Manuscript source: Wugong Kiwi Experimental Station - Wang Xirui
1. What are the characteristics of canker bacteria?
A: Kiwi canker disease is caused by pseudomonas syringae pv. Actinidiae (PSA)) is a bacterial disease caused by infection, and studies have shown that multiple pathogenic strains can be isolated from different disease strains. The pathogenic capacity of these pathogenic strains varies.
Kiwi canker bacteria are low-temperature bacteria. When the temperature is about 5 °C, it can reproduce, 15 ~ 25 °C is the most suitable temperature for its growth, and obvious diseases can be seen 7 days after the disease. It can also reproduce for a short time at a temperature of 30 °C, but it dies after 39 h.
2. Canker bacteria are bacterial diseases, why do they cause devastating harm?
A: There are several main reasons why canker diseases of bacterial diseases cause devastating harm:
(1) There are many ways of infection of canker bacteria. Germs can be transmitted from wounds, wind, rain, insects, management tools, and pollen.
(2) Ulcer disease generally occurs in the branch cortex, and may invade the xylem in the later stages of the disease. After the onset of the vine, the cortex decays and the xylem catheter is blocked, so that the nutrient transmission path up and down is blocked, thus causing the branches to die, and even the dead trees to destroy the garden. The impact on yield is significant and devastating.
(3) Observation found that canker disease cannot decompose the transparent waxy layer on the surface of the branch skin layer. Once the germs invade the cortex in some way, the waxy layer plays a protective role, making it difficult for the spray control drugs to contact the bacteria (rat barn), resulting in the retention, infection and outbreak of the bacteria in the tree, resulting in difficulties in prevention and control.
3. What are the symptoms of canker disease?
A: The symptoms of ulcer disease can be seen in the leaves, branches, fruits, flowers and other parts. The incidence of branches is the most typical, and the harm is also the most serious.
Leaf symptoms: the spots are polygonal and have a yellow halo around the spots.
Branch symptoms: at the beginning of the disease, a translucent pus-like liquid flows out of the graft interface, bud eyes, and branching cracks, gradually becoming cloudy, and showing rust red in the later stages of the disease. It occurs mainly in the cortex, and the soft decay decomposition of the cortex occurs. Later lesions can extend to xylem. If the disease spots cause the branches to peel off, after the temperature rises, it will cause the upper part of the disease spots to suddenly dry up and die.
Flower symptoms: after the onset of flowers, the buds wilt, the flowers are half-open or not open, the stamens become black, the fruit set is poor, and the fruit is easy to fall. Flower symptoms are similar to flower rot.
Fruit symptoms: The young fruit is partially sunken, like a sunburn, but the sunburned patches appear everywhere in the fruit, not just on the shoulders. The heart of the fruit pulp turns brown.
4. What are the characteristics of the incidence of ulcer disease?
A: The incidence of canker disease varies greatly depending on the variety, tree load, climate, tree age, tree potential, and management techniques.
There are differences in susceptibility between varieties, Chinese kiwifruit is more susceptible to disease than delicious kiwifruit, and Hongyang is the most susceptible;
The overload is serious, the tree is weak, the older the tree, the more susceptible it is to disease; the male plant has a serious disease, and the long branches are more serious than the middle branches. The backbone branches and shears of Huayou varieties have many diseases, but they can often heal themselves.
Autumn cooling early and amplitude (early frost) large, winter for a long period of extreme low temperature caused by frost damage, winter warm winter and spring temperature is low or fluctuating, humidity is large, the occurrence of spring cold, easy to cause disease;
Unscientific cultivation management, serious overload, late application of nitrogen fertilizer in autumn, and poor ripeness of branches are prone to disease.
5. How do canker bacteria survive and what is the way of infection?
A: Canker bacteria mainly overwinter on diseased branches, but can also overwinter in the soil with disease residues. In autumn, winter and early spring, pathogens invade the cortex by the petiole marks, skin holes, insects, frostbite wounds and other parts of the plant, and begin to occur in the late winter and early spring injury flow period. The pathogen mainly infects the cortex, causing the cortex to decay and flow out pus. The pathogenic bacteria in early spring spilled out of the diseased area with pus and repeated infections with wind and rain, gall mosquitoes and agricultural tools. Onset occurs 3 to 5 days after infection. From mid-March to mid-April, the germ hazard is at its peak, the spots are enlarged, and a large amount of yellow-brown liquid flows out of the pores of the skin of the spots, and the infection is repeated. Later, the pus turns rusty red. In rainy weather, the bacteria pus overflowed in large quantities, resulting in repeated cross-infection.
