Never blindly introduce northern walnut seedlings. Although these walnut seedlings are all national high-quality grafted seedlings, due to too much rain in the southern region, the environment is not suitable, especially the serious diseases, the introduction is often unsuccessful, causing great losses.
walnut
1. Garden selection
Walnut is not strict with environmental conditions, as long as the annual average temperature is 9 ~ 16℃, the extreme maximum temperature is 38℃, and the extreme minimum temperature is -25 ~-2℃. Walnut can be planted when the annual rainfall is more than 800 mm Walnut has wide adaptability to soil, but because it is a fleshy fruit tree with deep roots and leafy leaves, it is not resistant to water and humidity, and has strong drought resistance and pest resistance.
plant
In order to bear fruit early and improve the yield per unit area, we should carry out dwarf and close planting cultivation, select grafted seedlings and pull seedlings to realize early and high yield. Grafted seedlings can bear fruit in 2 ~ 3 years after planting, and enter the high-yield period in 4 ~ 5 years, the seedlings can bear fruit in 8 ~ 10 years, and enter the high-yield period in 15 years. At present, 3×2 (per mu11plant) is suitable for close planting gardens. Walnut is a dioecious fruit tree. Female flowers and male flowers on the same plant generally bloom at different times, so pollination between different plants is needed. Therefore, only the walnut orchards planted in pieces can achieve high yield. Walnut is most suitable for planting in autumn (September ~165438+1October) or before germination. Before planting, you can dig a big pit (80 cm long, 80 cm wide and 80 cm deep) and press in organic fertilizer, phosphate fertilizer and soil in layers, then plant it in the pit, water the roots, and cover the trees with weeds to survive. After planting, it should be fixed in time to prevent drought and seedling death.
Second, soil management.
1. culture
Deep ploughing and pressing green or organic fertilizer in walnut orchard is an effective measure for young trees to bear fruit early and big trees to produce high yield. Deep tillage can be carried out in spring, summer and autumn, before germination in spring and after rain in summer and autumn, with fertilization and burying weeds in soil. Deep tillage should be carried out year by year from the planting point, with a depth of 60 ~ 80 cm, but the thick roots with a diameter of 1 cm should not be damaged.
Young walnut trees grow slowly, so it is feasible to intercrop leguminous crops or green manure. Adult orchards are weeded with herbicides 2 ~ 3 times a year from April to September, with autumn and winter seeds 1 time.
fertilize the soil or land
The main components of walnut are nitrogen and potassium, and nitrogen is more than potassium. Increasing nitrogen application can significantly improve yield and quality. Phosphorus-deficient soil must also be supplemented with phosphorus and calcium, and organic fertilizer should be added at the same time. Fertilization of young trees should be based on the principle of thin application and diligent application. Top dressing should start from the year of planting to germination, once a month 1 time, and base fertilizer should be applied once at the end of September. Fertilize four times a year from the second year to the fourth year, namely in March, June, August and 10 * *.
Adult trees (4-5 years after grafted seedlings) can apply base fertilizer 1 time and topdressing twice a year. The base fertilizer is applied in the autumn when the soil is deeply ploughed and green (September ~ 65438+1October), with 5000 kg of organic fertilizer (livestock manure), 50 kg of phosphate fertilizer, 0/00 kg of plant ash/kloc and 0/5 kg of urea/kloc-0. Topdressing is applied twice, the first topdressing is applied before germination, with pig manure water 1500 kg and urea 20 kg per mu. The second topdressing was carried out in hard core stage (June-July) to increase fruit weight and promote flower bud differentiation. 2500 kg of pig manure water, 30 kg of urea, 20 kg of potassium sulfate and 20 kg of calcium superphosphate can be applied per mu.
irrigate
Walnut enjoys wet, waterlogging and drought resistance, so irrigation is an effective measure to increase production. If the soil is dry and short of water during the growing period, the fruit setting rate is low, the peel is thick and the seed kernel is underdeveloped; Without irrigation after fertilization, fertilizer efficiency cannot be fully exerted. Therefore, irrigation should be done in time during flowering period, rapid fruit growth period, fertilization period and winter drought period.
