No.

http://www.erowid.org/plants/cannabi...is_myth2.shtml

Marijuana of under 0.5% potency has almost no psychoactivity. While it is possible that people sometimes obtained marijuana of such low potency, for the drug to have become popular in the 1960s and 1970s, most people must have regularly obtained marijuana with higher THC content.

Until the late 1970s, PMP samples included none of the traditionally higher-potency cannabis products, such as buds and sinsemilla, even though these products were available on the retail market. When changes in police practices resulted in their seizure, PMP potency averages increased.

Every independent analysis of potency in the 1970s found higher THC averages than the PMP For example, the 59 samples submitted to PharmChem Laboratories in 1973 averaged 1.62%; only 16 (27%) contained less than 1% THC, more than half were over 2% and about one-fifth were over 4%. In 1975, PharmChem samples anged from 2 to 5%, with some as high as 14% - nearly 30 times the .71 average reported by the PMP.
beachguy in thongs Reviewed by beachguy in thongs on . Current THC levels vs. Parents generation THC levels Is there any truth to the popular conception that current THC levels is far higher than previous due to selective and interbreeding of strains? Not heresay or secondhand talk but empirical scientific evidence. Just curious. Rating: 5