Rice Diseases (Essential for Large Households)
Rice blight
Hazard characteristics:
It is mainly harmful to leaf sheaths, followed by leaves.
Leaf sheath infection: initially produces dark green water-soaked edge blurred small spots near the water surface, and then gradually enlarges to be oval or moiré, with dark brown edges, gray-white translucent in the middle, and gray-green when wet.
Leaf infection: the spots are also cloud-like, the edges are yellow, the spots are dirty green when the disease is fast, and the leaves rot quickly.
Stem infection: symptoms like leaves, yellow-brown in the later stages, easy to fold.
Panicle neck infection: initially moist bluish-black, often can not be drawn, the ear of the grain is more, the weight of a thousand grains decreased. When the humidity is high, the disease develops white reticulated hyphae, which later form sclerotia.
Prevention and control methods:
(1) Selection of disease-resistant varieties; salvage sclerotia, reduce the source of bacteria; scientific management of water, the implementation of the "before shallow, medium sun, after wet" water principle, to avoid long-term deep irrigation or excessive sunning; reasonable fertilization, the implementation of "full base fertilizer, early application of topdressing, flexible topdressing" principle, enhance plant growth; reasonable dense planting, increase permeability.
(2) The disease point rate in the late stage of tillering is 15%, that is, the treatment of drug administration, the following agents can be selected: benzopyrcycrazole; fluconazole; or hexazole.
(3) In the gestational panicle stage, when the incidence of the cluster reaches 10%, the disease still develops, and 30% of the benzo•propiconazole emulsion 2400~3000 times liquid is sprayed again.
Rice blast
Because the pest period and location are different, it is divided into seedling plague, leaf plague, festival plague, spike neck plague, and grain plague.
Seedling plague: occurs before the three leaves, and the diseased seedlings die of yellow-brown.
Leaf plague: chronic type spots, mostly fusiform, brown edges, central grayish white, yellow halo, with brown necrotic lines extending to both ends; acute type spots, generally susceptible to disease varieties occur, forming dark green nearly round or oval spots, both sides of the leaf produce brown mold layer.
Knot plague: often occurs after panicle extraction, the initial production of small brown dots, and then gradually expand around the node, so that the entire node becomes black necrotic, easy to break, early formation of dry white spikes.
Panicle neck plague: the initial formation of brown dots, after the spread of the ear neck brown, but also caused by the dry white panicle, the onset of late disease caused by the valley.
Grain plague: brown edges, gray-white spots in the middle.
(1) Selection of disease-resistant varieties; scientific management of water, bottom fertilizer, early topdressing, application of fully decomposed farm fertilizer, increase the application of phosphorus and potassium fertilizer, enhance the ability of plants to resist disease; reasonable dense planting, increase permeability.
(2) At the beginning of the disease, the following agents are selected for prevention and control: rice blast, sulfur • tricyclazole; or tricyclazole, and the severe disease area needs to be prevented and treated twice, and the interval is 7 to 10 days.
Rice white leaf blight
The entire growth period can be affected, the seedling stage, tillering stage is the most seriously affected, all organs can be infected, and the leaves are the most susceptible to infection.
1, generally there are faded green and yellow spots, when the weather is wet, the diseased leaves can be seen on the milky white dots, dry into yellow small rubber particles, very easy to fall off. At the tillering stage, dead heart seedlings begin to appear, and symptoms such as water loss, rolling, and green wilt appear in the heart leaves or the 1 to 2 layers below the heart leaves of the diseased plant, and finally die.
2. After the white leaf blight forms a wilt heart seedling, other leaves also gradually wither and shrink, and finally the whole plant dies, peeling off the heart leaf of the new green curl or the broken stem or cutting off the diseased leaf, squeezing hard, it can be seen that there is a yellow and white fungus pus overflowing. It can be divided into three types: leaf wilt, acute wilting, and yellowing.
(1) Strengthen fertilizer and water management, wet irrigation in the rainy season, full of fertilizer at the bottom, early topdressing, application of fully decomposed farm manure, increase the application of phosphorus and potassium fertilizer, enhance the ability of plants to resist diseases; timely and moderate roasting of the field.
(2) Soaking seeds: soaking seeds with dip fruit spirit or strong chlorine, and conventional germination and sowing after washing with strong chlorine.
(3) In the early stage of the disease, the following agents are used for prevention and control: yekuzole, chlorobromoisocyanuric acid, or agricultural streptomycin sulfate.
