Suitable cultivation area and terraced planting techniques of Green Ridge Walnut

Suitable cultivation area and terrace planting techniques of walnut in Lvling

Lvling walnut is an excellent variant plant discovered from 5-year-old "Xiangling" by Forestry College of Hebei Agricultural University and Hebei Lvling Fruit Industry Co., Ltd. In recent years, Lvling walnut has passed the examination and approval of forest varieties in Hebei Province, and has been identified as green food, and has also won the title of "Olympic Recommended Fruit." Lvling walnut has strong cold resistance, drought resistance, strong bacterial resistance, beautiful fruit shape, full kernel, high kernel rate, thin skin without astringent taste, rich protein and fat content, which is the key demonstration and promotion variety of national science and technology department. The variety grows vigorously and has strong branching power. It is suitable for planting walnut in Taihang Mountain, southern foot of Yanshan Mountain and Xingtai Plain. Planting green ridge walnut on terrace is of great significance to improve local walnut yield, scientifically utilize land resources and promote local agricultural economic development.

1 Biological characteristics of green ridge walnut

The fruit of Lvling walnut is nut, oval, pale yellow, with an average diameter of 3.42 cm and an average fruit weight of 12.8 g. Fruit smooth and beautiful, suture smooth and not prominent, gently pinch with your hand can be peeled. The seed coat is light yellow, without astringency, and the seed kernel is full and fragrant.

Green ridge walnut tree posture into open form, crown was semicircular, trunk and perennial branches were taupe, relatively smooth, annual branches were yellow-green. Green ridge walnut began to sprout in the middle of April and spread leaves in the late part of April; male flowers bloomed in the early part of May; walnut fruits grew rapidly from the middle part of June to the early part of July; the hard core period of green ridge walnut was in the middle part of July; the fruit maturity period was in the middle part of September; green ridge walnut began to shed leaves in the late part of October. The young trees of Juglans regia L. have a strong growth tendency and strong branch forming ability. They begin to bear fruit after 4 years of planting. The main fruiting area is medium and short branches. Lvling walnut has strong adaptability, high cold resistance, drought resistance, stress resistance and disease resistance, and good planting income.

2. Establishment of Lvling Walnut Garden

2.1 jianyuan

Lvling walnut cultivation garden is generally established on sloping land, flat land or mountain terrace, which requires good soil water retention and permeability, and the soil layer of the plot should be deep. Terraced fields should be constructed along contour lines, the width of field surface is 2m, and the depth of soil preparation is 80cm. The common row spacing is 5m×3m, 4m×5m, 6m×4m and 5m× 2.5 m. In cultivation, the cultivation personnel should select the appropriate row spacing according to the specific soil fertility, the management level of the cultivation garden and the environmental conditions to determine the planting site. Excavation of planting holes is carried out in autumn one year before planting, 30kg of manure is added into each planting hole, mixed with topsoil and mixed evenly into the planting hole.

2.2 Preparation of seedlings before planting

Before planting, seedlings should be prepared and treated. The requirements for seedlings are as follows: (1) the varieties of seedlings should be pure, and the types of rootstocks should be the same;(2) the seedlings should have no mechanical injuries or pests;(3) the length of the main roots of the seedlings should be greater than 20cm, the number of lateral roots should be greater than 15, and the main roots and lateral roots should not be split.

Before planting seedlings, root pruning treatment should be carried out. The roots that are too long or have cracks should be pruned off. Then the seedlings should be graded and bundled according to their height and thickness. Finally, the roots of seedlings should be soaked in the liquid made of rooting powder for more than 12 hours. After soaking, the roots should be disinfected with stone sulfur mixture.

2.3 seedling planting

The planting position of seedlings shall be corrected to ensure that the roots and the ground are kept horizontal. The roots shall be naturally stretched in the planting holes, and then the soil shall be backfilled. When the backfilling is half done, the seedlings shall be gently lifted, and then the soil shall be backfilled. The soil shall be compacted while filling, so as to ensure that the roots and the soil are fully contacted. After planting, irrigation should be carried out immediately, and sufficient irrigation should be required. After the irrigation water seeps down, soil should be sealed to preserve moisture, and then tree trays with a diameter of 1m should be made to facilitate rainwater accumulation or irrigation.

