Sorghum ergot, or sugary disease, is a fungal disease of sorghum plants, causing significant global losses. It is a major problem in sorghum production worldwide in many tropical and subtropical regions. To prevent and manage this disease, sorghum producers must understand the disease cycle, its environmental interaction, and risk factors.
Farmers should practice crop rotation and deep plowing and use certified and disease-free seeds to prevent the spread of the disease. This article will provide an overview of sorghum ergot or sugary disease, including its symptoms, biology, and control.
Ergot or Sugary Management in Sorghum
The Causal Organism of Sorghum Ergot or Sugary Disease
- Sphacelia sorghi cause the ergot disease in sorghum. It will develop septate or compartmentalized mycelium.
- The honeydew is a bunch or a tuft of suspended conidia that are uni-cellular, transparent, elliptical, or oblong.
The Disease Cycle of Sorghum Ergot or Sugary Disease
The disease cycle of the Sorghum Ergot, or Sugary Disease starts with the production of asexual spores called conidia, spread by wind and water. These conidia come into contact with the sorghum plant’s flowering head and germinate, forming a haustorium. This haustorium penetrates the flower’s ovary and forms a structure called a sclerotium, the overwintering stage of the fungus.
In the spring, the sclerotia produce sexual spores called ascospores. These ascospores are spread by wind and can infect other sorghum plants, initiating new disease cycles. The ascospores penetrate the ovaries of the flowers, where they germinate and form a structure known as an ascogenous hypha. This hypha then produces conidia, which spread by wind and water and infect other sorghum plants.
The conidia germinate on the surface of the sorghum plant, producing structures called stromata. These stromata are the structures responsible for producing the ergot bodies, which are black and hard, and contain the fungal spores. The ergot bodies are spread by animals or rain splashes to other plants.
Mode of Spread And Survival of the Pathogen In Sorghum Crop
- The sclerotia of the fungus can survive in the soil for many years, making the disease difficult to control.
- The primary means of disseminating the disease is ascospores that emerge out of sclerotia after its germination, infecting the ovary of the flowers.
- The secondary means of spread is via wind and conidia carried by insects. The rain splashes and infected seed heads contaminating healthy seed heads are other sources of disease spread.