Also known as kernel smudge
Associated with various fungi (e.g. Alternaria spp., Fusarium spp.) and physiological circumstances
- Symptoms: The pericarps of maturing wheat kernels turn dark brown to black, with the discoloration usually restricted to the germ-end of the kernel (picture on left; seed picture on right is healthy seed). If caused by Alternaria spp., the dark color affects only the pericarp; if caused by Fusarium spp., the germ may be invaded and injured or killed. There are other fungi that can cause black point, but the three noted here are the most common.
- Development: Usually, kernels are infected by these fungi during the dough stage. If humid weather prevails for a few days to a week just prior to harvest, the incidence of infection will increase and black point will develop in many cultivars.
- Hosts/Distribution: Wheat is the principal host; triticale and several related grasses also can be affected. Distribution is worldwide, wherever small grain cereals are grown.
- Importance: Losses are due mainly to discounted prices paid for discolored grain; if Fusarium spp. is involved, the viability of the seed also may be reduced.
