Posts Tagged: cannabis
Several scientists affiliated with the University of California Agriculture and Natural Resources have received grants from the California Bureau of Cannabis Control. The BCC awarded on Nov. 13 a total of $29,950,494 in public university research grants across California for research projects related to the implementation and effect of Proposition 64.
Research proposals had to fall within one of the several specified categories, including public health, criminal justice and public safety, economics, environmental impacts and the cannabis industry.
UC ANR-related cannabis projects and their principal investigators include:
Cannabis industry: Assessment of the location, structure, function, and demographics of licensed cannabis, focusing on geographical price differences, and differential impacts of local Prop 64-related regulations on the competitiveness of licensed businesses – Daniel Sumner, UC Davis professor in the Department of Agricultural and Resource Economics and director of the UC Agricultural Issues Center, $726,816
Economic impacts: Market prices for licensed and unlicensed cannabis and the effects of the current and alternate cannabis tax structures and tax rates on the private and public sectors in California, including government administrative costs and revenues - Sumner, $655,564
Environmental impacts of cannabis cultivation in California as affected by the farm economics of licensed and unlicensed cannabis production, including effects of testing regulations and compliance with the criminal prohibition of unlicensed cannabis - Sumner, $562,240
Assessing environmental impacts of cannabis-related noise and light disturbance to inform management of California wildlife – Justin Brashares, UC Berkeley professor in the Department of Environmental Science, Policy and Management, and Phoebe Parker Shames, graduate student, $489,762
Examining tribal sovereignty over cannabis permitting on native ancestral lands – Jennifer Sowerwine, UC Cooperative Extension specialist; Peter Nelson, professor; and Van Butsic, UC Cooperative Extension specialist; all in the UC Berkeley Department of Environmental Science, Policy and Management, $465,902
Cultivation bans, local control, and the effects and efficacy of Proposition 64 – Christy Getz, UC Cooperative Extension specialist in the UC Berkeley Department of Environmental Science, $328,916
Cannabis and wildfire: Current conditions, future threats, and solutions for farmers – Ted Grantham, UC Cooperative Extension specialist in the UC Berkeley Department of Environmental Science and Butsic, $319,091
Cannabis water-use impacts to streamflow and temperature in salmon-bearing streams – Mary Power, professor in the UC Berkeley Department of Integrative Biology, and Grantham, $314,417
The effect of local cannabis regulation on property prices – Butsic, $270,269
California cannabis workers: perceptions, beliefs, and knowledge of occupational health and industry hazards – Marc Schenker, professor in the UC Davis School of Medicine's Department of Public Health Sciences, $144,949
Cannabis Research Center at UC Berkeley https://rausser.berkeley.edu/news/2020/11/researchers-receive-grants-bureau-cannabis-control.
Cannabis and Hemp Research Center at UC Davis https://cannabis.ucdavis.edu/news/BCCawards
For a list of all public university projects funded by the Bureau of Cannabis Control, visit https://bcc.ca.gov/about_us/documents/media_20201113.pdf.
The Camp Fire started on federal land. This rule would make PG&E clean up its power lines
(Sac Bee) Emily Cadei, Sept. 30
…“In California, it is fairly clear that PG&E did not keep an up-to-date inventory and accomplishment schedule on vegetation clearance on all of their power lines,” William Stewart, director of the Berkeley Forests program at UC Berkeley, said in an email. “ I think the Forest Service wants to make sure that they are sending the same signals to their staff and partners that judges are now sending to PG&E — do proper power line clearance or some entity (or entities) is going to be on the hook for billions of dollars of damages.”
UC ANR Takes In-Depth Look at the Cannabis Industry
(AgNet West) Brian German, Sept. 27
Following the passage of Proposition 64 which legalized recreational cannabis, there was significant excitement surrounding the potential for a legal and regulated cannabis industry in California. However, the development of the guidelines for cannabis cultivation has undergone significant delays as the state works to build infrastructure for a commodity which is still federally prohibited. The July-December 2019 issue of the research publication from UC Agriculture and Natural Resources, California Agriculture, highlights multiple components for the development of legal cannabis in California. The special issue details the history of cannabis in the state, as well as some of the research being conducted on various aspects of cannabis.
