What are the common pests and diseases of rake oranges? How should I prevent it?

If it is a large area of yellow leaves, it should be paid attention to, and it should be with a rake of oranges.

growth and development. The nutrients of the rake mandarin orange have been almost consumed when the fruit is hung, and a lot of new branches and new leaves grow at this time, and secondly, spring see.

The leaves are thin, and the nutrients stored in the leaves are less, and when the growth of spring shoots is large, due to transpiration.

The nutrients in the lower old leaves are easily pulled up to the upper new leaves, and yellowing occurs.

Generally speaking, if you reasonably control the amount of fruit hanging in Harumi, dig deep trenches, store more grass, apply fertilizer reasonably, pay attention to pruning, and often go to the ground to observe, you will find that Harumi is actually more worry-free than other varieties. Improper selection of fertilizers and sprinkling of livestock and poultry fertilizers. Abuse of non-fruit tree fertilizers, and indiscriminate application of fertilizers according to the nutritional needs of fruit trees; Partial and violent application of chemical fertilizers.

sprinkle unrotted livestock and poultry fertilizer; Ignoring the application of organic fertilizer, microbial fertilizer and liquid fertilizer.

<> after a large number of fruits, its diseased and weak branches will increase, and this is the time when it is most likely to cause anthrax.

, mancozeb can be used.

and other agents to spray fruit trees; In spring and summer, to strengthen the prevention and control of mites, you can use drugs such as dadifrin and alkyne mite; Prevention and control methods: Combined with strengthening cultivation management, the diseased fruits are picked and burned in a concentrated manner during pruning. Spray 1:

1: 200 times Bordeaux liquid.

or 400-600 times of 80% Dasheng wettable powder, or 500 times of 70% mancozeb powder, spray once every 10-15 days.

Prevention and control methods: Combined with strengthening cultivation management, the diseased fruits are picked and burned in a concentrated manner during pruning. Spray 1:

1: 200 times Bordeaux liquid, or 80% Dasheng wettable powder 400-600 times liquid, or 70% mancozeb powder 500 times liquid loquat macroflora grows rapidly, has strong adaptability, and is easy to manage at seedling stage. After the seedlings are unearthed, the weeds between the seedlings should be pulled out in time, and 0 1 urea can be applied after weeding.

to facilitate the growth of seedlings. The nursery land should be selected in sunny and well-drained sandy loam soil. Before sowing, the nursery should be dug deep and 3 quicklime should be used.

Carry out disinfection. The seedbed is 1 2 meters wide, the bed height is 20 cm, the bed surface should be meticulous and flat, the stones and weeds should be removed, and the side ditch and trail should be straight.

After planting rake citrus seedlings, the most worrying and most feared thing is pests and diseases, because these pests and diseases will lead to the erosion of fruit trees, so that the fruit does not produce fruit, so in the planting process, we should pay attention to the disinfection and sterilization of these pests and diseases, and do a certain amount of prevention and control management.

Harumi has strong resistance to canker disease and decay disease, but is sensitive to anthrax, especially after a large number of fruits, weak trees and weak branches are more diseased, and attention should be paid to timely prevention and control. Strengthen the control of mites in spring and summer, and pay attention to the prevention and control of leaf miners in July and August. Spring is more sensitive to rust ticks, and attention should be paid to the prevention and control of rust ticks in autumn and winter.

After a large number of fruits, its diseased branches and weak branches will increase, at this time it is most likely to cause anthracnose, you can choose mancozeb and other agents to spray fruit trees; In spring and summer, to strengthen the prevention and control of mites, you can use drugs such as dadifrin and alkyne mite; In July and August, pay attention to the control of leaf miners, and you can use avermectin for spraying.

Aphids absorb nutrients from the shoots, which affects the growth of the plant and the quality of the fruit. You can prune the shoots to block the further growth of aphids and cut off the broken branches. Eating the young branches and leaves and burying them inside, which will eventually lead to the death of the entire citrus tree, and whitening the lower part of the trunk at a distance of one meter can also prevent the star beetle from laying eggs.

Thrips. Use spirofen ethyl to add high chloride, emamectin salt, ethyl multichloride, etc.

Flower bud maggots. It can be poisoned, prevented with inulinoid agents, and sprayed on the leaves after unearthing.

