Does the improved seed base of Larix gmelinii not blossom and bear little fruit? Flowering and fruiting techniques of Larix gmelini

The improved variety base of Larix kaempferi in Zhouzhi County was founded in 1988 and was identified as a key forest variety base by the State Forestry Administration in 2009. The mother tree materials built in the base are all from Liaoning Province in northeast China. More than 300 fine individual trees were selected from the fine stand of Larix gmelinii in Liaoning, 286 superior tree seeds were collected, and more than 50,000 seedlings of improved varieties were cultivated. More than 50 hectares of seed orchards and mother forests of Larix kaempferi were established to lay the foundation for the breeding of improved varieties of Larix kaempferi. Due to the differences in climate and geographical location, the introduction of Larix kaempferi in Zhouzhi improved variety base has particularly strong growth, less flowering and fruiting, and low yield, which makes it difficult for the improved Japanese larch variety base to play its due role. Aiming at the problem of non-flowering and less fruiting in the improved variety base of Larix gmelinii, this paper puts forward the technical measures and methods to promote the flowering and fruiting of the improved variety base of Larix gmelinii in Japan.

General situation of improved seed Base of Larix gmelinii in one week

The improved variety base of Larix gmelinii in Zhouzhi County is located in Qinling Forest region of Shaanxi Province, with an average elevation of about 1 500m. It belongs to warm temperate semi-humid continental monsoon climate, with an average annual temperature of 6.4-8.4 ℃ and a frost-free period of 150 days. The average annual precipitation is about 1 000mm, and the rainfall is abundant. The soil of the improved seed base is mainly brown soil, loose texture, rich humus content, soil layer thickness in 40~80cm, good permeability, especially suitable for the growth of Larix kaempferi.

Analysis on the causes of low seed yield of Larix kaempferi in improved Variety Base

The purpose of establishing an improved seed base is to provide high-quality improved varieties for forestry production. If the mother tree of seed collection can not blossom and bear fruit normally, the seed yield is low and can not meet the demand, the purpose of the improved seed base will not be achieved. At present, the main problem existing in the improved variety base of Larix gmelinii is that the mother tree has a small number of flowers. Because the construction materials of Larix kaempferi in Houyazi improved seed base are mainly introduced from Huanren and Qingyuan in Liaoning Province, the difference of climate and site is the main reason why the mother tree blossoms late or does not bear fruit. Liaoning, located in northeast China, has a continental monsoon climate in mid-temperate zone, cold in winter and hot in summer. The annual average temperature is 5.3 ℃, the frost-free period is only about 120 days, and the annual average rainfall is 800mm. When Larix kaempferi moved from northeast to south to Qinling forest region, the rainfall of woodland increased and the growing period was prolonged. The temperature is more suitable, which makes the Japanese larch show exuberant growth, the trees have been in a state of nutrient accumulation, and the age of flowering and fruiting has been postponed indefinitely. In addition, the seedlings used in the construction of improved seed base are seedlings, not grafted seedlings, which aggravates the lag of flowering and fruiting. In addition, the early growth of larch is faster, the initial planting density is higher, the growth space of larch mother tree is restricted, and the ventilation and light penetration is poor, which is also another main reason that affects the flowering and fruiting of larch.

3 main technical measures to promote flowering and fruiting of Larix gmelinii

The factors affecting the flowering and fruiting of Larix kaempferi mainly include two aspects, one is environmental conditions, such as climatic factors, land conditions, management measures and so on. The other is the factors of Larix kaempferi itself, such as tree age, provenance, tree type, density and so on. Through technical management measures, improving the ventilation and light transmission conditions of fruiting mother trees, adjusting the transformation ratio of vegetative growth and reproductive growth, and improving pollination conditions can promote the flowering and fruiting of Larix kaempferi and increase the seed yield.

