Course Content
Common bunt of wheat
Angular leaf spot/ bacterial blight/boll rot/black arm of cotton
Rice tungro virus
Rice grassy stunt virus
Rice ragged stunt virus
Rice yellow dwarf disease
Learn crop diseases and their management with Braimy- B.Sc agriculture
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Asexual stage: pyricularia oryzae ( p. grisae )

Sexual stage:  Magnaporthe grisea

First time reported in Nepal in 1966 A.D.

The typical symptoms appear on leaves, leaf sheath, rachis, nodes and even the glumes are also attacked.

Leaf blast

  • Small water soaked bluish green specks,soon enlarge diamond shaped spots with grey centre and dark brown margin.

Arkansas Rice: Leaf Blast Alert – AgFax

Node blast:

  • In infected nodes, irregular black areas that encircle the nodes can be noticed.
  • The affected nodes may break up and all the plant parts above the infected nodes may die (Node blast).

What Is Rice Blast – Tips For Recognizing And Preventing Rice Blast Fungus

Collar blast:

  • The collar of a rice plant refers to the junction of the leaf blade and the sheath.
  • Necrosis at the union of the two tissues.
  • Collar infections can kill the entire leaf and may extend a few millimeters into and around the sheath.

Rice Flag Leaf Collars

Neck or Panicle blast:

  • The neck of the rice plant refers to that portion of the stem that rises above the leaves and supports the seed head or panicle.
  • At the flower emergence, the fungus attacks the peduncle which is engirdled, and the lesion turns to brownish-black.
  • Referred to as rotten neck/neck rot/neck blast/panicle blast.
  • In early neck infection, grain filling does not occur and the panicle remains erect like a dead heart caused by a stem borer. In the late infection, partial grain filling occurs.
  • Lesions can be found on the panicle branches, spikes, and spikelets.
  • The lesions are often gray brown discolorations of the branches of the panicle, and, over time, the branches may break at the lesion.

Rice blast disease | Agriculture and Food

Rice seed

  • Brown spots, blotches, and occasionally the classic diamond-shaped lesion often seen on leaves.

Rice blast

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