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Sunday, April 17, 2011



3 comments:

  1. recently lunched logo of DEPARTMENT OF AGRICULTURE JAMMU

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  2. PADDY CROP
    Nursery diseases

    1.
    Blast: Pyricularia grisea (P. oryzae)
    2.
    Bacterial Leaf Blight: Xanthomonas oryzae pv. oryzae
    3.
    Rice tungro disease : Rice tungro virus (RTSV, RTBV)

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  3. Nursery diseases

    1. Blast :Pyricularia grisea (P.oryzae)

    Occurrence

    *
    Earliest known plant disease
    *
    Also known as rotten neck or rice fever.
    *
    Reported from 80 rice-growing countries. First recorded in India during 1918.
    *
    Expected grain loss : 70 to 80%


    Symptoms

    *
    Disease can infect paddy at all growth stages and all aerial parts of plant (Leaf, neck and node).
    *
    Among the three leaves and neck infections are more severe.
    *
    Small specks originate on leaves - subsequently enlarge into spindle shaped spots(0.5 to 1.5cm length, 0.3 to 0.5cm width) with ashy center.
    *
    Several spots coalesce -> big irregular patches

    Infected leaf

    Healthy leaf



    Healthy leaf

    Leaf

    collar

    nodal

    neck


    Leaf Blast :

    *
    Severe cases of infection - entire crop give a blasted or burnt appearance- hence the name "BLAST"
    *
    Severe cases - lodging of crop (after ear emergence)

    Neck Blast

    *
    Neck region of panicle develops a black color and shrivels completely / partially grain set inhibited, panicle breaks at the neck and hangs

    Nodal Blast: Nodes become black and break up
    Management

    *
    Avoid excess N - fertilizer application
    *
    Apply nitrogen in three split doses.
    *
    Removes weed hosts from bunds.
    *
    Use of tolerant varieties (Penna, Pinakini, Tikkana, Sreeranga, Simphapuri, Palghuna, Swarnamukhi, Swathi, Prabhat, Co 47, IR - 64, , IR - 36, Jaya)
    *
    Burning of straw and stubbles after harvest
    *
    Dry seed treatment with Pseudomonas fluorescens talc formulation @10g/kg of seed.
    *
    Stagnate water to a depth of 2.5cm over an area of 25m2 in the nursery. Sprinkle 2.5 kg of P. fluorescens (talc) and mix with stagnated water. Soak the root system of seedlings for 30 min and transplant.
    *
    Spray P. fluorescens talc formulation @ 0.5% from 45 days after transplanting at 10 day intervals, three times.
    *
    Seed treatment at 2.0 g/kg seed with Captan or Carbendazim or Thiram or Tricyclazole.
    *
    Spraying of Tricyclazole at 1g/lit of water or Edifenphos at 1 ml/lit of water or Carbendazim at 1.0 gm/lit.
    *
    3 to 4 sprays each at nursery, tillering stage and panicle emergence stage may be required for complete control.

    Nursery stage

    *
    Light infection - Spray Carbendazim or Edifenphos @ 0.1 %.

    Pre-Tillering to Mid-Tillering

    *
    Light at 2 to 5 % disease severities - Apply Edifenphos or Carbendazim @ 0.1 %. Delay top dressing of N fertilizers when infection is seen. Panicle initiation to booting
    *
    At 2 to 5% leaf area damage spray Edifenphos or Carbendazim or Tricyclazole @ 0.1 %.

    Flowering and after

    *
    At 5 % leaf area damage or 1 to 2 % neck infection spray Edifenphos or Carbendazim or Tricyclazole @ 1 g /lit of water.

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