The phenomenon of fruit drop occurred during the cultivation of walnut, which led to the low yield of walnut. What caused it?
First, the reason why walnut trees are easy to drop fruit: 1, the pollen activity is low, and the flowering time of the corsage and female flowers of walnut trees is generally around the solar term, from Tomb-Sweeping Day to Grain Rain. At this time, it is easy to encounter cooling weather, which leads to the decrease of pollen activity of walnut trees, and the abnormality of walnut trees during fertilization, which leads to walnut fruit drop.
If it encounters continuous rainy weather, it will adversely affect walnut pollination.
2. The vegetative growth and reproductive growth of walnut trees are unbalanced, especially when too much nitrogen fertilizer is applied to walnut trees, which leads to excessive vegetative growth. Most nutrients in trees are occupied by growing branches. The crown of the upper walnut tree is too large, which affects ventilation and light transmission, and the growth of the lower part is too weak. Young walnut fruit can't get enough nutrition, which leads to fruit drop.
3. Pests and diseases cause walnut trees to drop fruit. Common diseases and insect pests of walnut trees generally include bacterial black spot, anthracnose, longicorn, walnut and other diseases and insect pests, which will cause walnut fruit rot and fruit drop.
Second, the prevention methods of walnut fruit drop are mainly protective measures, scientific management to reduce the occurrence of fruit drop: 1, standardized cultivation measures, walnut tree is one of the fruit trees that grow for a long time, and it takes a long time from planting to full fruit stage. At first, the planting density is often relatively large, and temporary plants are added. All right.
When the walnut trees grow to a certain size, the fields become shaded and the ventilation and light transmission are poor, which will affect the normal fruit setting of walnuts cultivated in rows permanently. Temporary trees and rows should be thinned in advance and the crown width should be strictly controlled. Generally, in summer, the upper competitive branches will be thinned out, and more flowers and less cuttings will be used to promote the formation of fruiting branches.
For planting areas with strong wind, it is best to plant windbreaks at the windward side of 22 meters to 25 meters. Too close will affect the normal growth of walnut trees, and windbreaks can reduce the impact of excessive wind on flowering and pollination.
2, reasonable water supply, walnut trees like loose, fertile, breathable soil, walnut trees in the dry season, proper watering, to avoid excessive rain caused by waterlogging.
Some planting areas are difficult to water, so it is better to remove some leaves in spring, which is not only beneficial to reduce leaf transpiration and plant nutrient loss, but also beneficial to control nutrient growth, promote reproductive growth, improve fruit setting rate and reduce fruit drop.
3. In order to supplement boron, boron fertilizer can be applied together with winter fertilizer. The application of boron fertilizer 10 ~ 15g to young walnut trees and about 25g to big walnut trees is beneficial to the demand for boron from flower bud differentiation to young fruit expansion, and can also be combined with chemical fertilizers. The earlier the application, the better.
In addition to basal application of boron fertilizer, foliar spraying 1000 times liquid chelated boron+Tianda 2 1 16 foliar fertilizer is more conducive to flowering and pollination, improving fruit setting rate and reducing fruit drop.
(4) Prevent and control pests and diseases in time. Before the onset of anthracnose, chemical agents can be sprayed on the leaves, such as Bordeaux solution, basic copper sulfate, mancozeb 800 times solution+10% difenoconazole 3000 times solution, or prochloraz 800 times solution+chlorothalonil wettable powder 600 times solution+tebuconazole 80% 4000 times solution.
When bacterial black spot occurred, ningnanmycin 500 times solution or ethylicin 1000 times solution, zhongshengmycin, zinc thiazole, etc. Can be added to drugs.
Ok, this chapter is over. Welcome to collect. Like a friend, click a favorite and then go.