The application of sodium chloride (NaCl) can increase nut production, copra weight per nut and copra yield per tree. Research studies on chloride nutrition and fertilization of coconuts were extensively reported in 1972 on the positive responses of young and bearing coconuts to chlorine application. This was the result of adding potassium chloride to palms at the Davao Research Center of the Philippine Coconut Authority in Bago Oshiro, Davao City.
The beneficial role of chlorine in the normal growth, accelerated development, and high nut and copra yields of coconuts was confirmed in the inland coconut-productive areas in Davao.
Leaf chlorine is the main factor for copra yields; and for foliar diagnosis (a tool for nutritional diagnosis and predicting fertilizer needs), the critical level of leaf-Cl was found at 0.30% C1 and optimum level at 0.50-0.55% C1. The addition of 60-70 g NaCl/seedling can increase the plants girth and fresh weight.
It was found that seedlings from seednuts produced by NaC1-fertilized parent palms had bigger girths, more leaves, and higher total germination percentage, indicating that chlorine nutrition of parent palms is a positive factor in affecting the conditions of the seedlings in the industry.