Red Swiss Chard disease??
Hi! I'm a Master Gardener with Baltimore County. I also work at a Nursery in the area. I found this on the red swiss chard we are growing in our nursery currently. It reminds me of cercospora leaf spot... but I talked to a well-educated friend of mine at the Nursery and he doesn't think so. He thinks it's just from overexposure to the sun. I wanted to see what you all think. Thanks!
Baltimore County Maryland
In general Swiss chard can get all the diseases that are subject to beets. This looks like cercospora on the foliage. The disease is more noticeable when conditions are warm and humid. Pick off infected leaves and lay a dense organic mulch (grass clippings, compost) around plants and water around the base of plants, not overhead. See our website for more information on this leaf spot http://extension.umd.edu/growit/cercospora-leaf-spot-vegetables
Thank you for your help. I told my friend you all responded, but he still thinks it's sunscald... He said he thinks so because there is no die back of leaves from it. Are there die back of leaves or necrosis from this disease?
Based on your photos the symptoms look like cercospora leaf spot on the foliage. Since you are a commercial nursery you can send samples to the U of MD Plant Clinic. See the attached link https://extension.umd.edu/plantdiagnosticlab
Ok! Thank you so much!! :)