3.1 fertilization

The growth of trees is inseparable from the nutrients of the soil, and N, P, K and other elements in the soil are the main elements to promote the growth of trees. Fertilization can improve soil nutrition structure, increase soil nutrients and promote the rapid growth of trees. Nitrogen-containing fertilizers mainly promote vegetative growth, improve plant photosynthetic efficiency, and promote tree growth more tall and luxuriant, so N is the main element to promote the accumulation of trees. The main function of P and K fertilizer is to enhance the resistance of trees and improve the nutritional balance of tree growth, which can obviously improve the flowering and fruiting of middle and young forests. Previous studies have shown that through the continuous application of compound phosphate fertilizer in June and compound potassium fertilizer in August, the seed setting amount of larch can be significantly increased, and the average yield can be increased by more than 43%. And larch seed quality, 1000-seed quality, cone emergence rate, seed germination rate and so on were improved in varying degrees. The characteristic of the improved seed base of Larix gmelinii is that the tree itself has excess nutrition and the tree growth is exuberant. Therefore, reducing the application amount of N fertilizer and increasing the application amount of P and K fertilizer can obviously improve the flowering and fruiting of Larix kaempferi.

3.2 Tree management technology

The tree management techniques of Larix kaempferi mainly include branch thinning and topping.

3.2.1 thinning mainly removes overdense branches, overlapping branches, disease and insect branches and some overgrown branches, in order to improve the ventilation and light transmission conditions of larch mother trees, reduce the harm of diseases and pests, and promote flowering and fruiting. However, the number of thinning branches has a great influence on the flowering and fruiting of larch. The results showed that when 1 / 4, 1 / 3, 1 / 2 and 2 / 3 of the main branches of adult larch mother trees were removed, with the increase of branch thinning intensity, there was a positive correlation between seed setting and branch thinning strength in the second and third year, and the seed quality was also improved accordingly. However, the large branch thinning intensity has a great influence on the yield of the mother tree in the same year, so the branch thinning intensity should not be too large, and 1 / 3 to 1 / 2 should be thinned every year. In Zhouzhi Larix gmelinii improved variety base, because the mother tree of Larix kaempferi is in the stage of middle and young forest, the skeleton of fruiting branch has not been fully formed, so the branch thinning is mainly light, only by removing the disease and insect branches, dry and withered branches and overlapping branches of the mother tree.

3.2.2 Top cutting is a common tree management method in improved seed base, and its main purpose is to restrain the apical dominance of the tree, prevent the overgrowth and overgrowth of the fruiting mother tree, and regulate the transformation from vegetative growth to reproductive growth of the mother tree, so as to promote the flowering and fruiting of the mother tree. In Zhouzhi Larix gmelinii improved variety base, due to the influence of climate and site conditions, the vegetative growth of Larix kaempferi has been very exuberant, so breaking the top advantage of Larix gmelinii growth and promoting the transformation from vegetative growth to reproductive growth is the main way to promote the flowering and fruiting of Larix kaempferi. Truncation is a very effective way to implement this approach. Generally speaking, the greater the chopping intensity is, the more obvious the effect is, but it should not exceed 1 / 2 of the tree height. The clipping time of Larix kaempferi is usually carried out in April in spring, because the larch trees in Zhouzhi improved variety base are in the stage of middle and young forest, so it is not suitable to cut off too much, and 1 / 4 / 3 of the tree height is more suitable.

3.3 thinning

At the initial stage of mother tree planting, because the tree age is small and occupies relatively little space, so the initial planting density is larger. With the continuous increase of tree age, the crown width is getting larger and larger, and the woodland is gradually closed, the growth space of the mother tree is limited to each other, and the mother tree forms the competition for light, water and fertilizer and other nutrition space, which affects the normal flowering and fruiting of the mother tree. Although reasonable thinning reduces the number of mother trees in the improved variety base, it improves the ventilation and light transmission conditions of the mother trees in the base, promotes the crown growth of the mother trees, and increases the effective attachment area of flowering and fruiting, thus increasing the number of flowering and fruiting of the mother trees in the improved variety base.

The principle of thinning is that the mother trees with poor growth, more diseases and insect pests, weak resistance, poor fruiting ability and low genetic quality should be thinned first, leaving the mother trees with strong growth, strong fruiting ability and high genetic gain. Therefore, thinning also promoted the further improvement of seed genetic quality in the improved variety base.

