The leaves of your plants are much more than pretty appendages. The plant's foliage is where its food production, or photosynthesis, occurs. These little machines not only produce the food for your plant, they help transport food and nutrients throughout the rest of the tree. Leaves that become ill or infected with fungal diseases become unable to complete their duties. While the loss of a few leaves will not have much effect on your plant, the severe infection of foliage or complete loss of your plant's foliage can have a detrimental effect to the plant's health.
Fungal foliage diseases are spore-borne diseases. These diseases are most commonly presented after periods of cool, damp weather, high humidity and decrease air circulation throughout, and around, the plant. The fungal spores normally lie dormant during the plant's dormancy period and take shelter in leaf's crevices and in decomposing foliage around the plant. During the cool, damp periods, these fungal spores become active and are swept onto the plant's foliage by wind and rain. Once in position, the fungal spores infect the foliage and begin its spread throughout your plant.
Leaf spots are the most common signs of a fungal foliage infection. These discolored spots will range from dark, necrotic browns to purples and reds, depending on the fungal species. The spots may be raised lesions or depressed spots; they may be very tiny or overwhelm the entire leaf. While leaf spots are the most prevalent, they are not the only symptom. Fungal foliage diseases can cause growth stunt and dieback, in severe cases, which results from the plant's lack of nutrients and water.
Fungal diseases can be controlled with regular care and maintenance of your plant. Densely foliated plants should be thinned, at least annually, to allow good air circulation and light penetration throughout. Properly fertilized plants will remain vigorous and less susceptible to fungal diseases. Your plant's environment should be kept free of debris and defoliation as fungal spores often lie dormant in these areas. Also, you should water your plants at soil level to keep the foliage dry, as settled water on your foliage will attract fungal infections.
Chemical treatments can provide effective prevention and control of most fungal infections. However, timely and accurate applications of these chemicals are required for successful treatments. Chemical treatments should be applied according to the label's directions and reapplied, only if instructed. These chemical treatments can range from fungicidal sprays to fungicidal soaps and should be chosen according to the actual fungal disease and the type of plant. Speak with a horticultural or nursery specialist for selection assistance.
There are many types of fungal diseases that can range from mere nuisances to plant killers. Powdery mildew and anthracnose are two common fungal diseases that infect plants all across the country. These fungal diseases produce mild symptoms on the foliage, cause little plant damage and are easily treated, when addressed in a timely fashion. Severe fungal infections include fusarium wilt and phytophthora infections which cause death of the plant in most cases. These soil-borne, fungal diseases infect the plant through its roots. While initial infectious symptoms may appear display foliage infections, further inspection will show a root-rotting disease.