From material absorption to backflow, chemical contamination in agricultural applications is a huge challenge, one that can cause thousands of dollars in damage to crops and rob time-strapped producers of their most valuable time. Hose + Coupling World was grateful for the opportunity to interview Katelyn Duncan, a farmer and policy analyst, and Tom Wolf, Senior Scientist at Agrimetrix Research & Training, about the causes of chemical contamination and what producers can do to minimize risk.
By Jody Hewitt, Editor
Duncan has been deeply entrenched in the agricultural sector and community for as long as she can remember, having worked alongside her older siblings on the family farm just south of Regina, Saskatchewan. “My sisters and brother and I would take turns driving a water truck for my dad,” she recalls. “We had a 2” hose at that time and we had to lift it onto the back of the grain truck—that hose was bigger than us! It was definitely a challenge.”
Having completed her BSc in Agriculture at the University of Saskatchewan and certificate in Agricultural Mechanics and Equipment/Machine Technology at Saskatchewan Polytechnic, her current off farm role involves analyzing and writing regulatory policy for industry associations; all while continuing to be actively involved in the family farm. It can’t be easy to wear so many hats, but Duncan enjoys the work. “I like working in a role that challenges me to advance a skillset that I don’t use on the farm and makes a difference in the industry,” she says, “and I get to meet and interact with intelligent and influential people every day.”
Wolf, who was raised on a grain farm in Southern Manitoba, found himself drawn to the sciences, completing a BSc in Agriculture, Plant Sciences from the University of Manitoba. After graduating, he planned to make farming his full-time job, but record droughts, sky-high interest rates and low commodity prices threatened his chances for success. “It was the worst time to farm,” says Wolf. “My father actually advised me against it, so I went back to school and completed my MSc and later a Ph.D. in Spray Application Technology at Ohio State University. I have been active in sprayer research for 30 years.”
While performing day-to-day tasks on the farm, Duncan and Wolf use a variety of different hoses, including industrial rubber hoses, layflat hoses, rubber discharge hoses, suction hoses and steel web reinforced hoses. They also use agricultural sprayers, a piece of equipment that is used to apply pesticides, and fertilizers on agricultural crops, which are equipped with suction and/or discharge hoses. We asked our experts about the physical properties of the hose material in their equipment—and were surprised by the answer.
A black box
“We accept the sprayers as they are shipped to us,” explains Wolf. “As far as we know, the hoses are made of a rubber compound, but it is not known or reported in the industry what the hoses are made of. Are they lined? We don’t know, we can’t see inside them. Even if we could, we wouldn’t know what we were looking for. It is a bit of a black box, and because we don’t know what they are or what their physical properties are, we don’t know for sure how to clean them.”
This lack of availability of information is a significant handicap, as Duncan explains: “Some crops are incredibly sensitive to certain herbicides, even in tiny quantities—1/1000th of the label rate or less. We have to be incredibly diligent in cleaning out hoses after use to prevent sensitive crops from being exposed to even trace amounts of residue.”
Herbicides come in a number of different formulations: true solutions, emulsifiable concentrates, dry material suspensions— aka “flowables”—and dry formulations (granular). While the chemical in a true solution is fully dissolved, the solubility of emulsifiable concentrates, flowables and granules depend on other physical and chemical factors, such as water PH, water temperature or hardness. “Products that are not true solutions may not clean out very easily,” explains Wolf. “As a result of these factors, the herbicide may precipitate out slightly, going back into the solution gradually over time and forming residue inside the hose or tank.”
Failure to remove chemical residue from the interior of the hose can have disastrous financial consequences for a producer; yet, there appears to be no sure-fire way to avoid the risk.
“You rinse them until they look clean,” says Wolf, “but you don’t know for sure if they are. We are talking about chemistry here, so there may only be a trace of it left but you can’t see it or smell it. It would make a big difference if we knew more about the properties of the hose material, particularly with regards to absorption. Currently, the general rule of thumb is to do everything you can—then do it one more time to be sure. It can be a very frustrating and time consuming process.”
We ask our experts if improved labelling on the equipment—including the material properties of each part—would be beneficial to the industry as a whole.
“This is a widely known issue in the agricultural sector,” replies Wolf. “Material absorbency and preventing contamination is top of mind in the community. A manufacturer could gain a significant competitive advantage if they could provide assurance that their product is non-absorbent or less absorbent. It is a major paint point for most applicators.”
Stay tuned for part two of this interview, or contact the Editor to get it now!