I. Management of Young Longan Orchard
Longan generally takes 3-4 years from seedling to fruiting, which is called longan juvenile. The key points of cultivation and management of young longan orchards should be different according to the age of trees. In the first year, the plant has just been planted, with few roots, shallow distribution and weak stress resistance. The focus of management work is to protect roots and new branches and leaves to improve their survival rate. In the second year, plants resumed normal growth, and many tender buds sprouted and grew vigorously. The focus of work is to strengthen fertilizer and water management and promote the rapid expansion of crown. In the third and fourth years, plants begin to enter the fruiting period. Management should pay attention to shaping and pruning, cultivate evenly distributed fruiting mother branches, strengthen soil improvement and ripening, expand the growth range of roots and increase the number of roots, so as to lay a good foundation for early fruiting and high yield.
soil management
1. Tree disk cover: Tree disk is the place where the root system is most distributed, and it is the base for providing nutrients and water for trees. In addition to frequent shallow ploughing, loosening soil and weeding, cultivation management should also cover trees well. Grass, straw or orchard weeds can be used as materials to cover the ground around the trunk. Before covering, the intertillage is loosened, and the covering thickness is generally 5- 10 cm. Tree tray mulching can not only reduce water evaporation and increase soil water content, but also prevent soil erosion, inhibit weed growth, make soil loose and breathable, and create good environmental conditions for root growth.
2. Soil improvement: In the longan orchards planted on hillsides and hills, in addition to planting holes and furrow ploughing before planting, hole enlargement (furrow soil improvement, layered filling with green manure, weeds, mixed lime, phosphate fertilizer and soil miscellaneous fertilizer) will be carried out year by year after planting to improve the soil fertility of longan orchards.
(2) Fertilization
Fertilization in young longan orchards can be carried out all year round, but the method, quantity and types of fertilization vary with the age of trees. In the first year of field planting, Qin Ying should apply fertilizer thinly, with better water and fertilizer, twice a month 1-2 times, generally with water spraying. Generally, 30-50g compound fertilizer or 20-25g urea is applied to each plant. In addition, spraying pesticides and adding 0.3% urea can also be used for root topdressing. In the future, gradually expanding the crown can increase the amount of fertilization, so that the topdressing can be 1-2 times each time, and the three-or four-year-old trees are ready to enter the fruiting period. At this time, attention should be paid to properly controlling the amount of nitrogen fertilizer, increasing the application of phosphorus and potassium fertilizer, especially the application of organic fertilizer, in order to cultivate developed roots and strong branches.
(3) Drainage and irrigation
The new orchard should pay attention to the construction of irrigation and drainage system, and keep the soil moist as much as possible during the growth of new shoots.
(4) trimming and shaping
Young longan trees should be lightly pruned, and plastic work should be the main task, so as to cultivate branch skeletons with evenly distributed branch angles. In addition, it is necessary to erase the buds of the trunk in time to reduce nutrient consumption.
(5) Shooting management
The green leaf area of newly planted young trees is small, so we should try our best to increase the growth of branches, protect leaves and expand the green leaf area, so that they can have enough nutrients to meet the needs of root growth, so as to achieve the purpose of promoting growth. Therefore, during the growth of new shoots, attention should be paid to spraying pest control and disease prevention drugs every time to protect new shoots.
Second, the results of longan orchard management
Results There are three technical links in the annual management of longan orchard: one is to cultivate strong autumn shoots and fruiting mother branches, the other is to control winter shoots to promote flowers, and the third is to strengthen flowers and protect fruits. All technical measures of orchard cultivation should be carried out around these three technical links. The growth and development characteristics of longan trees are different because of their different age, tree vigor and fruiting conditions. In the process of implementing cultivation management, corresponding technical measures should be applied flexibly to achieve the goal of high and stable yield.
(1) Fertilization
Longan is a fruit tree that needs a lot of fertilizer. It is very important to obtain high and stable yield.
Especially when planted in barren red soil hilly land, a higher level of fertilization is needed. In this way, the fertilization of trees is more complicated and strict than that of young trees, because fertilizer directly affects the vegetative growth, flower bud differentiation and flowering and fruiting of trees. Therefore, according to the biological characteristics and environmental conditions of Gracilaria lemaneiformis, the fertilization period and amount should be carefully controlled to adjust the balance of longan growth and fruit.