The thinning intensity directly affects the fruiting yield of larch improved variety base, and the thinning intensity is closely related to larch tree age, crown width and canopy density. Previous studies have shown that intensive thinning has a very significant effect on promoting the flowering and fruiting of larch. Larix gmelinii thinning should follow the principle of gradual and orderly, each thinning should not exceed 30% of the total.

Techniques and planting methods for the establishment of thorn dragon teeth

Longya is one of the outstanding wild vegetables, which has broad market prospects and important economic value. The new shoots germinated after picking can not or rarely blossom and bear fruit, the 1000-grain weight and germination rate of the picked seeds are also seriously reduced, the seedling yield is low and the quality is poor after sowing, and the commercial bud yield is low after planting. The poor quality affects the economic value and seriously affects the development of the cultivation industry. Therefore, it is of great practical significance to carry out the breeding base of improved varieties of thorn teeth in this paper to provide excellent seedlings for production.

1 the technology of establishing garden

1.1 the choice of garden sites

Select leeward to the sun, deep soil layer, good drainage, no pesticide residues, avoid stagnant water and frozen plots. Root propagation requires repeated excavation and utilization of root system, as well as flat nursery with convenient transportation and irrigation facilities or ≤ 10 °slope nursery.

1.2 make a bed by preparing the ground

The soil was prepared by deep ploughing and 25~30cm, and farm manure of 30,45,000 kg/ hm2 was applied to facilitate digging and cutting.

The height of the planting bed is 25~35cm, the width of the bed is 1 to 1.2m, and the length of the bed varies with the topography and the convenience of operation. In general, the length of the bed is more than 10m. In order to facilitate management, the working path between beds is 40~50cm.

2 planting techniques

2.1 Plant selection

The selection criteria of excellent plants transplanted to the seed root orchard are as follows: wild or transplanted to the four sides of the land, the sturdy plants that are free from mechanical damage, diseases and insect pests for 5 years, the height growth should be more than 1.2m, the stem thickness should be more than 2.5cm, and there should be no thorns or less thorns. The commercial buds should grow to about 15~20cm, the single fresh mass is about 20 ~ 35g, and the tender buds do not fully expand, and there are no prickles or less prickles on the tender stems.

2.2 planting methods

2.2.1 planting techniques

2.2.2.1 Plant planting techniques

The planting time is divided into spring and autumn. Spring planting is usually in the middle of April, before the apical bud is germinated; in autumn, it is planted in late October, before the soil is frozen, and 1 month after the defoliation. The root system of the plant must be pruned and moisturized before planting. After pruning, the main root was more than 1 30cm, the fibrous root was more than 6, the length of 20cm was more than 6, the lateral root of the sprouting plant was more than 3, the length of 20cm was more than 3, the number of fibrous root was 3, and the length of 20cm was more than. The root system should be stretched when planting, because the tree body of the planted plant is large, the depth of burying soil can be higher than that of 5cm in the rhizome, and the burying process should be stepped on many times, and finally covered with a layer of topsoil. After planting, watering once permeates into the 20cm under the bed, and it is suitable to have runoff on the surface.

2.2.2.2 Root planting technique

When the soil was frozen in the first ten days of April, the roots of fine plants were collected, the thickness of 0.4~1cm, the length of 13~15cm, and two buds were retained on the roots. Store in a clean, wet river sand and store in a cool and leeward place outside. Planting time, surface temperature above 10 ℃, one week after terminal bud germination, 0.1% potassium permanganate solution before planting to disinfect 30min, planting pit depth 5cm, long 20cm, wide 20cm. Put 1-2 seed roots across each pit, bud upward, covered with soil 4~5cm, watered thoroughly, and covered with a layer of grass curtain to moisturize.

2.2.2 planting density

Fixed-point planting on the bed, planting in the middle of the seedbed, plant distance 150cm. The stinging dragon teeth on the adjacent lines should be planted in dislocation to facilitate the root excavation operation. The fixed point was carried out according to the row spacing of 60cm × 150cm.

