Chestnut has a wide range of adaptation to climate and soil conditions. The suitable annual average temperature is 65438 0.5—265438 0.8℃. Excessive temperature will lead to insufficient hibernation, poor growth and development, and low temperature will easily lead to frostbite. Chestnut likes moist soil, but it is afraid of rain and waterlogging. If there is too much rainfall, the soil will accumulate water for a long time, which will easily affect the growth of roots, especially mycorrhiza. Therefore, it is not suitable to develop chestnut orchards in low-lying and waterlogged areas. Chestnut is sensitive to soil PH value, and is suitable for growing in slightly acidic soil with pH value of 5-6. This is because chestnut is a high manganese plant, which can activate nutrients such as manganese and calcium under acidic conditions, which is beneficial to the absorption and utilization of chestnut. Xuzhou is located in the southern edge of Huangtan, with an annual average temperature of13.7-14.1℃ and an annual precipitation of 782-946 mm, which is suitable for the growth and development of millet trees.

Cultivation management technology

(1) Selection of Chestnut Garden: Chestnut (Figure 8)

Chestnut orchard should choose sandy loam with low groundwater level and good drainage. Avoid planting in places with saline-alkali soil, low humidity and strong wind. In order to open up millet orchards in hilly areas, we should choose areas near mountains with gentle terrain and thick soil layers, and then gradually expand to areas with poor conditions. (2) Variety selection: the local excellent varieties are mainly selected, such as Paoche No.2, Chen Guo 1, etc., and Shi Feng, Jinfeng, Haifeng, Qingmao Soft Spine, Chushuhong and other varieties are introduced appropriately. According to different edible requirements, fried chestnut varieties should be given priority to, and excellent chestnut varieties should be developed appropriately, taking into account foreign trade export and domestic market demand. At the same time, early, middle and late varieties should be reasonably matched. (3) Rational allocation of pollination trees: Chestnut trees mainly spread pollen by wind, but because chestnut trees are dioecious and self-pollinated, a single variety often produces empty buds due to poor pollination. Therefore, new chestnut orchards must be equipped with 10% pollination trees. Practice has proved that it is better to use Chushuhong as pollination tree in Xinyang City. (4) Reasonable close planting: Reasonable close planting is the basic measure to improve the yield per unit area. It is advisable to use 30-40 plants per mu in plain chestnut orchards and 40-60 plants per mu in mountain chestnut orchards. It is planned to plant 60-11plant per mu in close planting chestnut orchard, and then gradually carry out alternate thinning.

(5) Rational fertilization: Rational fertilization is an important basis for high yield of chestnut garden. The base fertilizer should be mainly soil mixed fertilizer, so as to improve the soil, improve the soil's ability to retain fertilizer and water, and provide more comprehensive nutrient elements. The best application time is autumn after fruit picking, during which the temperature is high and the fertilizer is easy to decompose; At the same time, it is in the new root stage, which is beneficial to absorption, thus promoting the accumulation of nutrients in the tree and playing a good role in the differentiation of female flowers in the coming year. Topdressing is mainly available nitrogen fertilizer, combined with phosphorus and potassium fertilizer, and the topdressing time is early spring and summer. Generally, topdressing is 0.3-0.5 kg urea per plant of newly planted fruit trees in spring, and 2 kg urea per plant in full fruit stage. After topdressing, water should be combined to give full play to fertilizer efficiency. Topdressing in summer is carried out from late July to mid-August. At this time, the application of available nitrogen fertilizer and phosphorus fertilizer can promote the increase of fruit grain number, full pulp and improve fruit quality. Top dressing outside the roots can be carried out many times a year, and the key points should be done twice. Spraying 0.3%-0.5% urea and 0.3%-0.5% borax for the first time in early spring when the basal leaves of branches turn from yellow to green, promotes the function of basal leaves, improves photosynthesis and promotes the formation of potted flowers. The second time is to spray 0. 1% potassium dihydrogen phosphate twice at intervals between1month and half a month before harvest, which is mainly used to improve photosynthetic efficiency and promote the transfer of nutrients such as leaves to fruits, and has a significant effect on increasing single grain weight. chestnut

