How to Identify and Treat Anthracnose

Anthracnose is a fungal disease that can infect many types of plants including tomatoes, peppers, beans, carrots, squash and even some flowers. This fungus goes by several other names depending on where you live or what type of plant it attacks. It's also known as Glomerella blight in cucurbits (cucumbers, melons and squashes) and Colletotrichum in roses.

There are three different types of anthracnose:

1. Leaf spot (foliar form): This is the most common, it appears as raised dark areas on leaves that eventually turn brown; the spots may be surrounded by a yellow border; once lesions reach about 1/3 of the leaf blade, they can coalesce (combine) to form large dead areas; these spots may also appear on stems.

2. Fruit spot (fruiting structures): This appears as small dark brown circular spots on ripe fruits; if you cut open an infected fruit, you will see black or brown lesions in the center of the spot.

3. Stem canker (rooted structure): This appears as sunken dark areas on stems which eventually turn brown, the lesions are usually surrounded by a yellow halo; if you cut open an infected stem, you will see black or brown lesions in the center of the area.

All three forms of the disease are caused by various species of the fungus Colletotrichum. Anthracnose is a disease that will usually only attack part of your garden at any one time, so if you become obsessive about the disease you can just plant something new in another section of your garden.

One way to reduce the chance of future infections is to rotate crops on a yearly basis. If you've had anthracnose problems with peppers, don't plant peppers in that area again. You can also try planting varieties that are resistant to the disease such as 'Early Jalapeno' for peppers and 'Caro Rich' for tomatoes.

Powdery mildew is another fungus that, like anthracnose, attacks many types of plants. Powdery mildew thrives in hot, dry weather and is usually not a problem until late August or September; the fungus will only attack the upper part of your tomato plant and won't affect fruit production. When dealing with this fungus, make sure you've watered your garden deeply at least once every week (tomatoes like water, especially in hot weather) and ensure there's plenty of air circulation (add more fans if necessary).

Anthracnose is usually found during the late summer and early fall; it is most active when temperatures are between 60 – 77°F (15 – 26°C) and humidity levels are over 90%. The fungus also needs free water to spread so it will only attack plants that are already stressed from a lack of water.

One way to tell if your plant is infected is by cutting into an affected leaf or stem; you can also spot anthracnose by the small fruiting bodies (acervuli) which appear as tiny black dots on leaves, stems and fruit. These fruiting bodies will release spores which can infect other plants.

The best way to treat anthracnose is to catch it early, before the lesions have a chance to spread. If you're dealing with a small infection, you can try using a fungicide such as copper sulfate or wettable sulfur. For larger infections, you may need to use a systemic fungicide which will be absorbed by the plant and will protect it from future infections. Always read the label of any fungicide before using it and make sure you're using the correct amount.

It's also important to water your plants properly, especially during hot weather. Tomatoes need at least 1 inch of water per week, but they can survive under more extreme conditions with less water.

If you're dealing with powdery mildew, the best way to control it is by increasing air circulation around your plants and not watering them in the middle of the day. You can also try planting varieties that are resistant to powdery mildew such as 'Early Jalapeno' for peppers and 'Caro Rich' for tomatoes.

To prevent fungal growth from overpowering the plants and stopping the spread from tree to tree, Tree Doctor offers effective Anthracnose treatment to cure the disease. Shake off the fungus growth with precise Anthracnose control, which begins with proper sanitation, picking, and disposing dead plant parts of the infected soil.