RUST
Rust disease of wheat caused by three different species of Puccinia and it is one of the earlier known disease of plants. All three types of wheat rust disease ( Black or stem rust caused by Puccinia graminis tritici , brown or leaf rust caused by P. triticina and yellow or stripe rust caused by P. Striiformis that occur almost universally .
Symptoms:
Black rust ( stem rust)
This rust generally appears in wheat late in the season ( during March - April) in North India. Elongated dark reddish brown pustules appear mainly on stem and less frequently on leaf and leaf sheath.
Rust disease of wheat caused by three different species of Puccinia and it is one of the earlier known disease of plants. All three types of wheat rust disease ( Black or stem rust caused by Puccinia graminis tritici , brown or leaf rust caused by P. triticina and yellow or stripe rust caused by P. Striiformis that occur almost universally .
Symptoms:
Black rust ( stem rust)
This rust generally appears in wheat late in the season ( during March - April) in North India. Elongated dark reddish brown pustules appear mainly on stem and less frequently on leaf and leaf sheath.
Telia pustules are brown - reddish to black in colour and these pustules burst early which release rusty power mass.
Brown rust ( leaf rust).
It is earliest rust to appear on wheat in plains and more damaging than black rust. Orange to orange brown , round shaped uredia pustules mainly scattered irregularly on the leaves and rarely on leaf sheath and stem .
The telia are rare produced, if produces they are oval , dull black in colour and produced mainly on lower surface of leaves which is covered by the epidermis.
Yellow rust (Stripe rust) Yellow rust is generally more destructive than other rust . Yellow to lemon yellow coloured,oval shaped uredia pustules arranged in narrow stripes on leaves.The telia are dull black in colour and produced mainly on lower surface of leaves , which is covered by the epidermis.
Causal Organism :
Puccinia belong to Kingdom Fungi , Phylum Basidiomycetes , Subphylum Pucciniomycotina, Class Pucciniomycotina , Order Puccinia les , Family Puccinia ese , Genus Puccinia . Three stages of spore viz. Uredia spore , teliospore and basidiospore are found in wheat plants where's, pycniospores and aeciospores ate found on alternate host plants in hills.
Disease cycle.
Rust of wheat is an air born disease . The summer temperatures are very high in a plain which dose not survival of the fungus. The Fungi survive in the form of uredinial stage on wheat plant dedris , self sown wheat plant . The uredia pores are disseminated by wind from hills to plains and cause infection in wheat plant. The optimum temperature for P. graminis tritici, P.recondita and P.striiformis is 24℃,20℃and 09-13℃,respectively.
Management:.
1-Use resistant varieties - HD 2888, DBW- 17,NW-2036 .
2-Excessive use of nitrogenous fertilizer should be avoided.
3- Foliar spray of Dithane M 45 @ 0.2%.
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