The Purdue Plant and Pest Diagnostic Laboratory

P&PDL Picture of the Week for
August 14, 2006

Tubakia (Actinopelte) Leaf Spot on Oak

Gail Ruhl, Senior Plant Disease Diagnostician, Dept of Botany & Plant Pathology, Purdue University

Tubakia leaf spot (formerly called Actinopelte leaf spot), is a common late-season fungal disease of oaks. Although all species of oak appear to be susceptible to this disease, oaks in the red oak group such as black, red and pin oak, appear to be most susceptible. Symptoms include small to large dark brown or reddish-brown spots or blotches. Spotting that occurs on leaf veins may cause large extended areas of dead leaf tissue along the veins. If trees are heavily infected with Tubakia leaf spot, premature defoliation may occur, however, disease usually develops late enough in the season such that adverse affects on the health of trees are minimal. Fungicide sprays are not recommended. Maintain good tree vigor by watering during drought stress periods and fertilizing trees appropriately

Refer to HO-140 Fertilizing Woody Plants

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Tubakia leaf spot

Tubakia leaf spot

Tubakia leaf spot

Tubakia leaf spot

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service