Canadian potato growers are curious about Bayer’s new product Velum Prime. It’s being positioned as the first non-fumigant nematicide for potatoes in Canada with a secondary benefit of fungicidal activity on early blight.
    

“We really liked the product,” says Dave Buhler, Haskett Growers Limited. He and his family farm 3,000 acres of fresh and processing potatoes near Winkler, Manitoba. In last year’s growing season, they managed a side-by-side, 20-acre trial with Umatilla Russet 
potatoes. They compared the Velum Prime treatment versus Quadris fungicide. “We got a very significant response of 60 cwt/per acre using Velum Prime.”  
    

Darin Gibson, Portage la Prairie, Manitoba has the same opinion. As a research consultant conducting 60-plus potato trials for Gaia Consulting, he has seen consistent yield increases of 10 to 20 per cent.  “I’m impressed with the early blight protection of an in-furrow product,” he says. “It buys you some time before you need to apply other fungicides for early blight.” 

Excellent plant mobility

“This is a very unique product with limited soil mobility and excellent plant mobility,” says Andrew Dornan, agronomic development, horticulture at Bayer. “It was first discovered as a foliar fungicide with the nematicidal properties just recently quantified.”
    

Bayer is encouraging growers to use Velum Prime primarily for its nematicidal properties. Its early blight activity is a secondary benefit. For resistance management, the first foliar fungicide applied after Velum Prime (applied in-furrow) must be a non-group 7 mode of action. Examples include chlorothalonil or mancozeb. 
   

In the laboratory, all nematicides will show 100 per cent control of nematodes. However, the reality is different in a potato field where nematode populations may fluctuate in density. That’s why the label is for suppression of nematodes, specifically root lesion, root knot and potato cyst nematode. While the eel-like, microscopic worms are notoriously difficult to control, Bayer’s trials have recorded anywhere from 30 to 80 per cent suppression.  
    

“The reality is that nematode activity is hard to measure accurately in field conditions, but yield increases from Velum Prime are consistent and easy to see,” says Jon Weinmaster, crop and campaign marketing manager for horticulture at Bayer.

Advice to growers

The best advice to growers is to soil test and understand what nematode species are present and at what levels. With a soil sample in hand, conduct your own cost-benefit analysis. For example, those growers planning to plant Superior, a fresh market variety, should be cautious because the variety is already very susceptible to root lesion nematode. The economic threshold for Superior is 2,000 root lesion nematodes per kilogram of soil.
    

In some geographies, Velum Prime might be used with a fumigant. A fumigant goes beyond nematicidal activity which makes it a chosen practice in some areas. The application of Velum Prime after a fumigant is providing additional nematicidal activity, early blight protection and yield gains over a fumigant alone.
    

MRLs that will support trade in countries such as Japan are expected by early spring. Until then, Bayer is asking processing potato growers to not use Velum Prime until it is trade-enabled and/or approved by their processor. Bayer will communicate any changes in MRLs as soon as they are established. 
    

More research is underway in the United States and Canada on the best delivery mechanism for getting the active ingredient to the root zone in crops other than potatoes. Current research includes work on carrots, radishes and ginseng as well as tree fruit and caneberries, all of which is being conducted through the Minor Use Pesticides Program in Canada. 
    

Velum Prime, available in 4.04 L jugs, is applied as a liquid formulation in-furrow at planting. 
    

Andrew Dornan will be on the nematicide program for the OFVC on February 23.