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Prevention Methods for Sweet Potato Cellar Rot and Storage Management Techniques
The biggest problem during sweet potato storage is cellar rot. Once cellar rot occurs, it may at best reduce the quality of the sweet potatoes, and at worst cause all the sweet potatoes in the cellar to rot, resulting in varying degrees of loss. Sweet potato cellar rot is mostly caused by physiological diseases and infectious diseases. Physiological diseases mainly
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Control Methods and Technical Key Points for Sweet Potato Brown Spot Disease
Sweet potato brown spot disease, also known as angular leaf spot. [Pathogen scientific name] Cercospora batatac Zimm [Host crops] Sweet potato, water spinach, morning glory, etc. [Disease diagnosis] It mainly damages leaves. When leaves are affected, water-soaked small spots first appear, then the lesions gradually expand
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What are the control methods for sweet potato black star disease?
Sweet potato black star disease, also known as black spot disease. [Pathogen scientific name] Alternaria bataticola Ikata. [Host crop] Sweet potato. [Disease diagnosis] It damages leaves, petioles and stems. When leaves are affected, water-soaked brown spots first appear, and after expansion the lesions become round, ell
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Occurrence Patterns and Control Methods of the Sweet Potato Hornworm
The sweet potato hornworm, Herse convolvuli (Linnaeus), belongs to the order Lepidoptera, family Sphingidae. It is distributed in Japan, and in China it is also found in Liaoning, Hebei, Henan, Shandong, Shanxi, Zhejiang, Taiwan, China, Guangdong and other provinces. It mainly damages plants of the Convolvulaceae, Solanaceae and Fabaceae. I. Morphology
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Control Methods for Sweet Potato Scab, a Must-Read for Growers
Sweet potato scab, also known as sweet potato bud-shrinking disease, is commonly called leprosy disease, hard stem disease, etc. [Pathogen scientific name] Sphaceloma batatas Sawada. [Host crop] Sweet potato. [Disease diagnosis] It mainly damages young shoots, leaves and stems, and can also damage tubers. Leaves are mostly tender
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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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Methods for controlling freeze injury in sweet potato cultivation
Sweet potato freeze injury, also called hard-heart sweet potato. [Disease diagnosis] When storage roots are frozen, at first the skin color shows no obvious difference from healthy roots, only slightly losing its luster. Later, the skin can be seen to take on a slightly dark, lusterless appearance; pressing the frozen part lightly with a finger gives a springy feeling; cutting open a frozen sweet potato shows that the flesh near the skin rapidly turns brown, does not exude white milky sap, and squeezing it by hand releases clear water. Generally, based on the speed at which the flesh turns brown, the degree of freezing can be estimated; the faster the browning, the more severe the freezing. Frostbitten storage roots often form a hard heart, taste bitter, and will not cook soft. After storage roots are frozen, they are easily attacked by weakly parasitic fungi, causing rot. ⟦4 <p>Sweet potato freeze injury, also called hard-heart sweet potato. </p><p></p><p>[Disease diagnosis] When storage roots are frozen, at first the skin color shows no obvious difference from healthy roots, only slightly losing luster. Later, the skin can be seen to take on a slightly dark, lusterless appearance; pressing the frozen part lightly with a finger gives a springy feeling; cutting open a frozen sweet potato shows that the flesh near the skin rapidly turns brown, does not exude white milky sap, and squeezing it by hand releases clear water. Generally, based on the speed at which the flesh turns brown, the degree of freezing can be estimated; the faster the browning, the more severe the freezing. Frostbitten storage roots often form a hard heart, taste bitter, and will not cook soft. After storage roots are frozen, they are easily attacked by weakly parasitic fungi, causing rot. </p><p>[Cause] When storage roots are exposed to a low-temperature environment below 9°C for a relatively long time, their physiological functions are disrupted, the flesh tissue is frostbitten, a hard core forms, and the skin and tissue become necrotic. However, after freezing, a period of time must pass before rotting begins. The lower the temperature, the more severe the freeze injury. The longer the low temperature lasts, the more severe the freeze injury. When storage roots suffer freeze injury, rotting generally has two peaks: one is when harvesting is too late in production and the roots freeze in the field, called freeze injury outside the storage pit, and rotting begins about 15 days after being put into the pit; the other is during the middle and late stages of pit storage, when freezing occurs because the pit is shallow or cold protection and insulation are poor and the pit temperature is low, followed by rotting. Generally, at 4-5°C, rotting begins after lasting half a month, and at 6-7°C, rotting occurs only after 1 month. </p><p>[Control measures] (1) Harvest and put into the pit at the proper time to prevent storage roots from freezing. The suitable harvest time for sweet potato should be when the local average temperature of the ten-day period drops to about 14-15°C. Harvest promptly on a sunny day, and the storage roots should be put into the pit on the day of harvest. (2) Disinfect the storage pit. Before the storage roots are put into the pit, a layer of soil should be scraped from the walls of an old pit, and then chemicals should be used for disinfection: fumigate with 30-40 milliliters of 402 water-based fungicide per cubic meter of space, or spray the walls around the pit with a 50-fold formalin solution; in either case, it must be sealed for two days, then opened for ventilation, and used after another two days. (3) Carefully select storage roots. Any storage roots that are diseased, insect-bitten, or frostbitten by frost should be removed and must not be put into the pit. (4) During harvesting, transport, and pit storage, handle them carefully, lifting and setting them down gently, and prevent wounds as much as possible. (5) Manage the temperature and humidity of the storage pit well. To prevent storage roots from freezing and ensure safe storage, the pit temperature should be kept at 11-13°C and the relative humidity at 75%-80%.</p>
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