1500 mm, and annual sunshine hours of greater than 1200 hours.

In areas where the annual average temperature is less than 17°C, areas with short-term low temperatures of -5°C and periodic freezing damage are not suitable for open-field economic cultivation.

The soil and terrain requirements are not strict, and both flat land and hilly slopes are suitable for cultivation. However, the soil layer must be deep, loose, rich in organic matter, strong in moisture and fertility, good drainage, low groundwater level, and pH value in Slightly acidic soil between 5.5 and 6.5 is best.

1. Lemon distribution range

Lemons are native to Malaysia and are distributed in the United States, Italy, France, the Mediterranean coast, Southeast Asia and the Americas, including Taiwan, Fujian, Guangdong and Guangxi in China. It is also cultivated in other places.

2. Lemon pest control

Lemons are very resistant to pests and diseases, especially when cultivated in the north, where the climate is dry and there are fewer pests and diseases. Prevention of pests and diseases is the main focus, and attention should be paid to cleanliness and hygiene in cultivation and management. If there is dust on the leaves, spray water to wash it away. Ventilation and light transmission are also important.

Diseases

The main diseases include anthracnose, scab, gum disease, foot rot, yellow spot, brown spot, etc. The main prevention and control methods are: strengthening cultivation management, paying attention to drainage and irrigation, applying more organic fertilizers, and timing cutting and pruning to avoid orchard canopy closure. The prevention and treatment of gum disease and foot rot is to cut off the diseased part first, then apply lead copper or ethyl phosphorus aluminum liquid on the diseased part, once every 7-10 days. For other diseases, spray Dasheng M-45 once a month from April to September (can be mixed with other pesticides). When you are sick, just add Xiansheng or Xinsheng.

Pests

Mites

Artificial release of predatory mites, interplanting of fragrant thistles in orchards, etc. Pay attention to the use of Bordeaux mixture or stone as much as possible when preventing diseases. Sulfur compounds, and broad-spectrum fungicides to avoid killing natural enemies. After picking the fruit and before the shoots emerge in the spring of the second year, spray 0.5% Fruit Sage 500 times once to eliminate overwintering eggs and treat other diseases and insect pests. When the spring buds are about 2 cm long and the young leaves are stretched, which is around late March, check the annual leaves of lemons once every 7-10 days. When the number of mites and eggs reaches 200/100 leaves, or there are mites on the leaves. When reaching 50%, spray pesticides in time, and spray again when the number of mites reaches 600/100 leaves after flowering. The agent should be 0.5 Vitolin 2000 times liquid, or 5% Nisolan 2000 times liquid, or 15% Dafenil 2000 times liquid, or Red Mite Killer 3000 times liquid, Mikax 1000-1500 times liquid, etc. When the density of rust mites reaches an average of 2-3 per field of view (10x portable magnifying glass) in summer and autumn, or when a few black-skinned fruits are found on individual trees and rusty brown leaves appear on individual branches and tips, you should spray the mites through your mouth.

Bud maggots

According to pest and disease forecasts, take advantage of the favorable opportunity when adults first emerge from the ground and crawl on the ground instead of flying immediately, or when buds are emerging (the buds are as white as a mung bean). Or spray when the flower buds just turn white and the adults are about to emerge. You can choose 1.5kg of 25 carbaryl powder per acre, or 1.5kg of 2.5% trichlorfon powder mixed with 30-35kg of dry fine loess for dusting. You can also choose to spray the ground with 2.5% fenmethrin 2000-2500 times liquid or 20% Chinese and Western permethrin 3000-4000 times liquid, once every 7-10 days, and spray twice in a row.

Scale Insects

During the hatching period of nymphs, apply pesticides 2-3 times. The pesticide can be 70% Emerald 6000-10000 times, or 3% Mobiran 2000-2500 times solution, 1000-1500 times solution of Micox, 1000 times solution of 48% Lesbon, 15-20 times solution of pine-base mixture, etc. Cut off insect branches, dry branches and dead branches.

Mealybugs

Combined with winter pruning, cut off dense and weak branches, sprouting branches and insect branches to improve ventilation and light transmission conditions. Reduce the population base of overwintering insects. Carry out chemical control during the peak period of 1-2 instar nymphs. For the type and concentration of chemicals, please refer to scale insects. Protect and utilize natural enemies. The natural enemies of whitefly pests include parasitic bacteria, parasitic wasps and predatory natural enemies. When preventing and treating pests and diseases, pay attention to choosing agents that are less harmful to beneficial organisms.

Papilly butterfly

When the number of larvae is not large, the eggs can be removed and the larvae can be killed. When the larvae occur for a long time, spray pesticides during the peak period of 2-3 instars. The pesticide can be 20% killing pyrethroid 2000 times, or 2.5% Kungfu 3000-4000 times.

Leafminer

The main purpose is to eliminate sporadic early-emerging and irregular summer shoots, and to concentrate the shoots to reduce the base of the insect population. When it is found that the new shoots are being pulled out and the damage rate of the new shoots reaches 5%, or when the egg (worm) rate of the young shoots after the shoots are released reaches 30%, start spraying. Spray 2-3 times every 7-10 days. The agent can be 7% Aimele 1000-1500 times liquid, or 0.5% Vitolix 800 times liquid, 2.5% Kungfu 2000-3000 times liquid, 20% acetate emulsifiable concentrate 800 times liquid, etc.

Reference link: Lemon (Citrus plant of the Rutaceae family)_Baidu Encyclopedia