Wildones

I had same issue with a few autoflowers. After looking around i found it's an iron deficiency.

Chelated iron can be bought in several forms: granules and powders. Granules and powders are water-soluble and can be mixed into water to create foliar sprays. Spray these liberally on the foliage of the entire affected plant. I also seen a guy juice some spinach. He used the juice with water and fed his plants. Gl