Collection, treatment and sowing methods of Strawberry Seeds

Strawberry is a perennial herb of the genus strawberry in Rosaceae. The propagation methods include seed propagation and plant division propagation, which are often used in production. Seed propagation is more often used for long-distance introduction or cultivation of strawberry seedlings to select new varieties. It can also be used for courtyard greening and fresh food planting. Let's take a look at the planting method of strawberry seeds.

Seed collection

During the fruit harvest from May to June, the well-developed and fully mature fruits were selected for seed collection, peeled off, put into water, washed, removed and dried. Or dry the peel directly, then crush it, and then separate the peel from the seed.

Seed treatment

Wash the strawberry seeds in 60-70 ℃ warm water and keep stirring until the water temperature drops to about 25 ℃. Soak for another 2-3 hours, remove and rub with hands until the seed coat is clean and shiny. Then rinse with clean water and cover with several layers of wet gauze. Germinate under the condition of 25: 30 ℃, soak the gauze with warm water three times a day (morning, noon and evening) to maintain the moist environment of the seeds, and sow seeds after 60: 70% of the seeds are white.

Sowing method

Before sowing strawberry seeds, irrigate the border with small water, then rake the border surface, and then sow when the border seeps under water. The seed of strawberry is small, so it is better to sow it. The appropriate sowing rate is 2.5-4.5 grams per square meter. immediately after sowing, spread the mulch evenly on the border surface with a thickness of 0.3-0.5 cm, shade with straw mats and scatter after finishing the seedlings.

Seedling land preparation

Strawberry nursery land is selected from fertile soil and applied sufficient base fertilizer, which is dried with manure, and then mashed and applied to the seedling field that has yet to be ploughed. The amount of fertilizer applied is 5 jin per square meter, and compound fertilizer should be added appropriately. After fertilizing, careful ploughing should be carried out, and the depth can be about 33 cm. After ploughing, it is necessary to rake fine and flat, and make ridges according to a width of 0.8 meters and a length of 8 meters, so as to make the border horizontal, so as to facilitate drainage and irrigation and management.

Seedling stage management

1. Watering: strawberry seedlings are not suitable for flooding irrigation, sprinkler irrigation can be used to meet the water supply, and small water flooding irrigation can be used after 6 true leaves.

2. Weeding: strawberries should always pull out weeds in time at the seedling stage.

3. Replenishing seedlings: strawberry seedlings can be transplanted with 3 or 5 true leaves.

4. Topdressing: when strawberry seedlings grow to 6 true leaves, topdressing can be carried out for the first time, and urea is suitable for topdressing.

Strawberry planting techniques and daily management methods

Strawberries are widely welcomed because of their bright appearance and pleasant aroma. Strawberries are ripe from January to February or March every year, and strawberries packed in small baskets or baskets on the roadside are quickly sold out, and some people go directly to the strawberry orchard to pick them themselves. The benefits of growing strawberries are also considerable.

Strawberry planting techniques and daily management methods

1. Select suitable varieties or mixed planting of different varieties: Fengxiang, Mingbao and other varieties with more flowering, large amount of pollen, large and neat fruit, good coloring, light sour taste and less abnormal fruit are selected under the condition of low temperature. Varieties such as Qiuxiang, Baojiao Zaosheng and all-Star have less pollen and more abnormal fruits. Chunxiang, Dana and other varieties should be planted as pollination plants to facilitate pollination and fertilization, reduce abnormal fruits and improve the rate of big fruits.

2. Select disease-free strong seedlings: disease-free strong seedlings have developed root system, strong disease resistance, large strawberries, high yield and good quality.

3. Adequate application of high-quality basic fertilizer: increasing the application of high-quality mature farm fertilizer can provide sufficient nutrients for strawberry growth, flower bud differentiation, flowering, fruit setting and fruit development, increase fruit number, and improve fruit sugar content and coloring. 2000 kg of rotten chicken manure is applied per mu, and ditch application is combined with spreading.

4. implement crop rotation to avoid repeated cropping: rotation can improve the disease resistance of strawberries and reduce the number of deformed fruits and diseases and insect pests. The open-ground rotation between the shed and the shed can be made full use of.