6. What is the incidence of ulcer disease in the annual cycle?
A: Because canker bacteria are low-temperature bacteria, mainly in the low-temperature autumn, late winter and early spring infection and repeated infection, winter bacteria lurk in the branches of the tree, focusing on the onset of the disease between the injury flow period and before and after budding.
There is a deviation between the time and space of the onset of canker bacteria and infection: in general, after the temperature drops in autumn, the bacteria begin to infect and lurk, at this time the symptoms are not obvious, it is easy to ignore the prevention and treatment, so that the potential pathogen base is large. Under the influence of precipitating factors such as low temperature, large variation and late frost in spring, a large outbreak of ulcer disease will be caused. Ordinary people will pay attention to it at this time and pay close attention to prevention and control, but the effect is not significant. Therefore, autumn prevention is an extremely important part of prevention and control.
At the same time, only pay attention to spray prevention and control, do not pay attention to other measures to cooperate, but also make the prevention and control effect poor.
7. Why is the spraying grasped very tightly, but it is always ineffective?
Answer: First, the spraying time and drug selection are not good; the second is that spraying alone cannot solve the fundamental problem of ulcer disease prevention and treatment.
The spray can effectively suppress the base of ulcer bacteria and reduce the chance of infection, which is the basic measure for the prevention and treatment of ulcer disease. However, there are many factors involved in the pathogenesis of ulcer disease. Production practice observation, the same species, different plots, different yields, tree age, tree potential, different years of climate differences, all cause canker disease incidence is different. Simple drug spray prevention and control, often the agent is difficult to directly contact the pathogen, the bacteria lurking in the cortex can not be killed, so only rely on spray to prevent disease is not good, especially for the serious harm of the disease branch.
8. When is the best time for spraying prevention and control?
A: Spraying to prevent diseases should seize the three key periods of autumn, the beginning of dormancy, and the beginning of budding. Pharmaceutical prevention and treatment mainly use copper preparations, antibiotics and other drugs.
Autumn spraying
Foliar spray control began in late August. Spray 20% leaf subclizole (quick-up) wettable powder 500 to 600 times liquid, 800 to 1000 times liquid 45% daisen ammonium, 50% chlorobromo isocyanuric acid, 20% copper thiamethiacidate 600 times liquid, 1.5% thiameridone 600 to 800 times liquid, killable 600 to 800 times liquid, or 0.15% penninmycin 800 times liquid, 1.8% caprylamine acetate 1000 times liquid, 50% mytoxic acid 500-1000 times liquid, or mesophyticin 600 times liquid, or 30% Fungicides such as copper microemulsions of nonobacterium are sprayed once every 10 to 15 days until the leaves fall.
Special attention should be paid to spray prevention and control after fruit picking and after leaf fall, so as to minimize the infection of pathogens into the cortex through the stalk and petiole marks.
After winter shearing to before budding
On the trunk and branches, 4 to 5 ° Be stone sulfur compound, 500 to 600 times liquid 1.5% thiamethion ketone water emulsion, 800 to 1000 times liquid 45% daisen ammonium, 0.1% peracetic acid and other eradication and therapeutic fungicides are evenly sprayed, and the base of diseases and insects is depressed; spray 1 ° Be, 1:1:200 Bordeaux liquid (separated from the stone sulfur compound for 15 to 20 days) before and after the injury period, and 150 times liquid is slaughtered.
After budding to before flowering
Spray every 15 days. The agent selects 50% chlorobromoisocyanuric acid, 800 to 1000 times liquid 45% daisen ammonium, 20% leaf subazole (quick supplement) wettable powder 500 to 600 times liquid, or 0.15% wunin 800 times liquid, 50% mytoxic acid 500-1000 times liquid, or mesobicin 600 times liquid, 0.1% peracetic acid and the like. Protective fungicides and therapeutic fungicides are used interchangeably. Special attention is paid to spray control in the early stages of germination (5 to 10 cm long of the new shoots). At the same time, it prevents and controls flower rot. Pay attention to adding 3000 to 5000 times liquid silicone penetrant to improve the efficacy.
