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Control Methods for Stem Rot in Sweet Potato Cultivation
Sweet potato stem rot, also known as sweet potato wilt, fusarium wilt, stem blight, etc. [Pathogen scientific name] Fusarium bulbigenum Cke. et Mass. Var. botatas Wollenw. [Host crops] Sweet potato and other Convolvulaceae plants. [Disease diagnosis] Diseased seedlings show swollen, bluish roots, with the vascular bundles turning brown and the upper parts turning yellow and thin. When mature plants are affected, the diseased plants are stunted, with swelling at the stem base and a bluish halo on the surface. When the diseased part is cut open, the vascular bundles can be seen to have turned brown after infection, extending upward from the stem base for 20 to 30 cm. Apart from a few green leaves at the top, all other leaves of the diseased plant turn yellow, and the lower old leaves successively wither and drop off. In the later stage, the cortex of the diseased part cracks, appearing fibrous, and pink mold-like growth appears on the surface. When storage roots are affected, the root end becomes rotten, and a cross-section of the discolored vascular bundle area in the upper part of the diseased root shows dark brown ring-shaped spots. The pathogenic fungus is Fusarium oxysporum f. sp. batatas. Macroconidia are sickle-shaped, with slightly pointed apical cells and slightly curved tips on the end cells, having 3 to 5 septa. Microconidia are single-celled, oval to elliptical. Chlamydospores are brown and spherical.</p><p>[Disease occurrence pattern] The pathogen overwinters as mycelium and chlamydospores in diseased storage roots or attached to diseased residues in the soil. The pathogen can also survive in the soil in a saprophytic state. The pathogen mostly invades through wounds and spreads along the vascular bundles. The cut end of transplanted seedlings is the most important invasion site, and wounds on roots and leaf scars can also allow invasion. The pathogen can also invade poorly growing seedlings. The disease can spread over long distances through diseased storage roots and diseased seedlings, and over short distances mainly through soil, flowing water, and farm tools. A soil temperature of 27 to 30°C and high soil moisture favor disease development. Frequent rainfall and large amounts of rain often cause severe outbreaks of the disease.</p><p>[Control measures] (1) Select disease-resistant varieties, such as Chaoshanbai, Nanjing 92, Jinshan 247, Taichengshu, Nanruishao, Jinqing No. 9, Xuzhou 18, etc. (2) Select disease-free seed storage roots and raise seedlings in disease-free soil. (3) Before planting, soak the sweet potato seedlings in 0.2% "401" antimicrobial agent for 10 minutes for disinfection. (4) Apply fully decomposed manure. Irrigate appropriately and drain field water promptly after rain. (5) In heavily infested plots, carry out crop rotation with grain crops for more than 3 years; rotation with rice for 1 year can already be effective. (6) Remove diseased plants promptly when found and burn them in a centralized manner or bury them deeply. (7) In the early stage of disease, spray promptly with 30% Luyedan wettable powder at 800 times dilution, or 50% benomyl wettable powder at 1500 times dilution, or 40% Shuangxiaoling aqueous solution at 800 times dilution, or 50% thiophanate-methyl wettable powder at 500 times dilution. </p>
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What are the control methods for sweet potato violet root rot?
Sweet potato violet root rot, commonly known as "red vein net," "retained skin," etc. [Pathogen scientific name] Helicobasidium mompa Tanaka [Host crops] Sweet potato, potato, soybean, peanut, cotton, mulberry, tea, fruit trees, forest trees, etc. [Disease diagnosis] It damages the tubers and underground stems
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Control Methods for Sweet Potato Wrinkle Mosaic Disease
Sweet potato wrinkle mosaic disease, also known as sweet potato latent virus disease. [Virus English name] Sweet potato latent virus, abbreviated SPLV. [Host crops] Sweet potato, Convolvulaceae, Chenopodiaceae, and some Solanaceae crops. [Disease diagnosis] During the seedling-raising period, diseased seed potatoes sprout in greater numbers than healthy potatoes
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What are the control methods for sweet potato stem nematode disease?
Sweet potato stem nematode disease, commonly known as "chaff heart disease." [Pathogen nematode scientific name] Ditylenchus destrutor Thorne. [Host crops] Sweet potato, potato, lily, ginseng, mint, Angelica sinensis, etc. [Disease diagnosis] It mainly damages the tuberous roots, followed by the stems and vines. Tuberous roots affected
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What are the control methods for sweet potato weevil
The sweet potato weevil is also called the sweet potato ant-weevil; in Guangdong it is called shazi bug or shala bug, and it is one of the main pests harming sweet potatoes. In autumn sweet potatoes cultivated on dry sloping land, it occurs rather severely in the middle and late stages, with a general damage rate of 10%-15%, and in severely affected plots up to 40%-50%. Control methods
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What are the control methods for sweet potato soft rot?
1. Harvest at the right time and avoid mechanical injury. Summer sweet potatoes should be harvested completely around the time of Frost's Descent, and autumn sweet potatoes should be harvested completely before the Start of Winter. Choose a sunny day for harvesting, and when digging the potatoes, minimize or avoid causing wounds. 2. Select healthy potatoes carefully to ensure safe storage in the cellar. Before the sweet potatoes are put into the cellar, they must be carefully selected,
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What are the multiple control methods for sweet potato black spot disease
Sweet potato black spot disease, also known as sweet potato black scar disease, has become one of the most widespread and serious diseases in sweet potato producing areas of China. According to statistics, the annual yield loss caused by this disease in China is 5%-10%, and livestock eating diseased tubers can also cause poisoning, with severe cases leading to death. I. Symptoms
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What are the control methods for pepper seedling leaf curl disease?
When peppers are grown as seedlings in winter and spring, after transplanting (dividing seedlings) leaf curl, arrested growth and even death often occur. I. Causes and symptoms (1) Physiological disease: long-term low temperature and high humidity in the seedbed cause poor plant development, yellowing of stems and leaves, curling and shrinking of the terminal leaves, and stunted growth; in severe cases the roots are waterlogged and rot, the roots turn rusty in color and then decay.
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What are the methods for controlling pepper seed diseases
According to experts, pepper seeds generally carry the following latent diseases: damping-off seedlings, Rhizoctonia rot, bacterial leaf spot of pepper, pepper viral disease, pepper Phytophthora blight, pepper Verticillium wilt, etc. 1. Hot water seed soaking Soak the seeds in hot water at 60°C, with a water volume 3
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Prevention and Control Methods for Pepper Flower and Fruit Drop in Spring
Because spring temperatures vary greatly and remain unstable, peppers at the flowering and fruit-setting stage are easily affected by environmental conditions, leading to flower and fruit drop. There are many causes of pepper flower and fruit drop, including physiological ones and pathological ones. Peppers prefer air
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