3. Nursery site management and tree management

3.1 Orchard management

3.1.1 Water and fertilizer management

Weeding in the nursery should first be carried out in the periphery of the tree and weeding in the comprehensive nursery, according to the principle of "removing early, except and small", and be careful not to hurt the root and rhizome as well as the sprouting seedlings when weeding. According to the soil moisture to determine the amount of watering and watering times, thorn dragon teeth in the growing season to keep the soil moist, but to prevent stagnant water caused by root rot. Fertilization was applied once in early June and mid-July, and potassium chloride compound fertilizer or calcium superphosphate was applied on the root of the plant. Plant ash or farm manure was applied in the park 2 months after defoliation (from mid-November to early December) to improve the growth vitality of the plant in the second year.

3.1.2 Disease and pest control

The main results are as follows: (1) if the plant blight occurs in the transplanted plant in the park, the diseased plant should be dug up in time, removed from the park and burned directly. The root system of adjacent plants could not be used as root propagation material in the second year.

(2) when root propagation seedlings appear blight, the bed surface can be sprayed with 0.125%-0.2% bedixone solution in cloudy days or in the evening.

(3) when scab occurs, 0.2% concentration of pentachlorophenol sodium is sprayed in mid-November to prevent scab.

(4) when white silk disease occurs, the root system or propagation of the plant shall be treated with 0.2% solution of carbendazim or thiophanate methyl before planting. The insect pest on the growth of dragon teeth is mainly aphids. To control aphids, 0.1% concentration of dimethoate EC can be used to spray or apply insecticides on the branches where aphids occur to kill aphids.

3.2 Tree management

In order to collect the seed root conveniently, the tree should be pruned when transplanting the plant. When the tree entered the dormant period in the second year of the planting site, the branches of the same year retained 20~40cm, the number of buds was 4-6, and the rest was cut off. Two or three strong buds were retained on the branches in the spring of the third year, and the remaining buds were cut off or erased. Two months after falling leaves in the autumn of that year, the 20~40cm was cut off from the bifurcated parts. 1-2 sprouting tillers were retained in the 4th year, and 2 plants were repeatedly cultivated in the 5th year, and the old plants were cut down in the first ten days of December of that year. Before Frosts Descent to snow, cut off the aboveground part of the seedlings of the same year at 3~5cm from the ground, cover the roots with grass curtain against cold, and remove the grass curtain before sprouting in spring.

Collection of four kinds of roots

The principle of root collection is to shorten the storage time as much as possible, and it is best to plant as soon as possible, which can improve the reproduction rate of seed roots. The way and time of collecting roots are also different with different planting time. Transplanting fine plants in spring can be collected within one week of terminal bud germination in spring of the second year; transplanting good plants in autumn can be collected within one week of terminal bud germination in spring of the second year; the time of root collection of excellent plants for root propagation can be collected before the terminal bud is germinated. The whole plant needs to be dug out for collection. The standard of seed root cutting for propagation is as follows: rough 0.6~1.2cm root segment, cutting long 13~15cm. After collection, it is stored in a clean and moist river sand. Disinfect 30min in 0.1% potassium permanganate aqueous solution before planting.

The above are the key points of planting techniques related to dragon teeth, like farmers to HuiNong network to learn more, more reference!

How to plant ginkgo? High yield cultivation techniques of early Fruit of Ginkgo biloba

Ginkgo biloba, also known as Gongsun tree, has a very long life, and the whole body of ginkgo is a treasure and has medicinal value. While the cultivation of Ginkgo biloba in our country is mainly with fruit, the following is mainly to learn the growth and fruiting habits of ginkgo biloba and the cultivation techniques of early fruit and high yield.

1 growth and fruiting habits of Ginkgo biloba

Ginkgo biloba is a dioecious plant, once flowered and pollinated, the fruiting is very guaranteed, and the fruiting part is not easy to move out, and the inner chamber of the crown is not easy to be bald, so it is a typical spur fruit tree. The long branches and short branches of Ginkgo biloba can be transformed into each other, the lateral buds of new long branches can all germinate and form short branches in the coming year, the life of short branches can reach 20 years, and the terminal buds of some perennial short branches can also grow branches.

