Tabukia Leaf Spot
What is Tubakia Leaf Spot?
Tubakia leaf spot disease is caused by the fungal species Tubakia dryina. The fungus can overwinter on foliage that remains on your tree and also on leaves that have fallen to the ground. As your tree sprouts new growth in spring and summer, the fungus can infect the new growth.
What Causes It?
The cool, wet spring months encourage the infection to spread; however, you may not notice the disease during this time. By July and August you’ll start to see the brown spots showing up more predominantly. The very wet weather we had this past spring brought on many fungal diseases and we’re now seeing their effects.
Poor air circulation also encourages fungal diseases such as Tabukia. If the tree canopy is overcrowded, selective pruning to improve air flow can help reduce the disease if your tree is heavily affected. Proper watering also goes a long way: Too much water and fungal diseases become more active. Yet, not enough water puts your tree under stress and susceptible to infection.
What Damage Does it Do?
In late-summer, you’ll begin to notice small to large dark brown spots on leaves with a dark brown border and yellow halo around the spots. You may also see lesions along the leaf veins. If the damage progresses, it can eventually cause wilting followed by defoliation. Tubakia leaf spot is sometimes confused with anthracnose. However, visible signs of anthracnose begin to show in late-spring, versus late-summer. To the untrained eye, it can also be mistaken for deadly oak wilt disease. Be sure to have an experienced certified arborist inspect your tree for the right diagnosis.