Third, shaping and pruning
1. Pruning period
During dormancy, walnuts bleed and are not suitable for pruning; The most suitable pruning period is autumn, which is beneficial to the early healing of wounds in that year. Young trees do not bear fruit, and can start from the end of August in advance. It is suitable for adult trees to start after fruit picking 10 months and before leaves turn yellow.
2. Young tree shaping
Walnut trunk is stout, and the advantage of terminal bud is particularly obvious. The development of terminal buds is fuller and fuller than that of lateral buds, and the crown layering is obvious. Combined with this feature, the shape of sparse layer of trunk is more suitable and easy to form. The shaping method is as follows: the height of the stem is 50-80cm (if the seedling is not high enough in that year, it can be shaped after the seedling has grown for one year), and the trunk is straightened without any pruning in that year to protect the terminal bud (if the terminal bud is damaged, it can be replaced with a strong bud first). After spring germination, the terminal bud will grow upright and serve as the main stem, and 5-6 buds at the lower part of the terminal bud will germinate lateral branches. In the second year, the second layer of main branches is also cultivated, and 2 ~ 3 main branches are reserved in the second layer (60 ~ 80 cm away from the first layer). In the third year, the main branch of the third layer is selected, and 1 ~ 2 main branches are reserved to compete with the second layer. 0 ~ 70 cm. 1 ~ 4 years, the main branches do not need pruning, and they can naturally branch and expand the crown. It usually takes 3 ~ 4 years to form, and the height of the tree is about 3 ~ 5 meters when it is formed.
Step 3 prune fruit trees
Walnut has entered the full fruit stage, the crown is still expanding, and the number of fruiting parts is increasing, which is prone to the contradiction between growth and fruiting. Ensuring high and stable yield of walnuts is the main task of pruning in this period. Therefore, in pruning, we should always pay attention to make good use of auxiliary branches and long branches, cultivate good branches, and deal with back branches and drooping branches in time.
From the initial stage of fruiting, it is necessary to cultivate strong fruiting branches in a planned way, constantly increase the fruiting parts and expand the fruiting area. Prevent the cavity of the crown from becoming empty, causing the parts to move outward. After entering the full fruit stage, it is necessary to strengthen the cultivation and rejuvenation of branches. The pruning methods of "putting first and then shrinking" and "removing back branches, leaving oblique branches and back branches" can be used in the culture branch group. Generally, no long branches are left at the beginning of the fruit, so as not to disturb the tree. The back branches should be controlled in time during the full fruit period so as not to affect the main branches and fruiting mother branches. The drooping branches are not full, the fruiting ability is poor, and only nutrients are consumed. The specific situation is specific.
Fourthly, artificial pollination and male inflorescence thinning
Artificial pollination of walnut can increase the fruit setting rate 10 ~ 30%. When the stigma of the female flower is split into an inverted eight shape and the stigma secretes a lot of mucus, the auxiliary pollination is carried out at 9 ~ 10 in the morning, and the effect is ideal.
During the development of male and female flowers, a lot of nutrients and water stored in the tree are needed, especially when the male inflorescence grows rapidly and the female flowers bloom in large numbers, the water in the tree often becomes the limiting factor for the growth and development of female flowers. Removing too many male flowers can reduce the consumption of nutrients and water in the tree, so that more nutrients and water can be supplied to the development and fruit setting of female flowers, thus improving the yield and quality, being beneficial to the growth of new shoots and enhancing the tree potential. The earlier the male flower thinning period, the more obvious the yield increase. The effect of sparse male flowers is the best from dormancy to expansion of male flower buds, but the effect of sparse male flowers is poor after the male inflorescence is obviously elongated. The number of "sparse males" should be determined according to the number of male flower buds and the ratio of mixed buds to female flower buds. If artificial pollination is not carried out, the male flowers should not be too sparse. For plants with many mixed buds and few or no male flowers, it is advisable to sparse them. The method of thinning male flowers can be combined with pruning, and the branches can be pulled down by hand with a wooden pole with a hook.
/wzly.asp？ Id=20 1 The above introduced some walnut varieties suitable for southern cultivation for your reference.
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Southern walnut is only planted in Guizhou, Yunnan. I wonder if they are suitable for southwest Guangdong. If not, walnut wood is also very valuable. I spent a lot of time looking for these for you, hoping to help you.