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Brown Rust of Wheat Host: Triticum aestivum Systematic Position Pathogen: P.recondita Division:Basidomycota Sub-division:Basidomycotina Class:Pucciniomycetes Order:Pucciniales Family:Puccinniaceae Genus:Puccinia Species:recondita Introduction This is the common blast disease in India. Mainly the damage is done is due to the leaf rust causing loss at about 25% in the yield and also due to destruction of foliage, sterility of spikelet’s and production of shriveled grains. The pathogen affects the plants in three types of rusts namely: • Stem/black rust: P.graminis • Stripe/yellow rust: P.striformis • Leaf/brown rust: P.recondita Symptoms • Small brown pustules develop on the leaf blades in an irregular manner. • Orange colour pustules are formed on the upper surface of leaves. • Rupturing of leaf takes place in the pustules region. • Pustules are also formed on leaf sheaths and stalks. Casual organism The fungus "Puccinia recondita” causes leaf rust disease of wheat. Structure of fungus They are three types of spores namely: • Urediospore: reddish spore is present on the rust leaf, single celled, brown and spherical • Teleutospore: club shaped spore is present on the rust leaf , two celled, brown, flat-conical • Basidiospore: resting spore of the rust leaf (produced in late summer) single celled, pale with oval-oblong. Disease Cycle Urediospore is the primary spore form involved in infecting the wheat crop. These spores are carried by wind and germinate by falls on moist leaf leading to "secondary infection”. Infected leaf Urediospore Teleutospore Basidiospore Disease cycle Favorable conditions • High humidity i.e., 90% • Optimum temp., i.e., 15-20⁰c Control measures: • Using disease resistant varieties • Changing the crop frequently • Field sanitation • Use of fertilizers: N.P.K(same ratio) • Use of fungicides like Sulphur, Dithane, Zineb, Bayleton