Peach rot
Peach canker
Symptoms hurt tree trunks or branches. The diseased part of the branch is slightly concave, and the outside is covered with a layer of sticky glue with large particle size. The diseased skin under the sticky spot is rotten, wet, yellow-brown, and smells of distiller's grains. In the later stage, the lesion atrophied and sank, and the surface was taupe nail-headed. When the humidity is high, the reddish-brown filamentous spore horn spews out, and the diseased spot rotates around the stem and branch, forming a ring cutting phenomenon, and the diseased tree or the whole branch dies. The disease is similar to apple rot, but it is dark in color and reddish brown in spore angle, which is the characteristic of peach rot. This disease is also a very harmful disease.
The main pathogen is the black rot shell of Japanese rot fungus. ) Fr, all belong to the class Ascomycetes. Japanese black rot shells are dominant in Northeast China, and black rot shells of drupes are reported in North China, Northwest China, East China and Southwest China. The asexual form of Leuconostoc albicans is Leuconostoc albicans Sacc. It's called Sclerotinia sclerotiorum, and it belongs to the half-knowledge bacteria. Ascomycetes are oblate, spherical or irregular, with a long neck, embedded in the matrix, rod-shaped to spindle-shaped, colorless and transparent, with a thick top and a size of 25 ~ 30× 5 ~ 7.2 (micron). There are 8 ascospores in the ascus, which are arranged in a double row. Ascomycetes are banana-shaped and single-celled in color, with a size of 7.2 ~ 7.5× 1.9 (micron). There are also several conidia in the pedestal, and each conidia consists of a plurality of chambers divided irregularly, and a hole with the same orifice extends out of the peach skin. The conidia wall is dark brown, and many colorless and slender conidia cells are densely distributed on the inner wall. The conidia at the top of conidia are banana-shaped and colorless, and the size is 3.9 ~ 5.8×1.2 ~1.5 (micron). This fungus will not only harm peaches, but also other stone fruit trees, such as plums, apricots and cherries. V. japonica is large, for example, the cortex of the host branch is thin, and the matrix in the cortex is raised like steamed bread. When the weather is wet, the tendril-like spore angle is light brown to brown, and the ascomycetes, ascomycetes and ascospores are larger. Asexual conidia are obviously divided into several chambers, which are different from the black rot shell of drupe.
Transmission route, onset conditions and prevention methods The pathogen of the disease is a weak parasitic bacterium that invades from wounds or natural orifices. The optimum growth temperature of the pathogen is 28 ~ 32℃. The onset began in March-April, peaked in May-June, and the high temperature stopped expanding in summer. Frostbite is often an important cause of peach rot. There will be serious freezing damage. Please refer to apple tree rot for prevention and control methods, but it should be noted that the wounds caused by peach trees during the growth period are not only difficult to heal, but also easy to flow glue. Therefore, after curettage, you must apply wound protectant. After scraping, it can be disinfected with 30 times of 45% crystal stone sulfur mixture solution, and then covered with stone sulfur mixture slag for protection. You can also use 1: 05: 100 times bordeaux solution or 40% bordeaux fine wettable powder 1000 times solution for disinfection and protection.
Peach rot
Peach tree wood rot
Symptoms peach rot is also called heart rot. It mainly harms the branches and heartwood of peach trees, making the heartwood rotten and ring-shaped. The xylem of infected trees turns white and loose, becomes soft and brittle, and decays and becomes brittle. Gray pathogen fruiting bodies grow on the surface of the disease area, mostly from saws, and a few from wounds or insect mouths. Each plant has 1 to dozens of pathogen fruiting bodies. The base of branches is seriously damaged, which often leads to weak trees, yellow leaves or premature defoliation, resulting in reduced production or no fruit.
