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Symptoms and control methods of potato ring rot
This disease is a bacterial vascular disease, characterized by stunted and wilted aboveground stems and leaves, and ring-shaped rot of underground tubers along the vascular ring. Early and severe infection leads to dead seedlings; most diseased plants grow slowly, are stunted and thin with few branches and small leaves, and the leaves are wrinkled and do not expand; when infection occurs late and is mild, plant height, leaves, and branching grow normally, but the top leaves become smaller, and later one or two branches or the whole plant wilt. Symptoms are most obvious after flowering, with the lower leaves first wilting, drooping, and dying; the upper leaves roll inward from the edges, appear dehydrated, turn grayish green, and then
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What are the control methods for potato ring rot?
Ring rot is caused by the bacterium Corynebacterium sepedonicum (potato ring rot corynebacterium). It can occur on stems and leaves as well as on tubers, and can continue to cause damage during storage, causing tuber rot in severe cases. In recent years, with the promotion and application of virus-free seed potatoes, the occurrence of ring rot has decreased significantly. 1. Symptoms Ring rot is also a vascular bundle disease. Aboveground symptoms generally appear after the flowering stage. Initial symptoms appear on the lower leaves of the plant, showing chlorosis between the veins, appearing mottled
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Occurrence Patterns and Control Methods of the Potato Tuber Moth
The potato tuber moth, also known as the potato borer and the tobacco leafminer, is commonly called the "string-skin worm," "embroidery worm," and "potato maggot" by farmers. 1. Damage symptoms: The larvae cause damage mainly by boring and feeding, usually entering through the buds and broken skin of the tubers. Larvae hatched on the plant spin silk and spread with the wind, boring from the leaf surface into the leaf interior to feed and cause damage. After the damaged leaves wither and die, the larvae move to other leaves to cause damage. 2. Occurrence patterns: The potato tuber moth produces several generations a year, overwintering in various stages on mother tubers in the field and on the residual plants and fallen leaves of various hosts. Adult
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Occurrence and Control Methods of Potato Tuber Rot Nematode
Fengning and Weichang counties in the north of Chengde City plant more than 40,000 hectares of potatoes annually, producing more than 800 million kg of seed potatoes and commercial potatoes per year, with about 120 million kg stored in winter, making it one of the four major potato production bases in the country. In recent years, the damage caused by the potato tuber rot nematode has led to great losses in stored potatoes. In 1994, it caused 5%-7% loss of stored potatoes, and in severely affected potato cellars, losses reached as high as 20%-30%. According to the currently retrieved data, this nematode is widely distributed in potato-growing areas of Asia, Europe, the Americas and Africa
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Symptoms and Control Methods of Potato Rhizoctonia solani Disease
〔Pathogen scientific name〕Rhizoctonia solani Kühn 〔Host crops〕Solanaceae, Fabaceae, Poaceae and many other crops; hosts are widespread. 〔Disease diagnosis〕It mainly damages young sprouts, stem bases and tubers. When young sprouts are infected, those that have not emerged rot, forming sprout rot and causing missing plants; after emergence, infection begins with yellowing of the lower leaves and brown sunken lesions on the stem base, 1-6 cm in size. The lesions and their surroundings are often covered with a purple mycelial layer; sometimes on the stem base and tubers there are sclerotia of varying sizes (1-5
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What are the control methods for zinc deficiency stunt seedling in rice?
Phosphorus deficiency stunt seedling generally occurs at the tillering stage after seedling recovery, manifesting as slow growth, short plants, slender and upright leaves, dark green leaf color, neat leaf cluster tips, significantly shortened leaf sheath distance, red tips on some tiller leaves, and brownish-red or even dead old leaves. Causes: first, the soil lacks available phosphorus; second, low soil temperature and water temperature, or the presence of reducing harmful substances such as hydrogen sulfide and ferrous iron in the soil, which reduces the root's absorption capacity; third, excessive application of nitrogen fertilizer, causing the effective nutrients to lose their relative balance. Control measures are based on the available phosphorus data measured by the "soil testing and fertilizer recommendation method"
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What are the control methods for rice brown spot?
Symptoms Also known as rice sesame leaf blight. It occurs in all rice-growing regions nationwide. Disease can occur from the seedling stage to the harvest stage, and all aboveground parts of the rice plant can be affected, with leaves being the most common. When seeds are affected at the germination stage, the coleoptile turns brown, the sprout fails to emerge, and the cotyledon dies. Leaf and leaf sheath disease at the seedling stage mostly appears as elliptical lesions, the size of sesame seeds, dark brown; sometimes the lesions enlarge and merge into strips, and when there are many lesions the seedlings die. On leaves of adult plants, infection begins as small brown spots, gradually enlarging into elliptical spots the size of sesame seeds, with the center of the lesion brown to grayish white, the margin brown, and around it yellow halos of varying
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What are the methods for controlling rice pests?
2.5% rotenone EC and other rotenone-cypermethrin patented series products are new plant-based insecticides developed to address two major problems in current agricultural production in China: pesticide-resistant pests and the frequent occurrence of food poisoning from pesticide residues. They have obtained a national invention patent and the Guangdong Provincial Science and Technology Progress Award. Large-scale trial demonstrations by plant protection experts in our province show that for controlling pesticide-resistant pests such as rice leaf roller (Cnaphalocrocis medinalis), rice planthopper, striped stem borer (Chilo suppressalis), armyworm, diamondback moth (Plutella xylostella), red spider mite, thrips, rust mite and scale insect, using a 1000
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What are the control methods for the rice green leafhopper?
Scientific name Inazuma dorsalis (Motschulsky), synonym Recilia dorsalis (Motschulsky), belonging to Homoptera, family Cicadellidae. Distributed in the rice-growing regions south of the Yellow River. Hosts include rice, corn, sorghum, millet, sugarcane, wheat, barley, etc. Occasionally damages sesame, citrus, etc. Damage characteristics: adults and nymphs pierce and suck sap on rice leaves and leaf sheaths, inhibiting the growth and development of damaged plants, causing leaves to turn yellow or the whole plant to wither.
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What are the control methods for rice kernel smut?
Symptoms Also known as smut, rice dark smut, black kernel smut, etc. It is distributed in the Yangtze River Basin and areas to the south in China, mainly occurring from the flowering stage to the milk-ripe stage of rice, and only infecting the grains. Each panicle may have 1, several, or even dozens of infected grains, with symptoms generally appearing when the rice is near maturity. Infected rice grains turn a dirty green or dirty yellow color, containing black powdery material inside. At maturity, the abdomen splits open, exposing the black powder. Between the inner and outer glumes of the diseased grain there is a black tongue-shaped protrusion, and a black liquid often oozes out, contaminating the surface of the grain. When the diseased grain is opened, the seed can be seen to be partially or entirely transformed into black powdery material.
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