5. Increase the light: the lack of light from 2 weeks before flowering to the flowering stage of strawberry will affect pollination and fertilization and produce deformed fruit. Lack of light during the coloring period will lead to light taste and poor color of the fruit. Under the premise of ensuring the temperature in the shed, the covered grass should be uncovered as early as possible. A reflective screen is hung on the north side of the greenhouse, which uses reflected light to increase illumination. On rainy or snowy days, incandescent lamps can be used to make up the light.

6. Ridging cultivation and plastic film mulching: ridging cultivation can reduce fruit dripping contact with greenhouse film, enhance sunlight exposure to fruit, reduce the occurrence of gray mold and promote fruit coloring. Plastic film mulching can increase soil temperature, reduce air humidity, avoid direct contact with soil, and help to keep fruit surface clean.

7. Strictly control the temperature: the suitable greenhouse temperature is 22-25 ℃ at flowering day and 8-10 ℃ at night, and 20-24 ℃ at day and 6-10 ℃ at night during fruit expansion. Too high temperature in the greenhouse will shorten the fruit development period and make the fruit smaller.

8. Proper watering and topdressing: appropriate watering during flowering and fruiting period, drip irrigation should be adopted. Insufficient moisture during flowering will lead to poor pollination and fertilization, resulting in deformed fruit. The lack of water during the fruit expansion period will affect the fruit expansion. 0.3% potassium dihydrogen phosphate solution should be sprayed continuously for 3-4 times during flowering and fruiting period.

9. Auxiliary pollination: poor pollination and fertilization is the root cause of abnormal fruit, the use of bee-assisted pollination can effectively reduce the production of abnormal fruit. Generally, one case of bee pollination is put in each greenhouse during flowering.

10. Timely prevention and control of diseases and insect pests: strawberry spraying during flowering is easy to induce abnormal fruit. If diseases and insect pests occur during the flowering period, spray the beehive out of the greenhouse before spraying, and then move back to the greenhouse 1 week after spraying.

Growing environment of strawberries

1. Temperature: strawberry likes warm and cool climate, strawberry root growth temperature is 5-30 ℃, optimum temperature is 15-22 ℃, suitable temperature for stem and leaf growth is 20: 30 ℃, bud freezing injury occurs at-15 ℃, flower bud differentiation temperature should be maintained at 5: 15 ℃, flowering and fruiting stage should be kept at 4: 40 ℃. When strawberries pass the summer, shading measures should be taken when the temperature is higher than 30 ℃ and the sunshine is strong.

2. Light: strawberry is a light-loving plant, but it has strong shade tolerance. When the light intensity is strong, the plant is short and strong, the fruit is small, the color is dark and the quality is good. Medium light, large fruit, light color, low sugar content, long harvest time, weak light is disadvantageous to strawberry growth.

3. Moisture: strawberry has shallow root distribution, large transpiration and strict requirements for water, but it has different growth periods. Strawberries have slightly different requirements for moisture. For early spring and flowering coral, the lint percentage per grass is less than 70% of the maximum soil water holding capacity. The demand during fruit growth and ripening period is more than 80%. After harvest, the stolon and new adventitious roots are extracted, and the soil water content is not less than 70%. Autumn is the period of plant nutrition accumulation and flower bud formation, and the soil moisture should not be less than 60%. Strawberries are not tolerant to waterlogging, requiring good soil permeability and paying attention to drainage in the rainy season.

4. Soil: strawberries should grow in fertile, loose neutral or slightly acidic loam, too clayey soil is not suitable for cultivation, sandy soil more stable fertilizer, frequent irrigation, can also grow strawberries.

Collection methods of Strawberry Seeds

During the fruit harvest from May to June, the well-developed and fully mature fruits were selected for seed collection, peeled off, put into water, washed, removed and dried. Or dry the peel directly, then crush it, and then separate the peel from the seed.

Preservation of strawberries

1. Keep it in a ventilated place

Strawberries contain a lot of water, and the skin is so thin that they will rot at the slightest touch, so you should keep them carefully and gently when you buy them, and put them in a ventilated place when you buy them back, so you can keep them for a day or two.

