Black Spots on Pindo Palm
Two of my butia capitata palms developed black spots on the stems and leaves of the lower branches. Afterwards, the branches turn yellow and die. The spots are spreading to more and more branches. I sprayed them with liquid copper three times with a week interval in between, but it did not seem to slow it down.
Out of 8 palms, the two that I mentioned have about 30% of the foliage affected, another 3 palms have very few spots that do not seem to spread, and the rest are not affected. All are pushing new leaves and seem ok otherwise. I planted the palms this summer from 5 gal pots.
Any idea what it is and how it can be fixed?