Used by the plant to make healthy green leaves and stems; it promotes strong green foliage. A70-139
Used in excess of requirements it causes plants to grow soft and dark green; will not produce good flowers; bifoliate cattleyas such as C.Portia and C.Porcia do not require as much nitrogen as the regular unifoliates. A71-400
Used in increasing amounts, it is found that dramatic reduction in growth in cattleyas follows an increase in nitrogen levels; possibility of a limiting factor exists. OA79-131+; absolutely wrong. OWD