Rust of linseed
- 1. RUST OF LINSEED S.S. JAIN SUBODH P.G. (AUTONOMOUS) COLLEGE , JAIPUR NAME :- AJAY BANSHIWAL Flax Rust
- 2. • Rust disease of linseed, which cause great damage to the crop, is experienced in most of the linseed ( Linum utitatissium ) growing areas of the world. • In india, the crop is sown in October / November ,the rust appears in the month of February/ March. • The disease so severely affects the linseed plants that they impart fired appearance during their harvesting time • This result in ultimately reduction in seed yield and injury to fiber in flax. • Oil content of seed is also affected INTRODUCTION
- 3. SYMPTOMS • First the leaves and then almost all areal part of the plant get infected. • Infected plant part possess large orange yellow coloured uredopustules ( uredia, uredosori ). • The uredia are nearly round and small occurring on both the surface of the leaves. • Uredia elongate and irregular on stem. • Heavily infected leaves showing necrosis • In the later stage of infection reddish – brown teleutopustule develop on leaves and most commonly on stem.
- 4. CAUSAL ORGANISM • The causal organism is Melampsora lini . • Melampsora lini is an autoecious rust as all it’s the four stage occur on the linseed plant. • (1)Pycnial (2) Aecial (3) Uredial (4) Telial • The pycnial and aecial stage of fungus have not been observed in india. • The mycelium of the fungal pathogen is septate, branched, dikaryotic, sub-epidermal and intercellular • The uredia are orange-yellow coloured , scattered or in groups usually rounded on leaves but elongated on the stem. • The uredospores are binuclate ovate, possessing fine warts and indistinct germ spore on their walls and measuring 15- 25*13-18µ.
- 5. The telia are produced during the end of the season. The telia are elongated reddish-brown in colour and are mostly formed on the stems, leaves are also affected. Teleutospore arranged in palisade like manner. The teleutospore are sessile, cylindrical, unicellular, reddish-brown in colour, measure 42-80×8-20µ.
- 6. • In temperate countries, primary infection takes place through basidiospores which are produced as a result of germination of teleutospores perennating in the soil. But in tropical countries, the teleutospores, produced at the end of growing season i.e. April-May, loose their viability due to excessive heat of summers. • Uredospores too are killed due to excessive temperatures. It is presumed that the uredospores produced on linseed at hills come down to plains to cause infection. Thus the primary inoculum, windblown, fall on the host, germinate and cause infection. • Because the transportation of uredospores from hills takes some time, the outbreak of the disease in plains takes place only after 2-3 months of the sowing of the crop. • Uredospores produced as a result of primary infection cause secondary infection. Since the uredospores take very little time to germinate the secondary infection is caused within a short time. Secondary infection along with primary infection cause heavy damage to the seed crop. • Teleutospores produced at the end of the growing season appear to have no role to play in the continuance of the life cycle of the rust. DISEASE CYCLE
- 8. Control Measures of the Rust of Linseed • Use of disease resistant vars. like NP (RR) 9, 10, 56, 95, 218, 279B 279K3, 368, 381, 389, 415 and 501 is the only effective method to control the disease. • Seed treatment to kill the teleutospores in hills has also been suggested. • Avoidance of excessive nitrogenous manures is recommended.
- 9. Thank You