BLAST OF RICE

DR. RAJBIR SINGH Assistant Professor

Department of Plant Pathology Gochar Mahavidyalaya, Rampur Maniharan, Saharanpur (UP), India Affiliated to Ch. Charan Singh University, Meerut (UP), India

Email: rajbir25805@yahoo.com, rajbirsingh2810@gmail.com

Cell No. 91-9456613374

BLAST OF RICE• 1704 - Seen in Japan

• 1913 – Tanjavur by Butler

• Loss – 75%

• Symptoms:

• All parts except root infected

• Appeared in Nursery

• Boat Shaped water soaked

spots of > 0.5 mm long

• Corner of spot – dark brown red

• Middle – white grey / ash color

• Spots enlarge & collapse – leaf blightning

• Neck Infection / Neck Rot Phase (most dangerous)

• Black grey mycelium on the neck

• No grain formation/ partial formation

http://upload.wikimedia.org/wikipedia/commons/c/c1/Rice_blast_Magnaporthe_grisea.jpg

Pathogen – Pyricularia oryzae

P. grisea (Imperfect stage)

Magnaporthe grisea (Perfect stage)

• Survive in seed & plant residues

• Mycelium survive in puwal – 1-2 years

• Survive on weeds – Penicum repens, Digitaria marginata

• R. H. – 90%

• Tem. – 20-25° C

Systemic Position

Kingdom – Mycota/ Fungi

Division – Eumycota

Sub division – Deuteromycotina

Class – Hypomycetes

Order – Hypomycetales

Family – Dematiaceae

Genus – Pyricularia

Species - grisea

Conidia of Pyricularia gresia

• Reproductive structures -

(1). Conidia – Pear shaped with 2 septa

(2). Chlamydospore

(3). Sclerotium

• Toxin -

(1). Pyricularin

(2). ά– Picolinic acid

• Enzyme - (1). Pectinolytic enzyme

Disease cycle

Disease Management• Use healthy seed

• Seed treatment – Tricyclazole or Beam 75 WP - @ 4 gm/ kg seed

• Removal of weeds

• Use balance fertilizers – no heavy use of N2

• Spray - (i). Beam @ 6 gm/litre or

(ii). Bavistin – 0.1 %

First spray - tillering stage

IIend spray – flowering stage

(iii). Contaf – 0.2 %

• Dis. Res. Var. - IR- 64, Pant Dhan-16, Pant Dhan Sankar - 1

Thank You