Industry advocates weigh in on California's proposed rodenticide ban
(Pest Management Professional) Diane Sofranec, Heather Gooch and Marty Whitford, Sept. 26
…Dr. Niamh Quinn, Human-Wildlife Interactions Advisor University of California Cooperative Extension, Irvine, Calif.
There have been several iterations of bills in California over the past four years. Most of them are targeting anticoagulant rodenticides, although they morphed along the way; they started with all of the rodenticides, and now they're particularly focused on SGARs. As it was written, AB 1788 proposed serious restrictions on the use of SGARs, with some fairly limited applications throughout the state. In essence, it would have been an almost total ban of SGARs for structural pest control.
California farm region faces furry new threat: swamp rodents
(AP) Samantha Maldonaldo and Terry Chea, Sept. 26
…Damage to the region's soil or water infrastructure would be devastating to the economy and diet.
“It would mean no more sushi because the alternative would be to buy rice from Japan or Korea, where the price is five times higher,” said Daniel Sumner, director of the Agricultural Issues Center at the University of California-Davis. “Kiss off carrots, or live without table grapes in the summertime.”
New California lab seeks cure to deadly citrus disease
(Washington Post) Amy Taxin, Sept. 26
RIVERSIDE, Calif. — In a lab southeast of Los Angeles, researchers are opening a new front in the yearslong battle against a tiny pest that has wreaked havoc on citrus groves around the world.
California citrus growers and packers and the University of California, Riverside on Thursday marked the opening of an $8 million lab dedicated to finding a solution to the tree-killing disease known as Huanglongbing that has ravaged groves in Florida, Brazil and China.
…Georgios Vidalakis, director of the Citrus Clonal Protection Program at University of California, Riverside, said citrus boomed in California in the late 1800s. In the decades that followed, researchers in Riverside started a citrus breeding program, which helped develop new varieties, and a citrus collection, which now has more than 1,000 kinds of trees, he said.
Vidalakis, a plant pathologist, oversees a program aimed at ensuring trees don't introduce diseases into the region. But without the ability to study the illness, research was hampered, he said, until experts and growers joined together to build the lab.
“This disease is like nothing we have ever faced as plant pathologists,” he said. “We need all hands on deck.”
These Big Plans to Protect California Homes From Wildfire Fell Short in the Legislature
(KQED) Lauren Sommer, Sept. 26
…While Cal Fire has a goal of inspecting 33 percent of structures in its jurisdiction each year, a KQED investigation found the agency only did half that in 2018. In some parts of the state, only 6 percent of homes in risky areas were inspected.
“It's becomes really clear that our defensible space has been insufficient to protect homes from embers,” said Yana Valachovic, a fire expert with UC Cooperative Extension. “What's immediately adjacent to a structure affects the probability of a structure's survival.”
…“The science has been clear for quite a while, but it's been slow to incorporate into codes, standards and practices,” said Valachovic.
… “There's no single solution that's going to solve the fire problem,” said Valachovic. “It takes an all-hands-on-deck approach.”
Lindcove dedicates conference center to Exeter man
(Sun Gazette) Sept. 25
A late Exeter man who donated most of his fortune to local agriculture and educational institutions, will soon have his name affixed to University of California research facility.
The Lindcove Research and Extension Center, part of the UC Agriculture and Natural Resources system, will rename its conference center after the late Ray Copeland. The Ray Copeland Citrus Center will be dedicated during the Lindcove Citrus Gala on Oct. 4.
Participating in Agricultural Meetings Creates Long-Term Benefits
(AgNet West) Brian German, Sept. 24
…“It's an all-encompassing benefit for everyone,” said Brooke Latack, Cooperative Extension Livestock Advisor serving Imperial, Riverside and San Bernardino Counties. “Not just the farmers, but the people putting the workshops on also benefit a great deal from it.”
A Healthy Agriculture Approach
(CSU Stanislaus Signal) Aliyah Stoeckl, Sept. 23
UCCE Vegetable and Irrigation Advisor Dr. Zheng Wang held an insightful lecture at Stan State among students and faculty discussing the values of vegetable grafting.
… “Grafting conveys a lot of merits in terms of disease resistance and yield maintenance, it enriches the production practices by introducing more variety. And by making impossible things become possible,” said Wang.
