Host and Symptoms
L. maculans causes phoma stem canker or blackleg. Symptoms generally include basal stem cankers, small grey oval lesions on the leaf tissue and root rot (as the fungus can directly penetrate roots).L. maculans infects a wide variety of Brassicae crops including cabbage and oilseed rape. L. maculans is especially virulent on Brassica napus. The first dramatic epidemic of L. maculans occurred in Wisconsin on cabbage. The disease is diagnosed by the presence of small black pycnidia which occur on the edge of the leaf lesions. The presence of these pycnidia allow for this disease to be distinguished from Alternaria brassicae, another foliar pathogen with similar lesions, but no pycnidia.
Read more about this topic: Leptosphaeria Maculans
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