Oat crown rust, an emerging threat to Pakistan

Date:12-15-2009


Oat has a special position in Pakistans economy, where it is mostly used as fodder. It is suitable to local conditions because it is high yielding and nutritious with 3 crops a year. It covers the "lean" periods December-January and May-June when no other fodder is available. But a global threat to oats has recently been reported in Pakistan -- crown rust (_Puccinia coronata_). The word "crown" refers to the shape of a type of spore and is not related to disease features.
 
Crown rust ( What is it? ) is difficult to control because of its life cycle, rapid changes in pathogenicity, and host resistance breakdown. While oat crops for grain have clearly defined seasons limiting the spread of rust, oats for forage are grown as continuous green crops creating a "green bridge" on which the rust can survive all year round. Despite a large number of resistance genes available, the average effective life span of new crown rust resistant oat cultivars is 3 to 5 years.
 
In Pakistan more than 35 per cent of land is under forage. Green yield of oat in rain-fed areas is about 20 ton/ha [8 ton/acre] and 60-80 ton/ha [24.3-32.4 ton/acre] in irrigated areas. Crown rust is an emerging threat to Pakistan that hit some areas in the last 4-5 years. Pakistan and India are not big producers of oat, but this crop makes a major contribution to their national income. If their high dependency on oat fodder and low actual production potential is superimposed with crown rust, it will leave a bad memory in the history of Pakistan.