2 cultivation techniques of early fruit and high yield of Ginkgo biloba

In recent years, due to the rapid development of the manufacturing industry of traditional Chinese medicine, the pharmacology of ginkgo biloba has been excavated, the demand for ginkgo biloba has increased greatly, and the planting efficiency has also increased greatly, which has greatly stimulated the planting enthusiasm of the masses and formed the planting fever of ginkgo biloba in the whole country. at present, more than 10 million ginkgo biloba trees have entered the fruiting stage, with an annual harvest of more than 30,000 tons of ginkgo biloba leaves, and can produce more than 300,000 tons of ginkgo biloba extract, worth more than 1 billion yuan. According to the average fruit yield of 25 kg per plant, the annual output of ginkgo biloba fruit is 2.5 billion tons, the output value is more than 9 billion yuan, and the annual contribution of ginkgo industry is more than 10 billion yuan. However, due to the unique growth and fruiting habits of Ginkgo biloba, its cultivation is very different from other fruit trees, and its efficiency has not been brought into full play in actual production. According to the growth and fruiting habits of Ginkgo biloba, combined with the planting experience all over the country, some relevant experts put forward the cultivation techniques of early fruiting and high yield of Ginkgo biloba, in order to provide reference for production.

2. 1 seedling breeding

Ginkgo biloba has a long life, so we must choose improved varieties when planting in order to improve the management efficiency. For the purpose of seed and leaf cultivation, the varieties with large species (average single nucleus weight more than 3 grams), white nucleolus, strong waxy, strong aroma, nucleation rate (percentage of ginkgo biloba with fleshy pericarp) and high kernel rate should be selected. Generally speaking, the low nuclear rate is less than 19%, the high one can reach 25%, and the highest can reach 29%. At present, the varieties of ginkgo that perform well in production are: big golden pendant, long waxy ginkgo, round ginkgo, bergamot, horse bell, big ginkgo, big fruit, Jingyin, Hong an king and so on.

Ginkgo biloba is easy to reproduce, such as sowing, dividing plants, cutting and grafting. The fruiting period of ginkgo biloba seedlings is late, it generally begins to bear fruit in about 20 years, and the income is slow in about 40 years, while the grafted seedlings begin to bear fruit in 5 years, enter the full fruit stage in 10 years, and the full fruit period can be as long as a thousand years. Grafted seedlings should be mainly used in production.

(1) Seedling

Sowing and raising seedlings of Ginkgo biloba has the advantages of early emergence, uniform emergence, less susceptibility to disease, more mature seedlings and simple operation. Ginkgo for raising seedlings should be collected in the producing area or orchard where pollination is sufficient, and wet sand should be stratified in winter. Generally sowing in the middle of March, sprouting before sowing, sowing amount of about 100 kg per mu, 50, 000 ~ 70, 000 seedlings per mu.

a. Seed treatment

The method of accelerating germination of ginkgo biloba seeds is generally used in the pit. Select a place with leeward facing sun and good drainage to dig a ditch with a depth of 30 cm and a width of 1. 2 meters, and the length is determined according to the number of seeds. Sift the seeds from the sand, soak the seeds, combined with seed soaking to remove floating seeds, damaged seeds, soaking seeds for more than 24 hours, pay attention to change water. Spread sand 5cm to 10cm thick at the bottom of the ditch, then seed a layer of sand, each layer is about 2cm thick, to 15cm 20cm, cover with a layer of 2cm / 4cm wet sand, cover with film, 5 ~ 6cm from the ground. When sprouting, pay attention to the first 15-20 days, turn once every 3-5 days, and pick up seeds once in the next 2-3 days; keep the humidity, if dry, add water at 9: 00: 00, the water temperature is about 30 ℃, and the temperature in the ditch is controlled at 25: 30 ℃.