Fruit setting
Spray 20% leaf substiazole (quick-fill) wettable powder 500 to 600 times liquid. Or 0.15% penynin 800 times liquid, 2% chlormycin 500 to 800 times liquid, or 50% chloro bromide isocyanuric acid 1000 to 1500 times liquid, or mesobicin 600 times liquid and other fungicides, sprayed 1-2 times continuously. In previous years, in the garden field with sclerotium disease, isobacterium urea, sclerotium net, pyrimethamine, azoxystrobin agent and so on were added.
Combined with spraying, 0.3% ~ 0.5% potassium dihydrogen phosphate and 0.1% ~ 0.2% boron fertilizer, excellent fruit, trehalin, amino acids are added, which is conducive to enhancing disease resistance and improving the weight of single fruit.
9. Can ulcer disease be cured? When is it cured?
A: Conditionally treated. But the most effective method is prevention.
During the onset period, every 4 to 6 days the whole garden is inspected, and the fine diseased branches found are cut off 20 cm under the disease spots, and the scissors are smeared with medicament; the thick branches, the disease spots have caused the branches to be peeled off, and the 20 cm scissors under the disease spots are seen, and the orchard is burned; the disease spots have not yet caused the branches to be peeled, and the distance between the cuts is 1.5 cm (near the sound tissue is also drawn), with 4 to 6 times "84 disinfectant", or 4 to 6 times the liquid 10% peracetic acid solution, spray the mouth, and fully soak the scratch. The next day or the next day, if the red pus is still flowing from the sick class, continue to spray until there is no water flowing, or the outflow of water is clear. Then, smear "Slaughter" on the scratch. Before the heat comes, cover the large unhealed scissor saw and apply it with a flick of the blue.
10. What is the key link in the prevention and treatment of ulcer disease? What are the principles of ulcer disease prevention? When is the best prevention of ulcer disease?
A: The key links in the prevention and treatment of ulcer disease are: reasonable load, scientific management, removal of the source of infection, spraying and scratch protection at critical times.
The principles of canker disease prevention and control are: more branches, thinning branches, longitudinal stroke (spray) coating to protect the backbone branches; strong growth, healthy tree potential, spring and autumn leaves spray pressure disease base; sparse buds, semi-renewal, phosphorus supplementation and boron to promote disease resistance.
The prevention of ulcer disease should seize the key periods from late August to leaf fall, onset and early budding. Take a large area of meticulous spray rack surface prevention, timely remove the source of infection, scratch, spray, coat the disease of coarse branches, scientific fruit retention, re-application of organic fertilizer, formula fertilization and other measures to prevent and control.
11. After the branches are sprayed and applied, there is a wound on the branches, and after the effect of the medicine is over, will it be infected again?
A: After the branches are sprayed and smeared, there will be a liquid film to temporarily protect the wound and make the agent continue to absorb. At the same time, the slaughtering effect is long, the healing effect is good, and the medicinal effect can basically heal before it disappears. Therefore, there is no re-infection. For large wounds that heal problematically, apply flicking blues in time for protection.
12. What kind of medicine is good for the longitudinal stroke application method?
A: After several years of experiments and production demonstrations, it is best to treat spray scratches with killer sodium hypochlorite (the main active ingredient of "84" disinfectant), peracetic acid, etc. However, to dilute 4 to 6 times the liquid, can not be sprayed with the original solution. When there is no running water, apply the scratch to "slaughter".
13. When is the best time to prevent ulcer disease? What agents work better?
According to the characteristics of the prevention and treatment of ulcer disease, it is necessary to distinguish the priority and the secondary, and adopt the strategy of "grasping the big and not letting go of the small", focusing on prevention. Grasping the big finger mainly grasps the three key periods of February, June and September to prevent and "hunt down" germs.
After the minimum temperature in February, before the injury flow period, apply a solution of slaughter: water = 1:1 to the "key parts" of the main trunk, the main vine, the fork mouth and the base of the fruiting mother branch 20 cm to minimize the onset of these areas. These areas can also be carefully sprayed with a small sprayer.
In June, the same application or spraying of these areas was slaughtered. In September, the main trunk and fork can also be applied to the "slaughter" stock solution. February and September are the most critical.
"Do not put small" mainly refers to the prevention and control of large areas of diseases through the spray shelf surface. Sprays such as peracetic acid, 45% daisen ammonium, yeltiazole, and octylamine are used during the pathogenesis period, and antibiotics and 50% chlorobromoisocyanuric acid are used for prevention and control after germination and growth. It can also continue to use em, Bacillus subtilis, lactic acid bacteria, Streptomyces finesse, Bacillus amylogenes, Bacillus flankspora and other bacteriocins spray leaf back (fermentation of exuberant bacterial liquid or spray bacterial liquid dilution added to 5% sugar), to bacteriostatic bacteria, prevention of disease, and does not produce residues.