Rice bacterial stripe spot disease
1. Rice bacterial stripe disease is mainly harmful to leaves. Initially dark green water-soaked translucent spots, it rapidly expands between leaf veins into yellow-brown thin lines or short dotted line-like stripes, and the two ends of the spots are infiltrated green.
2. Many dew-like yellow pus are often spilled on the spots, which are yellow gelatinous particles after drying, which are not easy to fall off, and when the disease is serious, they are fused into irregular yellow brown to dry white spots, similar to white leaf withering, but many translucent thin strips are visible to the light.
3. When the disease is severe, the leaves are curled and the field shows a yellowish-white color, which causes early death of the plant or the inability to draw ears.
(1) Adopt comprehensive measures based on prevention: strengthen quarantine and control the spread of diseases; select varieties that are resistant to resistance; scientifically manage water, fully fertilize, topdress early, apply fully decomposed farm manure, increase phosphorus and potassium fertilizers, and enhance plant disease resistance; rational dense planting, increase permeability.
(2) Seed soaking: first pre-soak the seeds with water for 12 hours, and then soak the seeds with 85% trichloroisocyanuric acid wettable powder 300 to 500 times liquid for 12 hours, and then germinate and sow after purification.
(3) Initial onset of the disease: the following agents can be used for prevention and treatment: chlorobromo isocyanuric acid, mesobioxystin, or trichloroisocyanuric acid.
Rice aspergillosis
1. It only occurs in the panicle and is harmful to grain. Mycelial blocks are formed in the affected grains, which are cracked inside and outside, revealing pale yellow lumpy protrusions, which gradually expand and wrap around Quanying, showing a black-green color.
2. Initially wrap a layer of film, after rupture, scattered dark green powder, that is, the thick spores of pathogens, some sides of the black flat sclerotia, wind and rain are easy to fall off.
(1) Selection of resistant varieties; avoid retention of seeds in diseased fields, deep ploughing and burial of sclerotia, removal and destruction of disease particles when the disease occurs; scientific management of water, bottom fertilizer, early topdressing, application of fully decomposed farm manure, increase the application of phosphorus and potassium fertilizer, enhance the ability of plants to resist disease; reasonable dense planting, increase permeability.
(2) Pharmaceutical seed mixing, can be used 3% phenyl ether methylcyclazole suspension seed coating agent 50ml to mix seeds.
(3) At the beginning of the disease, the following drugs can be used for prevention and treatment: pentazole, oxime • pentazole; or nitrile benzazole.
Bacterial base rot in rice
1. It is mainly harmful to the root nodes and stem bases of rice. In general, the disease begins at the tillering stage of rice, and initially produces water-soaked oval spots on the leaf sheath at the base of the near soil surface stem, and then expands to an irregular large spot with a brown edge and a white middle.
2, serious disease plant heart leaf green roll, after withering yellow, like borer for pest dry heart seedlings, after the disease plant root nodes become black rot, easy to pull off, there is a foul smell, and even the leaves from top to bottom yellow, or even the whole plant withered yellow.
(1) Selection of resistant varieties; scientific management of water, bottom fertilizer, early topdressing, application of fully decomposed farm manure, increase the application of phosphorus and potassium fertilizer, enhance the ability of plants to resist disease; reasonable dense planting, increase permeability.
(2) At the beginning of the disease, the following agents can be selected: copper of thiamethia, copper of thiasen, or 50% trichloroisocyanuric acid, sprayed once every 5 to 7 days, and sprayed 3 to 4 times continuously.
Rice black-striped dwarf disease
The disease is mainly transmitted by gray planthoppers, followed by white-backed planthoppers and white-banded planthoppers. The tillers of the diseased plant increased, the leaves were short, broad, stiff, and thick green, and the veins and stems on the back of the leaves were initially waxy white, and then browned, and the short nodular bulges, no panicles or small spikes, and poor fruiting.
Onset of disease at the seedling stage: the heart leaf grows slowly, the leaves are short, broad, stiff, and thick green, and the leaf veins have irregular waxy white nodular protrusions, and then turn black and brown. The roots are short, the plants are short, do not draw panicles, and often die early.
Onset of tillering stage: neonatal tillers are pre-emerging, and the main stem and early tillers can still draw out short diseased panicles, but the diseased panicles are hidden in the leaf sheath.