b. Seedbed preparation

Choose acidic or neutral sandy loam soil with high dry terrain, sunny ventilation and good drainage and irrigation as seedbed. Plots selected as seedbeds should be ploughed in the autumn of the first year, combined with ploughing and applying rotten farm manure, 3000-4000 kg per mu, 100 kg of nitrogen, phosphorus and potassium ternary compound fertilizer, and 2. 5 kg of phoxim granules. Before sowing, the whole border should be 1. 2 ~ 1. 5 meters wide, 15-20 centimeters high, and the border surface is flat.

c. Sowing seeds

Shallow trenches were opened on the border surface according to the row spacing of 20 cm and sown on demand according to the plant spacing of 5 ~ 8 cm. When sowing, the seeds are laid flat and the overlying soil is 2cm.

d. Seedling stage management

The first topdressing was in the first ten days of June, applying urea 7. 5 kg per mu. 5 kg; 7 Mel 8 months depending on the growth of seedlings, topdressing 1-2 times, each time about 10 kg of urea per mu. Weeds should be removed in time during the seedling growth period to ensure the robust growth of the seedlings.

(2) grafting and raising seedlings

Ginkgo biloba grafted seedlings have the characteristics of early fruiting stage and high yield. Generally, ordinary ginkgo biloba is used as rootstock and excellent varieties are grafted. There are many grafting methods, including T-shaped bud grafting, double tongue grafting or skin grafting. Spring is the main season of grafting, and the survival rate of grafting is high from 5 days before germination to leaf expansion stage, which can be flexibly applied according to the actual situation in production.

a. Double tongue grafting or skin insertion tongue grafting

At present, large seedlings of more than 3-year-old rootstocks are widely used in production, and grafted when the rootstock is 50 ~ 60 cm high. The scion was collected 10 ~ 20 days before the mother tree germinated, and the collected scion should be treated with wax seal in time to prevent water loss and affect survival. When grafting, the length of the tongue surface of the grafted ear is 3 ~ 4 cm, the cutting surface is on the side of the lower bud, and the tongue is 2 mm away from the tongue surface, and 2 mm is exposed during insertion to facilitate healing. The bud is on one side of the rootstock, and the base of the scion is easy to heal with the rootstock.

b. T shape budding

Scions are generally collected with winter shears, and branches with strong growth and free of diseases and insect pests are selected as scions. 50 scions with a bundle are buried in the wet sand in the shade. The rootstock is grafted when it is peeled in spring and usually begins when the rootstock sprouts and spreads its leaves. Full buds are selected for bud grafting, and bud slices are required to have protective meat on them. Cut a "T-shaped" incision in the smooth part of the rootstock, the transverse cut is 1 cm long and the vertical cut is 1. 2 cm long. 2 cm, insert the shield scion bud and bind it. First tie it up from the top of the bud and wrap it down for 3 or 4 times. The binding should be tight and strict.

After 10-15 days to check the survival, those who did not survive should be made up in time. After the buds or scions survive, wipe out the sprouts on the rootstock in time.

2. 2 cultivation techniques

(1) Building a garden

In order to increase the early yield, ginkgo biloba can be established by the method of over-dense planting, with row spacing of 3 m × 2 m, 3 m × 2. 5 m, 4 m × 2. 5 meters, etc., 111, 88 and 66 plants per mu, respectively. With the growth of the crown, it was sparse year by year, and finally transformed into 33 or 22 trees per mu. Ginkgo dioecious, the amount of male flower powder is large, a small number of male plants can solve the problem of pollination, male plants account for about 2% of the total number of plants.

For ginkgo biloba seedlings of the same age, the female plant is generally shorter than the male plant, but the stem is stronger than the male plant, the female plant relatively falls leaves earlier, sprouts later, and there are more transverse branches. The leaves of the female plant are smaller than the male plant, and there is a gap around the vascular bundle of the petiole cross section, while the male plant does not; the angle between the main branch and the trunk of the female plant is large, growing laterally and even drooping around, and the growth is weak, while the angle between the main branch and the trunk of the male plant is small. The female plant forms the tree crown early, the branch distribution is disorderly, the lower big branch is more, the tree crown is oval, the male tree crown forms late, the branch distribution is uniform, the level is clear, the tree crown is mostly tower-shaped; the female flower bud is thin and slightly sharp, growing at the top of the pedicel, generally two flowers, shaped like a matchstick, the male flower bud is large and full, and looks like mulberry. In production, the male pollination plants can be distinguished according to the above-mentioned characteristics.