14. What should I pay attention to when applying to prevent ulcer disease?
Answer: The effect of applying to prevent ulcer disease is good, but the main attention should be paid to: (1) Mainly for susceptible varieties such as Hongyang and Cuixiang. The output of its control input is high, which offsets the increased cost; (2) the "key parts" such as the thicker backbone branches, forks, and the base of the resulting mother branches are carried out, and the smaller branches are directly removed 20 cm from the mouth of the disease and brought out of the garden to burn; (3) the dormant period is smeared with "slaughter" to avoid the coldest period.
15. Why should you stroke longitudinally when treating thick branches, and is it not good to spray directly after scraping?
Answer: Longitudinal stroke without scraping, the wound is small, the wound flow is light, and to a certain extent, the agent is avoided by the wound flow, which is conducive to wound healing. At the same time, the agent has strong permeability, and can also penetrate the ward and surrounding tissues, and play a therapeutic role. The small slit can adsorb more liquid medicine, which is conducive to continuous absorption and makes the drug work for a long time. After scraping, the liquid was sprayed directly, the injury flow was large, the agent was quickly washed away, and the wound was difficult to heal. Therefore, the prevention and control effect is not good.
16. How to prevent canker disease of Red Sun Tree?
Answer: Hongyang is most susceptible to ulcer disease, so it adopts a multi-trunk cluster method in production, which is grafted every year, "before the servant and successor". In fact, this is an unscientific method.
The method of "one trunk, two main vines, and the main vine directly produces the mother branch" should be adhered to for shaping. Then, while paying close attention to the prevention and treatment of "key parts", a variety of measures based on prevention are taken to prevent and control ulcer disease.
In addition to the spray prevention and control of the source of infection during the critical period (refer to the above contents), comprehensive measures such as cultivation management are grasped to ensure that the loss due to disease is controlled below 5%.
(1) In the autumn of September, all backbone branches (main trunk, main vine), forks, and the base of the mother branch are sprayed with medicine for prevention; (2) 1 to 2 fruiting branches at the base of the fruiting mother branch on the main vine are not fruited during the bud stage, and the tip of the tip is dipped with a branch treasure to promote the renewal of the branch. For the front fruiting branches, all the flower buds are removed every other fruit branch and left as empty fruit branches (empty moss) to reduce the load; (3) the mother branches that have borne fruit about half of the fruits in winter are retracted to the base renewal branches; (4) during the spring onset, the whole garden is checked every 3 to 5 days, and the fine branches are pruned from 20 cm under the disease spots, taken out of the garden to burn, and the medicine is applied to the scissors. Before the coarse twig spots do not cause ring peeling, spray and apply the drug (as mentioned above) (5) Foliar spray 2 to 3 times every 15 days from late May to late June 2 to 3 times 0.2% fulvic acid, bigu, brassica lactone, etc., to prevent sunburn. In late August, the young parts of the autumn shoots are cut off and pBO sprayed to promote the maturation of the branches. (6) Heavy application of organic fertilizer: after fruit picking, apply 3 to 5 cubic meters of decomposed organic fertilizer per mu, add 5 to 6 kg of wheat rice stone powder per plant, and add 1/5 biological bacterial fertilizer or fungal agent to the organic fertilizer. Add 150 kg of calcium superphosphate agent per acre, 50 kg of potassium chloride.
In the management of the red sun growing season, the growth and development should be reasonably regulated, the tree body should be promoted and the disease resistance should be enhanced. The principles of its growth regulation mastered:
(1) Promote and control before and after the growth period, and balance the tree potential.
Stimulate growth in the early stage of growth, increase the amount of canopy leaves, enhance the ability to resist anti-japanese burning, and maintain a strong tree posture;
Appropriate pruning in the middle and late stages of growth, increase canopy ventilation and light transmission, promote branch maturation, and enhance disease resistance.
During the life cycle, when the tree is weakening at the fruit stage, brassica (as described) is added 1 to 2 times in combination with spraying in the early stage of growth to promote the robustness of the tree and improve disease resistance
17. Is there a relationship between canker disease and production? How should I master it?
In addition to varieties, there is a close relationship with the incidence of canker disease is yield. Excessive yield will seriously damage the disease resistance of kiwifruit, and even disease-resistant varieties will weaken the tree and increase the incidence.
