Control techniques of apple-pear tree rot and wheel dry rot in winter and spring

The low temperature in winter and spring in    may be due to poor management of apple orchards and pear orchards, which are easy to be infected with rot and wheel dry rot, both of which have fungal branch and stem diseases, which damage the epidermis of fruit trees and make them rot, branches or branches die, and in serious cases, the orchards will be wiped out.

   1. Symptoms

   apple rot is one of the most important diseases in northern apple producing areas. It mainly harms fruit trees more than six years old, weakens fruit trees, withered branches and destroys the whole orchard. Pear producing areas are also affected by rot.

   wheel dry rot is also an important disease that harms apple and pear trees. Wheel dry rot and rot are fungal branch diseases, and the incidence of damaged pear orchards is very high, up to 50%-80%. There are differences in spot depth, smell, cracking and the presence or absence of "oil skin", the size of black spots and substances on black spots, but the causes and treatment measures of these two diseases are the same. Therefore, this paper explains these two kinds of diseases together.

   II. Etiology

The main factor of   : where the tree is weak, the incidence is high. The disease was caused by some factors, such as poor site condition, poor management, insufficient fertilization, drought and lack of water, serious red spider, deciduous leaf disease and root rot, serious fruit-setting phenomenon and so on. Winter tree frostbite, injury and shearing saw mouth injury, moth bite, sunburn of branches to the sun and so on can also cause rot. Untimely scraping of disease spots and improper post-pruning of diseased branches will lead to the accumulation of a large number of bacteria and serious diseases in the orchard.

   III. Ways of transmission and invasion

The pathogen of    overwinters in the xylem of diseased bark or scar, and the disease spot produces conidia in early spring. The spores spread with wind and rain, and can also be transmitted by pests such as pear subcutaneous moth and apple moth. After germination, the pathogen invades the tree from sawing mouth, freezing wound, disease and insect injury, or leaf scar, fruit platform, fruit stalk mark, fallen cortex with dead tissue, and lurks in the bark dead and injured tissue after invasion. Cortical decay occurs when the tree or local tissue weakens and the disease resistance decreases. The incidence peaked in spring and autumn.

   IV. Prevention and control measures

   control of apple tree rot should take the cultivation of tree potential as the center, timely protection of wounds and reduction of tree body bacteria as the main preventive measures, and disease spot scraping and chemical coating as the auxiliary means.

The prevention and control techniques of    rot disease are summarized as follows: one application, two scraping, three spraying and four spraying (abbreviated as "1234 method").

  -1 application: apply organic fertilizer once after fruit harvest to cultivate tree potential

   second scraping: scraping in early spring and late autumn to treat rot spots

   three sprays: after fruit picking, 2/3 fallen leaves, 15 days before germination in early spring, spraying after flowering and postharvest to prevent infection

   four smear: apply medicine to protect the wound after pruning, dry in the growing period to promote the shedding of the fallen cortex, white the trunk before winter to prevent frost injury, and apply medicine to prevent recurrence after scraping.

   [specific operation]

   1. Drug protection during dormancy

  ① wound, cut, saw spray protection: cut and saw are the main parts of apple rot. In winter, the wounds caused by pruning, as well as all the unhealed saws and insect wounds of the previous year, should be protected by medicine in time after pruning. Aoye smear set solution smear.

  ② trunk coating: the trunk is one of the main parts of rot, and it is also the place where the epidermis and surface ulcers are produced. After scraping and treating the rot spot in winter, smear the base of the trunk and main branch with Qingye smear set meal and 30 jin of water. It can not only help to eradicate rot bacteria, but also provide nutrients for trees and enhance disease resistance. However, anti-freezing measures should be taken for shaving in winter.

   2. Control during sprouting stage

Curettage of    plaque-timely curettage of rotten plaque found in early spring and autumn. Requirements: for the disease spot that has occurred to the xylem, scraped into oval shape and stubble, according to the thickness of the stem, it is required to scrape beyond the junction of the disease spot, 1 cm horizontally and 3 cm longitudinally; for the disease spot that occurs only in the phloem, scrape off the discolored phloem tissue. And then apply the medicine. Smear potion: smear the original solution of Qingye smear package. The medicine needs to be applied 2 to 3 times in a row, with an interval of 10 to prevent recurrence of the disease spot.