Pathogen Porphyra fusca (Scop). ) gills, also known as Phellinus igniarius, belong to basidiomycetes. The fruiting body is horseshoe-shaped or round-headed, the cap wood is hard, the surface is smooth at the beginning, and cracks appear after aging. At first, it is yellowish brown to grayish brown, then it is dark brown or light dark brown, and the edge is blunt and round and hairy. The pith is yellowish brown. The bacteria tube is round or polygonal, with a small nozzle, a diameter of 80 ~ 220 (microns) and a grayish brown wall thickness. The basidiospores are arranged in rows, and four basidiospores are terminal. The basidiospores are spherical and colorless, with a size of 4.4 ~ 5.8× 4.4 (micron). Mesenchyma is spindle-shaped, mixed in the seed layer, with dark brown base and light color at the end, and its size is11.6 ~14.5× 5.8 (micron). The growth temperature of the pathogen is 30 ~ 33℃, and the growth and development stop when it is lower than 14℃ or higher than 40℃. This fungus can not only harm peach trees, but also apricot and plum trees.
Transmission routes and pathogenic conditions Pathogenic bacteria produce fruiting bodies or basidiospores in the diseased parts of damaged branches. When conditions are suitable, spores mature, spread by wind and rain, and invade through saws and wounds.
Prevention and cure method
(1) Strengthen the management of peaches, apricots and plum orchards, and dig out dead and weak old trees and burn them as soon as possible. For peach trees with weak tree vigor and high tree age, formula fertilization technology should be adopted to restore tree vigor and enhance disease resistance.
(2) When the diseased trees grow fruiting bodies, they should be cut off immediately, burned centrally and disinfected with 1% copper sulfate.
(3) Protecting the trees and doing everything possible to reduce the wounds are important measures to prevent the occurrence and spread of wood rot. After the kerf is disinfected with the above copper sulfate, it can be coated with Bordeaux pulp or 40% Bordeaux essence or coal tar for protection, so as to promote wound healing and reduce bacterial infection.
Peach root rot
Fusarium root rot of peach
The root rot of peach trees mostly occurs in April-May after germination, and the rate of diseased trees in peach gardens is as high as 30%, and the disease is serious.
Symptoms are mainly root injury, and symptoms begin to appear in the upper part of the back ground. After the apple tree germinated in early spring, the fibrous roots turned brown and died, and then gradually spread to the fleshy roots and big roots connected with the fibrous roots, forming reddish-brown slightly concave small round spots around the fibrous roots. With the spread of the disease, the lesion expanded and connected to xylem, which made the whole root black and died. In the whole process of onset, the root of the disease repeatedly produces callus and regenerates new roots, so the diseased tissues are staggered or the diseased parts are uneven. Apple trees have four symptoms after the leaves are unfolded in April and May: one is wilting. After the diseased plant germinates, the whole plant or some branches are weak, it is difficult to sprout new buds, the leaves are wilted, the leaves are curled, the shape is small and light, the buds cannot shrink or do not set fruit after flowering, the branches are dehydrated, the surface shrinks or dies, and sometimes they become oily skin, especially around the buds. Generally, trees that have been ill for many years and are weak belong to this type. The second type is green dry type. In spring drought or high temperature, the leaves of diseased plants suddenly lose water and wither, mostly extending inward from the leaf margin or outward along the main vein, with obvious reddish-brown halo at the junction of diseased plants and healthy plants. In severe cases, the green leaves fall off. Third, the leaf edge is burnt. For plants with slow disease development, when there is no drought in spring, only the tip and edge of leaves are scorched, while the middle part remains normal and leaves generally do not fall off. The fourth type is the dead branch type. The root rot of the diseased plant is serious, which is a special symptom that the big root has rotted to the root neck. The main branch corresponding to the underground rotten roots partially died, the cortex turned brown and sunken, and the boundary of the lesion site of the cortex was obvious, and it expanded downward along one side of the branch. In the later stage, the necrotic cortex is easy to crack and fall off, and there are no small black spots on it. The xylem vessel turns brown and is always connected with the brown vessel in the underground rotten root.
Pathogens are caused by various Fusarium infections. Mainly: Fusarium solani (mart. )app。 et wollenw。 It's called saprophytic Fusarium. Fusarium oxysporum is called Fusarium oxysporum; Kantokras Warren. It's called Fusarium Curvularia. All belong to fungi with little knowledge.