(6) Irrigation: Castanea mollissima likes water. Generally, watering once before germination and once during the rapid growth period of fruit is beneficial to the normal growth and development of fruit trees and the improvement of fruit quality. (7) Plastic pruning: Pruning chestnut trees can be divided into winter pruning and summer pruning. Winter pruning from defoliation to germination in the following spring can promote the growth of millet trees and the formation of female flowers. The main methods are cutting short, thinning branches, retracting, slow releasing, pulling branches and carving. Summer pruning mainly refers to germination, pit removal, emasculation and branch thinning in the growing season, and its function is to promote branching, increase female flowers, and improve seed setting rate and single grain weight. 1, shortcut: cut off part of the annual branch. Short cutting can promote branching, enhance tree vigor, compact crown, reduce male flowers and adjust nutrient distribution. The leafy trees can be pruned in a delayed way, and they can be cut short after germination. 2. Retraction: it is a short cut of perennial branches. It is mostly used for perennial branches with weak growth, outward displacement of fruit and serious exposure in holes. 3. Drainage: that is, the raw branches, light blocking branches and slender branches in the cavity are drained from the base. 4, wearing a hat scissors: cut short near the new sharp wheel mark in winter, and the coring time is different. Leave 2-4 small buds on the ring mark of the new tip, which is called movable cap pruning. If handled properly, only the small buds on the cap and the big buds under the ring mark can produce fruiting branches. Leaving no short buds on the ring mark of the new tip is called wearing a dead hat to prune, so that the big buds under the ring mark produce fruiting branches. Under normal circumstances, the weak branches wear dead hat scissors, and the strong branches wear live hat scissors. 5, slow release: slow release is not cut. Its main function is to disperse nutrition and relieve tree vigor. Slow-release pruning is often used for lush trees. 6. Branching and scribing: For the strong and vigorous auxiliary branches whose crown is not pitted, flatten them when the juice flows to the bud in spring, and scribble above the bud that needs to germinate, so as to make them grow strong and vigorous branches. When pruning in winter, the slowly released and leveled branches are retracted to the part where the strong branches are drawn. 7. Nucleation: When the new bud grows to 30 cm, remove the top of the new bud. Mainly used for flourishing branches, the purpose is to promote early fruiting of branches. Pick your heart 2-3 times a year. The new buds of the first fruit-bearing trees are long and lush. When the front branches of the fruit grow out, 3-5 buds are left for picking. After the top of the fruit is pitted, about three stout branches can be formed, which increases the proportion of fruiting branches and slows down the outward migration of fruiting parts. 8. castration: only a few male inflorescences are left on the branches, and the rest are gone. Its main function is to control nutrition, promote the formation of female flowers and improve the strength of fruiting. (8) Flower thinning and fruit pollination: In flower thinning, young flowers and inferior flowers can be directly removed by hand, and Mr. Wang's big flowers and good flowers should be kept as much as possible. Generally, it is advisable to leave 1-3 female flowers per fruiting branch. It is best to use fruit thinning scissors and leave 1 single bract on each node. When thinning flowers and fruits, we should master the principle of leaving more outside the crown and less inside. Artificial pollination should choose varieties with good quality, large grain, early heating period and easy peeling as pollination trees. When the anthers of the male inflorescence on a branch or most flower clusters in the male inflorescence just change from green to yellow, spread the collected male inflorescence on glass or clean white paper before 5 am, put it in a dry and windless place, turn it twice a day, and put the fallen pollen and anthers into a clean brown bottle for later use. When the polymorphic stigma of three female flowers in an involucre completely extends to the inverted yellow stone, dip the pollen on the inverted stigma with a brush or pencil with a rubber head. If the height of the tree is not convenient for dipping, it can be made by shaking gauze bags or spraying powder according to the ratio of pollen 1 serving and sweet potato powder filler of 5 parts. (9) Harvest and storage: 1. Harvest: There are two ways to harvest chestnuts: picking chestnuts and threshing millet. The method of picking chestnuts is to pick chestnuts manually after the chestnuts are fully heated and naturally fall to the ground. In order to pick chestnuts easily, weeds on the ground should be removed before chestnut buds break out. When harvesting, shake the tree first, and then pick up all the fallen chestnuts. Be sure to pick it up every morning and evening. The advantages of chestnut picking method are full chestnut, high yield, good quality and strong storage resistance. The chestnut beating method is to knock down the mature chestnut bracts in batches with bamboo poles, and then pick up the chestnut bracts and chestnuts. Harvesting in this way is usually carried out every 2-3 days. When the buds are opened, tap the twigs inward from the periphery of the crown to shake off the chestnut buds so as not to damage the branches and leaves. It is forbidden to lay all chestnut buds with different maturity at one time. The harvested chestnuts should be treated as soon as possible, because the temperature is high, the water content of chestnuts is high, the breathing intensity is high, and a lot of heat is generated. Chestnuts are easily moldy if they are not treated in time. The treatment method is to choose a cool and ventilated place, spread a thin layer of chestnut bracts with a thickness of 20-30 cm, water them every day, cool down and sweat for 2-3 days, and then thresh them manually.

