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Symptom Identification and Control Methods of Rust Disease in Codonopsis pilosula
It damages the leaves. The diseased area on the underside of the leaf is slightly raised, forming the uredinium, which later ruptures and releases orange-yellow urediniospores. The disease is most severe from June to July. Control methods: (1) Clear away withered branches and fallen leaves in winter. (2) During the disease period, spray with a 200-fold dilution of 50% dinitro compound or a 400-fold dilution of 97% sodium dithiocarbamate, once every 7 days, for 2 to 3 consecutive applications.
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What are the control methods for the wolfberry rust mite?
The wolfberry rust mite belongs to the family Eriophyidae. Swarms of mites densely cover the leaves and suck the sap, causing the leaves to turn rust-colored and drop early. Adult mites overwinter in bark crevices, bud axils and other places. The following year, after the wolfberry leaves unfurl in mid-April, they begin their damaging activity, and they begin laying eggs in late April. Late May to late June is the peak period of reproduction. After that, because the leaves turn rust-colored and the nutritional conditions deteriorate, the number of mites drops greatly. From late July to early August, new leaves emerge and a second reproduction peak appears. In mid-September reproduction slows, and after leaf fall in October the adult mites move to
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Control Methods for Spruce-Bird Cherry Cone Rust
Spruce-bird cherry cone rust occurs in Inner Mongolia, Jilin, Heilongjiang, Sichuan, Yunnan, Tibet, Shaanxi, Gansu, Qinghai, ** and other places in China. The disease damages Picea asperata (dragon spruce), Picea purpurea (purple cone spruce), Picea likiangensis (Likiang spruce), Picea brachytyla var. complanata (oil wheat hanging spruce), Picea jezoensis (Yeddo spruce), Picea schrenkiana (Schrenk spruce), ** spruce and others. Symptoms: The disease damages the upper surface of female cone scales. Infected scales are twisted, rolled back and disorganized. On the upper surface, many purplish-brown small spheres are produced, arranged in a single layer; these are the aeciospore pustules of the pathogen. Sometimes aeciospore pustules also form on the underside of the scales.
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Wheat variety Jimai 20 can resist the new wheat stem rust fungus
Identified in Kenya through the International Maize and Wheat Improvement Center, Jimai 20 is the only wheat among China's 116 winter wheat varieties that is resistant to the new Ug99 wheat stem rust fungus. On April 12, the United Nations Food and Agriculture Organization issued a warning that a new type of wheat stem rust fungus named "Ug99" has spread from East Africa to Yemen. This new type of wheat stem rust may pose a threat to 80% of wheat varieties in Africa and Asia. Once it spreads over a large area, global food production will suffer heavy losses. Wheat stem rust is a fungal disease that affects plants
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Analysis of the Relationship Between Rusty Patches on Pear Fruit Surfaces and Pesticide Use
Irregular rust-colored patches often appear on pear fruit surfaces, affecting the appearance quality of the fruit. Fruit surface rust is generally called fruit russeting, which is formed by the gradual thickening and suberization of cell walls, with epidermal cells and the cuticle rupturing and exposing the surface, forming brown rust-colored patches. Another type of rusty patch is actually "pesticide russeting," caused by improper pesticide use or excessive pressure when spraying pesticides. There is also a type called "water russeting," mainly caused by poor environmental conditions, damp and rainy weather, insufficient light, and mold parasitizing the fruit surface. The occurrence of fruit russeting is related to many factors in cultivation. Such as variety, strain differences
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Symptoms and Control Methods of Korean Pine Blister Rust
Symptoms: The disease occurs on the bark of branches and trunks. In the early stage of infection, the affected bark swells slightly and softens, cracks begin to form in early May, and yellowish-white blister sacs, which are the rust pustules (aecia) of the pathogen, emerge from within. In early to mid-June, the rust pustules mature and turn orange-yellow. From mid-May onward, the sacs rupture and release powdery rust spores, finally leaving a membranous white covering that gradually falls away and disappears. By the end of June, most blister sacs have ruptured and dispersed; the old diseased bark becomes rough and often develops a layer of sooty mold fungi, appearing black. Because the disease occurs year after year, the bark thickens and swells, and resin flows out. In late August and September
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Symptom Identification and Control Methods of Spruce Bud Rust
Spruce bud rust is a newly discovered disease in the forest regions of northern China. It has been reported in the natural forest areas of the Greater Khingan and Lesser Khingan Mountains. Abroad, it is mainly distributed in countries such as the United States, Canada and Sweden, where it damages white spruce, black spruce and Norway spruce. It harms the terminal buds and lateral buds of seedlings, saplings and mature trees, seriously affecting seedling quality and the normal growth of plantations. Symptoms appear in late May when new leaves begin to grow. During the same period, diseased buds grow faster and longer than healthy buds, but soon stop growing. The diseased leaves growing from diseased buds
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How to prevent and control the damage of Lijuan spruce tip rust to Meijing?
Meijing tip rust is a newly discovered disease on Qinghai spruce (Picea crassifolia), mainly distributed in spruce forests at altitudes of 2600-2800 m in the eastern section of the northern slope of the Qilian Mountains in western Gansu, harming Qinghai spruce. Its harmfulness is second only to Qinghai spruce needle rust, and its onset period is about one month earlier than Qinghai spruce needle rust. Symptoms: Diseased buds of spruce sprout 10-15 d earlier than healthy buds. Starting in early June, the diseased buds swell into a conical shape, peach-red in color, with densely dotted small protrusions on the surface, which are the fungal spermogonia. New leaves emerging on the tender tips are deformed,
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Symptoms and Control Methods of Spruce Leaf Rust
Spruce leaf rust is distributed in Sichuan, Yunnan, Gansu, Qinghai, **, Taiwan, China and other places. The disease damages Picea likiangensis, Picea asperata, Picea crassifolia, Picea brachytyla var. complanata, Picea linzhiensis, Picea schrenkiana and Picea obovata, etc. Symptoms: When buds are infected, the needles on the newly grown tender shoots turn yellow or orange-yellow, short and thick; orange-yellow cushion-like telia or blister-like aecia are produced on the diseased leaves; the diseased buds resemble a yellow flower, and soon the diseased leaves turn black and die. On infected 2-year-old leaves, parts turn yellow, and blister-like aecia or orange-yellow cushion-like
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Symptom Identification and Control Methods of Spruce Rust Disease
Spruce rust disease is distributed only in the **Tianshan region. The disease has a high incidence rate, but few diseased cones. Infected cones stop growing and quickly die. Symptoms: The disease affects the scales of both female and male cones. Infected female cones are slender and small, curved, with open scales; the bracts become lanceolate, and the cones turn yellow and stop growing. The scales are small, yellow, and bear orange-red protruding telial pustules. Pathogen: The pathogen is Chrysomyxa deformans (Diet.) Jacz.
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