pest guide 5
Fungal diseases often appear as spots similar to bacterial spots, but they typically do not look wet and often have distinctive concentric rings (A & B). Fungi can also cause damping off, where stems of newly emerging seedlings and young transplants collapse inward and cause the plant to fall over and die. Some piercing-sucking insects such as aphids, secrete a sugary substance that can encourage the growth of some fungi such as sooty mold on the leaf surface (C), limiting photosynthesis.