Onset of jointing: short and broad blades, short and narrow spike necks, and low fruiting rate. There are short striped tumors on the dorsal and stalks of the leaves.
Prevention and control methods: (1) selection of disease-resistant (disease-resistant) varieties; removal of fieldside weeds.
(2) Timely treatment of insects, the following agents can be used to kill insects: chlorpyrifos • thiamethoxazine; prazidone; or thiazide.
(3) In the early stage of the disease, the following agents can be used to alleviate it: nimbycin, shiitake polysaccharide, or chitosan.
Bacterial brown stripe disease in rice
Hazard Symptoms:
Both the seedling stage and the adult stage can be affected.
Disease at the seedling stage: small brown spots appear on the leaves or leaf sheaths, and then expand into purple-brown long spots with clear edges and sometimes the same length as the leaves; the diseased seedlings wilt or the diseased leaves fall off, and the plants are short.
Infection at the adult stage: first in the middle vein of the leaf base, initially water-soaked yellow-white, then along the leaf vein to expand up to the leaf tip, down to the base of the leaf sheath to form a yellow brown to dark brown long stripe, the diseased tissue is brittle and easy to fold, and then the whole leaf curls and dies.
Leaf sheath infection: irregular plaque, later turned yellow-brown, and finally all decayed. Heart leaf disease: can not be withdrawn, died in the leaf bud, pulled out with a putrid smell, squeezed by hand with milky white to pale yellow bacteria overflow.
(1) Establish a reasonable drainage and irrigation system to prevent large water from flooding the rice field and drain it in time; increase the application of organic fertilizer, and rationally cooperate with the application of nitrogen, phosphorus and potassium fertilizers to enhance the disease resistance of plants.
(2) At the beginning of the disease, the following agents can be used for prevention: chlorobromoisocyanuric acid; mesophyticin; or trichloroisocyanuric acid.
Rice striped leaf blight
Infected by grey planthoppers alone, once poisoned, it can be transmitted through eggs for life.
Disease at the seedling stage: the initial plant heart leaf base appears faded green yellow white spots, and then expands into yellow stripes parallel to the leaf veins, and the stripes remain green; the diseased waxy, japonica rice and tall indica rice heart leaves are yellow and white, soft, curly and droopy, and become dry hearts; dwarf indica rice is not dry heart-shaped, yellow-green stripes appear, tillers are reduced, and the diseased plant dies prematurely.
Onset of tillering stage: in the early stage, a faded green macula appeared at the base of the next leaf of the heart leaf of the plant, and then expanded to form an irregular yellow-white stripe, and the old leaf diseased plants often withered pregnant ears or small panicle deformities and unrealistic; indica rice did not wither the heart, and half of the glutinous rice showed dry heart. Onset after jointing: yellow-green stripes appear in the lower part of the sword leaf, and all types of rice do not wither, but the panicle is deformed and the fruit is rare, forming a "false white panicle".
Prevention and control methods: (1) planting disease-resistant (resistant) varieties, adjusting the sowing period, avoiding the migration period of gray planthoppers during the transplanting period; preventing the weeds of the grass family on the edge of the field; ploughing and turning the stubble after autumn harvest to reduce the number of planthoppers overwintering.
(3) In the early stage of the disease, the following drugs can be used for prevention: shiitake polysaccharides, nimbyromycin, or chlorobromoisocyanuric acid.
Rice flax leaf spot disease
Diseases can occur from the seedling stage to the harvest stage, and the upper parts of the rice plant can be affected on the ground, mainly the leaves. Seed germination: the bud sheath turns brown, the bud does not withdraw, and the cotyledons die.
Leaf infection: there are small brown spots in the early stage, gradually expanding to the size of sesame seeds, central brown to grayish white, oval spots with brown edges, with different shades of yellow halos; in severe cases, they form irregular large spots; diseased leaves dry inward from the tip of the leaf, and black mold is produced on the dead seedlings.
Leaf sheath infection: dark brown at the beginning, light brown at the edges, oval spots with water stains, and irregular large spots with gray-brown centers later. Panicle neck and branch stalk disease: the affected area is dark brown, resulting in panicle withering.
Grain infection: the early victims of the grain gray-black expansion to the whole grain caused by the grain, the later victim disease spots are small, the edge is not obvious; in severe cases, the grain is brittle and fragile; when wet, the disease grows a black velvet mold layer.
