I. Introduction of Walnut Varieties
(A) the classification of walnut varieties
Walnut is a tree of Juglans in Juglandaceae. Walnuts are mainly walnuts and walnuts. In addition to walnuts and black walnuts, walnut growers should also pay attention to the black walnuts, wild walnuts and American pecans of this genus.
Walnut is cultivated in the Yellow River basin and the northern region, with a long history and many varieties, which can be divided into two categories: early fruiting and late fruiting. The origin of early fruiting walnuts is mainly in Xinjiang, and all varieties basically have the pedigree of Xinjiang walnuts. Its main feature is that fruits can be seen after planting for 1-2 years, but the disease resistance is weak. The main varieties are Xiangling, Yuanfeng, Luguang, Fenghui, Lin Zhong No.5 and Liaohe 1 ... Late-maturing walnuts begin to bear fruit 5-6 years after planting, but they have strong disease resistance, and the main varieties are fragrant.
(2) Introduction of walnut varieties
1. Introduction of early fruiting walnut varieties
Xiangling: shandong institute of pomology 1978 was bred by artificial hybridization, and 1989 passed the ministerial appraisal. The annual grafted seedlings will bear fruit after 2-3 years of cultivation. Nuts are oblong, the average single fruit weight is 9.5- 15.4g, the core-shell thickness is 0.9mm, the shell surface is smooth, the suture line is straight, it is not easy to crack, and the kernel yield is 53-6 1.2%, so the kernel can be complete and full. The oil content of nucleolus is 65.58%, and it tastes sweet. The branches of plants are strong, and trees have medium potential. The fruit branch rate is 85.7%, and the lateral bud fruit branch rate is 88.9%. Medium and short fruit branches are the main fruit branches, with an average of 1.3 per fruit branch, which is beneficial to high yield. It germinates in Tai 'an, Shandong Province in late March, the male flowers are completely dispersed in mid-April, and the female flowers are in full bloom in late April, which belongs to the male first variety. This variety has certain resistance to walnut black spot and walnut anthracnose. Suitable for field cultivation with deep soil layer.
Lu Guang: Shandong Fruit Research Institute 1978 was bred by artificial hybridization, and 1989 passed the ministerial appraisal. One-year-old grafted seedlings bear fruit after planting for 2-3 years. Nuts are nearly oblong; The average weight of single fruit is16.7g; The shell surface is smooth and beautiful, with good commodity and tight suture. The thickness of core-shell is 0.8-1.0 mm; The seeds can be intact, the endosperm is yellow, the seeds are full, the kernel rate is 56.2-62.0%, and the oil content is 66.38%. The plant has strong tree potential, open tree shape and strong branching; The fruit branch rate is 865,438+0.8%, and the fruit branch rate of lateral buds is 80.8%, mainly long fruit branches, with an average of 65,438+0.3 fruits per fruit branch. Strong fertility. It germinates in Tai 'an, Shandong Province in late March, the male flowers are completely dispersed in early and middle April, and the female flowers are in full bloom in late April, which belongs to the male first variety. It has certain resistance to black spot and anthracnose of walnut, and is suitable for planting in mountainous and hilly areas with deep soil layer.
Yuan Feng: shandong institute of pomology selected early-bearing walnut seedlings from Xinjiang. Early fruiting, male type, single fruit weight11-12.8g, shell thickness 1.3mm, kernel rate 46.25-50.5%, grain fat content 68.66%, protein/.
Liaohe 1: It was bred by artificial hybridization by Liaoning Institute of Economic Forestry. 1989 passed the ministerial appraisal. One-year-old grafted seedlings begin to bear fruit after 2-3 years of planting. Nuts are spherical, with smooth shell surface and tight suture lines. The average diameter of nuts is 3.4 cm, the average single fruit weight is about 10 g, the core-shell thickness is about 0.9 mm, and the inner partition wall is membranous or degenerated, which can be used for whole kernel. The kernel rate is 56.0-60.0%, and the kernel is yellow and white and full. The plant has strong tree vigor, upright tree posture and strong branching, with fruit branch rate of about 90%, lateral bud fruit branch rate of 100%, and average fruit setting per fruit branch of 1.3, which has strong sustainable high yield. It germinated in Dalian, Liaoning Province in mid-April, the male flowers were completely dispersed in early May, and the female flowers were in full bloom in mid-May, belonging to the male first variety. If Liaohe No.5 or Lin Zhong No.5 plants are properly arranged as pollination trees in the orchard, the fertilization rate and seed setting rate can be improved.
