Purple Blotch – 5 Things to Know

purple blotch
Garlic is one of the plants that purple blotch affects.

One of the things that you know about having plants is that your plants can suffer diseases and problems just like any other living thing. That’s why we have looked at some of the common problems that you may encounter with your plants. Today we are going to look at purple blotch so that you know what to look for and what to do if you find it.

What is Purple Blotch

This disease is caused by a fungus called Alternaria porri. It’s often found in humid, warm, onion growing areas around the globe. Leeks and garlic can be affected along with onions. Most of the long-day cultivators are susceptible to this disease. However, the sweet Spanish onion type is usually more at risk than the yellow ones. All of the short-day cultivars can be affected.

Hosts of Purple Blotch

  • Garlic
  • Shallots
  • Leeks
  • Onions
  • Raspberries

The infection will happen when the fungal spores come from close by plants get blown by the wind into the onion fields. They then infect any wounded plants.

Symptoms of Purple Blotch

Early symptoms that a plant has this disease are leaves that are spotted with elliptical spots brown in color. These will get large as time goes by and can result in necrotic, brown streaks. The lesions turn purple eventually as the fungus’s spores develop. In the more severe cases, the lesions get so large that the whole leaf is affected. The pathogen will require wounds that are from other types of diseases, hail, or thrips feeding in order to enter a plant.

Managing Purple Blotch

  • Watch for any symptoms that start on your older leaves during your growing season
  • Rotate your crops
  • Avoid using a lot of nitrogen
  • Dispose of or bury plant debris
  • Watch for symptoms starting on older leaves throughout the growing season.

Applying Fungicide

Use fungicide when you see the signs of this disease. This will help with preventing the disease from spreading. Purple blotch treatment also will control the leaf blight known as Stemphylium. .

If you are having trouble with your plants or you are looking for a way that you can help them to stay healthy, we offer a variety of plant health care services. if you are interested in knowing more, simply contact us here to find out more. We are happy to get back to you with a quote and show you what we can do for you.

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