Plants, just as humans and animals, battle fungal diseases. Fungi act as parasites, stealing energy from plants. Fungal diseases are problems for home gardeners, as well as for the agricultural industry. Usually, plant fungal infections show many clear signs of a problem, which are often noted by the name of the disease. Caretakers should detect common symptoms, such as water-soaked leaf spots, yellowed leaves and rust, so they can stop an infection before it spreads.
Powdery mildew is a common plant fungal disease that appears in most landscape plants. Signs of powdery mildew are a white or gray chalky-looking substance on the surfaces of leaves, flowers, stems or fruit of an infected plant. A leaf that curls and twists may be noted even before the fungus is seen, notes Ohioline. Yellowed, dried-brown leaves and disfigured flowers and shoots are other signs of a serious powdery mildew infection. The disease isn't fatal, but it's unattractive and can cause plant defoliation and fall dormancy.
Early blight is fungal disease that typically infects vegetable plants such as potatoes, tomatoes and eggplants. It's extremely damaging in humid and temperate climates. This fungal disease can attack a plant at all stages of its development, although it's called early blight. Symptoms are seen in the above-ground parts of plants, but the fungus can kill a seedling both before or after it emerges from the ground. Signs of early blight are brown circular leaf spots with concentric rings, resembling a target. The University of Connecticut suggests using disease-free transplants and seeds to prevent the disease. Regular weeding around plants and planting in highly fertile soil also helps control the disease. Water plants early in the day to reduce leaf wetness.
Septoria Leaf Spot
Septoria leaf spot is a fungal disease affecting vegetable plants including tomatoes, potatoes and eggplant. The disease causes leaf defoliation resulting in a reduction in crops. Signs of the problem are yellowish, round spots appearing on leaves with symptoms first starting on lower leaves. These spots later turn gray or brown and may have a dark or yellow border. Severe infections can cause leaves to fall off, usually at the base of the plant and then progressing upward. A plant's fruit is rarely affected. The University of Connecticut recommends practicing crop rotation and using disease-free seeds or transplants to help prevent the disease.
Cotton Root Rot
Cotton root rot is a fungal infection that attacks many types of plant. It inflicts the below-ground portions of citrus trees and is sometimes fatal to young trees. Plant maturity reduces the likelihood of contracting cotton root rot. The infection usually kills susceptible trees, but most of the tree's dried leaves remain on an infected tree, temporarily. Texas Agriculture Extension Service contends that the most effective protection against the problem is using resistant rootstocks.