2. Introduction of late-maturing varieties
Qing Xiang: It is an excellent walnut variety presented by Japanese walnut experts to Hebei Agricultural University in the early 1980s. The tree has medium potential, half-opened, thick branches, 37.39% branch-setting rate and lateral flower buds. Nuts are nearly conical, the shell is smooth and light brown, the appearance is beautiful, the fruit is large, and the average single fruit weight is13 ~16g; The kernel is full, the inner fold wall is degraded, and it is easy to take kernel, and the kernel yield is 52 ~ 53%; The kernel is light yellow and has a strong flavor. Strong disease resistance. Male flowers ripen first.
3. Liuhe 1 is a new walnut variety with both fruit and wood, which was selected from the offspring of early fruiting walnut in Xinjiang, and was designated as the superior line in 1996. The selective breeding was carried out in 1997-200 1 year, and the regional test and variety comparison test were carried out in Feicheng, Feixian and Taian. According to walnut seed selection standards and recording methods, the trunk growth rate, botanical characteristics, economic characteristics and biological characteristics of walnut were investigated in detail. The results showed that "Liuhe L" was an excellent walnut variety with fast trunk growth, early fruiting, high yield, strong stress resistance and excellent nut quality. June 5438+February 65438,00, 2002 passed the expert appraisal of Shandong Science and Technology Department.
The tree stands upright with a conical crown; The trunk is grayish white, smooth, with shallow longitudinal cracks; The branches are thick and smooth. The new shoots are green and brown, with an average length of 23.3cm and a thickness of 0.79cm. The mixed buds are round, medium and large, with small bud base and adhesion. The main and auxiliary buds on the secondary branches are separated, and the bud tips are green and brown. 2-3 female flowers are planted on the bearing branches of mixed buds, and the stigma of female flowers is green and yellow. The male inflorescence is 9cm long, the compound leaves are 43.2cm long, the leaflets are 5-9, the top leaflets are oval, the length is 17. 1cm, the width is 8.3cm, the leaf thickness is dark green, and the leaf margin is entire. The fruit is oblong, light green, with sparse hair, small and dense lenticels, medium-long stalk, 0.50 cm thick peel and an average of 4.64 cm in diameter.
This tree is strong, growing fast and upright. 10 mother tree is 9.5m high. Young trees grow fast, the average annual growth of 3-year-old trunk diameter is 2.5 cm, and the tree height is 2.5 meters; The 8-year-old grafted trees grow rapidly, the annual growth of main branch diameter is 2.56cm, and the average annual growth is 106.7cm~ 10 year. The new shoots of the mother tree are 23.3 cm long and 0.79 cm thick, and the annual growth is 65438 0.35 cm.
Nuts are cone-shaped, light yellow, with top, oblate base, smooth shell surface, slightly convex stitching, tight combination and not easy to crack. The core-shell has certain strength, and is resistant to cleaning, bleaching and transportation. The shell thickness is 1.2mm, the inner pleated wall is membranous, the mediastinum is underdeveloped, and the whole kernel can be taken. Endotesta is light yellow, with no astringency, full nucleolus and fragrance. The kernel yield is 55%, the fat content is 63.7%, and the protein content is 17.5%. The longitudinal diameter of nuts is 4 1.9mm, the transverse diameter is 32.0mm, the transverse diameter is 3 1.9mm, the single fruit weight is 13.2g, and the kernel weight is 7.25g. The comprehensive quality is excellent.
Grafted seedlings bloom in the second year after planting, bear fruit in the third year and bear fruit in the second year after high grafting. The mother branch has strong branching, the fruit setting rate is 68.7%, the lateral flower bud rate is 73.6%, and there are many double fruits, mainly medium-long fruit branches, which have great yield potential and strong stability.
In Tai 'an area, Liuhe/KLOC-0 germinated in late March, showed its leaves in early April, the male flowers opened in mid-April, and the female flowers flourished in late April. Male type one. The fruit ripens in late August, and the fruit development period is 123 days. 165438+1defoliation in early October, and the plant growth period is 2 10 days. The female flowering period is basically the same as the male flowering period of female pre-mature varieties such as Lufeng and Lv Bo.
