Absolutly no way of telling. You need to show a picture of the entire plant. My guess is it's the opposite. Plants will cannibalize old growth in order to keep the new growth vibrant and healthy. Usually due to a lack of Ca, P or K. Good luck.
The rest of the plants are dark green. These leave were on the inside of the plant. Sent from my iPhone using Grasscity Forum
Looks great man! Yup, cannibalizing the old fan leaves for new growth. Natural this time of year if its slow and a small %. I believe the very first sign of nutrient burn this time of year would be the hairs turning colors. Yours look great. If anything, I would bump an extra feeding or two before flower begins to end. Mostly K, little P. Once again, nice work.