Edit high-yield cultivation techniques in this section.

Chestnut originated in China, and was ranked as one of the five famous fruits in ancient China along with jujube, peach, apricot and plum. It is also a world-famous dried fruit tree species. Chestnut is rich in nutrition, with starch 60-7 1%, sugar 7-23%, protein 5.7- 10.75%, fat 2.0-7.4%, and various vitamins and inorganic salts.

Ecological characteristics

Chestnut is widely distributed in China, starting from Fengcheng, Liaoning, at 40 30 ′ north latitude, and reaching Hainan Island at18 30 ′ north latitude. The lowest elevation is less than 50 meters in coastal plain, such as Tancheng, Jiangsu Xinyi and Muyang, and the highest elevation is 2800 meters, such as Yongren and Weixi. Chestnut is a light-loving tree species, especially during flowering and fruiting, insufficient light is easy to cause physiological fruit drop, such as long-term shading will make the leaves in the inner chamber turn yellow, the branches become thinner and even die. The annual average temperature is10.5-21.8℃, the absolute maximum temperature does not exceed 4 1.6℃, and the absolute minimum temperature is not lower than -24.5℃. Chestnut has a strong adaptability to humidity. Generally, it can be cultivated when the annual precipitation is above 1000mm and the annual precipitation is 500-2000 mm Chestnut has low requirements for soil and is suitable for growing on sandy loam with deep soil layer, good drainage and low groundwater level. Soil humus is more conducive to the growth of mycorrhiza, and pH 5-6 is the most suitable.

