Ergot in sorghum

Ergot can be an economically devastating problem.In seed production fields, yield losses ranging between 10 to 80% due to ergot disease have been reported in India. Although yield losses associated with ergot infection can be significant, indirect losses may be even more important. Harvesting grain from ergot-infected fields can be difficult. Ergot contamination reduces grain quality and limits its use as a feedstock.

Ergot infested panicle

Ergot or sugary disease results from the ergot fungus infects the florets in the earhead (panicle) and prevents seed set in such florets (Fig.).

Honeydew exuding from florets

The first symptom is droplets of liquid honeydew exude from between the glumes of infected florets (Fig.). Honeydew may range from colorless to start with to yellow, brown or white with a thin to viscous consistency.

 

Ergot infested earhead

If honeydew exudation is profuse, it may drip down and smear the whole earhead, sometimes dripping down onto the soil. If the exudates is plentiful, the earhead appears with blackened grain (Fig.).

 

 

 

Management:

Sowing of ergot free seed. Soaking seeds with 5% salt solution will aid to remove ergot infested seeds, as ergot infested seeds will float in the salt solution. Seed treatment with fungicides such as Captan or Thiram.Control of ergot with fungicides such as Propiconazole or Tebuconazole has proved to be cost effective in seed production plots. Multiple sprayings at 5-7 days interval from flag leaf stage till end of an thesis are recommended to accommodate the variation in flowering within a field.

The grain on the left is physiologically mature; the one on the right is not.

The best stage to harvest sorghum is when the plants reach the physiological maturity. Physiological maturity can be determined by the black (dark) spot at the bottom of the grain as shown in the Fig.