When do walnut trees usually blossom? No, what about the result? How to promote premature and high yield of walnut?

Walnut trees, also known as walnuts, walnuts, spades, varieties are divided into wild hickory and artificial grafting improved varieties of walnut, planted all over China. So when do walnut trees usually blossom? No, what about the result? How to promote premature and high yield of walnut?

When do walnut trees usually blossom?

The main results are as follows: 1. Walnut trees need a period of adaptation after transplantation. in general, the growth cycle of walnut trees is three years as a cycle, blooming once every three years and bearing fruit every three years.

2. The general flowering period of walnut trees is about 20 days, and the flowering time of walnut trees is about April-May.

3. Walnut is a green flowering plant. Male catkin pendulous, ca. 5-10 cm long, sparse to 15 cm. The bracts, bracteoles and tepals of male flowers are all covered with glandular hairs. Stamens 6-30, anthers yellow, glabrous. Female spikes usually with 1-3 (or more) female flowers. Involucre of female flowers covered with very short glandular hairs, stigma purplish red.

What if the walnut tree doesn't bear fruit?

The reason why walnuts do not bear fruit:

1. Non-variety cultivation: walnut trees planted with seeds are called seedlings, and there is no grafting of fine varieties of seedlings. If the walnut seeds used are not selected, the walnut trees grow very different, the advantages and disadvantages are uneven, and some of them bear fruit late and will not see fruit until about 10 years after planting.

2. Poor site conditions: walnut trees have poor planting conditions, thin soil layer, barren soil, no tree growth and no management, resulting in long-term lack of nutrition, thin branches, no flower buds and no fruit.

3, improper management: first, the application of too much nitrogen fertilizer, there is no shortage of water, so that trees grow, branches are many and dense, ventilation and light transmission conditions are poor, short and medium branches that can not bear fruit will not bear fruit. Second, for the crops under the tree, the branches under the crown of the walnut tree have been trimmed off, the number of branches in the whole crown is too few and mostly grow branches, the tree posture is upright, the tree is strong and weak, and it can not form fruiting branches.

4. Poor pollination: walnut belongs to wind pollination tree species. Hermaphrodites are monoecious, but the female flower and male florescence of most varieties are different, and there are no other fruit orchards nearby, resulting in poor pollination and less fruit.

5. the occurrence of diseases and insect pests is serious: walnut trees damaged by diseases and insect pests will affect the growth and fruit. For example, flower bud maggots, which specialize in eating the female flowers of hickory trees, will not have the ability to bear fruit.

What if we don't end up:

I. soil management

1. Tillage: deep ploughing and pressing green or pressing organic fertilizer in walnut orchard is an effective measure to advance the fruit of young trees and the high yield of big trees. deep ploughing can be carried out in spring, summer and autumn, before sprouting in spring and after rain in summer and autumn. and combined with fertilization to bury weeds in the soil. Deep ploughing should be carried out from the fixed hole year by year, and the suitable depth is 60-80cm, but the coarse roots with a diameter above 1cm should be prevented. Young walnut trees grow better, and the interrow land can be intercropped with legume crops or green manure. Adult orchards are weeded with herbicides 2-3 times every April-September and ploughed once in autumn and winter.

2. Fertilization: nitrogen and potassium are the main elements of walnut, and nitrogen is more than potassium. The application of nitrogen fertilizer can significantly improve the yield and quality. Phosphorus and calcium must be supplemented in the soil deficient in phosphorus and calcium, and organic fertilizer must be applied at the same time. The principle of applying fertilizer frequently and thinly should be adopted in the fertilization of young trees, from the time of planting to the time of germination, applying base fertilizer once a month to the end of September, and in the second year, applying fertilizer 4 times in March, June, August and October every year. Adult trees (after 4-5 years of planting of grafted seedlings) can apply basal fertilizer once a year and topdressing twice a year. Base fertilizer was applied after fruit harvest in autumn combined with soil deep ploughing and pressing green fertilizer (September-October). Organic fertilizer (rotten chicken manure) 5000kg, phosphate fertilizer 50kg, plant ash lOOkg, urea 15kg were applied per mu. Topdressing was applied twice, the first topdressing was applied before germination, and organic fertilizer 1500kg and urea 20kg were applied at 667m. The second topdressing was applied in the hard kernel stage (June-July) to increase fruit weight and promote flower bud differentiation. Organic fertilizer 2500kg, urea 30kg, potassium sulfate 20kg and calcium superphosphate 20kg were applied per mu.

3. Irrigation: walnut likes to be moist, waterlogging-resistant and drought-resistant. Irrigation is an effective measure to increase production. During the growth period, if the soil is dry and short of water, the fruit setting rate is low, the pericarp is thick, and the kernel development is not full; if there is no irrigation after fertilization, the fertilizer effect can not be brought into full play. Therefore, it should be irrigated timely in various periods, such as flowering, rapid increase of fruit, fertilization and winter drought.

II. Shaping and pruning

1. Pruning period: during dormancy, walnut has bleeding phenomenon, so it is not suitable for pruning; the most suitable pruning period is autumn, which is beneficial to wound healing in the same year. The fruiting of young trees can begin in late August, and it is suitable for adult trees around October after harvest and before the leaves turn yellow.