Key points of cultivation

(a) Before planting seedlings, they should be 70 mm high and 0.7 cm in diameter. High-quality strong seedlings with normal development, no pests and diseases, and developed roots should be properly packaged to prevent root dryness or mechanical damage. (2) During the cultivation period, spring sowing should be carried out in the first half of March before seedling germination, and autumn sowing should be carried out after seedling defoliation, but spring sowing is suitable for higher altitude areas. (3) The plant spacing is deep and fertile, and the slope is gentle, and the plant spacing can be 5-7m, with 20-30 plants per mu; Under moderate conditions, the plant spacing can be 4-6-8 meters, with 30-40 plants per mu; On the hillside with shallow soil and barren soil, the plant spacing can be 3-4m, with 40-60 plants per mu; It can also be intensively cultivated according to the specifications of 2×2m, and then transformed into. (4) Planting method: hole sowing method, the hole size is 40×40cm, 3-5 kg of decomposed organic fertilizer is applied and mixed with soil, and then a layer of 5- 10cm surface is covered on it before seedling raising. Most of the newly developed chestnut orchards use grafting to raise seedlings, or they can also plant seedlings on the spot for grafting. The advantages of using seedlings are fast growth, short slow seedling stage and low cost, but local grafting on the mountain is labor-consuming and time-consuming. Therefore, grafted seedlings are generally used for planting, so that after transplanting, the slow seedling stage is longer and the root healing ability is weak. Therefore, you must be careful when raising seedlings. When planting, the roots of seedlings should be stretched evenly, the seedlings should be righted, the fine soil should enter the root gap, and the soil should be filled and compacted to make the soil in close contact with the roots, and then the root water should be poured. (5) Manage 1. Rational fertilization, according to different tree ages, different regions, soil conditions and management level, following the principle of suitable land and suitable trees, and appropriately adjusting the application ratio of nitrogen, phosphorus and potassium. Weak trees, adult trees with large fruit yield should be fertilized more, and young trees and strong trees should be fertilized less. Different ages +0-3 years, 0.67- 1.33, 0.67- 1.33, 0.67- 1.33, 4-6 years, 2.0-2.67,1.33. Apply flower-promoting fertilizer for the first time in early spring (mid-February), fruit-promoting fertilizer for the second time (from early June to early July), and basal fertilizer for the third time after fruit harvesting (from the end of September to 65438+ 10). Each plant can be applied with 1 kg oil cake or calcium superphosphate, and weeding and covering the soil after application. 2. Digging, reaming and weeding. Digging deep and expanding holes every winter can not only destroy the wintering place of pests, but also turn weeds or green manure into the soil, improve soil organic matter and reduce soil water evaporation. 3. Trimming is one of the main technical measures for high-yield and high-quality cultivation of chestnut trees. Chestnut trees are mainly natural and happy. After the garden was built, it was pruned, pitted and bud smeared in winter to form a moderate number of trunks, and the crown was ventilated and transparent, laying the foundation for high yield and early fruit. Winter pruning, also called dormant pruning, was carried out in 65438+February and 65438+1October. After the trees stop growing, the grafted seedlings can be cored for the first time when the branches are 20cm long, and the tender branches at the top of the branches can be cored for the second time in June, and the branches with uniform angles and distribution can be selected to cultivate into backbone technology to form a good crown. 4. For trees with vigorous growth, the redundant buds in the middle, lower and upper parts of strong branches should be erased, and the effect is similar to thinning. The strong branch leaves only four or five big buds, and the medium branch leaves 65,438+0-3 big buds. 5. Pest control Because chestnut has strong adaptability, wide distribution and many kinds of pests and diseases, it needs to be found in time and treated in time.

Edit fertilization techniques in this section.

When chestnut blossoms, bears fruit and shoots grow, it consumes a lot of nutrients. At this time, if sufficient nutrients are not supplied, especially the required boron fertilizer is lacking, the normal growth of chestnut trees will be affected, resulting in an increase in the number of empty buds, low yield and poor quality of chestnut in that year. Two fertilization methods of chestnut were introduced:

Soil fertilization method

This method is effective in chestnut orchard with thin soil and serious lack of fertilizer. The method is as follows: digging 1 circular groove at the crown drip line of chestnut tree, with the groove width of 25cm and the groove depth of 20cm, and applying 1 kg of calcium superphosphate, 0.3kg of urea and 0.25-0.5kg of borax per plant. When applying, urea and borax should be dissolved in water before applying to the border, and water should be splashed when applying fertilizer. The fertilizer and soil should be mixed evenly with a hoe to make the fertilizer water penetrate into the root system as soon as possible and be absorbed and utilized by the root system. After applying fertilizer, it should be returned to the border in time to prevent nutrient volatilization. If a proper amount of soil miscellaneous fertilizer is added to fertilize the soil, it will have a good effect on chestnut bearing more fruits in the coming year and reducing the rate of empty bracts.

