Leaf Rust /Brown Rust

Puccinia recondita tritici.

Distribution: Throughout wheat growing regions of India.

Development: Pathogen over-summers in low and mid altitudes of Himalayas and Nilgiris. Primary infections develop from wind deposited urediospores in eastern Indo-gangetic plains in middle of January where it multiplies and moves westwards by March. Temperatures of 20 :t 5° C with free moisture (rain or dew) cause epidemics. Severe infection causes upto 30 percent yield losses.

Management: The presently recommended varieties in most of the wheat growing zones are rust resistant.

Stripe Rust /Yellow Rust

Puccinia striiformis tritici

Distribution: Hills, foothills and plains of north western India and southern hills zone (Nilgiri hills of Tamilnadu).

Development: Spreads through air-borne urediospores, when temperature are 10­20°C but the spread is checked above 25°c. Pathogen survives in the cool temperatures of hills ( Himalayas and Nilgiris ) and the primary infection takes places by middle of January in the foot hills and sub mountainous parts of north western India. Also, infection comes from across the western border, hence the probability of evolution of new races increases in this area. Yellow rust from Nilgiri hills cannot come out of the zone due to high temperatures in the Peninsular and Central India.

Management: Most of the presently recommended varieties are resistant. Major emphasis is on host resistance and cultivation of resistant varieties is the main strategy of management.

 

Stem Rust /Black Rust

Puccinia graminis tritici

Distribution: Mainly in Peninsular and I Central India, may occur in traces in Northern India too'

were the infestation comes late.

Development: Develops from air-borne urediospores, needs free moisture and temperature above 20° C for spread. It can cause severe grain losses if infection is early. The pathogen perpetuates in Nilgiri hills during off season and becomes air­borne. If Peninsular and Central India experience rainfall during November then epidemics are severe. Late infections cause less damage in north India.

Management: The presently re­commended varieties in most of the wheat growing zones are rust resistant, hence the old susceptible varieties be avoided.