UC Cooperative Extension Survey Results on Cannabis Cultivation
(Sierra Sun Times) Jeannette Warnert (news release) Sept. 23
A UC Cooperative Extension survey of California registered and unregistered marijuana growers will help researchers, policy makers and the public better understand growing practices since cannabis sales, possession and cultivation first became legal for recreational use.
“This survey is a starting point from which UC scientists could build research and extension programs, if possible in the future,” said lead author Houston Wilson, UC Cooperative Extension specialist with UC Riverside. A report on the survey results was published in the July-December 2019 issue of California Agriculture journal, the research publication of UC Agriculture and Natural Resources.
In a Race Against the Sun, Growers Try to Outsmart Climate Change
(New York Times) Marla Cone, Sept. 21
…“We can't continue to do the exact same thing we are doing now,” said Katherine Jarvis-Shean, a University of California researcher who advises orchardists on how to cope with climate change. “There are a lot of solutions to the anticipated problems. We just have to get on top of them, testing them and making them available to growers.”
…“For the most part, the world gets fed by row crops,” said Pat J. Brown, an associate professor at the University of California-Davis, referring to wheat, corn and other staples. “But a lot of the stuff that makes life really worth living comes from trees. Think of the world without chocolate or wine or coffee.”
…The Agriculture Department has repositories that store genetic material from every type of tree on earth. Dan Parfitt, a now-retired University of California-Davis plant geneticist, started breeding pistachios using tissue from those repositories more than 30 years ago in an effort to help growers economize their harvest.
As the climate changed, Dr. Parfitt got the idea to plant a few hundred of the trees in the California desert. “The Coachella Valley is the closest to the warmer winters and drier conditions that we will see in the San Joaquin Valley in 20 to 30 years,” he said.
Cannabis findings presented in Mendocino County by Berkeley's Cannabis Research Center
(Ukiah Daily Journal) Carole Brodsky, Sept. 21
One knows times have changed when California Agriculture, the official magazine for the University of California's Agriculture and Natural Resources Division features High Times-worthy photos of cannabis flowers on the front cover. In fact, cannabis is the sole focus of the quarterly, peer-reviewed publication.
Since 2017, the University of California's Cannabis Research Center (CRC) has been hard at work. A 12-person research team, supported by 50 undergraduates, has been conducting groundbreaking research, some of which was presented to the public on Sept. 15 at the Hopland Research and Extension Center.
Team members presented their findings, including the results of a cannabis production survey, which was taken by 350 California cannabis farmers largely located in the Emerald Triangle region. Dr. Van Butsic, assistant cooperative extension specialist and co-director of the Cannabis Research Center, acted as presenter for the event.
Butte County suffers two more human cases of West Nile
(Chico Enterprise Record) Brody Fernandez, Sept. 20
…Maurice Pitesky, is a researcher medical professional for the Veterinary Medicine Extension at the UC Davis School of Veterinary Medicine. Pitesky specializes in poultry health and food safety epidemiology — the study of diseases and large populations.
“The reason chickens are ‘sentinels', are because they don't really get sick,” Pitesky said. “Chickens are the canaries in the coal mine for the West Nile virus. We use them to determine if certain areas contain infected mosquitoes and if they've contracted the virus themselves. It's also a good way to put chickens in strategic places and check to see if they are producing the appropriate antibodies to the virus. From a preventative health perspective, they do serve a beneficial service.”
Chickens can not transmit the virus, they are only carriers, Pitesky said.
A tiny beetle has decimated hundreds of SoCal trees. Now experts are worried about Sacramento
(Sac Bee) Michael Finch II, Sept. 19
…The shot hole borer is not a strong flier so it's unlikely to move far on its own. It can, however, move faster when hiding in firewood and other green waste or landscaping equipment, said Akif Eskalen, a plant pathologist and professor at UC Davis.
Eskalen is one of many investigators looking for ways to naturally eradicate the beetle. Eskalen's work focuses on using native plants, but there is an ongoing trial with pesticides and another using natural predators. The studies, he said, “may take several years to complete.”
… Once inside a tree, the female produces offspring that mate with each other when they grow up and the death-dealing cycle repeats. This sequence happens as many as four times a year, or more if the weather is hotter, said Beatriz Nobua-Behrmann, a researcher studying the insect for the UC Cooperative Extension in Irvine.
They're believed to have arrived in wood packing materials made with infested wood from Taiwan and Vietnam, she said. Climate change could make it worse since the beetle thrives in warm weather. Its reproductive cycle accelerates as the temperature rises.
