Blast disease in Rice

SHORT NOTES FOR UG

1. Dr. V. RAMESH
Assistant Professor & Head
Department of Botany
Vivekananda College
Tiruvedakam West –625 234
[email protected]
[phone]
BLAST DISEASE IN RICE

2. CAUSAL ORGANISMS: Magnaporthe oryzae or pyricularia oryzae
It causes areas with low soil moisture, frequent and prolonged periods
of rain shower, and cool temperature in the daytime.
INTRODUCTION
Blastisafungaldisease.Itcanaffectallabovegroundpartsofarice
plant:leaf,collar,node,neck,partsofpanicle,andsometimesleaf
sheath.
HOSTPLANT:Oryzasativa
Spores ofM. grisea

3. SYMPTOMS OF BLAST DISEASE IN RICE
Lesions on NodesLesions on Leaf
Lesions
AffectedRice

4. SYMPTOMS
Initial symptoms appear as white to gray-green lesions or spots, with
dark green borders.
Older lesions on the leaves are spindle-shapedand whitish to gray
centers with red to brownish or necrotic border.
Some resemble diamond shape, wide in the center and pointed
toward either ends.
Lesions can enlargeand growing together to kill the entire leaves.
Leaf blast lesions are usually elongated and pointed at each end

5. CONTROL MEASURES
Theprimarycontroloptionforblastistoplantresistantvarieties.
Adjustplantingtime.Sowseedsearly,whenpossible,aftertheonset
oftherainyseason.
Applynitrogenfertilizerapplicationintwoormoretreatments.
Siliconfertilizers(e.g.,calciumsilicate)canbeappliedtosoilsthat
aresilicondeficienttoreduceblast.
SystemicfungicideslikeTriazolesandStrobilurinscanbeusedfor
controltocontrolblast.

6. THANK YOU