Managing snow mold and other fungus problems on turfgrass is about to get more challenging. Golf course operators and others who work to keep turfgrass disease-free will no longer be able to use the fungicide pentachloronitrobenzene (PCNB) under a proposed decision announced Sept. 23 by the US Environmental Protection Agency.
The EPA wants to cancel all uses of PCNB, citing risks to human health and the environment.
In addition to use on turfgrass, PCNB can be applied to potatoes and cole crops, such as broccoli and kale, as well as to ornamentals. The chemical and its degradates are persistent in the environment, bioaccumulate in aquatic organisms, and can travel long distances, according to the EPA.
In 2021, the EPA identified risks of PCNB to human health, including adverse effects on the thyroid. The assessment found risks to bystanders from spray drift and to users of athletic fields.
The EPA claims that viable fungicide alternatives to PCNB exist. Those chemicals include azoxystrobin, pyraclostrobin, tebuconazole, propiconazole, and others, the agency says. The EPA also suggests crop rotation and the biopesticide Bacillus subtilis as alternatives to PCNB.
In comments submitted to the EPA in January 2022, the Golf Course Superintendents Association of America says a ban on PCNB will have negative consequences on golf course management. “Golf course superintendents could have to use products that are more expensive and use more products to make up for the loss of PCNB,” the association says. “You would most likely use 2 or 3 other actives to make up for the efficacy of PCNB.”
The EPA is accepting comments on the proposed ban until Nov. 22.