High-yield cultivation techniques of planting Lemon Young trees

In the countries and regions that produce citrus in the world, many countries and regions cultivate lemons. Lemon is a kind of citrus widely welcomed by consumers. It is rich in nutrition, rich in citric acid, vitamin C, vitamin B, vitamin P and other vitamins, and the acid content in lemon juice is as high as 6% to 7%. In addition, lemon also contains calcium, iron, magnesium and other mineral elements, which is beneficial to human health.

1. Lemon shoot growth characteristics lemon has a strong growth potential, drawing new shoots 3 or 5 times a year, drawing shoots, blooming and fruiting many times, with long, sturdy shoots and good yield.

Spring shoots from February to April: the germination time of new shoots was consistent, and the number was large, and the shoots were short, fine and neat, and most of them differentiated flower buds and formed fruiting mother branches.

Summer shoots from May to July: the branches grow strongly, absorb more nutrients, the leaves are dark green, and the cross section of the branches is rhombic, which is easy to form long branches.

Autumn shoots from August to October: most of them are female branches of the following year. Under the influence of flowering and fruiting, the number of shoots is small, the branches are slender, and the development is not full.

Winter shoot from November to January of the following year: due to the influence of low temperature and nutrients, the number of hair is small, the nutrition is insufficient, and it is easy to produce yellowing.

2. Pruning of lemon the main purpose of pruning young trees and first fruit trees is to cultivate the crown skeleton in order to expand the crown faster and better. Pruning of young trees is suitable in winter, coring and necessary truncation should be carried out in the growing season, and branches and leaves and auxiliary branches should be retained as much as possible. Pruning points:

1. Long shoot coring young trees should draw long shoots. After each season shoot is produced, except for keeping 8: 10 coring pieces for long shoots, the rest should be used as tender shoots. It is appropriate to leave a length of 20-25 cm to enrich the robust crown, early branching and multi-branching, so as to expand the crown as soon as possible.

two。 Timely erase the long branches and disturb the shape of the tree, waste nutrients, should be erased in time.

3. Pull branches for the vigorous growth of upright branches, it is appropriate to use the method of pulling and supporting. The strong branches are pulled down and the solution angle of the larger branches is 40 °~ 50 °. If the young trees are pulled and braced, the young trees can bear fruit 1 ~ 2 years earlier.

4. Wiping buds and putting shoots on young trees can be carried out in summer, that is, one autumn shoot, in order to expand the crown as soon as possible.

5. The young trees with strong growth after pruning in summer have more strong and prosperous shoots. As the strong summer shoots are not easy to produce autumn shoots and are not conducive to flower bud differentiation, bud wiping and thinning are carried out from May to July. Therefore, it was completely cut off in early August, so that more autumn shoots were produced from late August to early September. Most of these autumn shoots blossom and bear fruit the following year.

6. Auxiliary branches cultivate branchlets that usually grow in the crown and should generally be retained as long as they are not overgrown and over-dense branches. These twigs are often good fruiting mother branches for young trees.

7. Flower thinning and bud thinning should timely remove the buds and fruits of weak trees before planned fruit production in order to promote tree nutrition production and form a fruiting crown and put into production as soon as possible.

3. Measures for flower and fruit protection of lemon after spring bud germination, 0.2% zinc sulfate was applied first, 0.5% urea + 0.2% calcium superphosphate + 1% potassium sulfate was sprayed once before flowering, and 0.2% urea + 0.2% potassium dihydrogen phosphate was sprayed with 0.4% 0.5% urea + 0.2% potassium dihydrogen phosphate after blossom. During the fruit expansion period, 0.3% urea + 3% superphosphate + 0.5% potassium sulfate was sprayed. In order to maintain sufficient soil moisture after the young fruit is stable, the key is to water thoroughly 10 days before spring.

The purpose of applying fertilizer to young trees without fruit is to promote the crown to grow as soon as possible so that it can be put into production as soon as possible. However, attention should be paid to prevent the excessive growth of excessive nutrition caused by excessive fertilization, so as not to blossom and bear fruit. To apply fertilizer to young trees, it is necessary to grasp the principle of "applying frequently and thinly". Young fruit trees mainly apply fertilizer three times a year:

The first fertilizer is pre-flowering fertilizer in mid-February, accounting for 25% of the whole year. 800-1600 kg of farm manure, 8 kg of urea, 8 kg of superphosphate and 8 kg of compound fertilizer should be applied per mu.

The second fertilizer is from the end of June to early July, accounting for 50% of the whole year. 1600 kg of farm fertilizer, 16 kg of urea, 16kg of superphosphate and 8kg of compound fertilizer should be applied per mu.

The third fertilizer is from the end of August to early September, accounting for 25% of the whole year. 800-1600 kg of farm fertilizer, 8 kg of urea, 8-16 kg of calcium superphosphate and 8-16 kg of compound fertilizer should be applied per mu.

5. Comprehensive methods such as agricultural control, biological control and chemical control are adopted to control the sources of diseases and insect pests to the lowest level.

Agricultural control: increase the application of farm manure, enhance the resistance of trees, remove weeds and clean the garden, eliminate the hosts of diseases and pests, and prune withered branches, diseased branches and insect branches to prevent the spread of diseases and insect pests.

Biological control: raising chickens, ducks and bees in orchards has a certain control effect.

Chemical control: give priority to prevention, supplemented by treatment, understand the disease, grasp the insect situation, see the period, and prescribe the right medicine to the case. Spray control should be unified in all major areas, and pesticides should be used alternately.

(1) Diseases

Scab: harm to young leaves, twigs and young fruits, the disease spots on the leaves are watery at first, then wax-yellow cork, showing conical protuberances, causing leaf distortion and deformity in serious cases; tumor-like protuberances appear on the pericarp of fruit, and the diseased fruit is small, deformed and easy to drop fruit.

Control methods: (1) strengthening cultivation management, combined with winter pruning to remove diseased leaves, concentrated burning. (2) spray protection of new shoots, spray at 2 / 3 to protect young fruits, use 1000 times of 50% carbendazim and 800 times of 1000 times of Dafusheng.

(2) insect pests

1. Mites (red and yellow spiders, rust mites): harm leaves, so that leaves lose luster, gray-white, causing fallen leaves, withered shoots. The leaves damaged by yellow spiders are deformed and twisted. The back of the leaves damaged by rust mites were yellowish brown or rust brown, and the damaged fruits were dark brown.

Prevention and control methods: (1) spray once at the beginning of spring or apply stone-sulfur mixture on the main rod. (2) 73% gram acarate 2000 × 3000 times liquid; acaroid mites 1000 × 1500 times liquid spray. In order to control the red spider, we must first master "the insect strain in the control center and the control in a large area as a supplement."

two。 Leaf miner: the larva sneaks into the tender leaves and fruit epidermis to feed, forming a white worm channel, which makes the leaves curl and become brittle and fall off, and the fruit is easy to rot after being damaged.

Control methods: (1) control summer and autumn shoots, remove premature, too late and redundant shoots, and cut off the food chain of leaf miner. (2) focus on prevention and control in the summer shoot exuberant and autumn shoot emergence period, there are more pesticides available, and it is best to use them alternately in order to obtain better efficacy. Spray to protect the shoot, spray the medicine for the first time when the shoot extraction rate is more than 20%. 20% cypermethrin 1500m 2000 times solution can be used.