Seems to be a bad Phosphorus deficiency mid-flower.

[Rusty Trichome]

As she approaches harvest time, the lower fans and some lower (interior) growth will die-off on their own. As long as the yellowing and blotching is limited to the fans, and as long as the buds continue to fill-in...all should be ok. (but a picture would really help)

I'd keep her going till you see nothing but cloudy trichomes. (clear trichs=underdeveloped, cloudy trichs=harvest at any time, rusty trichs=starting to over-ripen...harvest soon or risk nanners) Until you witness the whole process, it will remain a nagging mystery filled with panic and overcorrections.

If the buds start weirding-out or mold or some other condition starts affecting them, then harvest at your discression. But if the primary and secondary branches are chugging along just fine, harvesting now will likely cut your yield in half, and you'll lose some flavor and effects. You're near the finish line...don't quit now. :jointsmile:

I treat my NL as if a sativa. Limited nutes when mature.

At this point, with your previous problems, I wouldn't go up with the nutrients.
A picture would explain a lot, if you could manage it. :thumbsup:

Rusty Trichome Reviewed by Rusty Trichome on 07-29-2009. Seems to be a bad Phosphorus deficiency mid-flower. I've taken advice from other threads, but I'm not getting too much improvement. More details follow the form. H=Answer if you grow hydro or aero C=Answer if you grow coco S=Answer if you grow traditional soil L=Answer if you grow soilless other than coco (Promix, Hyponex, SunshineMix) R=Answer if you grow in RockWool T=Answer if you grow in HydroTon D=Answer if you run any type of automatic drip system, including into soil or soilless E= EVERYONE needs to answer lol! Rating: 5

[FatSean]

Well I believe I found out why my leaves were yellowing so much. Turns out I was under watering. Once I started adding a quart of pHed water on the days in between the fert-days and the mini-flush-days, leaf drop stopped and the yellowing slowed and the buds grew faster!

My guess is that I fixed my pH issue with you guys' help, which meant the plant was 'working faster' for lack of a better term. Since it had all the P it needed, it was able to grow faster and so consumed more water than I was used to giving it.

Even though she is almost half-yellow, the buds look way better than anything I've grown before! Many thanks!!