Question: asking about the immature nut falling of coconut and along with fertilizer dose of coconut
Answer: apply planofix @ 1 to 2ml/ 5 l of water , 2 spray at 15 days interval.
apply borax 25gm along with multimicronutrients coconut for soil application 
=this is a powder formulation and ideally suited for coconut palms
it improves inflorescence setting, enhances nut size, decreases nut dropping and increases yield dosage:
apply @ 200 -250 g for bearing palm and @ 100-150 g for non bearing palm in two split doses. ( available in 1kg and 5kg).