NPK Requirements of Vanda Miss Joaquim Orchid Plants

Abstract

Vanda Miss Joaquim is field-grown commercially only in Hawaii. Unlike most orchids, Vanda Miss Joaquim produces flowers throughout the year (with seasonal peaks) and grows best in open fields. Studies of Vanda orchid fertilization have been generally confined to pot culture in greenhouses and not to field plantings. The objectives of this experiment were, first, to determine the effects of levels of N, P, and K fertilization on flower production, flower size, and plant growth when Vanda Miss Joaquim is cultivated on tree fern sections in open fields and, second, to obtain deficiency symptoms of N, P, and K as an aid in identifying plant nutrition problems. This study shows that a complete nutrient regime of N, P, and K is essential for hapu'u log culture of Vanda Miss Joaquim in the field. The mineral nutrient content of tree fern medium was reported to be quite low, and supplemental N, P, and K were found to be necessary to prevent deficiency symptoms and for optimum flower production.