The yield of general delicious kiwi fruit mu is controlled between 2500~3000 kg/mu, Chinese kiwi fruit is controlled at 2000~2500 kg/mu, and Hongyang is controlled at 750 kg/mu.
18. What is the relationship between canker disease and tree posture and pruning?
The moderate tree is a kiwi fruit, with strong organic nutrient synthesis ability and accumulation, so the disease resistance is improved. The tree is too strong (weak), too much nutrients for vegetative growth, and less accumulation. The result of the growth of new shoots is that the weak tree is not resistant to frost and disease; too weak tree potential nutrients are too much for reproductive growth, the root system is weak, which is not conducive to organic nutrient storage, and the disease resistance is also reduced.
Winter pruning regulates the amount of hanging fruit, which is related to the strength of the tree, which has a great impact on vegetative growth and reproductive growth balance, and profoundly affects disease resistance.
Winter pruning should be combined with growing season management to comprehensively regulate tree posture. When the pruning is too heavy and the amount of leaves and buds is small, pay attention to improving the germination rate, leaving more flowers and fruits, and alleviating the vigorous trend, and in the first and middle of May, the leaves with space and need to sprout will be removed (leaving the stalk), the branches will be emptyed, and the growth of the mother branches will be moderated; when the pruning is light, pay attention to the base branches, and if necessary, cooperate with the application of buds in the inner chamber in February. Appropriately retain flowers and fruits, strengthen the vitality of the root system, increase the storage of organic nutrients, and restore the tree potential.
Summer pruning should promote summer branches (branches that grow after summer), do not overstiminate the growth of spring shoots, and control the growth of autumn shoots.
Winter pruning results of the mother branch selection should be selected to leave a well-lit, robust and full of branches as the fruiting mother branch.
19. How to cultivate the moderate tree potential?
Mainly organic fertilizer, formula fertilization. When pruning in winter, most of the fruiting mother branches use strong fruit branches: that is, leave a proper shoot in front of its stalk to shorten the shoots, so that it becomes the next year's fruiting mother branch; when the new pruning, the base of the branching vine is cut off; the branches are cut at the sub-full bud at the end of the shoot; the current bud is removed at the shear, and all the buds are full of the next full bud; the overly long fruiting mother branch curls back to the nearby shelf in the spring to have space. In February, the buds are sprayed on the shelf to improve the germination rate, and in the summer in May, the leaves at the base of the branches are removed to promote the regeneration of branches, disperse the growth points, and ease the growth trend. There is a space for the capping branch, and in May, the top 1 to 2 leaves are removed to promote the emptying of the branches. The improvement of over-vigorous and over-weak trees can be seen above.
20. How to prevent canker disease of young trees in Hongyang?
Answer: The cultivation of young trees in Hongyang New Plantation should be managed from a long-term perspective and with the prevention of ulcer disease as the focus.
(1) Shape according to the method of "one main trunk, two main vines, and the main vine directly produces the mother branch". Cut from 20 to 30 cm under the shelf surface, leaving 2 buds under the shear. After the 2 buds germinate, the tip of the tip is dipped with a branch treasure to promote the development of a robust main vine; (2) when the grafting joint film is slightly deeper, the film is dissolved. At the same time, the film is applied to the graft interface, and then when the trunk above the grafting interface is semi-woody, the coating is smeared to promote the good disease resistance of the trunk; (3) when the main vine is semi-lignified, the same is smeared. Be careful not to stain the leaves and petioles.
21. What are the main prevention and treatment measures during the onset period?
The main prevention and control measures during the onset period include: timely pruning of diseased branches and removing the source of infection; timely spraying, lowering the incidence index, reducing repeated infections and treatment measures. In addition, it is also possible to irrigate the roots with em fungus.
Check every 4 to 6 days, cut off the diseased twigs from 20 cm under the sick class in time, and bring them out of the garden in time to burn them; 10 to 15 days, the whole garden is carefully sprayed to clear the garden. The agent is selected from 0.1% peracetic acid, 45% daisen ammonium, leaf subusole, octylamine and so on. Thick branches (without ring peeling) are treated with scratching, spraying and smearing. It is also possible to irrigate the roots with 100 times of liquid em every 15 to 20 days, for a total of 3 times.
SHAPE \* MERGEFORMAT
22. What is blackhead disease? How to prevent it?
Also known as black spot disease, it refers to the disease in which small black spots initially appear on the fruit surface of varieties such as Cuixiang and continue to develop continuous patches into black spots.