1. autumn bamboo shoot fertilizer: autumn bamboo shoot fertilizer can be applied in 2-3 times. The first fertilization was applied 10- 15 days before fruit picking, with the purpose of restoring tree vigor, promoting autumn shoots and being beneficial to fruit development in the later period; The second fertilization is applied after the fruit is picked and the autumn shoots begin to sprout; Apply it for the third time when the autumn shoots stop elongation, and the amount and period of fertilization should be flexibly controlled according to the tree potential, fruit bearing amount and shoot number. If there are many fruits in that year and the trees are weak, more early fertilization should be applied, and the number and amount of fertilization should be increased in the orchard in the second autumn. When the second autumn shoots turn green, the available nitrogen fertilizer should be controlled.
2. Winter fertilizer:165438+1Winter fertilizer is applied from early to late October, mainly organic fertilizer, accounting for 70-80% of the annual fertilization. Generally, bird droppings, pig droppings, garbage and phosphorus and potassium fertilizers are the main products. The main function of this fertilizer is to promote flower bud differentiation, enhance the stress resistance of trees, and provide material basis for flowering and fruit setting in the coming year.
3. Pre-flowering fertilizer: applied in late March to supplement the nutrient consumption of trees in flowering period, promote the development of small fruits and improve the fruit setting rate. Before flowering, the fertilizer is mainly available nitrogen fertilizer, and the fertilizer is urea compound fertilizer or human feces.
4. Strong fruit fertilizer: topdressing 1-2 times during fruit growth and development, usually after fruit thinning in May-June. The fertilizer is mainly available nitrogen fertilizer, and the amount of fertilizer applied depends on the results and tree potential.
(2) Cultivation of fruiting mother branch
Cultivating strong autumn shoots and fruiting mother branches is an important link for longan to obtain high yield.
It is also one of the main measures to overcome the result of too small a year. Long Fu and litchi are different. Litchi fruit ripens early, and the temperature and humidity conditions are suitable for the growth of branches after fruit picking. Generally, autumn shoots can be picked more than twice in the second year as good fruiting mother branches, but Longji is different. For some late-maturing varieties, due to the delay of fruit picking time, the temperature and water content gradually decreased during the growth of branches, making it difficult to put autumn shoots twice. As an early-maturing variety, the fruit has enough time after picking, and it should be put twice in principle. To cultivate excellent autumn shoots and fruiting branches, we should start from the flowering and fruiting period, and on the basis of paying special attention to fertilization, we should mainly do the following work:
1. Thinning flowers and fruits is mainly to adjust the balance between reproductive growth and vegetative growth, solve the contradiction between flowering and fruiting, maintain the relative balance between nutrient accumulation and consumption of trees, maintain the vigorous vitality of trees, and ensure the normal emergence and growth of summer shoots and autumn shoots.
Generally, flower thinning is carried out in mid-March, when the ear length is about 12- 15 cm, which is difficult to master. In production, this work is generally replaced by fruit thinning, which should be carried out when young mung beans are big, neither too early nor too late, and fruit thinning can account for 20-30% of the total in years with many fruits.
prune
Pruning can be done in spring, summer and autumn, but it should be light in spring and summer.
Generally, only branches damaged by pests and diseases and excessively dense internal branches are cut off. Autumn pruning is the most important pruning all year round. The period and number of pruning vary with the crown, growth and fruit yield of plants and the number of planting. Pruning young fruit trees should not be too heavy. The pruning time of an orchard should be postponed and can be carried out in late August.
Pruning must be carried out under the normal management of princess water, otherwise it will not play a role in pruning.
3. Irrigation: Try to supply enough water during the growth of new buds in autumn.
(C) control of winter buds to promote flowers
Winter buds are new buds spit out in winter. If it doesn't grow enough, it won't be a good fruiting branch. The germination and growth of winter shoots consume the nutrients accumulated by trees, which directly affects the differentiation of flower buds and the flowering and fruiting of the following year. Therefore, winter shoot control and flower promotion should be done well.
If young fruit-bearing trees shoot early in winter from late June 65438+ 10 to early October165438+10, measures such as foliar fertilization and irrigation can be taken to promote early maturity. Measures must be taken to control winter shoots from winter to the future. Generally, chemical treatment, manual removal and root cutting can be used to control its growth.
1. Use chemicals to control winter shoots, and often spray 0.03%-0.04% ethephon on the growth, and add 0. 1%B9 to control winter shoots. Generally, it is carried out before the winter buds germinate and sprout 3-5 cm before the leaves open. Because ethephon is mainly used to kill buds and promote leaves and trees to a certain extent, it should not be used when winter buds are not germinated. Longan is sensitive to ethephon, and high concentration or repeated use will cause serious defoliation. Therefore, it is generally appropriate to use ethephon to control winter bamboo shoots at 1 time, but not more than 2 times at most, and special attention should be paid to the concentration. The effect of ethephon on plants is closely related to temperature. High temperature takes effect quickly and has high efficacy, but it is also prone to phytotoxicity. Therefore, spraying should be carried out in the evening.
