Black point (disease)

Black point (kernel smudge or just smudge^[1]) is a fungal disease that affects wheat, barley and rye. It is caused by various species of Alternaria, Fusarium, and Helminthosporium, and possibly other fungal genera.^[2] The fungus forms after the seeds have set but while they are still green and it is potentiated by high humidity. Infected areas are brown to black in color, and as the disease spreads the kernels may become shriveled. Occasionally the infected areas have a reddish tinge.^[3]

Some authorities^[3] make a distinction between "black point" and "smudge". For them the disease is "black point" from initial infection until more than half of the kernel is infected, or when the disease has entered into the seed's crease.^[3]

Notes and references

1. Bockus, William W. et al. (2010). Compendium of wheat diseases and pests (third ed.). St. Paul, Minnesota: APS Press. ISBN 978-0-89054-385-6.
2. Wiese, Maurice Victor (1987). Compendium of Wheat Diseases (second ed.). St. Paul, Minnesota: APS Press. pp. 12–13. ISBN 978-0-89054-076-3.
3. "Blackpoint and Smudge of Wheat". Plant Disease, Crops Branch, Saskatchewan Ministry of Agriculture. Archived from the original on 25 October 2014.