Coconut palm trees have specific nutrient requirements. With the number of nutrients used by the coconut palm, it can be challenging to identify the specific deficiency. Recognizing the symptoms of a nutrient problem is the first step to resolving it.
Coconut Palm Fertilizer
Fertilizers made for palm trees have an analysis of about 8-2P2O5-12K2O+4Mg with micronutrients. Because nitrogen is easily leached away and because palm trees need a great deal of nitrogen, 100 percent of the nitrogen should be in slow-release form. Fertilizer should be broadcast spread under the entire canopy of the tree.
Palm trees require a great deal of nitrogen. Nitrogen deficiencies appear as yellowed leaves, first affecting the oldest leaves. If the deficiency continues, the entire canopy is affected and the growth rate of the coconut palm noticeably slows to a stop. Palm trees can live in this condition for long periods of time.
If there is a potassium deficiency, the most common nutrient problem faced by coconut palms, the oldest leaves take on an orange-yellow translucent appearance. There may be some necrotic spotting. As the deficiency becomes severe, the tip of leaves become necrotic and the trunk begins to narrow, resembling a sharpened pencil. New leaves sprout looking frizzled and chlorotic or yellow. If not addressed quickly, death will follow.
Older leaves display yellow bands along the margins. The center remains green. Younger leaves have wider center green sections but begin to show yellow banding along the margins. A magnesium deficiency alone is never fatal for palm trees. Often the magnesium deficiency is in tandem with a potassium deficiency, which can be fatal.
Manganese deficiencies tend to emerge in the spring after the coconut palm has faced a cold winter. New leaves are smaller than usual and carry a burnt-looking edge. When the cause of the manganese deficiency is the result of cool soil temperatures, the problem is usually temporary. It can be caused, however, by the use of composted sewage sludge as fertilizer. In these cases, the deficiency is often fatal.
Coconut palms can experience boron deficiencies during rainy weather. The rain leaches the boron out of sandy soil. Other factors that can lead to a boron deficiency include extended dry weather or a high soil pH. Premature fruit drop and dieback at the tips of new leaves are clear indicators of a boron deficiency.