Summary. The loss of leaves of the yellow leaves of the citrus is due to the lack of water, and the insects will cause this phenomenon to occur.

The loss of leaves of the yellow leaves of the citrus is due to the lack of water, and the insects will cause this phenomenon to occur.

1. When the soil is dry, the growth of the root system is inhibited, and when the transpiration of the tree is greater than the water absorbed by the root system, the leaves will wither and fall off, and the petioles will fall off in severe cases. 2. The soil moisture is too high, the soil permeability is poor, resulting in the lack of oxygen and even rotten roots in the roots, which affects the absorption function from the surface, and cannot meet the consumption of the upper branches and leaves and fruits. Second, the growth of leaves with poor light needs to have proper light.

The canopy is closed, the light is insufficient, the leaves of the inner hall are enlarged and thinned early, the photosynthesis of carbohydrates is not enough, and the assimilation amount is significantly reduced.

3. Nutritional deficiencies lack of nitrogen, phosphorus, potassium, calcium, boron, magnesium, iron, zinc, sulfur, molybdenum and other nutrients, especially nitrogen and magnesium, are the reasons for the early yellowing and early fall of old citrus leaves. Fourth, diseases and insects harm the sap of the old red spider and rust spider to suck the leaves, resulting in a shortage of nutrients and water in the leaves, resulting in premature decay and fall off of the leaves. In addition, such as anthrax, yellow spot, foot rot, longhorn larvae, drill pillars, tree branches, etc., also block the old and cause yellow leaves and leaf loss.

5. Other unfavorable factors such as pesticide damage, fertilizer damage, strong wind, frost damage, and improper circumcision will also cause abnormal yellow leaves and leaf loss. Phenomenon.

Reasonable dense planting: Carry out dense planting and strengthen fertilizer and water management to keep the tree strong and strong, which can improve the early benefit and is suitable for dwarf dense planting. The planting density should be 3m 3m.

Key points of fertilizer and water management: thin and frequent application of fertilizer at the young tree stage, mainly N and P, and N, P and K must be applied together after fruit bearing in the second year. Due to the good yield in spring, fertilizer and water management should be strengthened after entering the bumper yield period, especially in June and July. Fruit picking fertilizer was applied in advance to November, mainly P fertilizer and organic fertilizer, combined with a small amount of N fertilizer.

Key points of shaping and pruning: When pruning young trees, attention should be paid to opening the tree shape, thinning and combining short branches, improving branch quality and increasing ventilation and light transmission.

Key points of flower and fruit management: pay attention to fruit thinning, so as to ensure that the fruit is large and of high quality. The fruit thinning time should be carried out after the second physiological fruit drop in late June, and the small fruits, diseased fruits, insect fruits, deformed fruits and overly dense fruits should be thinned. However, the fruit should not be thinned excessively, otherwise it will form a coarse skin and large fruit.

Key points of pest control: After a large number of fruits, there are more cases of anthracnose in weak trees and weak branches, and attention should be paid to timely prevention and control. Strengthen the control of mites in spring and summer, and pay attention to the prevention and control of leaf miners in July and August. It is sensitive to rusty ticks, and attention should be paid to the prevention and control of rusty ticks in autumn and winter.

In your case, you should pay attention to the fact that from the perspective of plant growth rules, the fun agricultural circle believes that the damage to the pesticides will mainly affect two aspects, one is the damage to the photosynthesis of citrus trees, and the other is that the flowering and fruiting will be affected.

Funong Circle begins to analyze the reasons for you:

Why does it affect photosynthesis? When I use pesticides, I have high requirements, to dilute the pesticides to the level of clear as water (this is an analogy), so that not only is it easy to absorb and effectively eliminate insect pests, it is easy to wash away when it rains, it is easy to evaporate in the sun, and the residue will not damage the leaves.

After the residue is exposed to the sun, mildew will destroy the normal growth of the leaves, the leaves are damaged, they cannot photosynthesize, they cannot produce chlorophyll, they cannot breathe carbon dioxide and other gases, and accordingly they cannot synthesize organic matter, and they cannot synthesize organic matter, and the growth of citrus branches will be sluggish or dry, and once the yellow leaves begin, then the leaves and flowers and fruits begin to appear.