The disease generally only occurs in the epidermis, does not penetrate deep into the pulp, and does not affect the quality of consumption. However, it affects storage and sales, and during storage, it will become ill from this disease class, resulting in losses.
The disease is initially believed to be caused by a combination of disease infestation and calcium deficiency. The pathogens identified by the isolation are considered to be Mycobacterium, and there are separations as P. sylvestris. Studies have shown that Cuixiang's poor ability to absorb calcium and the low calcium content of plants may be the cause of serious cuixiang blackhead disease.
The onset of disease spreads rapidly under high humidity and high temperature conditions. Sometimes after the bag is removed, it will darken rapidly within a few days.
Prevention and control methods: Timely use calcium fertilizer (calcium chloride) plus chlorinated isocyanuric acid, or calcium fertilizer plus tepuzole, or calcium fertilizer plus em spray after fruit setting. Calcium supplementation should be carried out tightly before bagging. After picking the bag before harvesting in the later stage, the fruit surface is immediately sprayed with em plus calcium fertilizer to prevent rapid blackening. When resuspening to control other pests and diseases, 0.2% calcium fertilizer is added.
Spray prevention and control should pay close attention to before and after the rain. Especially attention should be paid to prevention and control during the fog season.
23. Is phylloxera disease? How to prevent it?
Nodule nematode disease is caused by nematodes multiplying in the root system, absorbing organic nutrients from the root system, secreting irritating substances, stimulating root cells to expand, vacuole, and form nodules. Not a disease in the traditional sense.
Symptoms: Small bean-like acne or beaded nodules on the root. The upper part of the ground of the diseased plant is wilted and yellowed. Gray-white tumors form at the site of onset, and the internal tissues of the tumors are soft.
Control method: irrigate with avermectin, or chlorpyrifos, or octylthion. Half a month later, irrigate the roots again with a penicillium lilac agent. For severe plots, from March to May and from August to October, irrigate with Penicillium lilac once a month.
Heavy application of organic fertilizer, when watering, with the water to apply lilac penicillium, by you to lead the way fungal agent has a better control effect.
24. What is the cause of gray mold? How to prevent it?
Kiwi gray mold is a fungal disease that occurs mainly at the kiwi stage, the young fruit stage and the storage period.
When the young fruit is onset, the remaining stamens and petals are densely covered with gray spores, and when the young fruit is first developed, the hair of the young fruit becomes brown, the skin is infected, and in severe cases, it can cause fruit drop. The stamens and petals of the bacteria are attached to the leaves, and after the leaves are damaged, the gray mold layer on the back of the leaves is white dots, which are extended with time, and the contact area forms a striated disease spot, and the later lesions expand, the leaves fall off, and the spores on the mold layer fall on the fruit, causing fruit infestation, affecting the color and quality of the fruit.
Prevention and control methods: In the budding stage to the young fruit stage, spray cellular mycosamine, or chlorobromo isocyanuric acid and other fungicides, or trichoderma green, Trichoderma harz and other fungal agents.
25. What is the manifestation of sclerotia? When are the critical prevention and control periods?
Sclerotia is a fungal disease caused by the infection of fruits by sclerotia bacteria.
The initial symptoms are a depression in the fruit surface, and the disease class does not change color. The pulp decomposition of the lesions in the later stages of infection shows stained green spots.
Sclerotiasis is a disease of infection at the young fruit stage, and once the lesions are formed, they cannot be eliminated.
Prevention and control methods: In previous years, in orchards with severe disease, within 3 to 4 days after the last pollination, spray isobacterium urea, or sclerotium net, or ethylene sclerotium, or pyrimidine, and spray again after 10 days. Add 0.3% potassium chloride and 0.2% calcium chloride.
26. When is the appropriate period for the prevention and control of flower rot?
Flower rot is a type of disease caused by the infection of Bacillus aeruginosa, mainly infecting kiwi buds and young fruits, causing the petals to be half open and fall off, stamens wet rot, poor pollination, falling flowers, hollow young fruits with mild disease, and a large number of fruit fall. The symptoms and onset of flower rot disease are close to those of ulcer disease, and the symptoms are not easy to distinguish. There are also manifestations that the bud eye in the middle of the branch (more than 50 cm) has died during winter shearing, which may be caused by infection with the latent bud core during the formation of the bud. Attention needs to be paid to the prevention and control of the growth period.
