blast of rice

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

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