BBKush

Yellowing on Older (Bottom leaves) would imply more nitrogen needed - its being sucked from them leaves to feed newer growth. If no other deficiencies showing up (that would imply root uptake issue) just up the nitrogen some for that plant.

Light burn, light stress, heat stress can most certainly create the type of issue you see here. A quick peek at your diary shows me you have a 1000w light 8 inches from your plant. That is way too close, you should be at a distance of 18 inches plus or minus a couple. @MrGreenMan, its not really good advice to tell someone to add more nutrients just because you're having the same problem and you "think" it might be a P deficiency. That kind of advice is only going to hurt someone's grow, and none of us want that. Happy growing.

If you've solved the problem, then let them go 2 more weeks. If you had a loupe or a really good camera phone, you can check the trichomes. 20-30% amber is what I look for. Light burn can cause early maturity, but your burn doesn't look too far advanced.