"I don't think most plants [would yield a pound] at any one time, unless it's a massive plant," [NORML's Keith Stroup] said. "What would make more sense would be to weigh the buds," which are the part of the marijuana plant where the intoxicant, a chemical called THC, is located.
Special Agent Casey McEnry of the federal Drug Enforcement Agency in San Francisco disagrees.
"We're not weighing the plants," she said. "When I give an estimate, it's based on how many pounds [a plant] is capable of producing."
No it's not, because you have no way of knowing that. Overall yield depends heavily on the strain and the growing conditions/techniques. It varies from a couple ounces to multiple pounds. Ever notice how some kinds of trees grow taller then others? Same principle.
The value of marijuana plants is hardly the biggest lie being passed around in the drug war debate, but it shouldn’t be ignored either. Every day, some poor soul gets sentenced to prison based on erroneous estimates like this. These simplistic calculations frequently serve to falsely equate personal growers with major suppliers, all because law-enforcement officials are too lazy to actually weigh the appropriate part of the plant.
Once again, the people enforcing our drug laws literally do not know what they're talking about.