2. Keep it in the refrigerator

If you want to preserve the strawberries, you can also put them in the refrigerator. Put the strawberries into the fresh-keeping bag and tie the mouth of the bag tightly. This can prevent the strawberries from losing moisture. The temperature in the refrigerator should be kept between 0-3 degrees Celsius, sometimes high and sometimes low. The sample can be kept for three to six days.

3. Sealing and storage of cling film

Endless strawberries can be sealed with plastic wrap, so that strawberries will not change color or rot during the day, but remember that the plastic wrap must be sealed without cracks.

4. Drain water for cold storage

Strawberries are more likely to go bad after touching water, so it is best to wash as many strawberries as you eat, and keep the rest in the refrigerator so that you can keep them for a longer time.

In addition to planting, picking and selling strawberries, preservation is also a matter of concern. The skin of strawberries is very fragile, and when ripe strawberries are picked and touched, the skin is easily destroyed, which is why merchants are reluctant to let customers choose when buying strawberries.

High-yield planting techniques and key points of cultivation and Management of Walnut

Cultivation of walnut seedlings

In order to ensure the seedling quality of afforestation in walnut base and avoid the quality variation caused by local walnut seedling growth, the grafting technique of efficient and rapid propagation was adopted to cultivate walnut grafted seedlings, that is, one-year-old iron walnut seedlings were used for rootstock or rootstock grafting to cultivate walnut grafted seedlings.

The main results are as follows: 1. It can maintain the excellent characters of the mother and accelerate the improvement of walnut varieties.

2. it can significantly increase the yield and improve the quality.

3. It can dwarf the plant and hang fruit early.

4. The germplasm resources of iron walnut can be fully utilized.

Planting of walnut

The planting of walnut starts from the selection of planting land, flat land, platform land and gentle slope land are selected as walnut planting base, and comprehensive or block soil preparation is carried out. planting to achieve large root sparse holes, close connection of root soil, pond soil full, irrigated enough water, heat preservation and moisture, adequate nutrients, in order to ensure the survival of walnut planting, which is conducive to the rapid growth of walnut trees. In order to master the feasible walnut planting technology, the forestry department has gained very good experience after years of exploration, which is referred to as the "six ones" technology of walnut planting, that is, "select a good land, hit a big pond, put a load of agricultural fertilizer, plant a strong seedling, pour a clear water, and cover a piece of plastic film."

1. Parcel selection

The relatively concentrated land such as flat land, platform land and gentle slope land with loose soil and good drainage are selected as walnut planting base, which grows best on slightly alkaline soil containing calcium. Walnut is a deep-rooted tree species, and the root system needs a deep soil layer of more than 1m to maintain its good growth and development. if the soil layer is too thin, it is easy to form "little old man trees" or withered shoots for years, which can not form yield.

2. Land preparation and planting

Seedling planting is an important basic work for the establishment of walnut base, and each planting link must be grasped to improve the survival rate and planting effect.

① soil preparation: the determination of planting ponds in advance is beneficial to soil ripening and the increase of moisture in planting ponds. The setting of planting ponds can be advanced to summer. The length × width × depth of the pond is 100 cm × 100 cm × (80 mi 100) cm. After the pond is finished, it should be backfilled in the form of one layer of topsoil and one layer of leaf weeds (or organic fertilizer) until it is close to the height of the surface and has a slight groove to facilitate stagnant water. The backfilled pond is kept until it is planted. Where there are no conditions for digging ponds in advance in summer, you can also plant them now before planting. The pond is 100 centimeters long and 100 centimeters wide and 80 centimeters deep. When digging, pile the topsoil and core soil (stone) in the pond separately. If the soil is heavy or the lower layer is gravel and impervious layer, the planting pond should be enlarged and deepened, and guest soil should be used for improvement. When returning to the pond, each pond should be filled with 50 kg farm manure (stable manure, green manure, compost, etc.) and 1 kg calcium or 1.5 kg calcium magnesium phosphate fertilizer mixed with topsoil. The lack of farm fertilizer can be replaced by leaves, weeds, turf soil, organic waste and so on. The position of the pond is generally arranged horizontally, that is, each row is on the same horizontal plane.

