I'm in my 8th week of flowering some Barney's G13-Haze, using a 600w hps flowering bulb. A quick disclaimer (for the pic), this is my first soil grow, and I had some nutrient deficiency problems due to PH and Cal/Mag being low. Anyway, on to my issue: I have a 40w incandescent bulb I use as a "maintenance light" when I'm forced to enter my 10'x10' grow area when it's in dark cycle. It got left on for 8 of the 12 dark hours when I was away at work. How will this affect my plant at this stage of growth? Should I be worried?
It could set back your harvest by a few days but as long as there aren't any other lighting issues, everything will be fine. I can't say much for sure without seeing more of the plant but it looks there's either a deficiency or a pH problem. Likely Calcium and/or Phosphorus deficiency, or else low pH.