This variety is an early fruiting variety, with strong budding ability, strong branching ability, high lateral flower bud rate, easy female flower formation and high fruit setting rate, but vigorous in the early growth stage, low yield, high yield with the increase of tree age, slow growth and great potential for high yield. The yield of 12-year-old mother trees is more than 15 kg, and the high-grafting trees enter the high-yield period in 6-8 years.
Second, the walnut garden construction technology
(A) the choice of site conditions
Walnut orchard should be built on the soil with gentle slope, deep and fertile soil layer, good drainage, sunny lee and limestone development. Walnut can be planted in the soil where shale and granite are developed, but lime should be applied to supplement calcium in the soil at the fruiting stage. Low-lying areas with heavy soil are not suitable for walnut development.
(2) Soil preparation
Early-bearing walnuts bear fruit early and have good yield: there is a small amount of yield in the third year; In the fifth year, it can enter the early stage of full fruit, and the yield per plant can reach 8 ~10 kg; In the seventh year, the yield per plant can reach15 ~ 20kg (800 ~1000kg per mu). In order to ensure and maintain high and stable yield, it is very important to supply sufficient nutrients in the soil, and high standard soil preparation is the foundation.
The best way to prepare soil is to build terraced fields and dig ditches to change soil. Where conditions permit, it is best to build terraces, and on the basis of terraces, ditch and change soil or dig big pits. It is also a good way of land preparation, which is usually carried out in places with gentle slope or flat land. According to the row spacing of 4 ~ 4.5 meters, dig trenches with a width of 0.8 ~ 1.0 meters and a depth of 0.7 ~ 0.8 meters, then backfill a layer of straw and a layer of soil in layers, and finally form ridges with a height of about 15 cm. When backfilling, the topsoil should be at the bottom and the core soil should be at the top. Straw, grass, straw, leaves, etc. It should be filled layer by layer to be completely practical. Land preparation with large pits requires less investment, the plant spacing density can be 4.0 ~ 4.5 m× 3.3 ~ 4.0 m, and pits of 1.0m× 1.0m×0.8m can be dug. After digging the pit, it is the same as pumping the trench to change the soil. The surface soil is below, and the core soil is above. The organic matter such as straw should be layered and compacted, slowly and steadily.
The best time for soil preparation is August-September, when there are a lot of straw and grass to backfill, and the higher temperature is beneficial to the decay of backfill soil. The latest land preparation time should also be completed before the year.
(3) Planting
Early fruiting walnut trees are dwarfed and suitable for close planting. It is suitable to plant 40 ~ 50 plants per mu, 4.5×3.5 meters or 4.0×3.3 meters. The culture time can be from defoliation in autumn to germination in the following spring. Planting as early as possible in this period can not only improve the survival rate, but also increase the growth of the year.
When planting, the root system should be trimmed first, and the damaged root segments and long roots should be removed, leaving the upper part of the root system 80 cm. When planting, the roots are layered with fine soil, then thoroughly watered with root fixing water (it is best to use 0.4% urea +0.4% potassium dihydrogen phosphate mixed fertilizer as root fixing water), and finally covered with a layer of loose soil (which cannot be compacted). Be careful not to plant it too deep, expose the wedding interface above the ground and don't bury it underground.
Third, high-yield cultivation techniques
(A) the management of infancy
Juvenile period refers to 1 ~ 3 years after planting. The main task of this management work is to strengthen fertilizer and water management, accelerate the growth of trees, and lay a good material foundation for premature delivery and high yield in the future; Do a good job in plastic surgery and cultivate the skeleton of a high-yield tree.
Management of length planting in the same year
When planting, it is mainly to accelerate the growth of seedlings on the basis of ensuring survival. The specific work should be carried out in the following aspects:
(1) After planting until the end of May, it is particularly important to water for drought resistance when there is severe drought, especially in bud stage and leaf opening stage; Clear ditches and drain water stains in time in rainy season to prevent root system from dying. Reasonable control of water is the key to survival rate.