② planting season: as the saying goes, "planting trees early, do not give spring dawn." The time of planting walnut should be after the seedlings enter dormancy in late autumn or before the seedlings germinate in late winter and early spring, that is, from the ninth month of the lunar calendar to the first month of the following year. It is not suitable to plant in the peak period of summer production.

③ planting method: the planting method of walnut is generally determined according to the mountain topography and topography. If the mountain is gentle and the slope is small, it can be planted according to rectangle; if the slope is large and the platform is narrow, it is appropriate to use triangle.

The planting density of ④ should be 16 plants per mu. The row spacing of plants in flat land is 7m × 8m or 6m × 9m, about 12 plants per mu, and the row spacing of plants in sloping land is 6m × 7.5m or 6m × 7m, and 16 plants per mu. Usually, the intercropping effect between walnut planting land and crops is better, ploughing instead of caressing, short raising and growing, so that high yield and high quality can be obtained.

3. Planting technology

Planting techniques can be summarized as "alignment, orientation, upright, burying soil, light lifting, stepping on solid, making plate, watering, covering film" 18-character formula.

① alignment: when planting, put the seedlings in the middle of the prepared pond, front and back, left and right.

② direction: set the seedlings in the direction before transplanting.

③ upright: straighten the seedlings and let the roots spread out in all directions.

④ buried soil: nutritious soil covered with mixed fertilizer.

⑤ light lift: after all the roots are buried, gently lift the seedlings to make the roots stretch and closely combine with the fine soil, and then gradually fill the soil. After the soil sinks, it is appropriate for the seedlings to be buried in the original nursery.

⑥ compaction: in the process of filling, step on it while filling, fill a layer of soil and tread again, until the soil is 5ml / 10cm above the surface.

⑦ plate: build a circular ridge around the pond.

⑧ watering: irrigate enough fixed root water, 50ml 80kg per plant.

⑨ mulching film: each plant is covered with a 1m × 1m agricultural plastic film. The center of the film is cut into a small hole with a diameter of about 6cm, and the seedling rod passes through it. After landing, the small hole is covered with fine soil and should be buried under the surface soil.

Management of walnut

The management of walnut refers to a series of management work, such as watering and fertilization, shaping and pruning, loosening soil and weeding and so on.

1. Water management

In the dry season of walnut planting, it is necessary to supplement watering 25kg for 3 times, each time, and irrigate 1 Mel twice a year before the walnut blossoms under suitable conditions. Walnut trees are sensitive to surface water and high groundwater level, so they should be drained in time. In areas with high groundwater level, deep trenches can be dug to lower the water level. According to the growth depth of walnut root system, a drainage ditch with a depth of about 2m can be dug to make the groundwater level drop below 1.5m below the surface. In low-lying areas prone to stagnant water, drainage ditches can be dug around to prevent the inflow of external water and eliminate stagnant water on the surface.

2. Fixed dry plastic surgery

Fixed-stem shaping is an important technical measure in walnut cultivation and management, which varies with different walnut varieties.

The fixed stem shaping was carried out when the walnut grew to 80-100cm after planting, and the four main branches were left open and stratified or naturally happy.

① evacuation hierarchical type (with trunk shape) generally has 6 Mel 7 main branches, which is divided into 2 Mel 3 layers. It is characterized by semicircular crown, good ventilation and light transmission, long life, high yield and large load. it is suitable for growing in places with good conditions and sparse planting trees with strong dryness.

The natural open heart type (no trunk) of ② generally has 4 main branches. It is characterized by fast forming, early results, easy shaping and easy to master. The tree shape is suitable for walnut varieties and early bearing varieties planted in areas with poor soil quality and poor fertilizer and water conditions.

The method of fixing the trunk of late-bearing walnut: after sprouting in spring, a strong bud or strong branch above the fixed stem height was selected as the first main branch, and all the following branches and buds were cut off. If the young tree grows too vigorously and the branching time is delayed, in order to control the dry height, a short cut can be made at the upper part of the required dry height to promote the sprouting of cutting buds, and then the first main branch can be selected.