(1) Deep ploughing and stubble removal, reducing the source of bacteria; preventing weeds at the edge of the field; paying attention to drainage of acidic soil, appropriate application of lime; shallow irrigation and frequent irrigation; increasing the application of decomposing organic fertilizer, increasing the application of phosphorus and potassium fertilizer, and improving the disease resistance of plants.
(2) Seed disinfection: 25% imidaminated emulsion 2000 ~ 3000 times liquid, or 50% Fumei double wettable powder 500 times liquid, soaked for 48 hours, fished out for washing, germination, sowing.
(3) In the stage from ear extraction to milk ripening, in order to protect the sword leaf, ear neck and grain from infection, spray once 4 to 7 days before the rice breach and the panicle stage, and can be prevented by the following agents: phenylmethicazole • propiconazole; azoxystrobin, or isola blast net.
Rice seedling disease
Hazard characteristics: 1, the victim rice seedlings are slender, thin, pale, leaf sheath elongation, about 2/3 higher than normal seedlings, the root system is weaker, the tillers are slow and less, the internodes are lengthened, and a large number of inverted roots are born on the nodes, especially more on the basal nodes, generally withering before the panicles are drawn, even if the ears can be matured, the panicles are small and small, forming white ears.
2. Stem damage: light red or white mold powder is produced on the leaf sheath; black dots are produced in the later stage. Grain damage: severe browning, not full, light red mold at the cracks of the shell.
(1) Selection of resistant varieties; removal of disease residues, timely removal of diseased plants and destruction; increase the application of decomposing organic fertilizer, increase the application of phosphorus and potassium fertilizers, and improve the disease resistance of plants.
(2) Seed disinfection: 25% imidaminated emulsion 2000 ~ 3000 times liquid seed mixing, or 50% Fumei double wettable powder 500 times liquid, soak the seeds for 72 hours, fish out the washing, germination, sowing.
Rice downy mildew
Symptoms of rice downy mildew hazards
1. The seedling stage is the main disease-inducing period of rice, and the symptoms begin to appear in the late stage of the seedling field, and the symptoms are obvious during the peak of tillering.
2. The leaves are initially yellow and white spots, and then become irregular stripes on the surface, mottled flowers and leaves; the heart leaves are yellowish, curly, and not easy to extract; the lower old leaves gradually wither;
3. The leaf sheath is slightly soft, the surface has irregular ripples or wrinkles and twists, and the tillers are reduced; the root system is dysplasia, and the plant is dwarfed.
4. Cannot conceive the panicle or has a distorted deformed panicle, and the panicle is small and unreal.
(1) Select higher plots of land for seedlings, build a drainage and irrigation system to prevent flooding seedlings; remove weeds and diseased seedlings in time to control the spread of diseases.
(2) At the beginning of the disease, the following agents can be used for prevention and treatment: methylstillin, enoyl morpholine, or oxalis • Daisen manganese zinc.
Rice leaf sheath rot disease
The disease can occur from the seedling stage to the panicle extraction stage, and the disease is severe from the pregnant ear to the panicle extraction stage. The leaf sheath of the sword leaf grows brown to dark brown irregular spots, the middle color is light, the edges are dark brown and clear, and multiple spots combine to form a cloud-like disease spot, sometimes with a yellow halo, which later extends to the entire leaf sheath, causing the leaf sheath and young ears to rot.
(2) Seed disinfection: 40% carbendazim gum suspension 500 times liquid soaked seeds for 48h, or 40% hequalin wettable powder 250 times liquid, soaked seeds for 24 hours, fished out for washing, germination, sowing.
(3) At the beginning of the disease, the following agents are selected for prevention and treatment: pentrazole; benzopyrazole, or benzopyramboprim.
Rice verticillium wilt
1. Mainly rely on black-tailed leafhoppers, two-point black-tailed leafhoppers, two black-tailed leafhoppers and so on to spread poison. The leaves are thinner, softer in texture, faded green to pale yellow, tillers soar, dwarf clumps, and poor root system. Plants infected at the seedling stage cannot shrink and cannot be spiked.
2. The incidence of infection in the later stage is mild, which is mainly manifested by increased tillering, clustering, high nodal branching of individual diseased plants, and leaves like bamboo leaves.
(1) Selection of disease-resistant and insect-resistant varieties; the seedling stage that is susceptible to disease is staggered with the peak period of leafhopper activity.
