What is White Mold?
White mold is a plant disease that is caused by the Sclerotinia scleroiorum fungus. The same pathogen is responsible for watery soft rot, blossom blight, crown rot, and cottony rot, among others. It forms sclerotia on the soil, which is a hard black-resting structure. The latter looks like a broken tip of a pencil. It will survive not only on the soil, but also plant debris for more than five years. They are comparable to seeds in the sense that once they are on the surface, they will survive and germinate.
This disease is common in places with moist soil and cool temperature, which usually ranges from 51 to 68 degrees Fahrenheit. Given these conditions, the fungus will create mushrooms and in turn, will release spores. The wind may speed up its spread to other plants, allowing the spores to travel by as much as a mile. Once it lands in the dead tissue of the plant, it will start spreading damage and will move up the plant.
Identifying White Mold’s Damage
White mold has a diverse selection of hosts. In fact, its infection can be apparent in more than 400 plant species. Some of the most common host plants include zinnia, marigold, petunia, sunflower, salvia, carrot, bean, pea, tomato, peony, chrysanthemum, lettuce, and cabbage, among others. These plants will be more vulnerable to damages during their flowering stages. Young seedlings will also be more susceptible compared to the older plants.
The following are some of the most common symptoms that will be indicative of white mold affecting plants:
- The soil will have a white and fluffy coating, which is similar to cotton wool.
- From the surface, the white mold will reach the lower part of the stem and cover it with the same fluffy coating. At this point, the rest of the plant will appear pretty much normal.
- Eventually, as the mold stays in the stem longer, it will discolor. It may turn tan or brown. The stem may also turn dry and brittle. The leaves will also show discoloration.
Results of Infestation
As with other plant diseases, the first thing that you will notice would be the cosmetic damages on the host crops. Especially on the lower parts of the plant, the hosts will turn unattractive. Because it restricts the transfer of nutrients to the other plants, it is not uncommon for the plant to wilt and die. Yield loss is a common problem arising from the disease. In severe instances, it can minimize harvest by as much as 50%. This means that commercial growers will also suffer from financial losses as a result of having unmarketable crops.
How to Get Rid of White Mold
Natural and Organic Solutions
To prevent and control white mold in a manner that is safe and effective, the following are some of the solutions that will work:
- The most important is to choose your plants carefully. Look for varieties that can resist the disease. Some of the highly-resistant varieties include ornamental reed and fiber optic grass. Those with moderate resistance, on the other hand, include elephant ear and canna.
- Controlling weed is also an essential preventive measure. If there is high-density of weed, there is a higher likelihood that the fungus will easily spread to other plants within the area.
- When using any harvesting equipment, make sure that it is clean. Even with pruning shears or scissors, sanitizing the tools or cleaning it is an essential. This will prevent the fungus from spreading to other plants.
- Cleaning up the field or the garden is another simple solution that will deliver effective outcomes. The fungus that carries white mold can overwinter in plant debris or soil, which makes it important to clean the ground. If there are plants showing early signs of the disease, take them out as soon as possible. Avoid composting the plant with infection.
- The reduction of moisture is also a must. If the plant is moist and humid, there is a higher likelihood that the pathogens will overwinter. Plants with an upright structure are better because they will dry quicker. Also, make sure that there is generous spacing in between plants so that the fungus will not travel easily. To add, drip irrigation is better than overhead watering. When watering plants, it is best to do it early in the morning, providing the plants with the time to dry out.
- Using protective barriers for the soil will also help. A mulch or plastic cover will prevent the infection from the ground to spread to the healthy plants.
For many people, especially for commercial growers, they commonly tackle plant diseases through the use of chemicals. However, this is one thing that you should do with extreme caution, especially if you will treat plants in the garden. Most of these chemicals contain toxic ingredients. Pay attention to the instructions from the manufacturer. Wear protective gear during the application of the chemicals. More so, to achieve the highest level of effectiveness, proper timing is critical.
Among others, one product that is effective in the treatment of white mold is DuPont Approach. The latter is a fungicide that provides essential protection for diseases that can limit crop production. It is effective for soil-borne and foliar diseases in a wide array of plants. It is made with unique properties that allow it to quickly move to and within the plants. This means that even without generously covering the plant, the chemicals can transfer to the other parts to offer the protection that it needs. Topsin is another fungicide that can prove to be equally effective.