Disease:False Smut/lakshmi Disease

Ustilaginoidea virens Anamorph Claviceps oryzae-sativae Telomorph

This has been regarded as a minor disease but recently false smut has assumed the status of a major disease in certain regions causing significant losses in yield up to 40%.

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  • Disease 1
  • Disease 2
  • Disease 3
  • Disease 4
  • Disease 5
  • Disease 6
  • Disease 8
  • Disease 9
  • Disease 10
  • Disease 11
  • Disease 12
  • Disease 13
  • Disease 14

Symptoms

  • The disease causes both quantitative and qualitative losses.
  • The symptoms produced are visible only after flowering.
  • In the maturing panicle, few individual grains are converted into greenish spore balls of a velvety appearance.
  • The affected grains are transformed into masses of spores that are greenish outside and yellowish inside, initially covered by a membrane.
  • The membrane bursts at the time of maturity of the spores and the ball becomes orange coloured and later yellowish green or greenish black.
  • The membrane bursts at the time of maturity of the spores and the ball becomes orange coloured and later yellowish green or greenish black.
  • The chlamydospores of the fungus also contaminate the rice grains and straws with their peptide toxins which are poisonous to humans and animals.

Control Measures

  • Avoid sclerotia and chlamydospores infected seeds for sowing.
  • The disease usually does not require special control measures. However, if severely infected area, spray mancozeb 0.2%, triadimefon 0.2 % (Bayleton 25 WP) before flowering.