Early fruiting walnut drying method: after sprouting in the same year, erase all lateral buds below the required dry height. If the growth of young trees does not reach the fixed dry height, it can be dried in the following year. If the terminal bud is necrotic, you can choose to leave a strong bud close to the terminal bud to promote its upward growth, and then dry it to a certain height. The method of selecting the main branch at fixed drying time is the same as that of late-bearing walnut.

3. Trim and reshape

Walnut pruning varies with young trees, fruit trees, and aging trees. At the same time, during the flowering and fruiting stage, thinning flowers and fruits should be carried out appropriately.

The pruning of young trees varies according to the growth and development characteristics of different varieties, mainly cutting off weak branches, cross branches, overlapping branches, parallel branches and diseased branches to cultivate all levels of backbone branches and fruiting branches. The specific methods are as follows: control the secondary branch, control the growing branch, deal with the exuberant nutrient branch, remove the dense branch and deal with the inferior branch.

Adult tree pruning has just entered the adult walnut tree, the tree shape has been basically formed, and the yield has gradually increased. The main pruning tasks of walnut trees during this period are to continue to cultivate main and lateral branches, make full use of the early fruit of auxiliary branches, actively cultivate fruiting branches and expand the fruiting position as much as possible. The pruning principle is to remove the strong and retain the weak, first put and then shrink, the combination of expansion and contraction to prevent the result part from moving outward.

For the large walnut trees in the full fruiting period, most of the canopy is close or has been closed, the number of outer branches gradually increases, and most of them become fruiting branches, and due to poor light, some of the branchlets are dry, and there is a bald zone at the back of the main branch. the fruit part is moved out, and it is easy to bear fruit every other year. Therefore, the main task of pruning in this period is to adjust the relationship between vegetative growth and reproductive growth, constantly improve the ventilation and light transmission conditions in the crown, and constantly renew fruiting branches, so as to achieve the purpose of high and stable yield.

The pruning walnut trees entered the aging period, the outer branches drooped and produced a large number of "scorched shoots". At the same time, a large number of overgrown branches sprouted, the phenomenon of natural regeneration appeared, and the yield decreased significantly. In order to prolong the life of the results, renewal and rejuvenation can be carried out. The specific pruning method: ① trunk update (big update) saws off all the main branches to make them re-branch and form the main branch. ② main branch renewal (medium renewal) retracts in the appropriate part of the main branch to form new lateral branches. ③ lateral branch renewal (small renewal) retracts the primary lateral branch in the appropriate position to form a new secondary lateral branch. Its advantages are: the formation of new crown and the increase of yield are rapid.

4. High grafting of walnut.

Walnut high grafting is an important way to improve walnut varieties and realize walnut cultivation. It can be divided into hard branch grafting and green branch grafting.

① hard branch grafting: the commonly used method is skin insertion and tongue grafting. First of all, the scion should be collected 20 minutes before germination, and the thickness of the scion should be about 1.5cm, with small pith, full branches, full buds and no diseases and insect pests. After the scion is adopted, it should be divided into varieties, specifications, label and put into the environment of fruit cellar or ice cellar 0Mel 5 ℃. When grafting, it should be taken with you. The grafting time is from early April to early May. The grafting object generally chooses the young trees of about 5 years old, and the trunk diameter of the trees growing vigorously above 1.5cm. Multiple grafting can also be used for trees over 10 years old. The grafting method is to first cut the scion into 10-15cm branches, on which there are more than 2 full buds, and cut the branches into 5-8cm-shaped Maltese-shaped cutting surface into tongue shape. Select the smooth and straight place of the grafting tree to cut off the upper end, flatten the saw and cut a 2-3cm-shaped cut at the interface cuttings, then cut off the thick old bark of the rootstock under the cut to expose phloem, its shape and size is slightly larger than the Malt-shaped cutting surface of the scion, insert the scion, and then bind it with plastic rope for 5 times and 7 laps, fastening from top to bottom, and the binding should start from the interface. The binding part is too low, which is not conducive to survival. After bundling and then heat preservation and shading treatment, generally use waste newspaper or cylinder to fill with fine wet soil, but not too wet, put on a plastic bag.

