-
What causes jujube witches' broom disease?
Jujube witches' broom is a devastating disease of jujube trees. After a jujube tree is infected, it shows the following abnormal phenomena: 1. Floral organs revert to a primitive state, the flower stalk lengthens to 3-6 times that of a normal flower, and the sepals, petals, stamens and pistils grow abnormally, becoming light green small leaves. On diseased trees with stronger vigor, thin, short, small branches may also sprout from the leaf axils of the small leaves, forming clusters of branches. 2. The main and secondary buds of the developing branches and the fruiting mother branches sprout and grow multiple times a year, continuously producing thin, small, yellow-green branches and leaves that form dense clusters of branches, which do not easily fall off in winter. 3. On the branches and trunk of the whole tree, the originally dormant
-
Kissing gourami pinecone disease is a common illness.
Pinecone disease (pinecone-scale disease): the scales of the sick fish stand up like a pinecone. Treatment methods: A. Soak the sick fish in a tetracycline aqueous solution at a concentration of 1 unit per 50,000, bathing twice a day for one hour each time. B. Mix a 2% sodium chloride solution with a 3% sodium bicarbonate solution, and give the sick fish a medicinal bath twice a day for 10 minutes each time. C. Add 0.5 g of chloramphenicol per 40 kg of water for soaking.
-
Prevention and Treatment of Fulminant Hemorrhagic Disease in Silver Carp and Bighead Carp in Hill Ponds and Reservoirs
In 2005, a large-scale die-off of silver carp and bighead carp occurred in the Mianhuatan Reservoir, affecting 200 mu with a mortality rate of 70%. The disease was prone to recurrence and difficult to control, and was diagnosed as fulminant hemorrhagic disease of silver carp and bighead carp. This disease is highly harmful, and fish farmers should attach great importance to it. I. Epidemic situation: The disease readily becomes epidemic from March to May and from August to October each year, with mortality during outbreaks reaching as high as 70-90%. II. Symptoms: "Dark floating head" often occurs, initially at
-
Symptoms and Control Methods of Potato Wart Disease
[Pathogen scientific name] Synchytrium endobioticum (Schilb.) Percival [Host crops] Potato, tomato, black nightshade, etc. [Disease diagnosis] It mainly damages the underground parts of the plant, occurring commonly on tubers and stolons. On the eyes of infected tubers and on stolons, because the pathogen stimulates continuous cell division, tumors of varying size, irregular shape and rough, protruding surface form, resembling cauliflower. The surface of affected tubers often cracks. The wart tissue is yellow-white in the early stage, the part exposed above the soil surface turns green, and later turns dark brown. The tissue is soft, prone to rotting and produces a foul odor, with brown slimy matter. During storage, diseased tubers can still develop, even causing the whole storage cellar to rot. Diseased tubers turn black and give off a foul odor; after prolonged boiling they do not soften easily and are difficult to eat. When the aboveground parts are affected, the appearance does not differ noticeably from healthy plants, but in the later stage diseased plants are taller than healthy ones, remain green longer than healthy plants, have more branches and bear more berries. On severely diseased plants, stems, leaves and flowers can all be affected, forming wart lesions or deformities. The causal agent is the endobiotic chytrid fungus. The pathogen is endoparasitic and does not produce hyphae; the vegetative thallus is initially a naked, wall-less protoplast (amoeboid body), and later becomes a walled unicellular thallus. In the reproductive growth stage, the unicellular thallus transforms into a resting sporangium sorus. The sporangium sorus is nearly spherical and contains 4 to 9 sporangia. The sporangia are spherical, rust-brown, and on germination produce zoospores. The zoospores have a single flagellum and are spherical to pear-shaped. Some zoospores mate to form zygotes. The zygote resembles a zoospore and has two flagella; both can infect the host.
-
What are the prevention and control methods for fish diseases and enemies?