After seedling planting, it is necessary to carry out stem fixing treatment at the full bud of 60~80cm of seedlings, and cover plastic bags with a length of 70cm and a diameter of 8~10cm on the seedling stem to avoid the harm of leaf-eating pests such as chafers to seedlings. In early May check the survival status of seedlings, if found dead seedlings, immediately make up seedlings. Wait until the temperature rises, ventilation treatment should be carried out first, and then remove the plastic bag. In addition, winter cold-proof measures should be taken in seedling stage, especially in the first three years of planting of Lvling walnut. After annual defoliation, 15~20 times of water should be used to boil vinyl alcohol, and polyvinyl alcohol should be coated all over the tree.

3 Park management

3.1 soil, fertilizer and water management

3.1.1 Deep soil reclamation

Deep ploughing and soil improvement should be carried out before fertilization in autumn. A ditch with depth of 0.4~0.6m and width of 0.3~0.35m should be dug on one side outside the planting hole. A certain amount of organic fertilizer can be mixed when backfilling, and a proper amount of water should be poured after backfilling. In addition, annual tree tray trimming, planting hole expansion and terraced reinforcement and repair.

3.1.2 Fertilization

The basal fertilizer should be applied after fruit harvest and before leaves turn yellow. 30kg organic fertilizer should be applied to each young tree, 40kg organic fertilizer should be applied to each tree in early fruit bearing stage, and 70kg organic fertilizer should be applied to each tree in full fruit stage. Topdressing was applied at early germination, young fruit growth and hard core stage, and the amount of topdressing after 5 years should be increased according to the age and yield growth. In addition, the foliar surface of Lvling walnut should be sprayed with fertilizer, such as urea or borax, at the initial flowering stage of female flower of fruiting tree; urea should be sprayed at the early stage of young tree, once every 15 days, and potassium dihydrogen phosphate should be sprayed at the end of August, once every 15 days, continuously spraying 3 times.

3.1.3 Water management

Irrigation should be carried out before germination, before flowering, after fruiting, hard core stage and before freezing when the soil is short of water, and drainage should be paid attention to in rainy years.

3.2 flower and fruit management

When the male flower of walnut germinates, artificial flower thinning should be carried out, and the best amount of male thinning is about 95%. When the female flower enters the initial flowering stage, fertilization treatment should be carried out, and a mixture of urea 500 times and borax 500 times should be sprayed once every 2 days, and a total of 3 times can be done. In addition, in order to improve the fruit set rate of walnut, artificial pollination should be carried out.

3.3 training and pruning

The most suitable tree shape for Lvling walnut is single-layer high-level open-center shape or trunk sparse layer shape. Among them, the trunk height of single-layer high-position open-center tree is 0.6m, 3~4 main branches at the base are arranged adjacently, one main branch is arranged every 0.2~0.3m upward, and these main branches are arranged in a spiral form on the central trunk; the trunk height of trunk sparse layer tree is 0.4~1.0m, there are 2~3 layers of main branches on the trunk, and the number of main branches is 5~7.

Spring pruning is usually to cut buds and wipe buds on young trees; summer pruning is generally carried out in May to June, for young trees with new shoots growing to more than 40cm, the core treatment is carried out, leaving about 20~25cm, and thinning measures are taken for buds at thinning branches; autumn pruning is generally carried out after fruit harvest to before leaves turn yellow, and there is no bleeding on the tree body, which is suitable for tree skeleton adjustment, and large branches and large branches in the retracted part are thinned out; The pruning in winter is generally between the cold and the beginning of spring. Before the germination in spring, when there is basically no bleeding, the long fruiting mother branches and the relatively thin and dense short fruiting mother branches are thinned out, and part of the long branches are heavily truncated as preparatory branches.

3.4 pest control

The main diseases and insect pests of walnut in Lvling are bacterial brown spot of walnut, walnut lifting moth and overwintering larva. Among them, strengthen the management of tree body, pay attention to the anti-freezing and drought prevention of tree body, can effectively avoid the occurrence of walnut bacterial brown spot disease; spray 5 Baume degree stone sulfur mixture in spring germination period, spray 1~2 times 21% fruit Fukang 400 times solution in growth period, can effectively control walnut lifting limb moth; deep turn the soil under tree crown before winter, if insect fruit is found in growth period, it should be removed immediately, so that overwintering larvae can be eliminated. In addition, at the beginning of late April, a frequency vibrating insecticidal lamp is installed every 5 hm2 to trap phototactic pests and adults, such as scarabs, walnut tumors and yellow thorns.