My palms either die soon after sprouting or before they even surface. Seedlings should always be planted in clean pots or flats using clean substrates, preferably on benches, to reduce their chances of infestation. My palm leaves have a rough texture and several small yellow to brown spots that swell and rupture. This disease, known as False Smut or Graphiola Leaf Spot, can be treated with three or four biweekly applications of protective fungicides such as mancozeb, copper, or propaconazole during active spore release periods. The trunk of my palm tree is stained with red streaks and some of the fronds have collapsed.
Lightning frequently strikes tall palms, usually with fatal results.
The only way to avoid this is to protect the tree with lightning grounds, though the practicality and effectiveness of this practice are questionable. These symptoms are signs of calcium deficiency, which can be treated with calcium nitrate or sulfate. Prevent this disease by using dolomite in all potting substrates. My palm has yellow bands that run along the borders of the leaves. Yellow banding signals magnesium deficiency, which can be treated with soluble magnesium fertilizers like kieserite.