Sunday, March 14, 2021

Cercospora leaf spot

Today I noticed that some leaves on the wild privet (Ligustrum vulgare) that grows, bird sown, in the north west corner of The Green Sanctuary had several leaves with brown ends.  The brown, dead part was differentiated from the rest of the leaf by a purplish semi circle and, on closer examination indoors, many spore-bearing pustules were seen on this band and across the rest of the underside of the leaf.

This is caused by cercospora leaf spot (Thedgonia ligustrina).  It is, I am sure, is quite common wherever privet grows in the British Isles, though it is rather seldom recorded. It does not appear to cause any great harm to the shrub apart from being, in gardeners' eyes, perhaps a little unsightly.