Prevention and control methods: germination stage, bud stage, spray agent before flowering for control. The agent is made of copper preparation, spring thunder king copper, daisen ammonium, 50% chlorobromoisocyanuric acid 1000 ~ 1500 times liquid and so on. During the growth period, the new shoots start from 30 cm, and the shelf surface is sprayed with Bacillus subtilis, Streptomyces aeruginosa, em, etc. for 20 to 30 days. Pay attention to the ventilation and light transmission of the shelf surface to improve the microclimate of the garden. Apply more organic fertilizer, balanced fertilization, more phosphorus and potassium fertilizer, medium and trace element fertilizer and bacterial fertilizer, prevent partial application of nitrogen fertilizer, and maintain the neutrality of the tree.
27. How to prevent and control leaf spot disease?
Leaf spot diseases are caused by bacterial diseases and fungal bacteria. Such as anthrax, brown spot disease, black spot disease and so on.
Fungal bacterial colonies are generally small, even less inconspicuous. Fungal colonies, especially mold colonies, are relatively large. Bacterial colonies are generally white, transparent, yellow, and basically relatively light and light colors. There are many colors of fungal colonies, common ones are green, black, brown, yellow, and green. Generally more colorful, mold is most commonly green and black.
In recent years, the initial embryonic basal leaf black spot disease (as it is called) has been fierce, causing people to be alarmed. There is no separation of this pathogen.
Leaf spot disease can generally be controlled by spraying 50% chlorobromoisocyanuric acid or 0.1% peracetic acid on the shelf surface 1000 to 1500 times liquid.
28. How to control root rot?
There are 3 types of root rot. Mainly due to the deep planting of the root system and the excessive compaction of the soil between the roots (neck), the soil ventilation is poor, the anorexia bacteria multiply, and the root system is infected.
Prevention and control methods: uncover a layer of soil in the root distribution layer, see the roots without exposing the roots, and irrigate the roots with xanthodolin, or 45% daisen ammonium 300 to 400 times liquid. After half a month, you will lead the way to the fungus plus rooting agent water irrigation. Yellowed leaves, add 0.2% iron fertilizer and 1% vinegar. After 20 days, if the tree posture does not improve significantly, the roots are irrigated with fungal agent plus rooting agent for 1 to 2 times.
29. Where is the harm of small salary A? How to prevent it?
The small beetle belongs to a chewing pest in the elytra class, with a small black-brown or brownish-red beetle with a body shape the size of a needle tip, and prefers to move in clusters. Two generations occur each year in kiwi-producing areas, with the first generation appearing in mid-May and the peak period of harm to kiwi fruit from June to July. The second generation appeared in August, and the small salary armor had a certain degree of difficulty in harming the basic aging fruit. In October, it overwinters in the crevices of soil, stone crevices and the skin crevices of fruit tree branches at the roots of weeds. In the Shaanxi kiwifruit producing area, small salaries are mainly endangered in the young fruit stage, nibbling on the pulp between two fruits.
Control method: within 2 weeks after fruit setting, spray imidacloprid, or chlorpyrifos, etc., and spray again every 10 days.
30. When are the main periods of leafhopper harm? How to prevent it?
Leafhoppers are mainly harmed in june and August during the high temperature and drought. It is a sucking mouthpiece pest. The dorsal distribution dilutes the leaf juice and, in severe cases, also sucks the fruit. Leafhopper hazards can cause amplification of canker disease transmission.
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Prevention and control methods: When the harm is serious, spray avermectin, or chlorpyrifos, or imidacloprid, or kung fu, etc., once every 15 to 20 days.
31. How to prevent red spiders?
Hazards in high temperatures and droughts from July to August. When the damage is severe, the leaves are like fire.
Prevention and control methods: spray avermectin, chlorpyrifos, imidacloprid, kung fu and other agents.
32. How to prevent scarab beetles?
Scarab beetles nibble on the roots with larvae, and adults fly to the leaves at dusk and nibble on the flesh of the leaves.
Prevention and control: spray permethrin drugs at dusk, imidacloprid, etc. Sweet and sour liquid booby-traps, solar black light booby-traps, etc. can also be placed in the field.
33. How to prevent spotted wax cicadas?
The spotted wax cicada sucks the kiwi fruit with adult insects, causing a cork-like dry spot on the fruit, which in turn falls and rots softly.
