80% of nitrate assimilation occurs during the vegetative growth period. Get em nice and dark green (a healthy dark green - there is a difference) with sturdy profuse branches and nodes during veg. Oh..btw..a large portion of photos on these forums of crops just before chop...wow the leaves stems and canopy looks beat to shit. Fried crispy leaves and just a plant on salt overload. Folks..this isnt how your plants should look at harvey.