Day 68 outdoor alpha- More yellowing leaves

Day 68 outdoor alpha- I've looked all over online and I can’t find anything that looks like what’s happening to the lower leaves. I don’t see any signs of pest infestation either. I read somewhere that the yellowing could be sun damage. I knew that couldn’t be the problem though because it was raining so much. Time for the google machine…in the end, the only thing that I could come up with is that the yellowing is due to the plant going into flowering. We know that the plants are turning that corner now so it makes sense. Now we get to look for buds.