After an extensive study by the California-based cannabis testing lab Steep Hill, researchers have determined that most have of the state’s ubiquitous pesticide problem is due to the process of cloning plants. This comes on the heels of a report from last October which estimated about 84 percent of California-grown weed was not “fit for human consumption.”
Clones Contaminated by Pesticides
Traditionally, there are several different ways a plant becomes contaminated by pesticides. The report cites the following most common causes:
- Knowingly use inputs that contain pesticides (such application may be known to some in the operation, but not others),
- Knowingly use a product whose pesticide content was unknown to them (lack of education, lack of proper labeling),
- Grow in locations that are subject to pesticide “drift” from the application by a neighbor (wind, water, soil, insects, animals).
Following the initial 2016 study, several licensed cannabis growers grew perplexed about the report’s findings. Most had claimed to have never given their plants any form of pesticides during the growing process and that their methods were 100 percent organic.
This led Steep Hill CEO Jmîchaeĺe Keller to come up with his own hypothesis.
“When we released the first study on pesticides in October of 2016, many growers approached Steep Hill saying that they did not use pesticides, they were organic, they were trying to do the right thing for their patients and consumers,” Keller explained. “After hearing this over and over again, we knew there was something wrong in the supply chain. It dawned on me, IT’S IN THE CLONES.”
Keller requested Steep Hill’s lab to confirm his clone theory.
The company acquired 124 clones from clients, clone producers and dispensaries in the surrounding Berkley/Los Angeles area.
Of the 124 subjects tested, a meager 17 plants contained no detectable pesticide residue. Furthermore, only 22 percent of all clone plants just barely passed under California’s stringent cannabis pesticide thresholds.
“Less than 14 percent of 124 randomly selected clones from different regions were free of any pesticide residue,” the report explained, “and 77.4 percent of the clones tested failed current proposed California cannabis pesticide regulations. It is clear there is a need for clone monitoring.”
The report did go on to say some of the pesticide levels reported were increasingly low and that they might not be a factor by the time the plant is fully mature and harvested.
“The threshold limits include very low levels, some of which could potentially be degraded by environmental conditions, thus potentially rendering some of the products passable by harvest,” the study explained.
The report also added that growth medium, rather than direct application of pesticides, could be responsible for the contamination. It argued this could be the result of old cannabis “lore,” which claims all pesticides are washed out from the system after four to five generations of plants.
However, this particular study proves this is clearly not the case.
“In some cases, the large amount of systemic pesticide (such as myclobutanil) in the growth medium would likely provide a long-term application reservoir if the clone growth medium were transplanted and remained in contact with the root system,” the report noted.
Final Hit: 77 Percent of California Clones Contaminated by Pesticides
Although the levels of pesticides vary, the report also mentioned that some plants were found with “8,300 times the threshold limit in the current California regulations.” Keller noted that this could prove troublesome for California’s expanding cannabis industry, which is expected to legalize recreational weed by January of 2018.
“We realized that serious problems in the California cannabis supply chain could result in 2018, if the very source material from which the cannabis was being grown for large-scale production was already contaminated with pesticides failing current regulations,” said Keller.
One potential solution? Stop using clones altogether, said Reggie Gaudino, the vice president of scientific operations and the director of intellectual property at Steep Hill and one of the study’s co-authors.
“We need to work together to insure that traditional practices in the industry are re-examined and changed in light of this data” Gaudino declared.