How to plant longan early and produce high yield in mountainous area

Longan is a kind of subtropical fruit with high economic value and a special fruit tree in China. In 1989, the planting area of longan in Xinyi City was about 467 square kilometers, but due to extensive management, longan young trees grew slowly, put into production late, and even bear fruit every other year, resulting in low yield and poor efficiency, which affected the enthusiasm of farmers. For this reason, we have carried out the early fruiting and high yield experiment in the mountain longan field of the Land Bureau of Xinyi City for 6 consecutive years in October 1991, and it has been put into production in the third year after planting, and the output has increased year by year, and good economic benefits have been obtained. Combined with the local reality, we have explored a set of early fruiting and high yield cultivation techniques of longan, which is suitable for planting in mountainous areas.

Management of young trees

The management of young longan trees is mainly through agricultural technical measures such as soil improvement, fertilizer and water management, shaping and pruning, pest control and other agricultural technical measures to rapidly form a skeleton with high and stable yield and irregular round-head crowns, so as to achieve the cultivation goals of early fruiting, high yield, stable yield and high quality.

1. Deep turning and pressing green to improve the soil

According to the characteristics of small root distribution of young longan trees, measures such as expanding holes and pressing green, interplanting crops and other measures were adopted to improve soil fertility and the regulation ability of water, fertilizer, gas and heat, and improve the growth environment conditions of roots, so as to lay a foundation for high yield, stable yield and high quality. Ditches are usually dug between two longan plants from September to December, with a width of 1.5 meters and a depth of 0.7 meters. After a period of time, the ditches are pressed into green manure or farm manure, and then sprinkled with lime.

2. Timely fertilization, timely drainage and irrigation

The crown and root system of young trees are small, the amount of fertilizer required is not large, and the roots of young trees are sensitive to fertilizer, so the principle of fertilization for young trees is to apply fertilizer frequently and thinly. In the first year after planting, the first fertilizer was applied after the first batch of shoots matured, each plant was drenched with 4 kg of dung water, or 25 jin of compound fertilizer was applied with water, and then applied 3 times a month. In the second year, the first fertilizer was applied before and after "the Spring Equinox", with 10kg of pig manure, 0.25kg of peanut bran and 0.25kg of superphosphate per plant, 0.25kg of compound fertilizer per plant and 5kg of pig manure and 0.25kg of peanut bran per plant. After planting, the first and second fertilizer was applied 20 cm away from the trunk, and then under the crown dripping line, the ditch was 10 cm 15 cm deep and 20 mi 25 cm wide.

Water management should pay attention to excluding waterlogging in rainy season and moisturizing in dry season.

3. Shaping, pruning and sprouting

Shaping and pruning is to cultivate the tree shape of high and stable yield, so that the branch distribution is uniform and the development is balanced. However, young trees generally do not need a large number of pruning, focus on shaping, cultivate a crown with high and stable yield, concentrate nutrients for the growth of effective branches, promote it to form a round crown as soon as possible, and carry out the fruiting period earlier.

After the young trees with ① sprouts survived, three new shoots with evenly distributed angles were selected as the main shoots 40 cm above the ground, and each time the buds were left weak and strong, inside and outside, and left on the bottom.

② truncation is carried out when the three main branches grow to 35cm long and 0.6cm thick, leaving 2530cm at the base, and then each truncation is carried out in accordance with the above-mentioned method.

③ bud thinning should be carried out after each truncation, when the new shoot length is about 5ml / 8cm. Generally, two new shoots are left on each main branch (robust, good bifurcation angle), and then the extra new shoots are wiped off.

Management of result tree

Excellent longan grafted seedlings are planted in mountainous areas. under scientific management, there are 4 Mel 6 branches in the third year after planting, with more than 30 effective branches and a crown width of more than 180 cm. After longan begins to carry on the fruiting period, the crown continues to expand, and every year it is still necessary to turn deeply and press green, increase the application of organic fertilizer, and make the orchard soil mature. Deep ploughing is carried out from December to January of the following year after the last shoot is mature, which can also control the winter shoot and promote the formation of flower buds.

1. Cultivate timely and healthy fruiting mother branches.

① timely fertilization was carried out for the first 10 days before fruit harvest, the second after fruit harvest and the third in October. The amount of fertilizer application can be determined according to the size of the crown and the number of fruits. Take the tree with a fruit of 30 kg as an example, the first application of peanut bran 1.5 kg (rotten) or 15 kg of chicken manure, the second and third fertilizer can be added with a small amount of chemical fertilizer. The fertilizer was applied in a half-shaped ditch under the crown dripping line, and the soil was covered after application.

② pruning and bud pruning was carried out from the second fertilization to before the first batch of new shoots, mainly cutting off weak branches, disease and insect branches, short cutting and growing branches. Bud thinning was carried out when the new shoots were pulled out to 5ml / 8cm. Only two new shoots were left on each fruit-picking branch in the first batch of shoots, only one new shoot was left on each fruit-picking branch in the second batch of shoots, and the remaining buds were removed. The new shoots left behind should be robust and well-angled, so that the stem of the developed mother branch is more than 0.6 cm thick.

③ shoots are often damaged by diseases and insect pests in the process of sprouting in autumn. The main diseases are anthracnose and leaf spot. Anthracnose can be controlled with copper oxychloride 600ml 800 times, and leaf spot disease can be controlled with methyl topiramate 1000 times, so as to ensure the healthy growth of branches.

