Answer: Leaf chlorosis in cycads (sago palm) can be a symptom of magnesium deficiency. The fronds become yellow, and any new fronds develop a "frizzy" top.
This can be corrected by spraying with a solution of magnesium sulfate (epsom salts) (1 tsp./gallon water). Be sure to check your plant for scale insects. Scale infestation can also cause yellowing of the fronds. Cycads are notorious for harboring scale insects. They will appear as small oval-to-round flat bumps, approximately 3 to 5.0 mm in diameter. With scale infestation, there will be a sticky "honeydew" on the fronds.
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