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Longer period of pest activity puts pressure on control programmes

This year’s early spring will increase the length of time that aphids pose a risk to key crops, such as carrots, where an extended period of activity by willow-carrot aphid (Cavariella aegopodii) and other species will increase virus pressure on crops.

“With just two specific products approved for aphid control on carrots, Movento and Biscaya, and an Emergency Authorisation for Teppeki, it could be a real struggle for growers to keep on top of aphid control this year in order to prevent the spread of virus diseases over an extended growing season,” warns Selchuk Kurtev, IPM Manager at Certis.

He believes that the combination of a longer pest season and limited product choice will leave growers looking for alternative controls and that many will consider broad-spectrum pyrethroid products to fill the one or two gaps which are likely to appear in their spray programme.

“If you are going to use another spray to control aphids on carrots this season, that will most-likely be a pyrethroid-based product,” he says. “If you are considering synthetic pyrethroids, you may well be better off with a biorational alternative like Spruzit. Not only does Spruzit contain a natural pyrethrin, but it is formulated with natural rapeseed oil which provides an additional physical mode of action against aphids, providing a double defence for the crop.”

As a result, Spruzit is a good biopesticide to use as an alternative active in control programmes as the two natural modes of action help manage resistance. “The benefit of the rapeseed oil in Spruzit is this double defence mechanism,” continues Selchuk. “Using a product which relies on a pyrethroid active ingredient on its own increases the likelihood of resistance building up, compared to the dual action provided by the natural rapeseed oil formulation.”

It is not just carrot growers who will face challenges caused by this year’s longer pest season. Brassica producers are likely to see higher pressure from whitefly (Aleyrodes proletella) and diamondback moth (Plutella xylostella). “Being a natural pyrethrum Spruzit also has activity against a broad range of pests,” says Selchuk. “It has approval for use in range of brassicas and can play a role in managing resistance in diamond back moth too, while providing control of many biting and sucking insects.”

Brassica whitefly can be particularly troublesome on niche crops, such as kale and organic brassicas, where residues are a particular concern. In this case Selchuk recommends that growers consider using another biopesticide, in this case Majestik. “Majestik has been proven to work well in Lincolnshire on leafy vegetable crops,” he points out. “Biopesticides like Spruzit, Majestik and Botanigard WP are becoming more widely used on field vegetable crops as growers and agronomists understand the crucial role they can play in spray programmes. As well as having a lower risk of resistance building up, often they are residue exempt  and they provide a much more sustainable way of controlling pests, including aphids and viruses. 

For more information on Certis’s biopesticide range for smart veg production, visit our smart veg page.