Rust is a relatively common and serious type of disease in flowers and landscape trees. It is distributed in many parts of the world. There are many types of rust, and in gardens, there are nearly 100 species of flowers such as Rosaceae, Leguminosae, Liliaceae, Gramineae, Pinaceae, Cyperaceae, and Willow. After morbidity, transpiration and respiration accelerate, photosynthesis is weak, growth potential is weakened, leaves yellowish off early, or cause trunk tumors, fruit malformations, etc., reduce the yield and ornamental value, even serious seedlings, causing serious losses. 1 Symptoms: The diseased plants have a large number of rust-colored spores and are named. In leaves, stems and other parts, light green spots appear first and then expand into rust-brown spots. After the rupture of the epidermis, yellow-brown powder is scattered. This is summer. Spore heap; some orange red to black heap of small powder, for the winter spores heap; also raw yellow to dark brown spots or granular, for sexual spores; there are many students pale yellow, grayish yellow to grayish brown slightly elevated Or bristles, rust, stem tumors, plexiform branches and rough skin, fruit deformity or cracking. 2 Pathogens and Life History 2.1 Pathogens Rusts are caused by rust. Rust fungi genus, basidiomycotina, rust, the common rust of infected flowers and trees are the following. 2.1.1 Puccinia Caused grass rust, lawn grass stem rust, leaf rust, stripe rust and crown rust, zoysia rust, appendix rust, chrysanthemum rust and black rust, purple rust, sunflower rust , Geranium rust and hollyhock rust and other more than 10 kinds. 2.1.2 Uromyces such as gladiolus rust, carnation rust, and purpura rust. 2.1.3 The phragmidium includes rose, rose and Chinese rose rust. 2.1.4 The genus Gymnosporangium has more than 20 kinds of rust, such as Platanus spp., Begonia spp., Malus spp. and Pyrus spp., and various cypress rusts such as cypress and Cypress. 2.1.5 The cronartium has peony, paeony rust, pine rust, red pine rust, and pine rust. 2.1.6 Coleosporium has purpura rust, Pinus koraiensis pine rust, Pinus tabulaeformis pine rust, Pinus sylvestris pine needle rust. 2.1.7 Pyricularis (phakospora) has chrysanthemum brown rust. 2.1.8 melampsora has rust of poplar, larch and poplar rust, and rust of poplar. 2.2 Life History 2.2.1 Spore Types The simplest life history of rust is teliospores (representing symbol III), and the most complicated are five types of spores, namely sexual spores (○), rust (spring) spores (I), Summer spores (II), teliospores, and spores (IV). 2.2.2 Life-history type The typical rust bacterium should undergo 5 different developmental stages in sequence and produce 5 types of spores to complete the entire development process. Some rust bacteria have mutations and lack one or more spore types. . The long (circular) life history type produces 5 kinds of spore stage type called long life history type or long cycle life history type, and in the long life history type, it can be divided into the main parasitic long life history type and single main parasitic length. There are two types of life history. In the former, the host infected after the rust spore germination was different from the host plant species of the original rust-producing sporulator, and the kinship was alienated, such as carnation rust, the ○ and I stages were parasitized on the plants of the genus Euphorbia, II and III. Stage, parasitic on Dianthus. Pine oysters, ○ and I cause pine rust on Pinus massoniana, Pinus tabulaeformis and other pine plants, perennial mycelium of the diseased part, can continue to produce rust spores in the second year, II, III and IV in the peony And peony. Pine rust fungus ○ and I on pine, II, III and IV on the genus of the Fagaceae. Each spore stage of the single main parasitic long life type is completed on the same host, such as rose rust caused by three species of rust fungus, sunflower rust caused by sunflower rust, and broad bean and pea rust caused by rust rust of faba bean. . The spore-type life cycle type was divided into two types, namely, the main and single host parasites, and the main parasitism was rust such as jellyfish, pear, and apple caused by Pear rust and Yamada rust. The occurrence of ○ and I occurred in sea otters, etc. III and IV occur in cypress trees such as cypress, Cypress, Sabina, and Juniper, producing unequal size and nodules on needles and twigs. They are called bacillary pods or teliospores, and they swell into orange gel. Things. In addition, there are short (circular) life history types, only ○, I stage, the mycelium in the diseased part of the winter, the next spring infestation of young shoots such as plum rust. Only stages III and IV, such as chrysanthemum white rust, broccoli rust, etc., all of these rusts are single host parasites. 3 Disease Epidemiology 3.1 The cycle of infection and infestation of circulating rust is relatively complicated, and different rust bacteria vary greatly. When pathogens pass through winter, some mycelium or mycelia and urelospores are found in diseased tissues such as buds, branches and leaves of replanted plants. Mycelia may survive for many years, and some may have teliospores and/or urelospores. In the litter and other diseased bodies, some of them can be overwintered in diseased and diseased tissues. The spores are born from teliospores, the spores are infested and the spores and rust spores are infested. The infestation of rust spores produces uredia spores. Winter spores. Among the five species of spores, only the rust spores, summer spores, and spores that can infect the host can be repeatedly infested by the spores, while the single-host rose rust can infect the spores and rust spores. Colleem rust due to lack of summer spores, so no reinfection, only one initial infection. Spores are mainly transmitted by the wind, but also by raindrops. After the rust spores and uredia spores germinate, they usually invade the host from stomata, and the spores can directly penetrate the host epidermis or invade from the stomata. Generally, young shoots, young leaves, and tender shoots are susceptible to infection. Transferred rusty germs, only when there is a transfer of the main plant to complete the infection cycle caused by the disease. Of the rust bacteria, only a few species such as safflower rust disease pass disease through the seeds, and most of them pass diseases such as seedlings, cuttings, and scions. Spores spread over a wide range of airflows, and the spores of Pear rust can reach about 5 kilometers. Some rust spores spread far away with high air currents of more than a thousand meters to hundreds of thousands of miles away from different natural geographical regions, different countries, and even different continents. The geographical regions span several tens of latitudes. 