In vitro fertilization

This fertilization method is suitable for chestnut trees in various soils in summer. The method is as follows: 0.3%-0.4% urea solution, 0.3%-0.5% potassium dihydrogen phosphate solution and 0.3%-0.4% borax solution are mixed, and the tree crown is sprayed at 9: 00 am or at night on sunny days, once every 10 day and twice continuously. After spraying fertilizer, in case of heavy rain within 10 hour, it must be sprayed again to ensure the fertilization effect. In summer, if soil fertilization method is combined with external fertilization method, the yield increase effect of chestnut will be better.

Boron application reduced the rate of empty bracts.

The problem of chestnut "empty bud" has a great influence on chestnut yield. At present, in addition to artificial pollination at the flowering stage of chestnut, there is also an effective method, that is, applying boron fertilizer. I. Types of Boron Fertilizers and Methods of Boron Application The commonly used boron fertilizers are borax, which contains 65,438+00.8% boron and is soluble in warm water; Boric acid, containing 16.8% boron, white crystal, soluble in water. Boron application in soil adopts annular ditch or radial ditch with a depth of 20 ~ 80cm. When it is rainy or combined with boron irrigation, it is not necessary to dig a fertilization ditch, and shallow fertilization can be used in blocks. Because the validity period of boron application in soil is as long as 2 ~ 3 years, the effect in that year was not very significant. Therefore, it is necessary to combine foliar spraying. The concentration of borax sprayed on the leaves is 0. 1%-0.3%, and that of boric acid is 0. 1%-0.5%. Second, the period, climate and application amount of boron are about 0. 1 kg per mature tree soil in mid-April, and the application amount per mu should not exceed 12 kg, otherwise it will cause chestnut poisoning. Deep application in sunny days, shallow application in rainy days. Foliar spraying should be done once in the early flowering period and once in the full flowering period in June. It is best to spray it on cloudy days in hot weather, and it should be sprayed on the back of leaves before 10 in the morning or after 4 pm in sunny days, but it is not suitable for spraying in rainy days. If 0.3% urea and 0.3%-0.5% calcium superphosphate are used together, the effect will be better.

store

Chestnuts have three fears: one is afraid of heat, the other is afraid of dryness, and the third is afraid of freezing. At room temperature, chestnut rot mainly occurs within one month after harvest, which is called dangerous period. 2-3 months after harvest, there is little rot, which is a safe period. Therefore, temporary storage before shipment or storage before kiln storage is the key to prevent chestnut rot. A relatively simple and easy temporary storage method is to choose a cold and humid place and build a storage shed with corresponding size according to the number of chestnuts. The roof of the shed is covered with bamboo (wood) poles, covered with reed mats, and surrounded by branches or corn and sorghum stalks to prevent sun drying. The ground in the shed should be leveled, and the river sand with a thickness of about l0 cm should be paved, and then l chestnuts should be mixed according to the ratio of 3-5 parts. The chestnuts should be piled on it with a height of 30-40 cm, and the periphery of the pile should be paved with wet sand of 10cm. Turn it once every 3-5 days at the beginning, and turn it once every 5-7 days after half a month, and pick out rotten chestnuts every time. In order to prevent air drying, we should also pay attention to watering and moisturizing.

