Rust of Groundnut

This disease occurs in Central and South America, West Indies, Venezuela, China, erstwhile U.S.S.R., U.S.A.  and India. In India it was first observed in 1971 in Punjab, Tamil Nadu, West Bengal mand Andhra Pradesh. This has become one of the serious disease of groundnut.

Etiology

Causal organisum : Puccinia arachidis Speg.

            The uredospores are one celled, sub-globose, ovoid or round, light brown or brown in colour and thin walled. They measure 24.9 x 21.2 µ. They have been reported from Punjab. Teliospors measure 38-42 x 14-16µ.

Symptoms

•  Orange coloured pustules (uredinia) on the lower leaflet surface
• Rupture as masses of reddish brown urediniospores
• Pustules appear first on the lower surface of leaflet
• Pustules may also appear on the upper surface of the leaflet
• Severely infected leaves turn necrotic and desiccate but are attached to the plant.

  orange coloued pustules on       later turn to red coloured pustules                  Severly affected plot                               

  lower surface of leaves

Epidemiology

            Primary source of infection self sown (volunteer) groundnut plants and. Secondary spread by Wind and rain splash. Conginal climate for disease development was wet weather, leaf wetness and temperature of 22-25 ⁰C.

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