F.solani on PDA medium, the front is pure white and the back is pink. The megaspore is caught at both ends, wide in the middle and curved in shape. There are 3 ~ 9 septa, and the size of the megaspore of the three septa is 30.0 ~ 50.0× 5.0 ~ 7.5 (micron). 5 megaspores with septa are 32.50 ~ 51.25× 5.0 ~10.0 (micron). The microspores are oblong to ovoid, unicellular or bicellular, and the size of single-celled microspores is 7.5 ~ 22.5× 3.0 ~ 7.5 (micron). The size of microspore is 65438 02.5 ~ 25.0× 3.75 ~ 7.50 (micron). The width of mycelium is 2.5 ~ 7.5 (micron). Fusarium oxysporum on PDA medium, the front is white and the back is rose. The megaspore is sharp at both ends, with obvious podocytes, curved at both ends and straight in the middle, with 3-4 septa, and the size is19-50× 2.5-5 (micron). Microspores are ovoid to ovoid, single cell, and the size is 3.75 ~12.5× 2.25 ~ 5.00 (micron). The width of mycelium is 2.5 ~ 5.0 (micron). On PDA medium, the front of the colony is white and the back is bronze purple. Large spores need long-term culture to produce a small amount. Most of them are upright, but a few are slightly curved. They are rectangular, round at the bottom and pointed at the top. The maximum width is 2/5 from the base, with 1 ~ 3 septa and no podocytes. The size of trispora is 17.50 ~ 28.75× 4.50 ~ 5.00 (micron). Microspores are easy to produce, oblong to oval, single-celled or bicellular, and the size of single-celled spores is 6.25 ~ 12.50× 2.5 ~ 4.0 (micron); The size of the two spores is11.25 ~17.50× 3.25 ~ 5.00 (micron). The width of mycelium is 2.50 ~ 5.60 (micron).
Transmission route and pathogenic conditions All three Fusarium species are soil residents or semi-residents, and can grow saprophytes in soil for a long time. When the roots of apple trees become weak, germs will invade the roots and get sick. Orchard soil is sticky and hard, with heavy salinity, long-term drought and lack of fertilizer, serious soil erosion, serious annual phenomenon and improper orchard management.
Prevention and cure method
(1) Strengthen cultivation management, strengthen tree vigor and improve disease resistance. Improve the irrigation and drainage facilities in the orchard, so as to water in drought and drain in waterlogging; Improve soil structure to prevent soil erosion, and orchards with conditions can be deeply ploughed. In the growing season, timely intertillage weeding and moisturizing; Prune reasonably, adjust the fruit yield of trees, and control the age; Orchards with poor fertility should use a variety of green manure and adopt formula fertilization technology to increase the application amount of potassium fertilizer. The general fertilization rate should be 350g pure nitrogen, 350g pure phosphorus 150g and 350g potassium per 50kg fruit.
(2) root irrigation with chemicals. In early spring or late summer, according to the size of the tree, dig 3-5 radiation ditches with a depth of 70cm and a length of 30-45 cm depending on the periphery of the crown. If necessary, water 600 times suspension of 40% quintozene powder or 50% thiophanate methyl? 1 0,000 times of sulfur suspension, 250 times of 80% sodium pentachlorophenol, 1 0,000 times of 40% formaldehyde, 1 0,200 times of 20% methylprednisolone EC and 25% benomyl? Zinc hexachloride EC 800 times solution. Cover the soil after application.
(3) Treating diseased trees. In spring and autumn, the roots can be removed, which can be dried to large roots, scraped or cut off the roots. Avoid watering or sprinkling water into the tree hole when drying the roots, and dry for 7 ~ 10 days. After scraping the diseased spots, irrigate the roots with Bordeaux pulp or Pomei 5-degree stone sulfur mixture or 45% crystal stone sulfur mixture for 30 times. You can also apply 50% carbendazim or 50% Likujing wettable powder to the wound for 300 times, and the effect is good.
