Sorry folks, but there is no such thing as "average yield" of anything off of a marijuana plant. There are dozens of variables and who's to say what's the average grow or set-up or plant size or strain, get my drift???? I see people watering with an eye dropper and others with flood systems powered by fifty gallon drums. Some use shitty soil while others have elaborate hydro systems. Some folks grow outdoors while others grow indoors. Some folks know what they are doing and some don't, yet! What's average and who's to say??? I have seen this .5 gr per watt stuff as well as 1 pound per light, as in 1000w metal halides. But who's to say, eh? Some folks look at a dollar value per plant but that is bogus as well. What if one plant is 6' tall and another is 3' tall? Just use the most wattage you can and feed them buggers as much as they can choke down and see what kind of yield you get. It won't be average, that's for sure.