“Knowing that they can travel in wood or in green waste or in equipment that makes it a little bit more dangerous,” Nobua-Behrmann said. “It could easily make it to the northern counties with people moving firewood because they find it for cheap or for free.”
CBD oil price likely factor in $100 million payoff predicted for Ventura County hemp crop
Kathleen Wilson, Ventura County Star, Sept. 18
…More than 25,000 products can be made from industrial hemp, said Oli Bachie, a UC Cooperative Extension farm adviser in Imperial County who is studying hemp production. The plant can be used for fiber, feed, textiles and oils, but most if not all of the strains of hemp being planted in the county are for CBD, apparently because of the large profits that are expected.
Bachie would not be surprised to see that happen around the state.
"There is a huge interest in this because people want to grab the first economic benefit out of it," Bachie said.
Federal Government Approves Release Of Non-Native Weevil In California To Combat Invasive Thistle
(CapRadio) Drew Sandsor, Sept 18
…The U.S. Department of Agriculture said Tuesday it will permit use of the weevil native to Europe and western Asia to control yellow starthistle, which is from the same areas.
Brad Hanson, UC Cooperative Extension weed specialist at UC Davis, says yellow starthistle thrives in part because of its prickly spines.
"So it's not very palatable to any livestock, especially once it's started to flower, and it's toxic to horses. So often times the other grasses and more palatable plants are grazed and the starthistle persists and is sort of the only thing left,” he said.
California farms, ranches strive to adapt as climate warms - it's a matter of survival
(San Francisco Chronicle) Peter Fimrite, Sept 18
…Josué Medellín-Azuara, the associate director of the UC Agricultural Issues Center at UC Merced, said the biggest issue will be irrigation. Decreases in the Sierra snowpack mean less melting in the summer, so more rainwater will need to be stored in the winter. Hotter temperatures would also mean crops and orchards will retain less moisture.
“Plants may actually lose water more quickly because of the heat, so they may actually need more water than they need now to survive,” Medellín-Azuara said. This at a time when California is expected to experience more droughts.
…Frank Mitloehner, a professor in the UC Davis animal science department, said that is why sensors are being installed to monitor water use, and more ranchers are adopting regenerative farming and grazing techniques that ensure the land sequesters more carbon than it emits.
Drought tolerant crop being studied in the Valley
(ABC 30) Cristina Davies, Sept. 17
Big research is happening at the Kearney Agriculture and Extension Center in Fresno County.
Sorghum, a crop that looks similar to corn, is under a microscope.
Jeff Dahlberg, director of the center, said that sorghum is very drought tolerant.
"What we are looking for is the mechanism behind the drought tolerance in sorghum and if we can elucidate the genetics behind that, what we believe is we can use those genetics to see if the genetics in corn, or in rice, or in wheat," he said.
UC Pot Researchers Working with 'Gray Literature'
(East Bay Express) Dan Mitchell, Sept. 17
… The problem was brought into sharp relief last week when the Cannabis Research Center at UC Berkeley made its first formal presentation of the work that it's been doing. The center began operating at the beginning of the year to "promote interdisciplinary scholarship on the social and environmental dimensions of cannabis production." Every one of the five researchers who spoke during the presentation addressed the often-ridiculous restrictions under which they still operate. As Chronic Town reported recently, researchers in public universities all over the state aren't even allowed to be around pot plants, thanks to the federal ban — a mighty hurdle for people studying health effects, cultivation methods, pest-management techniques, and the like.
"It's a tricky problem," observed center Co-Director Van Butsic, an adjunct professor who specializes in land use. "We don't want our researchers to stay in the academy."
Here's a talk about creating sustainable landscapes in Redlands, sponsored by Redlands Horticultural and Improvement Society
(Redlands Daily Facts) Sept. 17
Janet Hartin, an area environmental horticulture adviser for San Bernardino, Riverside and Los Angeles counties, will present a program on “Beautiful Sustainable Landscapes for Redlands” when the Redlands Horticultural and Improvement Society meets 7 p.m. Thursday, Sept. 19, at Redlands Church of the Nazarene, 1307 E. Citrus Ave.