1. Blue-green algae disease: Blue-green algae include Microcystis aeruginosa and Microcystis flos-aquae. They generally occur in summer and early autumn, and they like to grow in water with higher temperatures and relatively strong alkalinity. When the pH is 8-9.5 and the water temperature is 28°C-32°C, they reproduce fastest. If there are more than 500,000 colonies per liter of water, the dissolved oxygen in the water is often insufficient for their needs, and they will die in large numbers on their own. After the algal bodies die, proteins decompose easily, producing toxic substances such as hydroxylamine and hydrogen sulfide. When these toxins accumulate in the water, they can not only poison fish to death, but even cattle and sheep that drink this
-
How to prevent fish fulminant hemorrhagic disease? Introduction to practical methods
In autumn, as fish grow rapidly, pond farming density increases, water quality is prone to deterioration, and the reproduction rate of various pathogenic pathogens accelerates, making it very easy to trigger fulminant hemorrhagic disease. The preventive measures are as follows: 1. Before the fry and fingerlings are put into the pond, they must be soaked and disinfected with 1%-2% salt water. The soaking time depends on the fish's physique and the temperature. When conditions permit, fish fingerlings can be soaked with fulminant hemorrhagic disease vaccine. 2. Change water and increase oxygen in a timely manner. Keep the water quality fresh and change the water frequently. If conditions limit water changes and it is inconvenient, quicklime can be slaked into slurry and splashed over the whole pond, and at the same time, aerators should be used reasonably.
-
Symptoms and Control Methods of Potato Viral Diseases
(1) Pathogens and Infection. The pathogenic viruses that can infect potatoes and cause losses include Potato virus X, Potato virus Y and several others. Potato mosaic virus (PVX) is a filamentous virus with a length of 520-550 nm; sometimes the central hole of the virus particle can be seen under the electron microscope. When the viral coat is formed by subunits, its cross-striations can be seen, and this is the main difference in morphological structure between it and Potato virus Y. Potato virus Y (PVY) is a filamentous virus with a length of 680-900
-
What are the control methods for potato virus diseases?
Potato virus disease is a major disease of potatoes. According to symptom manifestations, potato virus diseases are often divided into two major categories: potato mosaic disease and potato leafroll disease. In most areas of our province, potato mosaic disease is the predominant occurrence, generally reducing potato yield by 20%-50%, and by more than 80% in severe cases. Symptoms Common mosaic disease: after the plant is infected, growth is normal, leaves are flat, but there is mild mosaic between the veins, manifested as uneven shades of leaf flesh color. Light mosaic with alternating yellow and green is easily seen on the leaves. In some varieties
-
Symptoms and Control Methods of Swim Bladder Fungal Disease
The pathogen is Phoma herbarum, belonging to the subdivision Deuteromycotina, class Coelomycetes. Its hyphae are branched and septate, about 50 micrometers to 100 micrometers long and 2 micrometers to 3 micrometers wide. New cultures on Sabouraud agar are light yellow, gradually turning light pink and finally black as the fungus ages, producing pycnidia, from which colorless, transparent conidia are generated. Symptoms: Affected fish are mostly fry and fingerlings. Diseased fish lose balance when swimming, the anus swells, the fins bleed, and the skin is damaged. In the early stage, only the swim bladder is damaged, with some white
-
Recommendations for the Occurrence and Control of Pests and Diseases in Winter Potatoes
In recent years, the potato planting area in our city has been continuously expanding, and various potato pests and diseases have been occurring in succession, seriously affecting potato yield and quality. It is currently the potato growing season. According to recent surveys conducted by our station and the Huidong station in Tieyong, Renshan and other places, the main pests and diseases occurring in winter potatoes in our city include: potato bacterial wilt, blackleg, late blight, viral diseases, as well as underground pests and aphids. All localities should strengthen surveys, and in particular, do a good job in controlling soil-borne diseases of potatoes. I. Occurrence of Pests and Diseases
条件筛选