Ace the Certified Arborist Test 2025 – Branch Out and Leaf Your Mark!

Curling and cupping of foliage accompanied by parallel venation is typically a sign of herbicide damage. Herbicides can cause specific physiological responses in plants, leading to characteristic symptoms. When a plant is exposed to herbicides, especially those that affect growth hormones, you may observe abnormal growth patterns, including the curling and cupping of leaves. This is particularly common in monocotyledonous plants, which often display parallel venation.

In contrast, insect feeding generally leads to different types of physical damage, such as holes in leaves or browning at the edges, but not specifically curling or cupping as a primary symptom. Fungal infections can cause a range of issues, including leaf spots, wilting, and overall decline, but again, these symptoms do not specifically include the curling and cupping pattern seen with herbicide exposure. Water stress can cause leaf drooping, scorching, or premature leaf drop but does not typically result in curling and cupping outcomes.