② green branch grafting: mainly square bud grafting, the time is June, the scion is grafted with improper means, and the rootstock is the new branch of the same year. The grafting of big trees should be pruned in January to shorten the old branches and leave new shoots for grafting after sprouting new shoots.

5. Points for attention in grafting.

Whether hard branch grafting or green branch grafting, post-grafting management is very important, mainly as follows:

Timely de-sprouting of ①: new buds germinated on rootstocks should be removed in time.

② timely release: the next 20 murals will be released for 30 days, the size of the first cigarette butt, the size of the second five cents, and the third removal of the bag without newspaper.

③ fixed bracket to prevent wind break: when the grafted twig grows to 20 cm, the bracket should be fixed in time to prevent wind break.

④ was loosened to remove the membrane.

⑤ cut cut anvil.

Young fruits were removed by ⑥.

⑦ fertilization and pruning.

Soil and fertilizer management

1. Horizontal intercropping

Horizontal intercropping refers to intercropping with perennial crops, trees and fruit trees. Walnut intercropping not only ploughs, loosens soil, weeds, fertilizes and irrigates walnut trees, but also plays a role in nurturing walnut trees. Walnut trees have strong growth, reduced diseases and insect pests and high yield.

2. Stereoscopic intercropping

Three-dimensional intercropping refers to the use of space and open space under walnut trees to interplant smaller crops and shrubs. Intercropping of grain crops is the most commonly used method in most mountainous areas of Yiliang, but the following points should be paid attention to when intercropping:

① walnut young trees should grow wheat, millet, sweet potato, dwarf beans and other low-stem crops because of their small body and root plate, and leave a tree plate of about 1.6m in diameter around the young trees to facilitate fertilization, weeding and prevent competition for nutrients.

After ② walnut trees grow tall, they can grow cereal, wheat, dry millet, legumes, peanuts, strawberries, radishes and so on. These are ideal intercropping crops.

The root system of ③ walnut can secrete an organic chemical-juglone, which can inhibit the growth of some plants. Therefore, walnut forests avoid planting crops that are sensitive to juglone, such as apples, black strawberries, tomatoes, potatoes, alfalfa and so on.

④ ploughing the soil: walnut trees without intercropping are barren. Desolation will lead to a large number of diseases and insect pests, reduce growth potential and yield, and even lead to tree death. Ploughing is carried out twice a year, the first in spring and the second in autumn. When ploughing, it should be deep outside the crown and shallow near the tree plate to prevent root damage. Ploughing the soil can achieve the purpose of eliminating weeds, storing water and preserving soil moisture, improving soil physical and chemical properties, improving soil fertility and eliminating some overwintering diseases and insect pests.

⑤ weeding: twice a year, once in May-June and August-September respectively, to protect the normal growth of walnut trees and facilitate the harvest of fruits.

3. Fertilization management

Fertilization is an important measure to ensure the normal growth and development of walnut trees and to achieve high and stable yield. It can not only supply nutrients directly, but also improve the mechanical composition and structure of soil, promote root development, flower bud differentiation and early fruiting of young trees.

① rational fertilization: walnut trees need adequate nutrient supply in the process of growth, especially after entering the full fruit stage. Walnut needs a lot of nutrients, including nitrogen, phosphorus, potassium, calcium, magnesium, boron, iron, zinc, copper, manganese and so on. Some of these elements are abundant in the soil, but some elements are missing in the soil and need to be supplemented by fertilization. Walnut needs more kinds and quantities of nutrient elements, but it is not that the more fertilizer is applied, the better. It must be applied reasonably. The so-called reasonable means to apply fertilizer timely, appropriately and scientifically in accordance with local conditions, so as to not only give full play to the effect of fertilizer, but also save fertilizer.