   3. White tree trunks to prevent freezing

Before the soil was frozen in winter,    prepared a whitening agent: water + quicklime + salt + Kuifuling according to 3-rig-1-rig-1-0. 025, dry and antifreeze. The trunk is required to finish painting, and the main branch is painted 50 centimeters away from the trunk.

   4. Clear the Garden

   purpose: to reduce the amount of bacteria in orchard and prevent conidia transmission.

   fruit picking, fallen leaves 2/3, 15 days before early spring germination Qingyuan: Qingye Qingyuan package spray.

   pre-anthesis and post-anthesis spray prevention: Qingye nutrition package spray.

   5. Cultivate strong trees.

  ① increased application of organic fertilizer, long-term application of livestock and poultry organic fertilizer changed to high-quality compost or bio-organic fertilizer, advocated organic-inorganic combined application; according to soil fertility conditions and yield level, appropriately reduce the amount of nitrogen and phosphorus fertilizer; pay attention to the combined application of calcium, magnesium, boron and zinc.

  ② combined with high-quality and high-yield cultivation techniques such as reasonable pruning, grass mulching, film mulching, natural grass growing and ridging, controlled the annual total amount of nitrogen and phosphorus fertilizer with reference to suitable fruit retention and soil fertility index, and regulated nitrogen, phosphorus and potassium fertilizer according to tree potential and tree age.

  ③ attaches importance to the application of autumn base fertilizer, and the autumn base fertilizer of apple is applied quickly after harvest, and the application method is furrow or hole application.

   therefore, fruit growers should strengthen the management of orchards in winter and spring to protect fruit trees from rot and wheel dry rot.

How to treat pear dry rot? Control methods of dry rot of pear trees

Pear is a favorite fruit, which clears away heat, removes fire, moistens the lungs and relieves cough. And pear trees will encounter a lot of diseases and insect pests in the process of growing. Today, the editor will explain to you the prevention and control methods of pear dry rot.

Symptoms of dry rot of pear trees

It mainly harms the branches and fruits. When the branches are infected, the cortex turns brown and slightly sunken, then the diseased branches wither and die, and there are dense black-brown particles on them, that is, the conidium of the pathogen. The main stem is infected with the disease, and the primary wheel-shaped ulcer spot, which is dry for a week, leads to the death of the aboveground part. When the fruit is infected, there are ring spots on the diseased fruit, and its symptoms are similar to those of pear ring disease, so it is necessary to identify the pathogen. Seedlings and young trees are infected, and the bark is dark brown and slightly moist, resulting in wilting leaves or withering branches. In the later stage, the disease was dehydrated and sunken. Cracked all around. In mourning, there are small black dots.

Causes of dry rot disease of pear trees

The disease of branches is related to the growth of trees. tree weakness, persistent drought and insufficient soil water content can cause the rapid expansion of disease spots. Generally, the disease is more serious in areas and orchards with poor water conservancy conditions, low soil fertility and extensive management, and the disease is more serious in the same pear orchard.

Control of dry rot of pear trees

1. Timely examination and scraping of disease spots: the initial damage of the disease is generally limited to the surface, disease examination should be strengthened, timely curettage of disease spots. After curettage, use Kuifuling solution to smear.

two。 Spray protection: spray Kuaikuling 300 times liquid + organosilicon before germination to eradicate latent infection bacteria and prevent the disease.

3. Avoid causing all kinds of mechanical wounds; protect the trees with Kuifuling solution to promote healing and prevent germs from invading.

4. rational fertilization and spraying leaf fertilizer: when spraying, dodasu and Vofengsu were diluted by 1000 times and sprayed evenly on both sides of leaves to improve the ability of photosynthesis and plant disease resistance.

Harmful symptoms and control methods of apple tree rot

Apple tree rot is one of the more serious diseases in apple producing areas in China, commonly known as smelly skin disease, skin rot disease, skin rotting disease and so on. Apple tree rot is very serious in northern China, with numerous scars and incomplete branches. often cause dead trees and destroy the garden, there is a trend of aggravation in recent years, let's take a look at the prevention and control techniques of apple tree rot.

