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Biopesticide gives growers a viable alternative for nematode control

At a technical briefing held by Certis in January to mark the launch of a new and improved formulation of NEMguard, agronomists were warned that the risk of nematode damage to a wide range of crops is increasing. Dr Colin Fleming, senior lecturer in parasitology at Queens University in Belfast, explained that several factors are probably significant in the increase of the nematode populations.

At a technical briefing held by Certis in January to mark the launch of a new and improved formulation of NEMguard, agronomists were warned that the risk of nematode damage to a wide range of crops is increasing. Dr Colin Fleming, senior lecturer in parasitology at Queens University in Belfast, explained that several factors are probably significant in the increase of the nematode populations.

“The climate is changing and we are seeing warmer, wetter weather patterns that favour nematodes and are encouraging ‘new’ species that prefer warmth to thrive,” he said. “The reduction in the number of active substances available for use in agriculture is also having an effect – there is less pressure on nematode populations so they are not as suppressed as in previous decades.”

Dr Fleming predicted that the root knot nematode (Meloidogyne minor) will be the number one nematode problem in the UK within the next decade. 

“Only discovered in 2004, it is believed M. minor has probably always been present in UK soils but numbers have increased dramatically with changing environmental conditions,” explained Dr Fleming. ”Generally nematode numbers have increased by 300% in the last 30 years, according to a 2011-2013 survey in Northern Ireland.” 

Robert Lidstone, Certis’ marketing and business development manager, explained that the addition of NEMguard DE – a proven, registered nematicide – to the Certis portfolio couldn’t have come at a more pertinent time, especially with the existing pressures on pesticides. 

“The active substance in NEMguard is garlic extract. The mode of action is fully understood through extensive research, and its efficacy has been confirmed in various field trials. 

“Since gaining an official EU pesticide approval, growers of carrots and parsnips have been turning to NEMguard as a viable alternative to carbamate chemistry. It also benefits from no MRL (maximum residue limit) and therefore no applicable harvest interval,” added Mr Lidstone.

One such grower is Guy Poskitt, who has been developing the use of NEMguard on his farm in Yorkshire for the last ten years and talked about his experience.  

“As a grower of 1,400 acres of carrots and parsnips, we supply fresh produce to retailers for 48 weeks of the year,” said Mr Poskitt. Carrots were recently identified as a crop where production is in danger of becoming unsustainable due to the impact of pesticide loss on food production. 

“Since we’re losing more and more pesticides, we’re looking at other ways of attacking our problems,” explained Mr Poskitt. “We need to have access to a range of products as part of our crop protection toolbox. Any pesticide development, including the introduction of natural products, is welcome and possibly where the future lies,” stressed Mr Poskitt.  

“NEMguard seems to work at a similar efficiency to Vydate (oxamyl) for nematode control, but has the major bonus of not having a MRL or harvest interval which means we can use NEMguard on early crops without a worry,” he added.

Dr Chris Hamilton, who has been working with sulfur chemistry at East Anglia University for a number of years, explained some basic biochemistry, and the background research behind NEMguard.

“When garlic cells are ruptured and then heated, a breakdown substance is produced which contains diallyl polysulfides, these molecules are able to elicit a cascade of different changes within the metabolism of the nematode that ultimately kills them,” he explained. 

There are extensive quality controls in place to make sure NEMguard consistently contains the ‘right’ mix of polysulfides to maintain its efficacy and ensure a long-term release, concluded Dr Hamilton.