② fertilizer amount: the amount of fertilizer application is determined according to soil fertility, walnut growth status and nutrient requirements of walnut trees in different periods. Generally speaking, young trees should apply nitrogen fertilizer mainly, while adult trees should apply nitrogen fertilizer and increase phosphorus and potassium fertilizer at the same time. Under the condition of medium soil fertility, the annual fertilizer application rate of 1-5-year-old unfruited trees was 100g nitrogen fertilizer, 30g phosphorus fertilizer and 30g potassium fertilizer per tree, and then increased 100g nitrogen fertilizer every year according to tree age, increased to 500g at 5 years old, and increased the amount of phosphorus and potassium fertilizer. After 6-8 years, the annual fertilizer application rate was 550g nitrogen fertilizer, 400g phosphorus fertilizer, 500g potassium fertilizer, and increased farm fertilizer 5kg.

4. Fertilization time

① base fertilizer: generally in spring and autumn, autumn is better. The base fertilizer is mainly slow-acting farm manure, such as barnyard manure, compost, green manure, straw fertilizer, dregs manure, mud fertilizer and so on.

② topdressing is generally carried out 3 times a year, the first topdressing is carried out before flowering or early leaf expansion, mainly available nitrogen, the main function is to promote flowering, fruit setting and shoot growth, the amount of topdressing should account for 50% of the annual topdressing amount. The second topdressing is mainly available nitrogen in the vigorous growth period in June, and its main function is to meet the nutrient demand in the exuberant growth period, so as to promote fruit development and shoot growth, reduce fruit drop, and be beneficial to flower bud differentiation. The third topdressing is carried out in the hard kernel period of nuts in July (if the young trees have not yet borne fruit, they can not carry out the third topdressing). It is mainly composed of nitrogen, phosphorus and potassium compound fertilizer, which is mainly used to provide nutrients for the development of nucleolus and ensure the fullness of nuts.

5. Fertilization method

The main fertilization methods of walnut trees are radial fertilization, circular fertilization, hole fertilization, strip fertilization, whole garden application and so on. Measures should be taken in accordance with local conditions and methods with good results should be selected.

① radial fertilization takes the crown as the center, and within the projection range of the crown, 8 furrows are excavated radially, with a width of 20mur40 cm and a depth of about 30 cm (deeper base fertilizer, shallower topdressing). The length of the furrow is similar to the radius of the crown, and the ditch depth gradually deepens from inside to outside the crown. After the fertilization ditch is dug, fill the ditch with fertilizer and soil, and then cover the soil. The location of the fertilizer ditch changes every year, and gradually moves out with the continuous expansion of the crown. This method is mainly used for trees with strong growth and older trees.

② circular fertilization takes the trunk as the center, along the outer edge of the crown, dig a ring-shaped ditch 30 cm deep and 20 mi 40 cm wide, mix fertilizer and soil into the ditch, and then cover the soil. The base fertilizer is buried deeper and the topdressing is shallower. Fertilization ditch can be dug half ring, can also dig the whole ring, dig half ring need to take turns to dig, one direction a year. This method is more suitable for young trees under 4 years old.

③ hole fertilization in the canopy projection range, dig a number of small holes (number and size according to the size of the crown), and bury the fertilizer. This method is generally used for topdressing.

④ strip fertilization is applied between rows or trees of walnut trees, cutting the opposite sides of the crown edge, digging parallel fertilizer ditches respectively, the width and depth of the ditch is the same as other methods, and the length is determined according to the size of the crown. The position of digging trenches changes every year. This method is mostly suitable for young and adult trees.

It is a common method to apply fertilizer to big trees in the whole garden of ⑤. The specific method is: first spread the fertilizer evenly into the whole garden, and then turn it shallowly. This method is simple and easy, but its disadvantage is that the fertilization is too shallow, and frequent application will lead the fine roots to the surface of the soil.

When applying fertilizer, it should be noted that plant ash cannot be mixed with feces and urine of mature people, because the main component of plant ash is potassium carbonate, and its aqueous solution is alkaline, while nitrogen in mature human feces and urine exists in the form of ammonium carbonate, when it meets alkalinity, ammonia will be volatilized, resulting in nitrogen loss and reducing fertilizer efficiency. The above five methods should be irrigated immediately after fertilization in order to increase the fertilizer efficiency. If there are no irrigation conditions, water conservation measures should be taken.

