Nope, it's clear to me that is a light problem... If light is unable to reach certain places its because something you are doing is not doing what the sun does outdoors...
I discussed the issue of the dynamics of popcorn buds (which is what this thread is all about) in a previous post but folks glossed over it. Why? Because my explanation goes against the paradigms of forum protocol, and that makes people uncomfortable. Familiarity breeds comfort. Enough Sociology 101......
Change gears - Botany 405
I'll try again. Grow outdoors like I have many times, you will
experience popcorn buds on the lower part of the plant, it's just what cannabis does and has NOTHING to do with light penetration to plant lower levels. That is another forum myth that just won't die, and with every new crop of noobs.....you get the rest. Popcorn buds are a RESULT of chronological plant development, (the top plant develops first and biggest, the bottom develops little or not at all), hormonal processes and most of all the affect of apical dominance. In plain Ingles, the top part of the plant gets all the goodies. Why do you think that when you deprive your plant of N that it sacrifices the N found in lower leaves and transports it to the upper leaves? The Herd of Calves hits their plants with bloom foods, the lower leaves yellow and fall off, and they sit there not able to figure out why.
Uncle Ben