Three methods of chestnut storage

1. Sand storage method: outdoor trench (pit) storage. Choose a well-drained site and dig a ditch with a width of 1m, a depth of 60cm and an unlimited length. After leveling, lay a layer of wet sand (water content 30-35%) on the bottom of the ditch, put a layer of chestnuts, and layer by layer in turn. Each layer of sand chestnut is about 5-6 cm thick. Top sand distance from pit surface 10 cm. You can insert straw into the pit for ventilation, and finally seal the soil into a roof to prevent rainwater from infiltrating. 2. Storage with bracts: choose a well-drained site, lay sand with a thickness of 10 cm on the ground, and pile bracts in the open air. The size of the pile can be changed, but the maximum is not more than 1 m, and it is easy to heat up if it is too high. Cover the pile with stalks. Pay attention to check. If the pile is hot or dry, it can be properly splashed with water to cool and moisturize. This storage method is simple and labor-saving, and the storage period is long, and it can be stored until March-April of the following year, but chestnuts stored with bracts are easy to germinate. If the bracts are damaged by weevils, it is not easy to use this method, because the storage humidity is high, which is conducive to weevil activities. 3. Normal and mature chestnuts are stored in plastic film tents or film bags. After 1 month sweating and heat dissipation, it can be stored in a plastic film tent or a perforated film bag. Film bags can be placed in bamboo cages, wastebaskets or wooden cases. In order to prevent mildew, the fruit should be washed before bagging, soaked in 500 times of Tobezin solution for a few minutes, dried and bagged. The suitable capacity of the film bag is 25 kg, the film thickness is 0.05 mm, and holes with a diameter of 2 cm are punched on both sides of the bag, and the hole spacing is 5 cm. If non-porous bags are used, they should be inspected at any time to facilitate ventilation and moisture dissipation. When the temperature is high and the humidity in the bag is too high, the Qin Ying should be checked to reduce rot, germination and weightlessness.

