I planted potatoes in February. They grew beautifully. I knew they should be mounded. I didn't want to put soil up on those beautiful greens. Mounding would help increase the size and quantity of potatoes produced. I mounded them last week. Now the beautiful greens have brown spots.
This looks like the brown spot fungus I regularly get on my roses. I treat those by spraying a 2:1 mixture of water and white vinegar on the affected area. Any fallen leaves are cleaned up quickly so the fungus doesn't spread. The potatoes got the same treatment this morning.
The problem could have been in the soil. I added some bagged soil when I mounded. It may have had the fungus that spread to the potatoes. Nonetheless, I hope I can nip this in the bud.