Peach purple feather disease
Root rot of tree violet
The symptoms of purple feather disease, also known as purple root rot, mainly harm the roots. Fine roots appear first, and then gradually spread to lateral roots and main roots until the base of the trunk. At the early stage of the disease, the roots are yellow-brown amorphous patches, the appearance color becomes darker, and the cortical tissue turns brown. Many lilac cotton wadding, i.e. pathogen hyphae and funicles, are feathery and gradually become dark purple fluffy hyphae, covering the whole diseased root and extending to the soil surface outside the root. In the later stage, purplish-red hemispherical sclerotia, with the size of 1 ~ 2 mm, was produced on the root of the disease, and the cortex of the root of the disease was easy to rot and fall off, and the xylem was decayed in the later stage. From June to July, a tiny powdery solid layer is produced on the mycelium. The diseased plants grow weakly on the ground, the leaves become smaller, the color becomes lighter, the internodes of branches become shorter or some branches dry up. Petiole and midvein of susceptible varieties turn red. The disease spread slowly and gradually weakened and died after a few years.
The pathogen is Heliobasidium mompatanaka. Synonym: h? Purple soil. Also known as Trichosporon mori and Trichosporon purpurea, they belong to basidiomycetes. The purple-black velvet attached to the root of the disease is the mycelium layer. It consists of five layers, the outer layer is a solid layer, and there is a burden on it. The basidium is cylindrical and colorless, and consists of four cells, the size of which is 25 ~ 40× 6 ~ 7 (microns), and it bends to one side. Then a small stalk, colorless and conical, with a size of 5 ~ 15× 3 ~ 4.5 (micron) extends from each cell. Basidiospores are colorless, single-celled, ovoid, round at the top, and sharp at the base, with the size of 16 ~ 19× 6 ~ 6.4 (micron), which are mostly formed in rainy season.
The transmission route and pathogenic conditions are that hyphae, strains and sclerotia overwinter on the diseased roots or in the soil. Under suitable conditions, mycelia can be produced by funiculus and sclerotia. The hyphae gather to form hyphae bundles, which extend on the soil surface or in the soil and directly invade the host root system. Generally, the bacteria first infect the soft tissue of the new root and then spread to the big root. The contact between diseased roots and healthy roots is an important way to spread and spread diseases. Although bacteria can produce spores, their life span is short. The chance of infection after germination is small, so the spores of the pathogen have little effect on the spread of the disease. The peak incidence is mostly in July-September.
Low-lying and wet orchards with stagnant water are seriously ill. Robinia pseudoacacia is the main vector of the disease, and apple trees near Robinia pseudoacacia are prone to disease.
Control method (1) was used to select disease-free seedlings. Pathogens can spread with seedlings over a long distance, so strict inspection should be carried out during seedling raising and transportation, diseased seedlings should be eliminated and healthy seedlings should be disinfected. For disinfection of seedlings, 50% thiophanate methyl or 50% carbendazim wettable powder 800 ~ 1000 times solution and 0.5 ~ 1% copper sulfate solution can be used to soak seedlings 10 ~ 20 minutes. (2) Isolation and prevention. Digging a deep ditch 1 m at the periphery of a diseased area or a diseased tree can isolate or block the spread of sclerotia, funiculus and diseased roots. Sophora japonica is an important host of the pathogen, which can enter the orchard with the roots of Robinia pseudoacacia, so Robinia pseudoacacia should not be used as a shelter forest as far as possible. The orchard with Robinia pseudoacacia as protective belt should be isolated by digging ditches. Prevent roots from invading the orchard. The roots of Robinia pseudoacacia that have invaded the orchard should be thoroughly dug up to avoid the spread of germs. (3) Strengthen orchard management. Pay attention to drainage, apply more organic fertilizer, improve soil, prune flowers and fruits reasonably, adjust the load of fruit trees, strengthen the prevention and control of other pests and diseases, and enhance the disease resistance of trees. (4) chemical control. For lightly diseased trees, dig up the rhizosphere soil, find out the diseased part and carefully remove the diseased root, then disinfect the wound with 400-500 times of 50% amobam aqueous solution or 1% copper sulfate, and then apply the protective agent Bordeaux solution. You can also use 20% limewater or 2.5% ferrous sulfate, 150 ~ 300 times of 50% mancozeb aqueous solution, 1000 times of 20% triadimefon emulsifiable concentrate, 900 times of 50% likujing wettable powder and 1000 times of 50% mirex water-soluble. After being buried in the pure land, the effect is good.