Drug technology

1 alternative medicine technology 1. 1 biological control of natural enemies of pests has obvious inhibitory effect on chestnut pests. When the pest can't reach the control index, such as the number of female scale insects per 10 cm branch of chestnut is less than 1.5, chemical control is not needed, and chestnut can completely reduce the natural enemies of scale insects. Natural enemies can be used to control pests, black soil peak can control scarabs, Chinese long tail peak and jumping peak can control chestnut gall wasps, ladybugs with red lips and harmonia axyridis can control chestnut aphids. This biological control measure can effectively inhibit the occurrence and spread of pests when the pest population is low. 1.2 Pruning chestnut trees properly, removing branches and dead branches, and centralized burning can effectively reduce the base of overwintering pests and diseases and reduce the harm of pests and diseases in the coming year. In early spring, according to the overwintering characteristics of pests such as chestnut aphid and chestnut gall midge, the overwintering egg pieces and female scale insects were scraped manually in time. According to the characteristics of suspended animation of adult scarab, the adult on the tree was knocked down at night and killed artificially. For chestnut orchards with more gall caused by gall wasps, artificial gall removal can be adopted to reduce the occurrence of pests. 1.3 light trapping and killing pests uses the phototaxis characteristics of some pests, and the effect of black light (or incandescent lamp) trapping and killing is endless. For example, in 1998, we hung four 40W black lights in Baiyanwan Village, Lutan Town, 13.3hm2 to trap and kill the third generation adults of peach moth, and the damage rate of the third generation larvae to chestnut was reduced by 70% compared with 1997. It is also very effective to trap and kill beetles and chestnut moths with black light. This method has low cost and no pollution to the environment, and is worth popularizing. 2 Less use of pesticide technology For the cause of chestnut blight, it is not necessary to spray liquid medicine or air drying in the whole garden, as long as it is scraped or sprayed on the branches with gills. In chestnut orchard damaged by scale insects, there is no need to dry or spray chemicals in the whole orchard, as long as there are more than 1.5 branches of female scale insects in 10 cm, which not only reduces the dosage of pesticides, but also protects natural enemies. To control the adults of scarab, it is not necessary to spray chemicals on trees and grass during the day, but to spray chemicals on trees at night when scarab is harmful to trees, which can reduce the amount of pesticides. Spraying with a sprayer requires a nozzle, which can reduce the dosage of pesticides and make the liquid medicine sprayed evenly without waste, while using a spray gun with a spray column will lead to a large amount of liquid medicine waste. When preparing the liquid medicine, measure the original medicine with a small measuring cylinder. Rough pouring is not allowed, which wastes the original medicine, especially the high-priced medicine. Should be prepared as needed. It is not allowed to dilute a large amount of liquid medicine after mixing with mother liquor, which will lead to excessive preparation at night and waste. When the number of pests reaches the control index, reapplication can reduce the frequency of application. When the liquid medicine is prepared at a low concentration, it is not necessary to prepare at a high concentration. For example, when 50% parathion EC or 40% omethoate EC is 65,438+0,000 times, it can effectively control pests such as beetle adults, chestnut aphid eggs and nymphs, chestnut nymph, chestnut moth and moth larvae, and is not suitable for preparation. 3. Clever use of pesticide technology 3. 1 In the early stage when pests and diseases are not active and harmful, preventive medication can prevent the occurrence of pests and diseases and effectively control the development and spread of pests and diseases, such as chestnut blight, chestnut anthracnose, chestnut scale insect and chestnut aphid. Before germination in winter and early spring, spray 1 Beibomei 3-5 degree sulfur mixture and 0.3 times respectively. In addition, deep ploughing in winter can also eliminate overwintering pests. 3.2 The pest control in chestnut orchard should be fast and unified in the shortest time, making it difficult for pests and diseases to breathe and escape. The rapid elimination of pests and diseases that have occurred can reduce the number of insect populations and the source of disease, making it difficult for pests and diseases to produce drug resistance. It must not be controlled at intervals, and the effect will be poor. It is worth noting that the same concentration of pesticides should be used at the same time to avoid the spread of pests and diseases in non-spraying areas to spraying areas and the invasion of pests and diseases in low-concentration spraying areas to high-concentration prevention and control areas. 3.3 To do a good job in the prevention and control of pest hatching, emergence and peak damage. During the peak period, prevention and control can get twice the result with half the effort. The overwintering larvae of scarab were unearthed in late May. At this time, spraying 50% phoxim EC on the ground for 300 times can inhibit the number of emerging adults. Or in mid-June, spraying pesticides at the peak of scarab damage can also greatly reduce the number of pests. Mid-June is the peak of adult emergence in Chestnut Peak, and prevention and control at this time can reduce the number of galls in the coming year. The first ten days of June and the middle and late days of July are the peak periods of the fruit-eating pest Spodoptera exigua 1 generation and the second generation larvae. At this time, spraying 1000 times of 50% parathion EC can effectively kill eggs and larvae. The first half of September is the peak of the third generation larvae of peach fruit borer. Using dichlorvos with short duration or high efficiency and low toxicity has good control effect, which can prevent the fruits to be harvested from being affected by pesticide residues and endangering human health. 3.4 The mouthparts of pests are different, such as chewing, pricking and licking. Stomach medicine is used to control chewing mouthparts pests, but it is ineffective for sucking mouthparts pests. For example, chewing mouthparts pests such as scarabs and grubs, chestnut beetles, etc. Stomach poison should be used for treatment; For sucking mouthparts pests such as chestnut aphid and chestnut gall midge, internal sucking conductive chemicals should be selected; Contact insecticides and fumigation insecticides have good control effects on adult chestnut gall midge and fruit-eating pests such as chestnut gall midge and peach fruit borer larvae. According to the characteristics that some pests and scale insects secrete wax, which is hydrophobic and lipophilic, we choose agents with strong adhesion, such as oil emulsion, pine alkali mixture or agents with washing powder and synergist, and the effect is remarkable. The relationship between drug use and meteorology: high temperature and low humidity have good effect on pest control, but low temperature and high humidity have poor effect. For chestnut aphid, chestnut aphid, chestnut red spider, chestnut blight, chestnut anthracnose and other diseases, in sunny days, when the temperature is high and low, pesticides can effectively penetrate into pests and be easily absorbed by trees, thus effectively achieving the purpose of prevention and control. From June to September, the temperature is particularly high, which is the fruit expansion period of chestnut. At this time, attention should be paid to the selection of concentration and medicament to avoid phytotoxicity and fruit drop. Pay attention to the weather changes in rainy season. If it rains heavily after application, it will not only waste money, but also fail to achieve the control effect. If pests and diseases have broken out, they must be prevented and controlled in rainy days. Synergistic adhesive should be added to the medicine to improve the ability of resisting rain erosion, so that the efficacy of the medicine can be maintained even if it rains heavily half an hour after application. If the rain stops soon, or it rains in Mao Mao, the concentration of medicine should be higher to reduce the dilution of medicine by rain. If there is wind when applying pesticide, it is best to stop applying pesticide, so as to avoid the pesticide being blown away by the wind, the leaves can not be adhered by the pesticide, and it is easy to cause poisoning to the pesticide users.