(2) Fertilize frequently in June. Generally, from June to September, urea is applied once a month, and the fertilization amount is 50g per plant (12). 10/0 ~150g (2 ~ 3 taels) per plant in October.
(3) Shaping: when the seedlings grow to 80 cm, it is not necessary to remove the core (for the seedlings that have been dried during planting). After germination, three robust buds with different directions and a spacing of 6-8 cm are selected as the main branches for culture, and all other buds in the range of 5-6 cm near the three main branch culture buds are wiped off to avoid affecting the growth of the three main branch buds; Buds that do not affect the growth of main branches are picked when they grow to 20 ~ 25 cm, and the post-treatment is the same as before.
When the remaining three main branches grow to 40-45 cm, the core is picked, and after branching, a bud is selected as an extension branch to grow, and a bud is selected as a side branch for culture; When the lateral branch is 30 cm long, the core is removed, and when the extension branch is 45 ~ 50 cm long, the core is removed; Using the method of pulling rope to pile, the three main branches are evenly distributed, and the branch angle is about 45 degrees. For buds that do not affect the growth of extension branches and lateral branches, smooth or leave buds according to their density: generally, leave 1 bud at the distance of 15 ~ 20 cm, and pick the core for auxiliary branch culture when it grows to 20 ~ 25 cm. Some walnuts have strong early fruiting, and most seedlings have female flower buds when they germinate in the same year of planting. Clear it in time after it is found, so as not to affect the survival and tree growth.
2. Management in the second to third years
The main task of management from the second year to the third year is to accelerate the growth of trees, promote their formation as soon as possible, lay a good foundation for high yield in the future, and let trees bear a small amount of fruit at the same time. Generally, all female flower buds are picked in the next spring to promote the growth of trees. In the third year, each tree bears 40 to 60 fruits (about 40 to 50 kilograms per mu). The focus of management work is plastic trimming and fertilizer and water management.
There are two aspects in shaping and pruning: one is to cultivate 1 lateral branches on the basis of the previous year, so that each main branch has 2 lateral branches and 1 extension branches, and the whole tree becomes "three branches with nine heads". The first side branch is 40-45cm away from the trunk, and the second side branch is 50-55cm away from the first side branch, which is completed by methods such as coring and pulling branches. The second is to cultivate fruiting branches on the upper and lower sides of lateral branches, extension branches and main branches, and use pruning methods such as coring and kinking to make fruiting branches of different sizes fill the space of the tree. Results the principle of branch configuration is that the inside is big and the outside is small. The dishes inside and outside are staggered in size, dense but not crowded, sparse but not empty.
Fertilizer and water management focuses on fertilization and drainage. Fertilize four times a year. After defoliation in autumn, 65,438+00 ~ 65,438+05 kg (20 ~ 30 kg) of decomposed organic fertilizer should be applied to each plant, 65,438+000 ~ 65,438+050 g (2 ~ 3 liang) of urea should be applied to each plant in spring germination, and 65,430 g of urea should be applied to each plant in the middle and late May. Buried in the periphery of the crown, after fertilization, in case of drought, it can be properly watered to facilitate the absorption of fertilizer. Pay special attention to drainage when it rains heavily, because walnuts are drought-resistant and afraid of waterlogging.
Adult management
Early-bearing walnuts were well managed in the early stage, and began to bear a large number of fruits in the fourth year, reaching the peak in the sixth to seventh years. The annual output of walnuts in high-yield orchards can reach 6-7.5 tons per hectare (800- 1000 kg per mu). The key point of management in this period is to keep the balance between fruit and growth and ensure stable and high yield year after year, mainly focusing on two key technologies: fertilization and pruning.
Generally, 50-60g of pure nitrogen, 25-30g of phosphorus pentoxide, 25-30g of potassium oxide and 5kg of organic fertilizer (farmyard manure) are applied per square meter. Buried organic fertilizer as base fertilizer before and after defoliation in autumn. Top dressing is carried out four times a year. For the first time, at the flowering and germination stage of walnut, the combination of phosphorus and potassium fertilizer was the main nitrogen fertilizer, and the topdressing amount accounted for 50% of the annual topdressing amount; The second time in the first half of June, nitrogen fertilizer was still the main fertilizer, with phosphorus and potassium fertilizer (but the proportion of phosphorus and potassium fertilizer increased slightly), accounting for 25% of the annual topdressing; The third time in mid-July, the proportion of nitrogen, phosphorus and potassium was basically the same, accounting for15% of the annual fertilization; After the harvest in the fourth season, phosphorus and potassium fertilizer are the main fertilizer, supplemented by nitrogen fertilizer, accounting for 10% of the annual topdressing. After fertilization, if it is dry, it can be properly watered to facilitate the absorption of fertilizer. Special attention should be paid to drainage.
