Brown Rust of Wheat
Host: Triticum aestivum Systematic Position
Pathogen: P.recondita Division:Basidomycota
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
• 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.
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.
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
• High humidity i.e., 90%
• Optimum temp., i.e., 15-20⁰c
• 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
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