Phoma mold is a diverse group of filamentous fungi. This genus encompasses opportunistic organisms, pathogens, and saprobes, which are organisms that live on dead or decaying matter. These fungi reproduce asexually, with their sexual forms found in other genera like Didymella and Mycosphaerella. Phoma species are widely distributed, commonly found in soil, organic matter, and various environments, including aquatic ones.
Identifying Phoma Mold
Phoma mold colonies often display a velvety or powdery texture. Their color can range from pale to reddish-orange, maturing into greenish-gray, dark brown, or black hues. Some species are even known to produce pink and purple spots on painted walls due to a diffusible pigment they release. It is difficult to identify the exact type of mold by visual inspection alone, as its appearance can vary significantly. While Phoma thrives in damp, dark environments, it does not have a distinct smell that can be used for identification.
Impacts on Plants and Structures
Phoma mold can cause considerable damage to various plants, including agricultural crops, garden plants, and ornamentals. It is known to cause diseases such as Phoma blight, which leads to wilting, browning, and death of plant parts, including entire plants. This fungus also causes dark brown to black lesions on stems, often near the soil, and dark spots on leaves. Phoma blight spreads quickly, affecting healthy plant parts that come into contact with infected soil. Plants that are wounded or stressed by conditions like overwatering or poor soil are more susceptible to infection.
Beyond plants, Phoma can also grow on non-plant structures, especially in damp or water-damaged areas. It is frequently found on materials such as concrete, wood, fiberglass, plaster, and wallpaper. Common indoor locations include wet paints, window frames, caulking in bathrooms, and even house dust. Phoma species are also known to spoil various food products, including fruits, vegetables, and dairy, and have been found on seeds, nuts, soybeans, potatoes, bananas, maize, and citrus fruits.
Health Implications
While Phoma species are generally considered contaminants, they can rarely cause infections in humans, particularly in individuals with weakened immune systems. Although Phoma spores are not easily airborne, they are recognized as common allergens. Exposure can lead to allergy symptoms in sensitive individuals, including sneezing, a runny nose, itchy, red, or watery eyes, and respiratory issues like difficulty breathing, chest tightness, and wheezing. Skin reactions such as rashes and hives may also occur. Phoma has been linked to conditions such as hay fever, asthma, and hypersensitivity pneumonitis. Phoma species can also produce mycotoxins, such as tenuazonic acid. These mycotoxins may cause toxic effects in animals and have been correlated with certain human disorders.
Controlling Phoma Mold
Managing Phoma mold involves both preventative cultural practices for plants and remediation strategies for structures. For plants, avoiding overhead watering and ensuring good airflow within plant beds can limit fungal spread. Removing overhanging plants that restrict air movement and thinning plants as needed also helps. Promptly removing any diseased or dead plant material from under healthy plants is important to prevent further disease spread.
For mold growing on structures, addressing moisture sources is paramount. This includes repairing leaky pipes, roofs, or windows to eliminate damp conditions. Cleaning methods involve thoroughly removing visible mold growth from surfaces. Professional intervention may be necessary for extensive mold contamination, especially in cases of significant water damage or if individuals with compromised immune systems are present. Since mold removal can stir up spores, professionals have the equipment and expertise to handle the process safely and effectively.