Pruning techniques are as follows: 1. Pruning of backbone branches: during this period, the backbone branches are basically shaped, and the backbone extension branches no longer extend outward. When pruning, we should pay attention to rejuvenating the extended branches with buds on the branches, and leave more branches and leaves on the main side branches; Peripheral branches should be thinned and retracted in time if they are densely overlapped. Second, the regeneration and rejuvenation of fruiting branches: the weak fruiting branches should be updated in time, the branches with strong growth potential and upward position should be cut off, and small, medium and large branches should be cultivated in the order of outer crown, middle crown and inner crown. In the process of renewal, it is necessary to control the growth of flourishing branches and prevent "trees grow on trees". The third is to use long branches: keep long branches when you have time, sparse when you don't have time, and cultivate branches by methods such as coring and short cutting. The fourth is to remove useless branches: all branches that are too dense, overlapping, crossing, pests and diseases, dry and too thin should be thinned.
Fourthly, soil management of walnut orchard.
Soil management in walnut orchard is very important, which is an important link to ensure high and stable yield. Soil management should do the following:
(A) reasonable intercropping
For young walnut orchards, it is advocated to interplant dwarf crops and cultivate instead of caress, which can not only obtain the income of the year, but also ripen the soil and be beneficial to the growth of trees. Intercropping should pay attention to two problems: first, corn, sorghum, sunflower and other tall crops, melons and other climbing plants should not be intercropped, so as not to affect the light of walnut trees; Second, intercropping should provide enough space for the growth of walnut trees and should be carried out on the premise of not affecting the growth of walnut trees. Generally, we should master the principle of extracoronal interaction. Adult walnut orchards can intercrop shade-tolerant crops such as ginger. The walnut orchard without intercropping should be topdressing and weeding once in spring germination, mid-June, mid-July and after harvest.
(2) Covering turf
Covering the soil of walnut orchard with grass and crop straw can not only reduce temperature and conserve moisture, inhibit weeds, but also increase soil organic matter and improve soil, which can be strongly advocated. The walnut orchard is covered with 2 ~ 3 cm each time, and then covered after rotting. The whole park has a heavy workload and can only be crowned. Covering seedlings around the newly-built gardens in that year can improve the survival rate and accelerate the growth of seedlings.
(3) Deep turning
Walnut orchards should be reclaimed once a year or every other year, with a width of 40 ~ 50 cm and a depth of 60 ~ 70 cm, along the outer edge of the crown, with human straw, soil mixed fertilizer, green manure, grass, etc. It should be buried to ripen the soil and increase the content of soil organic matter. In the adult garden, organic fertilizer, weeds, straws, etc. can be pumped into the grooves in different years between plants or between plants. Increasing soil organic matter and solidifying soil are the basic work to ensure high yield, and it is strictly forbidden to affect the yield if it is not done well.
Five, the main pest control of walnut
(A) the prevention and control of major pests and diseases of walnut
1. walnut
(1) Damage situation: the larva eats walnut kernel, and the skin turns black and sinks due to the damage, and the damaged fruit turns black and shriveled, so it is inedible.
(2) Morphological characteristics: the adults are 5 ~ 7 mm long, all dark brown and shiny, with filiform antennae and lanceolate wings, with marginal hairs longer than the width of wing feathers, hind feet longer than the body length, surrounded by three bundles of long hairs, and each node is black and white. When resting, the hind feet are raised to the rear, so they are called limb moths. Larvae is about 10 mm in length, with yellowish brown or dark brown head, milky white for newly hatched larvae, yellowish for mature larvae, and purple spots in the center of back. Its abdomen and toe hooks are single sequence, and its buttocks and toe hooks are single sequence horizontal belts. Oval, 0.3 ~ 0.4 mm long, milky white at birth, yellow white after hatching, yellow red before hatching; The pupa is spindle-shaped, yellow-white, yellow-brown, dark-brown, with red compound eyes. The petals are born on both sides of the pupa. Cocoons are dark red or light brown, rectangular and slightly flat, often with grass powder and fine soil particles attached.
