Coming down the pesticide pipeline
Eugenia Banks, Ontario potato specialist, attended a BASF meeting discussing several pesticides for potatoes will be coming through the pipeline for producers.
Banks says two pesticides caught her eye: Zidua and Cimegra. Zidua is a pre-emergence herbicide that controls red root pigweed and suppresses lamb’s quarters. It is in the same family as dimethenamid-p (Outlook) and s-metolachlor (Dual Magnum), which both are seedling shoot growth inhibitors.
Andrew Robinson, potato agronomist at North Dakota State University and the University of Minnesota, has been testing Zidua for three seasons. “Zidua needs to be tank-mixed with other herbicides. It should be used pre-emergence, when the potato shoots are still a couple of inches underground. If potato plants are emerging, it can cause some injury. Good timing gives it great crop safety, much better than Outlook or Dual,” Robinson says.
BASF hopes to have Zidua registered through the Minor Use program.
Cimegra is an insecticide that controls leafhoppers and tarnished plant bug when applied as a foliar spray. When applied in-furrow, Cimegra controls wireworms. The active ingredient is broflanilide.
Registration for Cimegra may occur in 2021. Robinson was hopeful in 2017 that Zidua would be available to growers in 2018, but this timeline has also been extended. Despite the delays, Eugenia Banks says “there has been so much talk recently of products risking cancellations that it’s nice to know that there are new products in the pipeline for registration.”
Banks is referring to ongoing re-evaluations on pesticides and seed treatments being conducted by the Pest Management Regulatory Agency (PMRA). In a March 2018 editorial, Jannen Belbeck, then Potatoes in Canada associate editor, summarized the issues. “The PMRA re-evaluations include eight fungicides, four insecticides and one herbicide. Although no one is certain what exactly the new regulations will look like, all 13 pesticides will not be able to maintain their uses as they were before. In fact, nine of these pesticides were originally planned to be completely removed from agricultural use, while the remaining four were proposed to have some uses cancelled, and limitations to other uses. For example, Dithane and Polyram are on the chopping block to be completely removed from agricultural use, while Captan and Bravo are two of the fungicides proposed to have some uses cancelled and others limited, come December.”
In October of this year, Health Canada proposed to cancel all uses of mancozeb, a broad-spectrum fungicide. The re-evaluation removed the exception that allowed foliar application of mancozeb on potatoes and the open consultation process will be wrapping up on Jan. 3, 2019. Despite all these barriers, the potato industry continues to innovate and develop pesticides to add to a grower’s toolbox.