I did some reading and it would appear that the oldest leaves are probably not the best receptors of foliars, unless the objective is to directly feed N to them.
As leaves age, they become disassimilated from much of the plant's nutrient pathways and are less likely to influence exudates, while the flowers and the newest growth take primary control of hormones and nutrient sinks. I still haven't learned if the flowers respond best to foliars - it seems a bit counter-intuitive, if so.
As leaves age, they become disassimilated from much of the plant's nutrient pathways and are less likely to influence exudates, while the flowers and the newest growth take primary control of hormones and nutrient sinks. I still haven't learned if the flowers respond best to foliars - it seems a bit counter-intuitive, if so.