The latest course on planting techniques and methods of lemon trees

Lemon is a citrus plant of Rutaceae, which is native to Southeast Asia. It is mainly produced in the United States, Italy, Spain and Greece. It is also cultivated in Taiwan, Fujian, Guangdong and Guangxi, and is rich in citric acid. Therefore, it is known as the "citric acid warehouse" and has high planting value. Let's take a look at the lemon tree planting technology.

Planting conditions of lemon trees

Lemon is warm, shade-tolerant, not cold-resistant and afraid of heat, so it is suitable for cultivation in subtropical areas where it is warm in winter and cool in summer. The suitable annual average temperature is 17-19 ℃, the annual effective accumulated temperature (≥ 10 ℃) is more than 5500 ℃, the average temperature in January is 6-8 ℃, and the extreme minimum temperature is higher than 3 ℃. The annual rainfall is more than 1000 mm and the annual sunshine hours are more than 1000 hours. It is suitable to be planted on a gentle slope with warm and deep soil layer and good drainage. The most suitable soil pH value of lemon is between 5.5 and 7.0. The plant grows fast, the plant is as high as 3-6 meters, and it needs a large amount of fertilizer. It has many shoots, blossoms and fruits in a year, and the yield varies greatly because of the good or bad management.

Grafting propagation of lemon tree

1. Splicing: splicing is often used in spring. The grafting effect is better when the sap begins to flow. Sichuan and Chongqing can be grafted within half a month before and after the Rain and Water Festival, and Guangdong has a high survival rate within 40 days after the Beginning of Spring. In years with low temperature, the grafting time can be postponed to May. The cutting operation is simple, the germination is fast and the growth is fast. It can reach the specification of coming out of the nursery in the same year, and can be planted in autumn or the following spring.

2. Abdominal grafting: abdominal grafting is generally used for autumn grafting, which can be carried out from Rain Water's festival to the first ten days of November. The survival rate of abdominal grafting is higher, which can be replaced for 2 or 3 times without one operation. Scion cutting method is the same as cutting method, about 10 cm from the ground, select the smooth surface to cut from top to bottom, about 2 cm long, the cutting depth is appropriate not to hurt or slightly damage the xylem. After the mouth is opened, the scion is embedded and the interface is tightly sealed with plastic film strip from bottom to top.

3. Budding: budding can be divided into two types: small bud grafting and small bud ventral grafting. Small bud grafting is mainly carried out in spring and small bud ventral grafting is mainly carried out in autumn. The budding speed is fast, the work efficiency is high, the wound of the rootstock is small, and it is easy to heal. When cutting buds, hold the scion in the left hand, hold the knife in the right hand, put the knife edge flat, cut from the lower 1 cm of the bud to the upper end of the bud to 0.5 cm above the bud, make the bud with xylem, and then cut the scion down vertically with a knife to remove the bud piece.

Lemon tree establishment and planting

1. Pingba garden: to build a lemon garden with paddy fields, water should be released from high ditches along the slope to dry the fields. After the soil is whitened in the coming year, according to the fixed point of planting, the steamed bread-shaped mound is 40cm high and 50cm high, and the diameter of the bottom of the pier is about 1 meter.

2, slope construction garden: slope construction garden can be adopted to build contour terraces, contour trenches or fish-scale pits to solve soil fertility and soil and water conservation, contour terraces are suitable for slopes with a slope of 100-25 degrees, contour trenches are suitable for slopes with a slope of 6-100, and fish-scale pits are suitable for steep slopes and complex terrain where it is difficult to build horizontal terraces or contour trenches.

3. Lemon planting: the planting density should be 3 × 4 meters and 55 plants per mu. The planting period is generally in spring and autumn, and transplanting in autumn should be carried out from September to October. Before planting, dig a fixed planting hole (ditch) with a specification of 60 × 60 × 60 cm, and apply organic fertilizer 30kg / kg, calcium superphosphate 0.5kg / kg, or mature human and animal dung water more than 20kg. Mix the fertilizer with the soil and cover the soil to make a planting pier with a high unearthed plane of 20cm. When planting, remove the grafting film, trim the injured roots, cut off the long main roots and tender late autumn, and so on. Make a small nest on the planting pier, put in the seedlings, cover the soil while trimming the roots, gently lift the seedling roots, and gently press the soil, so that the roots are closely connected with the soil. The planting depth should be consistent with the mud marks in the nursery stage, the root neck should be exposed to the ground, irrigated with fixed root water, and covered with straw, straw, green manure or plastic film to keep warm and wet.

4. Post-planting management: it takes about half a month for seedlings to survive. This half month should be watered frequently rather than topdressing. After survival, it should be checked frequently to ensure that the soil is moist but not soiled, so as to promote the growth of roots and shoots. Only after a small number of new shoots grow, can you apply clear dung water.

Management of young lemon trees

1. Soil management: every winter idle season, combined with shallow ploughing to cultivate soil, dig out 1 to 2 fertilizer holes with a length of 40 cm to 60 cm and a depth of 60 cm to 80 cm in the crown drip line, and apply compost of 100 kg / m2 (or barnyard manure). It is evenly mixed with the soil, which is beneficial to cultivate the well-developed absorption roots of young trees and enhance the absorption function of nutrients.

2. Fertilizer and water management: young trees are fertilized 5-10 times a year to apply fertilizer frequently and thinly. The main types of fertilizers are available nitrogen fertilizer, combined with phosphate fertilizer, potash fertilizer and human and animal manure. From the spring shoot germination in March to the autumn shoot emergence period in September, the seedlings were treated with 30% rotten human and animal dung once a month. For annual young lemon trees, it is usual to apply 80 grams of nitrogen, 40 grams of phosphorus and 30 grams of potassium annually, and then increase by about 10 grams year by year. 2. The fertilization period of 4-year-old young trees was concentrated before each shoot was drawn. The annual fertilization times were 5-6 times, and the foliar fertilizer was sprayed 3-4 times at the tender shoot stage.

3. shaping of young trees: the fixed dry height of lemon is about 40cm to 50cm. When the grafted seedlings produce spring shoots or mature summer shoots, they are coring at full shoots 40 cm from the ground, prompting them to shoot 4-6 new shoots at 25-40 cm to form branches. If the shoot is not ideal and less branches are formed, the buds can be wiped for 1 or 2 times to promote the trunk to produce new shoots. After the shoot is ripe, the strong branch is selected from the upper part as the first main branch, leaving 20-25 cm long, truncating the apex part, and the rest is reserved as auxiliary branches.