Sept. 18 meeting to explore prescribed burning
(Taft Midway Driller) Sept. 17
The SRWC's meeting will begin with an introduction from Etna Fire Chief Alan Kramer, after which Lenya Quinn-Davidson and Jeffery Stackhouse, advisors with UC Cooperative Extension and co-founders of the Humboldt County Prescribed Burn Association, will share the story of how their PBA got started two years ago. They'll talk about their PBA's work – more than a thousand acres of prescribed fire through 18 different projects – and they'll talk more generally about options for prescribed fire on private lands, permitting and regulations, project costs, and the benefits of prescribed fire on rangelands, forests, and woodlands.
Legalization of cannabis in California changes the dynamics of competing industries
Humboldt County has long been known for marijuana production. Over the last decade, the North Coast's Emerald Triangle – Humboldt, Mendocino and Trinity counties – have experienced a large influx of growers moving to the area to get into the cannabis business.
The greatest expansion of cannabis cultivation occurred within the remote corners of these counties.
“Forested and woodland parcels became valued, not for timber or ranching, but for their capacity to support cannabis operations,” said Yana Valachovic, UC Cooperative Extension director and forest advisor in Humboldt County. “Land prices skyrocketed and a whole wave of newcomers surrounded ‘traditional' producers of forest products and beef. The nearly exponential growth of the cannabis industry has been a shock to some and there has been a steady discussion of social, economic and environmental concerns.”
Of the 71 landowners responding to the survey, 18% said they had grown cannabis on their property and 40% said they had indirectly profited by trucking or operating heavy equipment for the cannabis industry. About half of the landowners didn't indicate whether they had or had not grown cannabis.
While the burgeoning cannabis grows have brought jobs to the economically challenged county, over 60% of the landowners agreed that cannabis had contributed to labor costs, 57% agreed it had negatively affected their livestock operations and the majority reported negative impacts to their property.
“Fences have been wrecked, roads damaged, and stream water theft,” wrote one rancher.
Since cannabis has become legal in California, most landowners (64%) have maintained their views on the industry. Yet, Valachovic and her colleagues are interested in seeing how this rural community adapts to protect its environmental health and economic prosperity.
“It's not news that ranchers can have issues with cannabis farmers, but the evolving perspective is what most excites me about this survey,” she said. “The cannabis industry is very dynamic and has experienced rapid expansion, price highs and lows, and an evolving public policy discussion trying to keep up with the changes. The results of this survey reflect opinions from 2018 and with the inclusion of hemp or low THC cannabis, perspectives will continue to evolve.”
The study was conducted by Valachovic, UC Cooperative Extension advisors Lenya Quinn-Davidson and Jeffery Stackhouse, and UC Cooperative Extension specialist Van Butsic in the Department of Environmental Policy Management at UC Berkeley.
The authors concluded that while public policy will not solve all social behaviors and competing industry needs, land-use policy can help mediate land-use conflicts and zoning to support new economic opportunities as well as existing multigenerational businesses.
“Humboldt has been at the forefront of these issues for decades and perhaps the lessons learned here can be helpful for other communities,” Valachovic said.
In 1953, amid reports that cannabis was growing around San Mateo County, the local sheriff's office and the UC Agricultural Extension Service in Half Moon Bay issued a booklet entitled Identify and Report Marihuana. The booklet envisioned “total eradication” of cannabis. The authors couldn't have imagined that, in 2017, the San Mateo County Board of Supervisors would pass an ordinance allowing greenhouse cultivation of cannabis in the county's unincorporated areas.
A lot can happen in 60-plus years — such as voter approval of Proposition 64, the 2016 ballot measure that altered California law to allow the recreational use of cannabis by adults.
That said, federal restrictions still inhibit many aspects of research (see page 104 for more detail). Cannabis research is also inhibited by funding constraints. The $10 million in annual research funding that Proposition 64 allocated to California universities has not begun to flow, and the Bureau of Cannabis Control — the entity responsible for disbursing the money — reports that it is still establishing guidelines for doing so.
Despite these obstacles, UC cannabis research in the legalization era is well underway, as attested by this special issue of California Agriculture. The research articles presented here fall into three broad categories — research into cannabis production, into the economics of the cannabis industry in California and into the social and community impacts of cannabis. The three articles focused on cannabis production include the results of the first known survey of California cannabis growers' production practices, by Wilson et al. (page 119). In the article “Characteristics of farms applying for cannabis cultivation permits” (page 128), Schwab et al. combine data on cannabis farms with information about applications for cultivation permits, establishing that, of farms within the dataset, those seeking permits tended to be larger and to have expanded faster than other farms. And on page 146, Dillis et al. analyze data submitted to the regional water quality control board to characterize the water sources used by cannabis cultivators in the Emerald Triangle region (Humboldt, Mendocino and Trinity counties).