(2) shaping and pruning

At present, the main tree shapes of ginkgo biloba are trunk multi-layer shape, open heart shape and natural round head shape. The height of the fixed stem is 50-60 cm, and there are 3-4 main branches and 3-4 lateral branches per main branch. Winter pruning mainly removes overdense branches. 6Mel moderates the growth of branches by pulling branches in July to promote flower formation. The method of ring cutting or ring cutting was used to control the vegetative growth of over-prosperous trees or branches, and the shoots that could not stop growing were coring in August to improve the Lignification degree of new shoots.

(3) soil, fertilizer and water management

Before planting, deep ploughing, combined with deep ploughing, applied 4000 ~ 5000 kg of high-quality farm manure, 5 ~ 10 kg of urea and 20 ~ 40 kg of superphosphate per mu. Fertilization after planting is mainly nitrogen fertilizer in the early stage of annual growth, phosphorus and potassium fertilizer in the middle and later stage, such as the application of compound fertilizer, high nitrogen compound fertilizer in the early stage and high phosphorus compound fertilizer in the middle and later stage. The amount of fertilizer application is determined according to the size of the tree, and ditches are dug at the outer edge of the crown. Irrigate after fertilizing. Weeding 5-6 times a year to loosen the soil and improve the soil moisture conservation capacity.

(4) Flower and fruit management

Ginkgo trees entering the fruiting stage should be pollinated artificially when there are few pollination trees or bad weather during the flowering period. Generally in late April, when the male inflorescence changes from green to yellow, the pollen or flower branches are collected and dried at room temperature, the pollen is collected, put into a gauze bag, hung on the bamboo pole, stand in the limelight, and gently pat the gauze with his hands for pollination. One part of pollen, 250 parts of water, 50 parts of sugar and 5 parts of boric acid can also be prepared into pollen liquid, which can be pollinated by spraying female inflorescence with high pressure sprayer at 10: 00 am 16: 00 on sunny day.

(5) Prevention and treatment of early chlorosis of Ginkgo biloba.

Ginkgo biloba has strong disease resistance and no serious diseases and insect pests. early chlorosis of ginkgo biloba is more common in production. Chlorosis will affect the yield of the second year, so prevention and control should be strengthened.

The causes of early chlorosis of Ginkgo biloba are complicated. Stagnant water and zinc deficiency can lead to chlorosis. Usually, when the root system is 15 cm deep for 10 consecutive days, it will cause yellowing of fallen leaves and rotten roots, and in serious cases, the whole plant will die. When the zinc content in leaves is less than 15 mg / kg, the phenomenon of element deficiency yellowing occurs. In general, the disease began in early June, first the leaf edge began to lose green and show light yellow, and then gradually expanded to the leaf base, and when half of the leaves were yellowed seriously, the disease spot in August expanded rapidly, and the color gradually changed to brown and gray, showing a withered appearance.

When yellowing occurs in the field, it is necessary to carefully observe and treat the disease in order to improve the effect of prevention and control. For the yellowing caused by stagnant water, drainage should be strengthened after rain to prevent stagnant water in the field so as to reduce the harm. For yellowing caused by zinc deficiency, after soil thawing in spring, 80 grams of zinc sulfate per plant is applied according to tree size, and 70% mancozeb wettable powder is sprayed 500-600 times every 10 days in the growing season or 400 mg / kg titanium fertilizer. 3% photosynthetic micro-fertilizer, sprayed 3 times in a row to control the harm.

