Disease Directory

    Stem Rust

    Puccinia graminis f. sp. tritici

    Fungus
    Stems
    Leaves

    Overview

    A devastating rust disease of wheat and other cereals that can cause complete crop loss. Historically one of the most feared plant diseases, with new virulent races (Ug99) threatening global wheat production.

    Symptoms

    Reddish-brown, elongated pustules on stems, leaf sheaths, and sometimes leaves. Pustules rupture epidermis and release masses of spores. Stems may weaken and lodge. Black teliospores form late in season.

    Environmental Conditions

    Humid

    Prevention

    Plant resistant varieties. Eradicate barberry (alternate host). Early planting to avoid peak spore periods. Monitor for new virulent races. Fungicide application at first signs.

    Management

    Apply triazole or strobilurin fungicides at first signs. Plant resistant varieties. Eradicate barberry bushes. Harvest early if infection is severe. Report unusual rust outbreaks to authorities.