(3) Habit and occurrence law: 65,438+0 ~ 2 generations occur every year, and the mature larvae overwinter in the soil, between rocks and soil, between roots and stems. Generally, the soil under the canopy is 1 ~ 2cm deep. Emergence began in early May of the following year, and the peak of emergence was from the end of May to the beginning of June. Eggs are mostly produced in the gap between two fruits, in the residual traces of pistil falling off, and in the scars on the surface of fruits. General 1 fruit yield 1 ~ 2 eggs. From late May to mid-July, the first generation larvae are in danger. In mid-May, the first generation larvae began to feed on seeds through the endocarp, and the moth holes were very small, resulting in a large number of fruit drops, but the epicarp was not obviously damaged. From mid-July to late July, the second generation larvae feed in the mesocarp, which makes the outside of the fruit black and sunken, forming "walnut black", and the damaged fruit does not fall off.
(4) Control method: from late autumn to winter, turn over the tree tray to kill overwintering larvae or cocoon pupae; Pick up the fallen fruit in time every day, burn the black walnut on the tree in autumn, and eliminate the larvae.
(2) Prevention and control of main diseases of walnut
Walnut Bacterial Blight
(1) Symptoms: It mainly harms young leaves, shoots, flowers and fruits of walnut. When the blade is damaged, there are small black spots that are nearly round or polygonal, and then spread to the whole blade, and in severe cases, they can be connected into large spots. Let the leaves fall early. The shoots and petioles are damaged, and the lesions are round or long and narrow, brown and slightly concave. When the lesion turns around the branch, it will cause skills to wither. When the inflorescence is damaged, black waterlogging spots first appear and do not spread. Later, floral axis turned black, bent and even dried up. When the fruit was damaged, black spots appeared in the early stage, which was waterlogged, and then the diseased spots expanded rapidly, resulting in all the peels turning black; Young fruits can invade the nucleolus, blackening the nucleolus and nucleocapsid, causing early fruit drop, and old fruits can only be damaged by diseased spots.
(2) Pathogenic law: Pathogens mainly overwinter on diseased branches, diseased fruits, diseased buds and insects, and invade from natural orifices and wounds through wind and rain, insects, diseased pollen and artificial active transmission. The onset is closely related to rain, which often spreads rapidly after rain. In rainy years, diseases are serious, weak trees are more important than healthy trees, and seedlings and old trees are more important than young trees.
(3) Prevention and control method: combined with winter pruning, diseased fruits, diseased branches and diseased leaves are removed, centralized burning is carried out, and lime-sulfur mixture with 3-5 Baume degree is sprayed once before germination; In addition to cold protection, female flowers should be sprayed with Bordeaux solution of l:0.5:200, or 0.4% copper sulfate, or 500-800 times solution, or 0.003% agricultural streptomycin +0.2% copper sulfate before flowering, after flowering and in young fruit stage.
2. Walnut branch blight
(1) Symptoms: After the l ~ 2-year-old branches are injured, they start from the top and gradually spread to the trunk. The leaves on the damaged branches turn yellow and fall off. At the early stage of the disease, the diseased branches changed from green and gray-green to brown or gray, and the tips of the diseased branches sank. When the diseased spots surround the branches for a week, the dead branches or the whole plant die, and dense and clustered small black spots, namely Acer truncatum, are produced on the dead branches. When the humidity is high, a large number of conidia and mucus gush out from the center of the dish, forming a black tumor-like protrusion at the mouth of the dish.
(2) Pathogenic law: germs overwinter on diseased branches, and spread through wind and rain in the following year to help wounds or dead branches invade. This fungus only harms weak branches, so strengthening management and strengthening tree vigor can prevent and control secondary diseases.
(3) Control method: Cut off diseased branches and dead plants. Centralized incineration to reduce the source of disease; Strengthen fertilizer and water management and enhance tree potential; In winter, whitewash 50 times with a whitewashing agent of quicklime 7.5: salt 1.5: vegetable oil 0.25: sulfur powder 0.5: water.