uavs in agriculture,geopositioning drones,pesticide spraying unmanned helicopter, battery powered drone

Shenzhen Eagle Brother UAV Innovation Co., LTD
  • uavs in agriculture,geopositioning drones,pesticide spraying unmanned helicopter, battery powered drone   uavs in agriculture,geopositioning drones,pesticide spraying unmanned helicopter, battery powered drone   uavs in agriculture,geopositioning drones,pesticide spraying unmanned helicopter, battery powered drone   uavs in agriculture,geopositioning drones,pesticide spraying unmanned helicopter, battery powered drone  
  • Chinese
    Espanol
  • location: Home > Explore > Blog >

    How to Control Rice Blast

    data:2018-05-26 10:26source:https://extension2.missouri.ed author:Allen Wrather & Laur click:
    Rice is one of the leading food crops of the world. And rice blast, also called rotten neck, is one of the most destructive diseases worldwide. Losses due to this disease have been on the increase since 2000. Blast does not develop every y
    Rice is one of the leading food crops of the world. And rice blast, also called rotten neck, is one of the most destructive diseases worldwide. Losses due to this disease have been on the increase since 2000. Blast does not develop every year but is very destructive when it occurs.
     
     
    Symptoms
    Some times this disease refers as pyricularia blight or rotten neck, generally distributed where ever rice is grown. Small spots appear on leaves, nodes, panicles and grains and sometimes on leaf sheaths. The spots begin as small, water-soaked, whitish, greyish or bluish dots. These spots rapidly increase and become grey in center. Brown to black spots also develops on inflorescence and glumes. In later stages, diseased heads appear blasted and whitish in color. Grain development is affected and the panicles droop.
     
     
    Cause
    This disease is caused by a fungus named pyricularia grisea, which overwinters in rice seeds and infected rice stubble. The fungus reproductive structures, spores, can spread from these two sources to rice plants during the next growing season and initiate new infections. Spores from these new infections can spread by wind to other rice plants over great distances. There are several races of pyricularia grisea around the world.
     
     
    Control

    Use preventive measures

    Incorporate or roll the rice stubble soon after harvest to promote early decomposition.

    Plant the least-susceptible varieties and use a broad-spectrum seed treatment.

    Grow rice in open fields free of tree lines particularly on east and south sides

    Grow rice in fields where flood levels are easily maintained. Damage from blast can be reduced by keeping soil flooded 2 to 4 inches deep from the time rice plants are 6 to 8 inches tall until draining for harvest. Draining for straighthead is incompatible with the flooding required for blast control,
    so avoid fields with a history of straighthead and varieties susceptible to straighthead, or plant blast-resistant varieties in these fields.

    Seed over a range of time to spread the heading dates. However, avoid planting late because blast will be more severe.

    Seed to a stand of 15 to 20 plants per square foot.

    Avoid excessive nitrogen application rates and apply no more than 30 pounds per acre of nitrogen per application at midseason. In fields with a history of blast, always split applications.
     
    Use fungicides
     
    Scout fields for blast symptoms from the seedling through heading stages (see Scouting). If symptoms are found, prepare to use fungicides at the late boot stage and again when 80 to 90 percent of plants are headed.
     
    Apply fungicides if blast symptoms have been observed in the field and the variety is very susceptible. Fungicides should be applied a second time about two days after 50 percent heading (90 percent head exsertion). In uniform stands, 90 percent heading will occur in 4 to 5 days after the first heads are visible.
     
    The decision to treat is more easily made when one or more of the following factors exist:
    • A susceptible variety is grown in the field.
    • The crop has excessive growth and a dense canopy.
    • Leaf symptoms have been found in the field.
    • Disease is present in southern parts of the field.
    • Cool, rainy, or cloudy weather with high humidity and heavy dews is predicted during heading.
    • The development of this disease is difficult to predict, and fungicide treatments are expensive. Therefore, you should treat on the basis of the above factors or automatically treat the field with a fungicide if you are unwilling to risk disease damage.
     

    Tricyclazole is a common fungicide
     
    Scouting
     
    Early
    Rice fields should be scouted for leaf symptoms of blast beginning at the seedling stage and continuing until early heading. Leaf symptoms will appear most readily on plants at the edges of fields, on levees, in areas of the fields that are shaded in the morning, or in areas that received excessive nitrogen. Symptoms usually are worse on drought-stressed rice.
    If you are uncertain about diagnosing blast symptoms, send a sample to your local MU Extension center for identification. A preboot fungicide application may be needed when foliage damage is severe and the stand is threatened. Proper fertilization and continuous flooding should minimize seedling damage.
     
    Midseason
    You should continue to scout for blast near the heading stage and watch carefully for flag leaf collar symptoms on early-planted susceptible varieties. Also, devote time to determine the stage of rice development to see if the DD50 predicted time frame for fungicide treatment for blast is correct. Symptoms appear 4 to 6 days after infection, so rice heads may be infected without symptoms appearing.
     

    Eagle Brothers's helicopter sprayed at full autonomous mode for rice protection


    Excerpt from:  https://extension2.missouri.edu/
    ------分隔线----------------------------