<h1>Rice planthopper</h1>
Harmful features:
Rice planthopper hazards Rice can be divided into two aspects: direct hazards and indirect hazards. The direct harm is to directly suck rice sap, consume the nutrients of rice plants, and cause harm. Adults and nymphs of rice planthoppers can suck sap and harm rice. Indirect hazards are adult rice planthoppers, nymphs sucking sap and female worms with ovipositors to puncture leaf sheaths and leaves, which is easy to dehydrate rice plants and infected with sclerotia, and their excrement breeds mold, which also affects rice photosynthesis and respiration. Predators include rice lice, brown-loined red-eyed bees, rice lice red claw bees, rice lice cord nematodes, black-shouldered green blind bugs and so on.
Prevention and control methods:
1. Select and promote anti-insect abundance products to prevent the emergence of new biological forms of rice planthoppers.
2. Protect and utilize natural enemies.
3. Use 20% ethermethrin emulsion 35 ml per mu, add 50 kg of water to spray, or use organophosphorus pesticides such as dichlorvos and chlorpyrifos to use drugs at the peak of nymph hatching.
<h1>Rice blight</h1>
1, Symptoms
This disease can occur from the seedling stage to after the ear extraction, generally in the tillering, the end to the panicle stage of the disease is dominant, especially before and after the panicle extraction stage, the disease is more intense, mainly affecting the leaf sheath and leaves, and when it is serious, it can harm the stable part and penetrate deep into the inside of the stem. After the leaf sheath is affected, small spots with dark green water stains and unclear edges are initially produced near or under the water surface. The spots gradually enlarge into an oval shape, with brown to dark brown edges, yellow to off-white grass in the middle, and gray-green to dark green when wet, with a slightly moist appearance.
There are many disease spots, but several can be fused with each other into a large cloud-like spot, causing the leaf sheath to dry up, and the leaves are also withered and shrunken, and die early. On the leaves, the shape and color of the spots are basically similar to the leaf sheaths. Severely ill leaves expand rapidly, appearing in the form of dirty green water stains, and finally die. When the sheath of the sword leaf is severely damaged, the rice plant cannot properly extract the ears. When rice ears occur, the ear neck, panicle shaft and even the shell and other parts are dirty green and moist, and then turn gray-brown, poor fruiting, and even the whole panicle dies.
1. At the beginning of the disease, spray 500-1000 times liquid of the water agent, or 5% jinggangmycin, or 20% powder rust ning emulsion, or 50% methyl thiophan, or 50% carbendazim wettable powder, or 30% striatum wettable powder, or 50% methyl liknilin, or 33% striated mold net wettable powder, or 20% rice foot green, or 10% rice rather wettable powder, pay attention to the dosage and use before pregnancy spikes to prevent drug damage.
2. When the disease is severe, use 20% carbocycline emulsion, or 75% carbolixim wettable powder + heterogeneous rice blast net, or 10% rust amine emulsion, or 25% hesui ning wettable powder, or 77% Hufeng'an wettable powder 700 times liquid, or Green State 98 rice special type 600 times liquid, or 25% powder rust rather wettable powder, or 25% hostile destruct oil 2000 times liquid, respectively, sprayed once at the beginning of the gestational spike and the end of the pregnant ear.
<h1>Rice blast</h1>
symptoms:
It is mainly harmful to leaves, stems and ears. Because the pest period and location are different, it is divided into seedling plague, leaf plague, festival plague, spike neck plague, and grain plague.
1. Miao plague
Occurs before the trilobaste and is caused by seed carrier bacteria. The base of the diseased seedling is gray and black, the upper part becomes brown, curls and dies, and when the humidity is large, the diseased part produces a large number of gray-black mold layers, that is, the pathogen conidia stalk and conidia.
2. Leaf plague
It can occur throughout the reproductive period. Tillering to jointing is more severe. Due to different climatic conditions and disease resistance of varieties, there are four types of spots. Chronic-type spots: begin to produce small dark green spots on the leaves, gradually expand into clostridium spots, often with an extended brown necrotic line. The center of the spot is grayish white, the edge is brown, there is a pale yellow halo on the outside, there is a gray mold layer on the back of the leaf, and when there are more spots, the patches form irregular large spots, and the development of this spot is slower. Acute lesions: Dark green near-round or oval spots are formed on the susceptible varieties, and brown mold layers are produced on both sides of the leaves, and the conditions are not suitable for the transformation into chronic lesions at the time of onset. White-spot spots: After the onset of disease-sensitive young leaves, they produce small white nearly round spots that do not produce spores, and when climatic conditions are favorablely expanded, they can be turned into acute spots. Brown spot spots: mostly in high-resistance varieties or old leaves, the brown spots that produce the size of needle tips are only produced between the leaf veins, and fewer spores are produced, and the disease can also occur in the leaf tongue, leaf ears, leaf pillows and other parts.
3. Temperature saving
It often occurs after ear extraction, and initially produces small brown dots on the rice nodes, and then gradually expands around the nodes, making the diseased part black and easy to break. Occurs early in the formation of dull white spikes. Occurs only on one side causing the stem to bend.
4. Spike-necked plague
Small brown dots form at the beginning, which brown the neck of the spike after release, and also cause a dull white spike. Late onset causes Shugu. Damage to the branches or shafts causes the spikelets to be untrue.
5. Grain plague
Produces brown oval or irregular spots that darken rice. Some of the shells are asymptomatic, and the skin is browned by the victims, so that the seeds carry bacteria.
1, soak the seeds with 1% lime water, soak at 10-15 °C for 6 days, soak at 20-25 °C for 1-2 days, the lime water layer is 15 cm higher than the rice seeds, stand still, rinse with clean water 3-4 times after fishing out. Soak the seeds with 2% formalin for 20-30 min, then cover the seeds with a film for 3 h.
2. At the beginning of the disease, spray 20% tricyclazole wettable powder 1000 times liquid, or 50% rice blast peptide wettable powder 1000 times liquid, or 40% grams of blast dispersion 1000 times liquid, or use 40% rice blast emulsion 1000 times liquid, or 50% carbendazim, or 50% methyl thiophane wettable powder 1000 times liquid, or 50% isola net emulsion 500-800 times liquid, or 5% bacteriotoxin clear water agent 500 times liquid.
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