Harvest and treatment of walnut fruit

The mature harvest of walnut varies with altitude, climate, site conditions, variety and tree age. The same variety has different maturity due to different elevations; under the same site conditions, old trees mature first, young trees mature later, wasteland ripens first, cultivated land ripens later, but most varieties mature before and after White Dew. Mastering the time of harvesting and beating walnuts is very important, harvesting and beating is early, and the seeds are not yet ripe and not full. It not only affects the fruit quality, but also the fruit is difficult to fall off, which is easy to hurt the flower bud and affect the fruit in the coming year. If the harvest is late, the seeds are overripe and fall off a lot, resulting in losses.

The ripening of walnut is characterized by the change of exocarp from green to yellowish green and cracking. The ripening of the walnut fruit on the same plant is inconsistent, and it can be harvested when the exocarp of the walnut tree is dehiscent. The method is to beat the twigs horizontally with a long bamboo pole and shake the walnut fruit to the ground. When beating, we should pay attention to protect the branches, do not hit hard, break the twigs and flower buds, affecting the fruiting of the coming year.

Control of main diseases and insect pests

Walnut diseases and insect pests mainly include walnut black spot and walnut anthracnose, stem borer-longicorn beetle, wood bark moth, leaf-eating pest-beetle, diamondback moth and so on.

1. Black spot of walnut

Walnut black spot does harm to fruit, leaves and shoots, causing fruit rot and early fruit drop, reducing kernel yield, is a bacterial disease, control methods:

Disease-resistant varieties were cultivated and cultivated by ①.

② keeps the tree growing healthily, enhances disease ability, and removes diseased fruits, leaves and other pathogens in time.

Before germination, ③ was sprayed with Baume 3 Mel 5 degree stone sulfur mixture. From May to June, spray 200 Bordeaux solution or 50% methyl thiophanate wettable powder 500 / 800 times, spraying once before flowering, after flowering and young fruit stage of female flower respectively.

2. Anthracnose of walnut

It mainly harms the fruit, is a fungal disease, and can be transmitted with apple anthracnose. Methods of prevention and treatment: spray Bordeaux solution of 1L / L 200 (copper sulfate: lime: water) before onset; spray 1000 times of 40% carbendazim wettable powder, 75% chlorothalonil 600x, 70% or 50% topiramine 800ml 1000 times, once every semimonthly, spray 2rel 3 times, if you can add adhesive (0.03% leather glue, etc.), the effect is better.

3. walnut longicorn beetle

Walnut longicorn beetle mainly harms the branches and trunks of walnut, resulting in the death of some main branches and central trunks of walnut trees, and some of the whole trees are dead. it is a destructive pest on walnut trees. Control methods: in the active stage of larvae, dichlorvos mud and wormhole were used to kill pests or carbofuran was used to bury roots to control pests in late winter and early spring.

4. Bark moth

The bark moth mainly harms the branches of walnut trees, causing some branches of walnut trees to die. Control method: in the active stage of the larvae, the cotton was stuffed with dichlorvos into the wormhole to kill the larvae or cut off the insect branches and burn them. When it is found that there is larval harm in the root neck, that is, pry open the cortex to dig out the larvae; remove the soil from the root neck, inject it into the wormhole with 40% dimethoate emulsion 20 times, then seal it with wet soil to kill the larvae; during the adult oviposition period, spray 50% parathion emulsion 400 times below 1.5 m of the tree trunk to the root neck twice to kill the newly hatched larvae.

5. Beetles and diamondback moths

When beetle adults and diamondback moth larvae mainly feed on leaves, walnut trees are eaten up, thus affecting the growth of trees. Control methods: when the occurrence is serious, a large number of adults are trapped and killed by heap fire or black light; 90% trichlorfon 800x liquid, dichlorvos 800x liquid, isocarbophos 800x liquid, parathion 2000 times liquid, the insecticidal rate can reach more than 90%.