Is this nitrogen deficiency

Growing some Cindy 99. It is in very early flower.

Some of the lower leaves are very pale green/yellow.

Rest of plant looks healthy.

I have not fed in 3 weeks.

Is this nitrogen deficiency?

Thanks

Yes, feed her.

Looks like it. N is a required element threw-out flowering.

Nitrogen Is a macro nutrient and is required threw out the entire life cycle. The plant just uses less during flowering since it switches it's concentration from growing to producing flowers. Thus the reason "flower" nutes have less N. Keep feeding her but just decrease the dose of nitrogen as flowering develops and completely stopping nitrogen 3-4 weeks before cutting the plant done.

looks like a nice sativa besides the yellowing

I specifically keep my N up high for the first three weeks of flower, as that is the stretch period and the plant is still growing. After stretch is done, I eliminate N and go with only flower nutes (far less N).

-spek