3.2 Epidemiological factors of diseases 3.2.1 Climatic factors Among various climatic factors, temperature, air humidity and precipitation have a greater impact on the disease. Most rust growth and development, spore germination and disease, suitable for slightly lower warm weather, generally Temperature at 10 ~ 26 °C when the onset of heavier, too high temperature will inhibit the formation of spores, survival, germination and infection, so most of the spring and autumn in China for the rust-prone period. The disease is closely related to the air humidity, and the relative humidity of the air is more than 80% for several days, especially the saturated humidity, which makes the disease serious. Spores can germinate in water droplets or in water films. It is rainy, especially on rainy days, or in dew or fog, causing disease epidemics. 3.2.2 Maintenance Management Factors Garden conservation management, that is, improvement of microclimate conditions, is conducive to the growth of garden plants, and can also enhance plant disease resistance. Species in the soil deep, loose and rich humus-rich loam flowers and plants, can reduce the incidence, and the soil is sticky, or poor sand and water retention and poor fertility on the incidence of heavy. If the planting is too dense, there is insufficient sunlight, partial nitrogen fertilizer is applied, flowers and trees are long, the nursery has long-term accumulation of water, plant growth is poor, disease resistance is weak, management is extensive, pruning is not timely, sanitation is poor in the garden, diseased branches and leaves are numerous, and pathogenic bacteria are abundant. The disease is heavy. 4 Comprehensive Prevention and Control 4.1 Eradicate and reduce bacterium source prevention and control The rust of host parasites, such as the arrangement of landscape plants in new parks, strictly isolates the ornamental plants from the main plant. For example, rust of sea otters, apples, pears, etc. must be separated from the host cypress. 5 km; Rhododendron and spruce, hemlock, aster, etc. with two needles pine, three needles, etc. can not be mixed. If it has been mixed, it is best to completely remove the main parasitic, if it is difficult to remove, should strengthen the control of the main parasitic disease. Spray prevention when spores will fly. In order to reduce the spore flying into the disease, the diseased plants will be planted on the upwind mouth of the disease-borne plant to reduce the incidence. Prevention of single-hosted rust disease, in the late autumn to early spring or plant dormant period, to thoroughly clean the leaves of the park, fruit drop and litter and other insect pests latent plant debris, the growing season often remove disease and concentrated treatment, can reduce the bacteria source. 4.2 Strengthen conservation management to improve the plant growth environment, improve disease resistance, select a suitable section before the construction of the park, improve the soil, increase soil permeability, improve soil fertility, and arrange garden irrigation and drainage systems; choose robust and disease-free branches Cutting, scioning and other clonal propagation materials, strict removal of pathogens; control of planting density, should not be too dense; timely removal of water; scientific fertilization, more decomposed organic fertilizer and phosphorus and potassium fertilizer, not partial nitrogen fertilizer; often pruning pruning, in addition to weak diseases and insects Branches, so that the park has good ventilation and light transmission; facilities cultivation to enhance ventilation and reduce indoor humidity. 4.3 Pharmacy control 4.3.1 winter application of pesticides from the end of the fall to the next year before germination, after cleaning the garden to prevent disease after the branch prevention, can spray 2 to 5 degrees lime sulfur, or 45% crystal lime sulfur 100 to 150 times liquid , Or 200 ~ 300 times sodium pentachlorophenol, or sodium pentachlorophenol plus lime mixture mixture, the first configuration of sodium pentachlorophenol plus 200 to 300 times water dilution, and then slowly poured into the lime sulfur solution, Stir thoroughly while mixing, and tune into Baume degree 2 to 3 degree liquid, do not add sodium pentachlorophenol powder without adding water to add lime sulfur to prevent precipitation. Prevention and treatment of rust on the main parasitic cypress should be sprayed 1 or 2 times in early spring in mid-March to kill the overwintering bacteria. 4.3.2 Spraying in the growing season In the initial stage of flowering trees, spray the Beauticidal 0.2 to 0.3 degree lime sulfur, 45% crystalline lime sulfur 300 to 500 times, or 70% mancozeb wettable powder 500 times, or 62.25% Xiansheng 600 times, or 500 times 80% Dasheng M-45, or 70% thiophanate-methyl 1000-fold, or 25% triadimefon 1500-fold. Newer agents for preventing and treating rust are 12.5% ​​of diniconazole 3000-4000 times, or 43% of Halonic 4000-5000 times, 25% of Fuli Library 1000-1500 times of liquid, and 25% of enemy force is 1000-4000 times of liquid. , 25% o-amylamide 1000 times, 30% love Miao 3000 times, 50% Tsuibei 3000 ~ 5000 times, 10% Shi Gao 3000 ~ 5000 times, 25% Fuxing 5000 ~ 8000 times, 50% Lei Neng Spirit 1000 ~ 2000 times liquid. 4.4 Strict Quarantine Many tree branches rust is a quarantine subject. Seedlings should be introduced from disease-free areas and clonal propagation materials such as cuttings should be collected from disease-free mother plants. 4.5 Breeding disease-resistant varieties of flowers and trees species and varieties have significant differences in the ability to resist rust. Therefore, breeding rust resistant flower and tree species is a cost-effective way to prevent and control rust.
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