Edit this autumn chestnut

Every autumn, sugar-fried chestnut shops that have been dormant for a year are reloaded. Every time they pass by, they will be attracted by the sweet taste and can't help but buy a bag to satisfy their hunger.

Chestnuts are different in north and south.

Chestnut, commonly known as chestnut, has the reputation of "king of dried fruits". The sugar-fried chestnut oil we usually eat is smooth and bright, but it is a "big thorn ball" when it grows on the tree. Usually there are 1-7 chestnuts in a "big thorn ball", but if you want to see their true colors, you have to "risk" peeling off the prickly coat. Chestnuts are mainly distributed in the northern hemisphere and cultivated in Asia, Europe, America and Africa, but both American chestnuts and European chestnuts are susceptible to fungal infection, and the former is almost extinct. Chestnut trees in China are resistant to this special fungus, so they are exported to the United States. Due to different growing environments, China chestnuts can be divided into two categories: northern chestnuts and southern chestnuts: the former has small fruit, dark brown skin, small base, high sugar content, strong fragrance and tender meat; The latter has large fruit, reddish brown skin, large base and crisp taste. There are several famous chestnuts in China. In the north, chestnuts in Qianxi County, Hebei Province are the most famous. The unique environment of "seven mountains, one water and half fields, half roads and half manors" here makes chestnuts grow thin, and the nuts are soft and sweet. More than 80% of finished fresh chestnuts will be exported to Japan, which calls Qianxi chestnut "the best food in Li Gan, China". In the south, chestnuts produced in Luotian County, Hubei Province are the most famous. "Silkworms spin silk, bees make honey, trees extract oil and mountains produce chestnuts", which is a specialty that Luotian people are proud of. Luotian began to cultivate chestnuts artificially as early as the Spring and Autumn Period and the Warring States Period. American scholars made a special trip here to investigate and decided that Luotian was the "world chestnut gene bank". At present, osmanthus fragrance and September cold are unique varieties here.

Chestnuts are good, but they should not be eaten more.

Because chestnuts in the north and the south have their own characteristics, they are eaten in different ways: northerners fry chestnuts with coarse sand and sugar water to make sugar-fried chestnuts, while southerners cook soup with chestnuts. Chestnuts are rich in nutrition, and the content of vitamin C is even higher than that of tomatoes, which is ten times that of apples. The minerals in chestnuts are also comprehensive, including potassium, zinc and iron. Although the content is not as high as that of hazelnut, it is still much higher than that of ordinary fruits such as apples, especially the potassium content is more than three times higher than that of apples. Chinese medicine believes that chestnuts can tonify spleen and stomach, tonify kidney and strengthen tendons, and promote blood circulation to stop bleeding. It has a good curative effect on kidney deficiency, so it is also called "the fruit of kidney". But chestnuts are hard to digest when eaten raw, and cooked food is easy to lag behind. Eating too much at a time will hurt the spleen and stomach, and eat at most 10 a day.