Rust flecks on leaves

Young plants are rarely affected by rust. The typical symptoms are seen in 1.5 to 3 months old plants. Scattered purple, red, or tan flecks appear on both surfaces of leaves (Fig.) and in resistant cultivars the symptoms develop no further.

 

 

 

 

 

 

Healthy leaf on left.Rust affected leaf on the right

In susceptible cultivars typical rust pustules develop, mainly on the lower leaf surfaces. When fingers are passed on such leaves reddish powder can be seen on the fingers. In highly susceptible cultivars the pustules occur so densely that almost the entire leaf tissue is destroyed (Fig.).

 

 

 

 

 

 

Pustules on inflorescence stalks

The pustules may also occur on leaf sheaths and on inflorescence stalks.

 

 

 

 

 

 

 

Management

In areas where rust becomes economically important disease, growing less-susceptible or resistant cultivars like PSH 1, SPH 837, CSV 17 etc. is the only solution. Selective fungicides that suppress the disease are usually not economical.