Symptoms caused by apple tree rot

The branches of diseased trees are damaged, and the disease spots can be divided into two types: ulcer and branch withering. The ulcerative part of the disease is reddish brown, watery, slightly raised, the diseased tissue is soft and rotten, often exudes yellowish-brown juice, has the smell of wine lees, shrinks and sinks in the later stage, and the disease has obvious small black spots (that is, conidia). An orange tendril emerges from the small black spot when it is wet. Branch withering type mostly occurs in branchlets, fruit platforms, dry piles and other parts, the diseased part does not show waterlogging, rapid water loss and drying up, resulting in the death of the whole branch, upper black small grain spots. The fruit is damaged, the spot is dark reddish brown, round or irregular, with wheel lines, soft rot, slightly alcoholic smell, and there are often obvious small black spots in the middle of the spot.

Transmission route of apple tree rot

Apple tree rot is mainly overwintered by mycelium, conidium and ascomycete in diseased tree tissue and remnant, and the pathogen can survive in the diseased part for about 4 years. In the following year, conidia were excreted from the conidia, which were spread by Rain Water spatter and invaded from the wound. The pathogen has the characteristic of latent infection, and it will spread when the tree or its local tissue is weak. In general, the infection began from March to May, and the disease began from July to August. The disease peaked in early spring, and the disease resistance increased and the incidence decreased sharply after late spring. The occurrence of apple tree rot is closely related to tree potential, number of wounds and callus ability. Extensive management and periodic freezing injury are the main epidemic factors.

Disease conditions of apple tree rot

The optimum temperature for the germination of conidia and ascospores of rot pathogen was 25 ~ 30 ℃, and it could germinate for a long time under the condition of 5 ℃. Extensive cultivation and management and freezing injury are the main causes of the epidemic of rot. The orchards with low soil organic matter, soil consolidation or poor water and fertility conservation, poor root growth, insufficient compound fertilizer, partial application of nitrogen fertilizer, too many results, serious years, early defoliation and so on, the disease is more serious, and vice versa. In the late low-lying orchard, the time of stagnant water in orchard is too long, the dormancy period is delayed, and the orchard is vulnerable to frost damage, and the disease is also serious. Periodic frostbite in northern China, resulting in a large area of bark frostbite, is an important reason for the widespread epidemic of rot.

Control techniques of apple tree rot

1. Strengthen cultivation and management: disease resistance of strong trees, reasonable pruning, adjustment of tree potential, adjustment of tree load, overcoming the phenomenon of big and small years, increasing application of organic fertilizer, reasonable collocation of nitrogen, phosphorus, potassium fertilizer and medium and trace elements, preventing cold of fruit trees, reducing freezing wounds, whitening fruit trees, commonly used whitening agent, lime: salt: water: animal oil (10, 1, 15, 30, 30, 35, 0.2), generally after fruit trees are defoliated. The drying height is 2 meters.

2. Timely cleaning of orchards: timely cleaning of orchards can reduce germs, scrape off diseased spots in time, remove diseased branches, stumps and diseased fruit tables when pruning, remove and burn diseased branches and dead trees in time, and seal saws and other wounds with chemicals or paints to reduce pathogens infection.

3. Medicament prevention: fungicides are sprayed before tree germination in early spring, including 500 times solution of Gerun or Schenanin water agent, 3% 5 degree stone sulfur mixture, 500 times liquid of 5% bacteriological dehydrated water agent, etc., and the above chemicals can be used to brush the big branches of the tree from June to July. Control has obvious effect for several consecutive years.

4. Treat with scar.

① curettage: extend 0.5cm around the scar and cut a protective ring deep into the xylem with a knife, then scrape off the diseased skin and healthy skin thoroughly, scrape off the diseased tissue on the plastic sheet and burn it. The exposed xylem was cut 1-1.5 cm deep with a knife and then treated with medicine. It can be smeared with Grun 5 times solution, 5% bacteriological detergent 5 times solution, and apply again 20 days after treatment.

② mud application method: make a mud cake with water and mud, apply to the scar and its periphery 5-8 cm, 3-4 cm thick, and then fasten it with plastic sheet or Kraft paper. This method should be carried out in spring, remove the bandage in the following spring, and apply disinfection protection after removing the diseased and disabled tissue.

③ foot connection: the use of foot connection (or bridge) can improve the transport capacity of the tree to nutrition and water, which is beneficial to the restoration of tree potential, and can prolong the fruiting life. This method is widely used in old fruit areas, and new fruit areas can be actively popularized.