2. Winter control and flower promotion

Longan controlling winter shoot germination and promoting flower bud differentiation is the key to blossom and fruiting in the following year. The main measures of controlling shoot and promoting flower in winter are as follows: ① cutting root, restraining shoot and promoting flower. After the last shoot was fully mature, the soil was turned over deeply under the crown drip line, and part of the root system was cut off. Half of ② restrained shoots and promoted flowers. After the end is fully ripe, tie the trunk of longan tree once with 14mur16 wire, so that you can't move up and down, and remove the wire immediately after the leaf color turns back. Chemical hormones were used in ③. 0.3% Mel 0.4% paclobutrazol can be used, or special flower promoter Huaguoling for litchi and longan can be used to spray leaves and shoots.

3. Protect flowers and fruits

① fertilization

The first fertilization was arranged from "the Beginning of Spring" to "Rain Water". It was mainly organic fertilizer, adding appropriate amount of potassium fertilizer, applying opposite half-moon ditch under the crown dripping line, and covering the soil after fertilization. The second fertilization was carried out in early May, mainly compound fertilizer, spread under the canopy, and loosen the soil immediately after application. The amount of fertilizer application depends on the size of the crown and the strength of the tree. Generally, for a tree with 15 words of fruit, 10 kilograms of pig manure or chicken manure, 1 kilogram of peanut bran, 0.5 kilogram of calcium superphosphate and 0.5 kilogram of compound fertilizer are applied for the first time.

② flower thinning

When the main axis of the spike grows to 5ml / 10cm, peeling and topping is carried out, and the lateral flower branches are generally retained to control the length of the main axis and lateral flower branches, so as to reduce the number of male flowers, increase the proportion of female flowers, and reduce the delicate flowers and over-dense flowers, so as to improve the fruit setting rate. The method of cutting off the ear of flowers can also be used, generally cutting off the spikes of 1, 3, 3, 1 and 2 flowers per tree, which can not only ensure the amount of fruit in the current year, but also cultivate strong fruiting mother branches for the next year, which can reduce the phenomenon of fruit in the next year, and achieve the goal of high and stable yield.

③ bee pollination

Placing a swarm of bees per 0.2mil 0.3 square kilometer orchard is beneficial to pollination and increase the fruit setting rate.

④ to prevent retting and burning flowers

In the case of overcast and rainy weather, the anther is difficult to crack during the flowering period of longan, and the phenomenon of rotten flowers is called retting flowers, which can shake branches at noon every day, shake off Rain Water on the flowers, air-dry the flowers and promote anther cracking, which is conducive to pollination. If there is continuous high temperature during longan flowering, the female flower stigma is easy to burn, and it is too thick because of nectar concentration, which is easy to cause burning flowers. It can spray water to the crown every afternoon to flush dilute nectar and increase humidity to prevent stigma burns and premature withering.

⑤ fruit protection

The physiological fruit drop of longan is lighter than that of litchi, but the young fruit is easily affected by bad weather and lack of nutrients, so Guoteling is sprayed once at 7 days, 30 days and late June after flowering, and extra-root fertilization can also be used to protect fruit. such as spraying Shengduosu, Cuikang Shengli liquid, Nong Yiqing and so on.

⑥ fruit thinning

The fruit setting rate of longan is relatively high, and some fruit branches have more than 100 fruits per panicle, or even 200ml / 300. if fruit thinning is not carried out, the fruit is small and uneven at maturity, has no market competitiveness, and the benefit is low, so fruit thinning must be carried out. Fruit thinning should be carried out when the fruit is the size of peanuts (that is, in mid-late May). The number of fruit left is generally determined by the variety and tree situation, with more strong trees and less weak trees; more inner branches and less outer branches; less in older years and more in younger years. For example, Chuliang Guangyan leaves 40 fruits per panicle, Shixia leaves 50 fruit per panicle, and Dawuyuan leaves 60 fruit per panicle. Removes the dense small fruit, double? Fruit, deformed fruit and disease and insect fruit, and cut off the ear with less than 10 fruit.

Pest control

The main diseases of longan are leaf spot, downy mildew, soot and anthrax, and the main pests are bugs, stem borer, wood lice, white moth wax cicada, leaf roll moth, beetle and so on. In addition to strengthening management and clearing the garden, drugs can be used for control.

1. Disease

Leaf spot disease can be prevented and treated with 1RV 100 Bordeaux solution, copper oxychloride 600Mel 800x, Dasheng Mmur45600Mel 800x, downy mildew and soot disease can be prevented and treated by methyl topiramate 1000 times or Dasheng Mrel 45600ml 800times. Anthracnose pathogens are fungi, which can be used to control fungi.

2. Insect pests

The stink bugs can be controlled by 80% trichlorfon 800mil 1000x, kung fu 2000mil 1000x, Arek 1000 times, pedicle borer 1000 times, Arek 1000 times, chlorpromazine 1000ml 1500times, wood lice 80% dichlorvos 800times, isocarbophos 1000 times, white moth wax cicada 80% dichlorvos 1000 times, or 80% isocarbophos 1000 times, or rapid culling 1000 times, etc. Leaf roll moths can be controlled by 90% trichlorfon or 1000 times dichlorvos; beetles can be controlled by 90% trichlorfon 800 times or 80% dichlorvos 1000 times; wood beetle moths can be controlled by 25% dimethoate 500 times or 40% dimethoate 500 times; inchworm can be controlled by 90% dipterex 800 times or 40% dimethoate 1000 times; shellfish can be used 1000 times or 40% omethoate 1000 times Mites can be controlled with 40% dicofol 1000 times, or 5% nisorone 2000 mi 3000 times, etc.