Lets Discuss Blast Disease
Of Rice
(Botanical name of rice- Oryza sativa)
1. Rice Blast Disease:-
·
Leaf Blast.
·
Nodal Blast.
·
Neck Blast.
2. Brown Spots of Rice.
3. Bacterical Leaf Blight (BLB).
4. Sheath Blight.
5. False Smut.
6. Khara Disease.
7. Tungro Disease of Rice.
Rice Blast Disease:-
Causal organism Magnaparthe
oryzae causing rice blast disease.
Symptoms- Leaf blast, Nodal blast, Neck blast
·
Leaf Blast:- A diamond shape or bload or
eye shape white to gray or red dish brown lesion with reddish to brown borders.
The lesions
may enlarge and kill entire leaves in favourable condition.
·
Nodal Blast:- Infection
at joint at stem.
Brown to
black coloured discoloration.
Pathogen grow
and girdle the node.
· Neck Blast:- Infection at joint of stem and panicle. Pathogen grow and girdle the neck. This is usually the most distructive symptom of the disease and is called the neck rot, neck blast or panicle blast stage of the disease. If Infection of the panicle neck occurs early, the grains do not file and the panicle neck is infected late, the grains become partially filled and because of the weight of the grains, the base of the panicle breakes and the panicle droops.
Favourable
Condition-
Intermittent
drizzles, cloudy weather, more of rainy days, longer duration of dew.
High relative humidity
(93-99%).
Low night temperature
(b/w 15-20 degree celsius or less then 25 degree celsius).
Availability of
collateral hosts and excess dose of nitrogen.
Management Practice:-
Grow resistant
varieties.
Sanitation,
remove and destroy the host weed, irrigation management, disease free seeds,
crop rotation with non host.
Seed treatment
with Pseudomonas fluorescens @ 10g/kg.
And treat the
seed with Tricyclazola @2g/kg.
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