1.Rice sheath blight
Rice sheath blight is one of the three major diseases of rice in each country . The high-yield fields of densely planted dwarf hybrid rice are the most serious , it will cause leaf death , reducing seed-sett rate and thousand-grain weight , generally causing a loss of 10%-20% , and it can reach above 50 %.
Hazard characteristics :
Rice sheath blight is commonly known as flower foot stalk and rotten foot stalk . It can happen to seedling stage to ear stage . It usually starts at the tillering stage . Water stained oval spots to-appear on the leaf tips near the water surface at first, and then the spots increase , and they often heal together to become irregular and large moire like spot with brown edges and green middle parts or to brown . The symptoms of the leaves are basically the same as those on the leaves . The disease spreads from bottom to top , and in severe cases , it can reach the tip of the leaf or even the ear , causing large areas of lodging .
In the seedling stage and the closure period, use Kresoxim-methyl, Fenoxiconazole + Azoxystrobin 1500 times liquid spray.
2. Rice smut
Rice smut is also known as smut, green smut, grain flower disease, and powdery mildew. The disease only occurs to the ears and damages some grains. The mycelial masses formed into the injured grains gradually swelled, and the inside and outside were split, revealing yellow masses.
Chemical control : the first control is 10-15 days before the break , and the control effect is poor in the full ear stage . Late stage of rice booting-breaking period (3-5 days before breakage), according to the weather forecast, it is rainy weather before and after breakage. Use difenoconazole, epiconazole, propiconazole, hexaconazole, tebuconazole and tebuconazole.
Rice blast is one of the important diseases that damage rice in each country . It occurs every-year to the north and south of China , and the degree of damage varies depending on the variety , cultivation technology and climatic conditions . It is mainly damaging leaves , stems and ears . According-to the damage period and location ,it can be divided into seedling blast , leaf blast , knot blast , ear neck blast , and grain blast.
- 5-7 days before the rice breaks (when there are about 6-8 ear buds per stalk), using tricyclazole + pyraclostrobin + silicone, spray evenly.
- Spray again when 80% of the ears are heading, and focus on the working row and field side.
4. Rice stripe leaf blight
Rice stripe leaf blight is a viral disease transmitted by Laodelphax striatellus , commonly known as cancer on rice . Diseased plants often withered booting or small ears deformed and imperfect . After joint , yellow-green stripes appear on the lower part of the flag leaf . All types of rice are not dry , but the ear is deformed and there is little fruit . The occurrence of stripe leaf blight is directly related to the occurrence of Laodelphax striatellus and the rate of venomous insects. In the spring, the temperature is relatively high, the rainfall is little, and the insect population is frequent and severe. The disease was severe in the rice and wheat cropping areas, and light in the barley and double cropping rice crops.
Comprehensive strategy : Adhere to the plant protection policy of ” prevention first, comprehensive control “, adopt the control strategy of ” cuting off the source of the poison , cure insects and diseases ” to severely treat Laodelphax striatellus and control stripe leaf blight .
5.Rice bacterial blight
One of the diseases of rice , the diseased plant has yellow-green spots on the leaf tips and edges , which develop into pale and yellowish-brown long strips along the leaf veins , and finally become gray and white and die . Diseased plants are prone to lodging , and the rate of false rice ears increases . The germs spread over the winter on seeds and diseased rice straws . Diseases at the tillering stage begin to develop . High temperature and humidity , storms , flooding with rice fields , and excessive nitrogen fertilizer are conducive to the epidemic
1.Strengthen fertilizer and water management, wet irrigation during the rainy season, adequate base fertilizer, early topdressing, fully decomposed farmyard manure, increased application of phosphorus and potassium fertilizers to enhance plant disease resistance; timely and moderate roasting.
2.In the early stage of the disease, use chemical control: 4% kasugamycin,ecumazole or agricultural streptomycin.
6.Rice bacterial leaf streak
Bacterial leaf streak of rice is also called thin streak and leaf streak , which mainly damages leaves . The lesions were small dark green water-soaked spots on / of the beginning , and quickly expanded into dark green to yellow-brown thin strips between the veins , about 1×10mm in size , and both ends of the lesions were infiltrating green .
A large amount of bead yellow pus is often overflowing with the lesion, which becomes gelatinous granules after drying . When the disease is severe , the streaks merge into irregular yellowish brown to withered large spots , similar to blight , but many translucent streaks can be seen from the light . When the disease is severe , the leaves are curled and the field appears yellowish-white .
- Take comprehensive measures focusing on prevention: strengthen quarantine and control the spread of diseases; select resistant varieties; scientifically manage water, adequate base fertilizer, early topdressing, fully decomposed farmyard manure, increased application of phosphorus and potassium fertilizers to enhance plant disease resistance ; Reasonable dense planting to increase permeability.
- In the early stage of the disease: the following pesticide can be used for prevention and treatment: 4% kasugamycin, ecumazole or agricultural streptomycin.