(2) Insecticides can be sprayed at the seedling stage and the tillering stage, and the following agents can be selected: imidacloprid; high-efficiency cypermethrin; chlorpyrifosium • thiamethiazide, or leafhopper dispersion.
Rice a pillar of incense
1, rice panicle before the victimization: the germ in the shell grows into a rice grain-like fruiting body, the flower bud is buried inside, the shell of the fruiting body from the inner and outer seams extend to the outside of the shell, the shape is different, the shell gradually becomes black, at the same time there are hyphae will be wound around the spikelet, so that the spikelet can not be scattered, the drawn out of the disease spike upright cylindrical, so called "a pillar of incense".
2. The ear of the disease is initially light blue, and then turns white, and the upper part is black granules, that is, the substation of the pathogen.
(1) Keep seeds in disease-free fields; strengthen quarantine and strictly prohibit seeds from disease-free areas from being transferred into disease-free areas.
(2) Seed disinfection: first pre-soak the seeds in brine and slurry water for 4 hours, and then soak the seeds in 52 ~ 54 °C warm water for 10 minutes, germinate and sow seeds; or soak the seeds with 50% carbendazim wettable powder 500 times liquid for 48 hours, fish out the washing solution, germinate and sow.
(3) At the beginning of the disease, the following agents are selected for prevention and treatment: carbendazim hydrochloride, or carbendazim.
Rice blight
1. The internal causes of rice red blight are insufficient potassium content in rice plants, imbalance in nutrient ratio, and poor quality of seedlings. Typical symptoms on the outside of the affected plant are the formation of russet rust-like spots of varying sizes on the leaves, which, in severe cases, polymerize into patches or strips.
2. The spots are first produced from the tip of the lower old leaves, and then gradually turned reddish brown downwards, and finally the whole leaves die; from the lower old leaves gradually spread to the upper leaves, in severe cases, only a few new leaves of the whole plant remain green, looking like fire in the distance.
3. Potassium deficiency type and phosphorus deficiency type caused by deficiency hormone are physiological.
4. Poisoned type of red wilt mainly occurs in long-term immersion in water.
1. Improve the soil, increase the deep ploughing layer, increase the application of organic fertilizer, improve soil fertility, and improve the soil aggregate structure.
2, green manure as a base fertilizer, should not be excessive, ploughing can not be too late; apply fully decomposed organic fertilizer, early application of potassium fertilizer, phosphorus fertilizer, avoid topdressing single application of nitrogen fertilizer.
3. Transform low-lying immersion paddy fields and do a good job in drainage ditches; early rice should be shallow irrigation and irrigation, timely field cultivation, and increase soil permeability.
4. The diseased rice field should be drained immediately, lime should be applied as appropriate, and the field should be gently shelved to promote the sedimentation of the floating mud, so as to facilitate the early onset of new roots, foliar spraying from the pregnant ear stage of rice to the filling stage of multi-functional high-performance liquid fertilizer once every 15 days.
Rice dry tip nematode disease
1. Nematodes drill in from the bud sheath seam, attach to the growth point, leaf bud and the tips of the newborn young leaves, and stab the cells with a kissing needle to suck the sap, causing the damaged leaves to form a dry tip.
2. The symptoms are not obvious at the seedling stage, and the leaf tip is occasionally grayish white and dry when there are 4 to 5 true leaves, and the dry tip is twisted.
3. The dry tip of the diseased plant is more serious after the pregnant ear, and the tip of the sword leaf or the 2 to 3 leaves under it is 1 to 8 cm gradually yellow, translucent, twisted and dried tip, becoming gray or light brown, and the boundary of the diseased part is obvious. #2020 Golden Rice Ear Project ##Rural# #农民 #
4. When the humidity is high, the dry tip blades are flattened into translucent water stains, fluttering with the wind, and then curled again after dew drying. Some diseased plants are not diseased, but the rice ears have nematodes, most plants can pull the ears normally, but the plants are short, the diseased ears are small, there are many grains, more infertility, and the ears are upright.
(1) Select disease-free seeds, strengthen quarantine, and strictly prohibit the transfer of seeds from the diseased area.
(2) Seed treatment: First pre-immerse the rice seeds in cold water for 24 hours, then put them in 45 ~ 47 ° C warm water for 5 minutes to warm up, and then put in 52 ~ 54 ° C warm water for 10 minutes, take out and cool immediately, germinate and sow. Or soak the seeds with 16% mixian • borer wettable powder 400-700 times liquid, wash and then germinate and sow.