Articles focused on the economics of the cannabis industry include a study by Goldstein et al. (page 136) analyzing online retail prices for cannabis flower and cannabis-oil cartridges as changes in regulation and taxation have taken effect in recent years. Valdes-Donoso et al. (page 154) analyze data from sources including California's cannabis testing laboratories to estimate the cost per pound of testing under the state's regulatory framework.
Four articles explore the social and community impacts of cannabis production. On page 161, Valachovic et al. report the results of a survey of timberland and rangeland owners in Humboldt County, who shared their experiences with the rapid expansion of cannabis production in their region and its attendant social, economic and environmental challenges. LaChance (page 169) interviewed noncannabis farmers, ranchers and others across Humboldt, Mendocino and Sonoma counties, eliciting their views on issues such as increased land prices amid cannabis legalization. For the article “Growers say cannabis legalization excludes small growers, supports illicit markets, undermines local economies” (page 177), Bodwitch et al. surveyed cannabis growers to gain insight into their experiences with the state's system for regulation of commercial cultivation. Finally, on page 185, Polson and Petersen-Rockney employed ethnographic methods to study cultivation regulations in Siskiyou County and their effects on the county's Hmong-American community. The special issue was conceived by Van Butsic and Ted Grantham — UC Cooperative Extension (UCCE) specialists based at UC Berkeley — and Yana Valachovic — a UCCE forest advisor and director for Humboldt and Del Norte counties. Butsic, Grantham and Valachovic developed the issue in collaboration with Daniel Sumner, a UC Davis professor of agricultural economics and director of the UC ANR Agricultural Issues Center, and with the staff of California Agriculture.
California has legalized marijuana, but commercial cannabis growers have been slow to obtain the required state and local permits. To find out what deters them from complying with new laws, University of California scientists are asking cannabis growers to participate in a survey about their experiences with the regulated market.
“The majority of cannabis farmers are not joining the legal market and we want to know why,” said Van Butsic, UC Cooperative Extension specialist in the Department of Environmental Science, Policy & Management at UC Berkeley. “The objective is to identify barriers to joining the legal market.”
The researchers plan to share the results with policymakers as well as with the cannabis farming community and other researchers.
“Cannabis growers will have an opportunity to tell us what's wrong with the regulatory system so we can advise policymakers on changes they could make to improve compliance,” Butsic said.
Butsic estimates that less than one-third of cannabis growers in Humboldt County have completed the permit process. He says it's difficult to estimate statewide how many cannabis growers are operating illegally because laws vary from county to county and in many parts of the state, local governments don't allow cannabis growing.
One impact from cannabis growers not joining the regulated market is the state receives lower revenues from cultivation taxes.
Beginning on Jan. 1, 2018, two taxes went into effect: a cultivation tax on harvested cannabis that enters the commercial market and a 15% excise tax on purchases of cannabis and cannabis products.
Prop. 64, approved by voters in 2016, stated: “The revenues will provide funds to invest in public health programs that educate youth to prevent and treat serious substance abuse, train local law enforcement to enforce the new law with a focus on DUI enforcement, invest in communities to reduce the illicit market and create job opportunities, and provide for environmental cleanup and restoration of public lands damaged by illegal marijuana cultivation.”
Legalization was projected to create $1 billion annually in new state revenue, but initial tax revenue has been significantly lower. In the Governor's May 1 budget revision, cannabis cultivation and cannabis retail salesrevenues were projected at $288 million in 2018-19 and $359 million in 2019-20.
Compliance is important not only for tax revenue, but also for the environment, Butsic said. Research has shown that illegal cannabis production causes environmental damage, including rodenticide poisoning of forest wildlife.
“We know there are environmental impacts from non-permitted farms,” Butsic said. “The more growers are able to comply, the better off our environment will be.”
The survey can be anonymously filled out online at https://ucanr.edu/sites/compliance until Aug. 1. Cannabis growers who wish to provide more information can volunteer to give the researchers an interview.