Why is flowering and fruiting affected? In fact, according to the above analysis, we also know that the impact is very large, after the leaves are destroyed, even if the nutrients are very rich, the flowers and leaves will also be affected, and the fruits will be lost or less fruits, and the fruits will be mutated. Nutrient water is transported through the leaf tip and then to each branch to the flower bud or flower and fruit, and when photosynthesis is disrupted, these transport processes are affected.

That. First, the use of pesticide degradation enzymes to neutralize it, timely removal of residues, plant absorption of pesticides is mainly from the root to the stem to the leaves, flowers and fruits, this process is to see if there is a lot of pesticides sprayed on the roots, timely neutralization in the roots. Timely cleaning of the leaves by watering can also achieve a certain effect, but it is too troublesome, but at this time, for our fruit farmers, it is the biggest harvest to be able to remedy.

That. 2. Prevention methods: try to choose pesticides with chronic reactions, which are less harmful to plants, such as BT biological insecticides or antibiotic insecticides and fungicides, which are more practical.

After spraying pesticides, observe in time to see if there is any residue, if there are more residues, we will deal with them in time, like your situation is caused by less observation of the situation of fruit trees, more observation of growth and leaf status, timely solution to the problem found is the key.

To sum up the analysis of the problem, when we use pesticides, choose less harmful pesticides for spraying, in the citrus growth stage, more weeding and reasonable fertilization, increase the resistance of citrus, generally not easy to be pested, timely removal of pesticide residues, careful management of orchards, is the most important way of prevention and control, more frequent pesticides, for a long time, the soil will deteriorate, the growth of plants is particularly large, so it is more troublesome.

After a large number of fruits, its diseased branches and weak branches will increase, at this time it is most likely to cause anthracnose, you can choose mancozeb and other agents to spray fruit trees; In spring and summer, to strengthen the prevention and control of mites, you can use drugs such as dadifrin and alkyne mite; In July and August, pay attention to the control of leaf miners, and you can use avermectin for spraying.

Second, the time of harrowing the citrus tree to hang fruit.

1. Specifications of rake citrus seedlings.

Now the wholesale rake citrus seedlings in the market have 1-year-old seedlings and 2-year-old seedlings. Generally, the size of the seedlings is determined according to the specifications of the seedlings, and the diameter of the seedlings is generally 1 cm in one year and 1 to 2 cm in two years. The larger the size of the seedling, the more difficult it is to plant, but the earlier the time to hang the fruit, the specific planting situation I hope you will choose the size of the seedling suitable for your own orchard to plant.

2. The fruit-bearing time of raking and raking citrus trees.

Rake mandarin orange still belongs to the kind of fruit that hangs fruit quickly, and generally starts to test flowers and fruits about 2-3 years. However, when the fruit just hangs, it is necessary to comb the fruit tree properly, generally only a few fruits are kept on a main branch as the best, if the fruit bears too much, because the tree itself is smaller, which will affect the growth and development of the fruit tree and the yield in the later stage; After the third year, you can gradually increase the yield of the fruit, and after four or five years, you can let it produce normally.

3. The harvest time of harrow citrus trees.

The production cycle of the rake citrus tree is still long, and the planting area is different from the environment, so its harvest time is also uncertain, just take the rake mandarin that grows in Sichuan area The variety of rake mandarin orange is generally about 3 years to bear fruit, and about 5 years to produce a bumper yield.

3. Leaf crushing disease of rake mandarin oranges.

1. The harm of leaf crushing disease.

The disease is mainly caused by the leaf crushing virus, which can cause the sapling to become shorter, rot the roots, or even kill the sapling outright.

2. Causes of leaf crushing disease.

It is some other diseased saplings in the orchard, which are transmitted by grafting; It has also been transmitted through knives or scissors that have been contaminated with the virus, but no pests have been found to infect the disease.

3. Prevention and control methods of leaf crushing disease.

When the probability of disease is less than 20%, it can be dug up, and then the soil can be disinfected or directly replaced with new soil quality, and then replanted healthy citrus seedlings for half a year or a year; When the disease rate is more than 20% early, you can take grafted wolfhead orange anvil or orange anvil to alleviate the disease, and wait until one year later, the seedlings can recover; Or it is possible to start a new shoot directly at the grafting interface and let it take root.

This doesn't have much impact, but um, try to ensure its safety.

Take some ** to see if the yellowing and falling leaves are still green and withered leaves.