Control method: remove the leaves when they gather on the back of the leaves at their young age and destroy them;
From mid-April to early May, spray 30% imidacloprid powder 1500 times liquid.
When preventing and controlling, pay attention to spraying together with the fence around the garden. Seedlings such as ailanthus and maple trees are not planted on the edge of the ground.
34. What are the symptoms of the harm of blind bugs and green mango bugs? How to prevent it?
Bug hazards cause most small holes in the leaves, fragmentation, yellowing around the bite (yellow edges)
Prevention and control methods: spray with chlorpyrifos, imidacloprid, 30% imidacloprid powder 1500 times liquid and so on.
35. What are the symptoms of reticulum bugs? How to prevent it?
Reticulo bugs suck on the leaves and young shoots of plants by adult insects and nymphs, and sting on the back of the leaves, secrete brown mucus, and yellow-white spots appear under the leaves, and the front is pale. It occurs more often during the high temperature and dry season.
Control method: remove the deciduous weeds near the trees and eliminate the source of overwintering insects.
Spray leaf back with 1.2% nicotine matrine emulsion 1000 times liquid, or avermectin, or chlorpyrifos, or 10% imidacloprid wettable powder 2000 times liquid, kung fu and so on.
36. What causes yellowing disease? How to overcome?
The causes of yellowing disease are iron deficiency yellowing, root dysplasia, insect infestation, soil compaction, root knot nematode disease and other factors, and the common ones are mainly iron deficiency yellowing and root dysplasia.
Prevention and control measures:
1. Foliar spray 0.15% ~ 0.2% chelated iron;
2, irrigation roots: the root distribution area of the soil using 1500 times the liquid by you lead the way plus 0.2% iron fertilizer, plus 1% vinegar. Or 50 to 100 times liquid em plus + 0.2% iron fertilizer (ferrous sulfate, chelated iron, etc.) + 1500 times liquid by you lead the way fungus irrigation roots, 5 to 15 pounds per plant. When irrigating, you will lead the way with the water and apply 10 kg / time · mu ferrous sulfate, plus 5 to 6 kg of fulvic acid per mu each time, a total of 2 times.
3. Re-apply decomposing organic fertilizer, with water and fertilizer integration facilities, flush with the water to apply fulvic acid. 5 to 6 catties per mu each time.
4. Due to grubs and other hazards, the root system must be eaten, causing yellowing, and in April, the root is irrigated with chlorpyrifos (fertilization gun infusion) and green (white) zombie agent, and then irrigated once every 20 days.
5. Yellowing due to root-knot nematodes and other hazards, in March to May and August to October, irrigate the roots with lilac penicillium agent once a month.
37. How is cleft disease caused? What kind of prevention?
Caused by diseases, frost damage, lack of vegetarians and fertilizer damage. Orchards where cracked skins occur, and the trunks are coated and slaughtered in September. After discovery, the entire trunk (including the crack) is coated with the rupture in time, and after a month, if it is still not healed, the crack is coated with a whisker. Pay attention to fertilization and mix with the soil. If you suspect that the fertilizer is harmful, use the root irrigation by your guide or flush with the water.
38. What is stubble disease? How to prevent it?
A: Heavy stubble disease is also known as heavy stubble replanting disorder. Refers to the planting of the same crop on the same piece of land for many years, which often causes a phenomenon of reduced yield and many diseases. Fruit trees refer to the phenomenon of digging up the senescent tree and replanting the same tree species again, with a low survival rate, and the trees planted for many years do not grow, becoming "old man trees". Some call it severe stubble disease.
Heavy stubble replanting should be prevented and controlled from several key points of harm such as guest soil, prevention (or suppression) of disease, detoxification, and fertile soil.
Specific operation:
(1) Dig out all the soil of the original tree that has been in contact with the original root system, fill the soil between the rows that have not touched the original root (guest soil), and mix the planting hole soil with 1/3 of the decomposed organic fertilizer (add 1/5 of the bacterial fertilizer) and wheat rice stone powder.
(2) The root system is planted after dipping in rooting agent. Fill the root water with 1500 times of the way (Bacillus breve diureus lateral spore), and then irrigate each one every other January, for a total of 2 to 3 times. As the root system expands, use organic fertilizer and gradually improve the soil in front of the furthest capillary roots with organic fertilizer and the way you lead the way, until the root system is all over the garden.
Cracked skin
The cracked skin (which has been cracked to xylem) is found and then coated with a decomposition recovery
After the skin is found, apply the butcher recovery