(6) harvesting, processing and storage

Ginkgo biloba leaves and seeds are the main harvests, and the appropriate harvest time should be determined according to the different harvests. Ginkgo biloba leaves contain flavonoids, which have a relaxing effect on cardio-cerebral vessels. The crude products of ginkgo biloba leaves are 1% ~ 3% of the dry leaf weight, and the price is relatively expensive, so the sale of ginkgo biloba leaves is a major income in ginkgo production. In general, ginkgo biloba leaves should be harvested in stages from the first half of October to the first ten days of November, first picking the old leaves inside the crown and on the lower branches, picking 3 leaves of the short branches each time, and finally picking them all at one time when the ginkgo leaves are about to turn yellow. Ginkgo biloba leaves collected should be dried in time to prevent heat and mildew.

The seed nucleus of Ginkgo biloba generally matures in late September, and the outer seed coat of mature species changes from cyan to yellow or orange, the surface is covered with a thin layer of white fruit powder, and the outer seed coat is soft when pinched by hand; the middle seed coat has been completely ossified and can be collected by bamboo pole.

The collected seeds should be peeled in time. Put the seeds on a hard, flat ground, about 30 cm thick, covered with wet grass, the Testa will rot gradually after 2-3 days, and peel off with foot or hand rub and wooden stick. The peeled seed is washed in clean water, and the impurities are removed while stirring. After many times of stirring and washing, the clean seed can be obtained. In order to make the surface of the seed nucleus white and shiny, the seed nucleus was bleached in production. At present, there are two methods of bleaching, one is bleaching powder treatment, a certain amount of bleaching powder is first boiled with 10 times warm water, and then diluted to 100 times with water. 1 kg bleaching powder can bleach 100 kg seeds. Pour the seed into the bleach solution and stir while soaking. Remove the seed coat when it turns white in 5-6 minutes and rinse with clean water several times until there is no trace or smell on the surface. After bleaching, it should be spread out indoors or outdoors to dry. The second is the sulfur fumigation method, in which the seed seeds washed with water are put on the mat to dry, put into the tank, put into the container volume of 2 + 3, then light a glass of sulfur, put into the cylinder and seal, fumigate for 30-40 minutes, open the seal, at this time, the seed coat is both white and shiny.

Ginkgo seeds after peeling and bleaching are called ginkgo. Ginkgo needs special storage under low temperature, low humidity and airtight conditions in order to avoid mildew deterioration, hardening and loss of water, and lose vitality.

Sand hiding method. Choose a cool room, store ginkgo mixed with sand according to the proportion of 1 seed and 2 parts of wet sand, control the heap thickness within 60 cm, check the humidity frequently, and feel wet when you hold it. This method can be stored for 3 to 5 months. Water storage. Dip the ginkgo into a water tank or pool and change the water frequently. It can be stored for 4-5 months.

Cold storage. Put the seeds into gunny bags and put them in cold storage at a temperature of 1 ~ 3 ℃. Spraying water every half a month can be stored for 5 to 6 months.

Storage. Load the ginkgo into 0. 5% thick. In 05mm plastic bags, each bag is controlled within 20kg and stored in a cold room of less than 5 ℃ for 5 to 6 months.

(7) Postharvest management of trees

Postharvest management has a great influence on the safe overwintering and the yield of ginkgo biloba in the second year. The following measures should be taken after ginkgo harvest:

① applied base fertilizer. The base fertilizer is mainly organic fertilizer, combined with delayed fertilizer such as phosphorus and potassium, and the general fruiting trees apply 3000 ~ 4000 kg of high quality farm manure and 150 ~ 200kg of ternary compound fertilizer according to the tree size per mu, usually 5 ~ 10 days before harvest. 30 ~ 40 cm wide and 30 ~ 35 cm deep ditch was applied on the outside of the crown.

② ginkgo garden is ploughed. Ploughing the ginkgo orchard before the soil is frozen, with a depth of about 30 cm, to enhance the soil permeability and water storage capacity.

③ cleans the garden. After the fallen leaves, clean the fallen leaves and weeds in time to reduce the overwintering places of diseases and pests.

These are all the cultivation techniques of Ginkgo biloba. If you are interested in the market prospect of Ginkgo biloba, you must first learn its planting techniques.