As a result of an increasing expertise among marijuana growers,
as well as a consumer demand for a better product, the marijuana Americans now smoke, both imported and home grown, is considerably stronger than it has ever been. By 1976 PharmChem, a California research institute, was routinely testing marijuana samples with a THC content of 5 percent and occasionally even 10 percent, which had been sent to them by curious smokers. Much of this recorded increase in potency is due to the popularity of Colombian over the generally weaker Mexican varieties. In addition, strong strains of marijuana are brought into the continental United States from Asia and Hawaii. Finally, there is a growing supply of domestic marijuana in the United States that is far more potent than it used to be.There are various myths and explanations to account for the difference in potency between one sample of marijuana and another. But by far the most important factor determining the potency of a given plant is the seed from which it has grown. The climate, the amount of sunshine, the soil, altitude, level of moisture, fertilizer, or curing process are all important, but it is the seed that contains the genetic code that determines the potency and other characteristics of the smoke.
The most potent part of the marijuana plant is usually at or near the top. In both male and female plants, the flowering tops are covered with tiny hairs that contain a sticky resin usually rich in THC. As the plant nears maturity, it sends resin to the top, perhaps to protect the flowers from the sun and birds. In the female plants, the resin also serves to help trap the pollen released by the males Female plants are more richly endowed with THC than male plants, but only because they have a greater total yield of leaves and flowers. Plants harvested too early or too late contain less THC than those harvested at the peak of maturation at summer's end.
Most users believe that they can determine potency and can distinguish between "good" and "bad" grass simply by smoking it. But the data suggest that this might not be so. In 1971 Prof. Reese Jones of the University of California asked a group of experienced smokers to rate two samples of marijuana on a scale from 1 to 100. The first batch had been rated by the researchers at around 1 percent THC. The second batch was actually a placebo, from which the THC had been removed. The subjects gave the first batch an average rating of 66. But they rated the placebo almost as high, at 57, and many of the smokers were unable to distinguish between the two samples.
Jones concluded that the relatively high assessment given to the placebo might be due to the fact that the subjects anticipated that they would be getting stoned, even though they were also informed that they might be given an inactive substance. Curiously, Jones found that those subjects who happened to have head colds during the experiment were better able to tell the real marijuana from the placebo, which suggests that tasting and smelling the marijuana may have misled some of the subjects who were smoking the placebo.[7]
Looking back on his experiment, Jones now says that it should be kept in mind that the comparisons were done with low-quality marijuana. He suggests that an experiment asking users to judge the difference between weak and strong marijuana would prove far less difficult:
I suspect the issue of distinguishing between good and bad grass is at least as complicated as the issue of distinguishing between "good" and "bad" beer, wine, whiskey, tobacco, or sex. That is, human beings seem to have a fair difficulty and a fair amount of inconsistency in making many of these distinctions. Certainly the advertising industry has learned quite well that one can shape the consumer's appreciation of many substances by clever and manipulative advertising. I suspect the same is true in the marijuana commerce.[8]
Jones's suspicion is borne out in a story told by an enterprising
smoker who once found himself with a pound of relatively weak Mexican, and no
interested buyers. He spread the word that he had just received a shipment of
rare "Korean Green." Although nobody, including the man who was
offering it, had ever heard of Korean Green, its appeal to smokers was
enormous, and the marijuana was quickly sold to eager customers, most of whom
couldn't wait to buy more.
"People want a story," claims a dealer in New York, "so
sometimes you have to give them one":
A
while back some beautiful Mexican stuff came in. People wanted to know what it
was. I told them it was from Rosie's in Yucatan. Who was
Rosie, they asked. I said that Rosie used to run a whorehouse in Mexico City, and when
she got older, she retired to her family's country home in Yucatan. She has a
couple of acres in the back of the house, and she tends to her plants every
day. It's the most beautiful pot in the world.
Another time we had some pretty ordinary grass from Colombia. We baked it
in the oven with some cloves. We called it Peruvian Temple Grass, and
people really got off on the cloves. We told them that this was used by the
Indians of Peru in religious ceremonies, and that they burned special spices
and exotic mushrooms next to the marijuana during the curing process.