Home Research Genetic test decides whether a cannabis plant develops CBD or THC

Genetic test decides whether a cannabis plant develops CBD or THC

by Will Gibbs

Researchers say that the ratio of THC to CBD, not THC, is used to decide if a plant should be legally considered to be marijuana or hemp.

A new genetic test to predict THC and CBD in industrial hemp — essential to decide if a plant is legally hemp or marijuana — could provide much-needed assistance to U.S. farmers as THC does not peak before plant maturity.

The amount of THC in crops is especially consistent, provided that if plants have more than 0.3 per cent, they cease to be considered law-abiding hemp and are considered to be marijuana, notes a statement by the University of Minnesota, led by a research team that developed the test.

The THC amount of 0.3 per cent for hemp is determined by regulation in both Canada (leaf and flowering heads) and the United States (dry weight). With the passage of the Farm Bill 2018 in the U.S., hemp was undisturbed from cannabis, which remains a substance of Schedule 1 (like heroin and LSD) at the federal level.

Despite the fact that legal hemp farmers in the U.S. routinely receive a chemical analysis of their plants during the season, the university statement suggests that because THC levels peak at maturity, all their efforts may be in vain, with crops needing to be destroyed if THC reaches the federal limit.

Couple the situation with other tough conditions for farmers. Hemp acreage in the U.S. more than trebled to around 285,000 acres in 2019 as of 2018, but the lack of Food and Drug Administration regulations around CBD, hemp oversupply, dropping wholesale prices and dubious claims by some CBD suppliers has left some once-inspired farmers wondering whether they want to hit their car to another crop.

Researchers propose using the ratio of THC to CBD to separate THC-type plants from CBD-type plants. / Photo: iStock / Getty Images Plus PHOTO BY ISTOCK / GETTY IMAGES PLUS

Researchers propose using the ratio of THC to CBD to separate THC-type plants from CBD-type plants. / Photo: iStock / Getty Images Plus PHOTO BY ISTOCK / GETTY IMAGES PLUS

University researchers hope that the new test would help to avoid the possibility of crop failure, ongoing problems and last-minute tension associated with THC levels. Published last week in the American Journal of Botany, researchers argue that the use of THC alone as a deciding factor in what makes hemp or marijuana “not biological,” notes the statement.

“Instead, they recommend that the ratio of THC to CBD be used to distinguish THC-type plants from CBD-type plants,” the university reports. “The ability to know that the seeds are CBD-type before planting is important and that the seeds could be certified to ensure accuracy and quality,” he adds.

 

Seeds could prove a sticking point unless the changes are introduced, the researchers say. They found “impurities in seed planting imported from Canada. Some varieties proved to be 100 % pure CBD-type, but some had too much THC to fulfil the legal definition of industrial hemp.

Biblography:

Thegrowthop.com. 2020. Genetic Test Identifies If Cannabis Plant Will Produce CBD Or THC | The Growthop. [online] Available at: <https://www.thegrowthop.com/cannabis-news/genetic-test-identifies-if-cannabis-sativa-plant-will-produce-mostly-cbd-or-thc-molecule> [Accessed 4 November 2020].