Agrobacterium tumefaciens
Peach crown gall
Symptoms: There are tumors of different sizes on the roots or branches of peach trees. Colostrum is white or reddish, smooth and soft, spherical to oblate, and becomes irregular after fusion, and then gradually changes from brown to dark brown, with rough and uneven surface, hard lignification, and later part turns dark brown, forming irregular cavities.
Morphological and biochemical characteristics of the pathogen, Agrobacterium tumefaciens Conn, were revealed in apple root cancer.
Transmission route and pathogenic conditions: the strain overwinters in soil and cortex of diseased tumor tissue, and its survival time is less than 2 years. If the pathogen leaves the host tissue and enters the soil, the survival time is short. Germs are mainly spread through rainwater, irrigation water, grafting tools, machine tools and underground pests. It can also spread. The main way of long-distance transmission is seedling transportation. Bacteria invade from wounds, such as insect injury and mechanical injury. The incubation period is several weeks to more than 1 year. When the pH value is 6.2 ~ 8.0, the pathogenic bacteria remain pathogenic, and alkaline soil with pH value greater than 7 is more conducive to the occurrence of diseases. Cohesive and poorly drained soil is more serious than loose and well drained sandy loam. The more root injuries, the more serious the disease. Splitting is generally more serious than bud grafting.
The control method (1) was strictly quarantined, and all the infected seedlings were found to be burned. Suspicious seedlings with asymptomatic growth near the nursery should be disinfected before planting. Methods The seedlings were soaked in 0. 1% potassium permanganate or 1% copper sulfate solution for 0. 10 minute, then washed with clear water or soaked in 0.000 1% ~ 0.0002% streptomycin for 20 ~ 30 minutes, and then planted. (2) Choose an area not infected with root cancer, with loose soil and good drainage, and avoid saline-alkali land. If infected with germs, pick up the residual roots in the soil after emergence, rotate them with crops and tree species that are not susceptible to diseases, and apply 75 ~ 225 kg/ha ferrous sulfate or sulfur powder for disinfection. (3) When peach trees are grafted, the scion is taken from the higher part of the improved mother tree, and bud grafting is adopted, and split grafting is not adopted as far as possible. The grafting tools were soaked in 75% alcohol for disinfection. Pay attention to cold and antifreeze, prevent underground pests, and avoid all kinds of wounds in seedlings when working in the field. (4) For rare species, the unruptured tumor can be removed with a sharp knife at the early stage of the disease, and the wound is disinfected with 50 times of 1% copper sulfate and 80%402 antibacterial emulsion, and then protected with Bordeaux solution.
peach bacterial shot hole
peach bacterial shot hole
Symptoms mainly harm leaves and can also infect fruits and branches. When the leaves are infected, light brown water stains begin to appear on the back of the leaves near the veins, and also appear on the back of the leaves, mostly scattered at the tip or edge of the leaves. After enlargement, the lesion becomes a purplish brown to dark brown round or irregular lesion with keratinization at the edge and a diameter of about 2mm, and there is a layer of waterlogged yellow-green halo around the lesion. Finally, the lesion dried up, a circle of cracks appeared at the junction of the lesion, and the central tissue of the lesion fell off to form perforations. Sometimes several diseased spots are connected together to form a large spot, and after burning, a large perforation is formed with irregular edges. The fruit is infected, which is a small round spot with brown waterlogging at first, and then expands to dark purple, with a slightly concave center and waterlogged edges. When the weather is wet, yellow and white mucus secretions often appear on the lesion; When drying, small cracks often appear on or around the diseased spots, and in severe cases, large irregular cracks appear, which are easily infected by other germs and cause fruit rot. But the disease is limited to the fruit epidermis, forming a painted face. When branches are infected, two different forms of disease spots are formed, namely, spring ulcer spots and summer ulcer spots. In the summer before 1 year, when the first batch of new leaves appeared, dark brown water-stained small herpes blocks were formed on the branches, with a diameter of about 2mm, and then extended to 1 ~ 10 (cm), but the width did not exceed12 of the branch diameter, which sometimes caused dead branches. At the end of spring, the epidermis of the diseased spot broke, and the bacteria overflowed and began to spread. There are more ulcer spots in summer than in the end of summer. In that year, waterlogged purple-brown spots were produced on the tender branches, which were round or oval with a slightly concave center, and the diseased spots were mostly centered on lenticels. Finally, the ulcer after longitudinal cortical fissure. The focus of ulcer in summer is not easy to expand, but when the focus grows, it can also make the branches die.
