Bakanae disease/foot rot:Gibberella fujikuroi
- Infected plants several inches taller than normal plants in seedbed and field
- Thin plants with yellowish green leaves and pale green flag leaves
- Drying of seedlings at early tillering
- Reduced tillering and drying leaves at late infection
- Partially filled grains, sterile or empty grains for surviving plant at maturity
- In the seedbed, infected seedlings with lesions on roots will die, which may die before or after transplanting
Identification of pathogen:
- The pathogen sexually produces ascospores that are formed within a sac known as ascus.
- The asci are cylindrical, piston-shaped, flattened above and are 90-102 x 7-9 µm. They are 4 to 6 spored but seldom 8 spored.
- Hyphae are branched and septate. This fungus produces micro and macroconidiophores bearing micro and macroconidia respectively.
- The sclerotia are 80 x 100 µm. They are dark blue and spherical. The stroma is more or less plectenchymatous and yellowish, brownish or violet.
- Clean seeds should be used to minimize the occurrence of the disease.
- Salt water can be used to separate lightweight, infected seeds from seed lots and thereby reduce seed borne inoculum.
- Seed treatment using fungicides such as thiram or thiophanate-methyl or benomyl is effective before planting or Benomyl at 1-2% of seed weight may be used as dry seed coating
- Seed treatment with organomercurials such as Agrosan GN or Ceresan @ 2 g a.i./kg seed is highly effective; steeping seeds in 1% copper sulphate solution or 2% formalin also recommended.
- TamilNadu Agritech Portal