Loose kernel smut of sorghum

Sphacelotheca cruenta (syn. Sporisorium cruentum) is a fungal pathogen within the kingdom Fungi and the phylum Basidiomycota. It is the causal agent of the loose kernel smut of sorghum, a widespread disease affecting various sorghum species globally.

The disease primarily manifests in the inflorescence of the plant. Unlike other smut types, the ovaries of the infected flowers are transformed into elongated, gall-like structures filled with powdery teliospores. These galls rupture early, releasing the spore mass to infect neighboring plants or contaminate the soil.

The life cycle of the pathogen begins at the seedling stage. Infection is triggered by the penetration of the fungus into the plant tissues. The pathogen remains systemic, developing quietly within the host's vascular system until the plant enters the reproductive phase, when it colonizes the inflorescence.

Environmental conditions play a critical role in disease spread. The optimal conditions for infection include moderate soil temperatures ranging from 18°C to 25°C and adequate soil moisture during the germination period. Dry weather during the early vegetative stages often suppresses the development of the disease.

Economic damage is significant, as the infection results in complete yield loss of the affected heads. Furthermore, infected plants may exhibit stunted growth and abnormal tillering. Control strategies focus on integrated pest management, primarily through the use of high-quality, fungicide-treated seeds and crop rotation.

• Use of certified fungicide-treated seeds.
• Selection of resistant or tolerant sorghum cultivars.
• Implementation of crop rotation to reduce soil-borne inoculum.
• Strict field sanitation and removal of infected debris.