2. Artificial removal of winter buds
3. Root cutting and bud suppression: in winter, combined with long-term winter fertilizer, some trees are controlled to be cut down.
Roots can control buds. If the longan tree grows vigorously and the terminal buds are full, when it is possible to sprout winter buds, you can dig out the soil 20 cm deep in the whole tree tray and hoe off the fine roots, but you should pay attention to not cutting the roots too heavily, especially for weaker plants, which will not only fail to blossom, but will cause the tree to decline. In addition, although girdling is a common measure to control shoots and promote flowers on fruit trees, it is not suitable for longan, because the wound healing ability of longan is poor and the ability of girdling plants to resist low temperature and drought in winter is obviously weakened, so it is not recommended to use it.
(4) Strong flowers protect fruits
1. Cultivating robust panicles: To cultivate robust panicles, we must first cultivate timely and robust autumn shoots and fruiting mother branches, and do a good job in controlling shoots and keeping flowers in winter; Secondly, in the flowering period, corresponding measures should be taken according to the flowering characteristics of longan and the change of climatic conditions to achieve the purpose of cultivating strong flowers and stabilizing flowers. Early flowering panicles are often easily affected by low temperature, so they can't become flowers when frozen. In production, try to cultivate late panicles or long panicles for topping, that is, when the flowering panicles reach 12- 15 cm, remove the top panicles. When the flowering temperature is higher than 18℃, the growth of leaves on the mixed panicle is dominant, and the new leaves lose nutrition, resulting in poor inflorescence development. But be very careful when using it to avoid killing old leaves and buds.
2. Protect flowers and fruits: Longan has a large panicle, a large number of flowers, a small proportion of female flowers and a concentrated flowering period. Flowering consumes a lot of nutrients accumulated in the tree, which makes the distribution of nutrients in the tree unbalanced and directly affects the normal development of embryos, resulting in a large number of fruit drops. Techniques such as pruning in spring, thinning flowers and cutting short ears are often used in production to reduce nutrient consumption at flowering stage, and measures such as fattening before flowering are taken to increase nutrient accumulation in trees.
Main diseases and insect pests of longan and their control
(1) Diseases and Control Measures
1. Ghost broom disease: Ghost broom disease harms leaves, branches and flower spikes of longan. The damaged leaves are curled and shriveled, uneven, easy to fall off, diseased branches are clustered, internodes are shortened, and there are deformed leaves with different shapes at the top. The whole branch is broom-shaped, and the injured spikes are clustered, the flowers are deformed and swollen, and the spikes are abnormally developed. After drying, the branches often hang. Pathogens are caused by viruses, which are mainly transmitted through asexual propagation materials and seeds with viruses. In addition, pests with sucking mouthparts, such as Lycopodium longicorniculatum and Lychee Disc Elephant, are also important media.
Prevention and control methods: First, quarantine is carried out to prohibit the export of seedlings, scions, seeds and other propagating materials from epidemic areas to prevent the spread of epidemic diseases to non-epidemic areas. If individual plants are sick in newly-built orchards, the diseased branches should be pulled out as soon as possible, and the vectors should be eliminated by spraying drugs; Second, cultivate disease-resistant varieties; Third, strengthen cultivation management, advocate fitness cultivation and enhance plant disease resistance. If individual plants are found to be sick, they should be cut off in time and destroyed centrally. At the same time, attention should be paid to the prevention and control of pests, especially stinkbug litchi, psyllid and other sucker pests.
2. Anthracnose: The pathogen is caused by fungi, which mainly occurs in new shoots. Spraying 50% carbendazim 1000 times solution or 25% Daphne manganese zinc 2000 times solution during the ear growth period.
(2) Pests and control measures
1. Litchi wax elephant: common name bug, which is one of the main pests of litchi and longan. The insect occurs once a year, mainly in late March, late April and early May. Spraying 500 times of 90% trichlorfon or 2000 times of 10% mirex can control the drug.
2. Fruit borers: There are many kinds of longan fruit borers, including litchi fruit borers.
Litchi, small gray butterfly, etc. The control time is mainly before flowering, and attention should be paid to spraying drugs in May and June. It can be sprayed with 48% Oxfam 1000 times solution, 10% toluene sulfonate 2000 times solution and 25% insecticide 500 times solution.
Pay attention to frequent investigation of psyllid, white moth wax cicada, tortoise shell, scarab, etc. If pests are found, they should be prevented in time, and spray control should be paid attention to during the growth of new shoots.
Pay attention to whether the pests and diseases on bananas have invaded longan, and nothing else seems to matter.