2. shaping of young trees: the trunk of walnut trees is strong, and the top advantage of buds is especially obvious. the development of terminal buds is fuller and fatter than lateral buds, and the canopy layer is obvious. combined with this characteristic, it is appropriate to adopt trunk thinning layer shape, and shaping is very easy. The shaping method is as follows: dry height 50-80cm (if the seedlings are not tall enough in that year, you can wait for the seedlings to grow for a year), do not make any pruning in the planting year, only straighten the trunk, and protect the terminal bud (if the terminal bud is damaged, you can choose a strong bud instead). After sprouting in spring, the terminal bud will grow upright upward. It was used as the central trunk and the lateral branches germinated in the lower part of the terminal bud. 3-4 lateral branches with uniform growth were selected as the main branches of the first layer from May to June, and the rest of the new shoots were wiped out. In the second year, the second layer main branches were cultivated according to the same method, and the second layer retained 2-3 main branches (60-80cm apart from the first layer). In the third year, the third layer main branches were selected, 1-2 main branches were retained, and the distance between the second layer and the second layer was 570cm. For 1-4 years, the main branch does not need pruning, it can divide lateral branches naturally and enlarge the crown. It is generally formed in 3-4 years, and the height of the tree is about 3mur5m.

3. Fruit tree pruning: walnut enters the peak fruiting period, the crown continues to expand, the fruiting position continues to increase, and it is easy to appear the contradiction between growth and fruit. ensuring the high and stable yield of walnut is the main task of pruning in this period. Therefore, in pruning, we should always pay attention to cultivate good branch groups, make good use of auxiliary branches and overgrown branches, and deal with back branches and drooping branches in time. From the initial stage of the result, the strong fruiting branch group should be cultivated in a planned way, and the fruiting site should be increased continuously. Prevent the emptiness of the inner chamber of the crown and the outward movement of the fruit part. After entering the full fruiting period, the cultivation and rejuvenation of branch groups should be strengthened. The pruning methods of "first releasing and then shrinking" and "removing the back branches, leaving oblique branches and upper dorsal branches" can be used in the culture branch group. The overgrown branches generally do not stay at the early fruiting stage, so as not to disturb the tree shape, and can be transformed into branch groups in the full fruiting period. The upper dorsal branch should be controlled in time so as not to affect the backbone branch and the fruiting mother branch. Most of the drooping branches are not full, the fruiting ability is poor, and nutrients are wasted, which should be dealt with according to the specific situation.

III. Thinning of male inflorescences

During the development of male and female flowers, a large amount of nutrients and water stored in the tree need to be consumed, especially when the male inflorescence grows rapidly and the female flowers bloom in large numbers, the amount of water in the tree often becomes a limiting factor for the growth and development of female flowers. eliminating too many male flowers can reduce the consumption of nutrients and water in the tree, so that more nutrition and water can be supplied to female flower development, flowering and fruit setting, thus improving yield and quality. And it is beneficial to the growth of new shoots and the enhancement of tree potential. The early period of thinning male flowers is appropriate, and the earlier the yield is increased, the more the ratio of bud to female flower bud is determined. After thinning male flowers, the ratio of male flowers to female flowers is 3-60:1. For the dwarf plants with more mixed buds and less or less male flower buds, there should be less or no male flowers. The method of thinning male flowers can be combined with pruning with hooked poles to pull down the branches and break them off by hand.

How to promote premature and high yield of walnut?

1. Grafted seedlings: walnut varieties such as fragrant bell and thin shell bear early fruit, early and high yield and excellent quality. Strong resistance. Unified planting of grafted seedlings of improved varieties can achieve the goal of early fruit, high yield and neat results.

2. Artificial pollination: in order to overcome the problem of pollination and fruit setting caused by different blooming of female and male flowers, artificial pollination can increase the rate of fruit setting. The suitable pollination period is when the female flower stigma opens with "inverted eight characters", at this time, the male inflorescences at the beginning of the fruiting tree can be collected and hung above the pollinated tree to let its natural pollination. After collecting pollen, it can be diluted 3 to 5 times with talc powder and placed in a three-layer gauze bag and taught manually above the pollinated tree. Pollination should be done at 9: 10 a.m. on a sunny day.

3. Fine management: fertilizing and watering, for prosperous trees, increasing the application of phosphorus and potassium fertilizer, controlling the amount of nitrogen fertilizer and irrigation, applying base fertilizer early, combined with deep turning and root cutting, to promote the tree potential to change from prosperous to strong. For weak trees, it is necessary to apply more organic fertilizer, more ground topdressing and foliar spraying fertilizer to strengthen vegetative growth and rejuvenate the tree potential. Walnut pests mainly include walnut limb moth that harms fruit, longicorn beetle that harms branches and so on, and walnut canker and so on. Comprehensive prevention and control of diseases and insect pests should be strengthened, management should be strengthened to enhance tree potential and disease resistance, drug control should strengthen the prediction and forecast of diseases and insect pests, and key drugs should be given when diseases and insect pests do not become a disaster.