My 4 mango plants (from 5 to 8 months) are now struggling with weird disease. It started about 3 weeks ago, lower leaves got brown and finally gone. Now I have noticed brown thing on younger leaves.
Plants sit in pots, in potting soil, with good light, being watered twice a week. Last month I gave them organic fertilizer (5-5-5), not sure if that could be the cause.
I would be thankful for any hint.