Though some Oregon farmers are worried about facing accusations of contaminating marijuana with pesticides, state investigation records show such allegations have been relatively scarce.
So far, the Oregon Department of Agriculture has initiated just 11 investigations into on-farm pesticide drift related to cannabis, which includes marijuana and hemp.
“From what we know, it’s a minor thing that is happening,” said Sunny Summers, ODA’s cannabis policy coordinator.
To compare, the agency has investigated more than 250 total cases in which routine tests detected pesticide contamination of marijuana, which was legalized by Oregon voters for recreational use in 2014, regardless of cause.
Under Oregon law, marijuana cannot be sprayed with any pesticides registered by the U.S. Environmental Protection Agency for specific crops or subject to maximum residue levels.
However, the agency has developed a list of general biological pesticides exempt from these federal requirements that can be sprayed on the psychoactive crop.
Some pesticide contamination of marijuana was likely caused by intentional spraying by growers, but the ODA has also identified several biological pesticides tainted with prohibited chemicals.
While it would appear that farmer-to-farmer drift contamination in the field occurs rarely, it’s possible that some marijuana producers may suspect pesticide drift without reporting it to ODA, said Summers.
“We only know what we know,” she said.
Last month, concerns about marijuana pesticide contamination prompted county delegates of the Oregon Farm Bureau to request that the organization’s leaders discuss the problem with ODA officials.
A public records request by Capital Press has found that only two drift complaints of the 11 investigated by ODA resulted in the agency citing a farm for pesticide violations.
In one case, a marijuana grower near Hood River claimed that pesticides from a neighboring pear orchard had drifted onto his property.
The ODA determined that chemical residues found on the marijuana grower’s property most likely originated from an application of Topsin, a fungicide, onto pear trees growing on the adjacent parcel.
The pear grower was cited for “faulty, careless or negligent” pesticide spraying, while the marijuana affected by the chemical was deemed adulterated and ineligible for commercial sale, even though the drift occurred before its psychoactive flowers had formed.
Dale Mitchell, manager of ODA’s pesticide program, said growers who are determined to have been impacted by pesticide drift can file a “report of loss” that can be used in civil litigation.
Farmers who are cited for causing pesticide drift receive a notice of violation if they have no history of previous problems, he said. If they have repeat violations within three years, the agency may issue a monetary civil penalty.
In the other violation case, a marijuana grower near Canby was worried about possible contamination after his hemp-growing neighbor had used a fogger to spray the crop with an unknown substance.
The neighbor claimed the complaint was based on the marijuana grower’s fear of cross-pollination, but ODA determined the hemp had been sprayed with Entrust, a product containing the biological insecticide spinosad.
While spinosad is a biological pesticide, it doesn’t meet the criteria for ODA’s list of substances approved for cannabis, so the hemp farmer was cited for a pesticide violation.
In a similar case, a cannabis grower was found to have sprayed the crop with Cinnerate, a biological pesticide primarily composed of cinnamon oil, but the case file doesn’t indicate whether he was cited for a pesticide violation.
In several cases investigated by ODA, the agency didn’t conduct testing because too much time had elapsed or the agency could not determine the origin of the alleged contamination.
In other instances, the agency found that a landowner accused of spraying marijuana didn’t actually grow the crop, while another marijuana producer didn’t pursue the complaint because he reached an agreement with his neighbor.
In two cases, marijuana growers claimed their neighbors had sprayed chemicals due to an antipathy toward the psychoactive crop.
In one instance, ODA warned the neighboring landowner against spraying rights-of-way with a vinegar solution on other people’s property. In the other, the agency referred the complaint to law enforcement as suspected herbicide vandalism.
The agency treats such cases differently depending on whether the application was intentional or not, said Mitchell. “We have a lot of different scenarios.”