A sequences approach using a liquid nematicide with a new mode of action along with an existing granular product is the best approach for tackling potato cyst nematode, according to trials carried out by specialist potato agronomy group Produce Solutions in the UK. Louise Impey reports for FWI.
The company has spent three years testing the nematicide in Shropshire, using it alone and in sequence with granular nematicides at different rates. The firm now has a clearer view on its place in potato cyst nematode strategies and the costs involved.
For agronomist James Lee, who has overseen the trials, the work has confirmed that Velum Prime (fluopyram) is not a replacement for granular nematicides on sites with moderate-to-high potato cyst nematode (PCN) pressure.
“What we’ve seen after three years is that Velum Prime has an important role in complementing other products,” he says. “In that respect, our findings tie in with what the manufacturer Bayer has always said.”
Up to last year, chemical control of the pest relied on granular applications of nemicides such as Vydate (oxamyl). Then came along Velum Prime in Spring 2019, which is based on the SDHI fungicide fluopyram, familiar to wheat growers managing foliar diseases like septoria.
In the 2019 trial, both the best yield and the highest gross margin came from the sequenced use of Velum Prime and full-rate Vydate, rather than half-rate of the granular product.
That approach represents a significant chemical cost to growers at the start of the season, adding to what is often the largest crop protection cost, he acknowledges.
“There’s a greater upfront cost, but it was the most profitable option. It delivered the highest yields and the best returns.”
The Produce Solutions large plot trial in 2019 was conducted in Shropshire in a commercial crop of Maris Piper being grown on a sandy loam soil.