Karnal bunt of wheat (Triticum spp) — A global scenario

Abstract

Karnal bunt of wheat was first reported in 1931 from Karnal, India. The pathogen infects the ovary and converts the grain into a sorus of dark coloured teliospores. The losses occur in terms of quality and quarantine reasons. The soilborne teliospores after germination produce primary and secondary sporidia under ideal conditions. The allantoid secondary sporidia become airborne by wind or rain splash and infect the emerging spikes. The heterothallic and compatible secondary sporidia fuse prior to infection. The infected grains emit a rotting fish smell due to the production of trimethylamine. The cultivation of resistant varieties, mulching of wheat with chickpea or polythene, use of biocontrol agents like Trichoderma spp and low doses of systemic fungicides like Tilt (propiconazole) and Folicur forms the major components for the integrated pest management strategies. Karnal bunt of wheat has become a major SPS issue in wake of recent Sanitary and Phytosanitary Agreement stipulated by World Trade Organization. Under this agreement each member country has to undertake pest risk analysis for import or export. In the present article, global scenario of Karnal bunt disease along with its different aspects like distribution, pathogen, epidemiology, detection and management strategies have been reviewed.