... DH, that's a micronute defc. starting on the uppers,.. looks like Zn to me,... check the soil pH and see if it's over 6.8, where most micro's start to lock out,... low feeds may have lead to this, as well as other pH problems, which screw with the chemistry and render them unavailable,.. you'll need a dedicated micronute supplement to treat this best... soil plus foliar is the best route; you'll need a wetting agent for spraying to be most effective, and spray tops and bottoms of leaves (more stomata there)... wetting agents allow the solution to coat and stick better instead of beading up; Earth Juice Microblast is a good one,.. Coco-Wet is my fav' agent,...