Xanthomonas campestris. Prugni dye synonym: Xanthomonas Prugni. Xanthomonas campestris var. Prugni is a kind of bacteria. The thallus is short rod-shaped, the size is 0.3 ~ 0.8× 0.8 ~ 1. 1 (micron), the two ends are round, the flagella is extremely simple, there is no blastocyst or capsule, and Gram staining is negative. The optimum temperature for pathogen development is 24 ~ 28℃, the highest is 38℃, the lowest is 7℃, and the lethal temperature is 565438 0℃. The pathogen can survive for 10 ~ 13 days under dry conditions and for more than 1 year in branched ulcer tissues.
Transmission route and pathogenic conditions: the pathogen overwinters in the damaged branches, and the pathogen begins to move in the diseased tissues in the following spring. Before and after peach blossom, the pathogen overflowed from diseased tissues, spread by wind and rain or insects, and invaded through stomata of leaves, bud marks of branches and lenticels of fruits. The incubation period is 7- 14 days. Spring ulcer is the main source of infection of this disease. In summer, with high temperature and low humidity, ulcer spots are easy to dry and surrounding healthy tissues are easy to heal. Therefore, the bacteria in the ulcer spot died after 10 ~ 13 days under dry conditions. The air temperature 19 ~ 28℃ and relative humidity 70 ~ 90% are beneficial to the disease. The disease usually occurs in May, and it is serious in July and August.
The occurrence of the disease is related to climate, tree potential, management level and variety. Appropriate temperature, frequent or foggy rainfall and foggy season are conducive to bacterial reproduction and infection, and the disease is serious. Bacteria are easily washed to the ground in heavy rain, which is not conducive to their reproduction and infection. Generally speaking, the disease spreads rapidly in the spring and autumn rainy season and slowly in the summer dry month. The incubation period of the disease is related to temperature: the incubation period is 4-5 days at 25-26℃ and 9 days at 20℃, 19℃ and 16℃. When the tree is strong, the disease is light and late, and when the tree is weak, the disease is serious early. The incubation period of diseases with strong tree potential is as long as 40 days. Orchard is low-lying, poor drainage, poor ventilation and light transmission, and the incidence of partial application of nitrogen fertilizer is serious. The diseases of early-maturing varieties are mild, while those of late-maturing varieties are severe.
The control method (1) strengthens the management of the peach garden and strengthens the tree potential. Pay attention to drainage, apply more organic fertilizer, avoid partial application of nitrogen fertilizer, and prune reasonably, so as to make the peach garden ventilated and transparent, enhance the tree vigor and improve the disease resistance of the tree. (2) remove the overwintering bacteria source. Combined with winter pruning, pruning diseased branches, removing fallen leaves and centralized burning. (3) Spray protection. Before germination, spray 30 times Baume sulfur mixture or 45% crystal sulfur mixture or 1: 1: 100 times Bordeaux solution and 400-500 times 30% Ludebao suspension. Spraying 72% agricultural streptomycin soluble powder 3000 times solution or streptomycin sulfate 4000 times solution or engine oil emulsion: mancozeb: water = 10: 1: 500 after germination is not only effective for bacterial perforation, but also can control aphids, scale insects, spider mites and so on. In addition, lime solution (0.5kg zinc sulfate, 2kg hydrated lime, water 120kg) in sulfuric acid bowl can be selected, once every half month, and sprayed for 2 ~ 3 times. (4) Before planting peach trees in the shed, apply organic fertilizer, prune them reasonably, cut off diseased branches on the trees, sweep off diseased leaves, burn them centrally, spray lime-sulfur mixture with 3 ~ 5 degrees Pomei on the trees, and pay attention to controlling humidity after buckling the shed to make them well ventilated. Spraying 72% or 68% agricultural streptomycin soluble powder 3000 times or 95% engine oil emulsion 10 part: 50% mancozeb wettable powder 1 part: 500 parts of water, and spraying 2-3 times every 15 days can control aphids and spider mites at the same time.