UK tomato growers were last week warned about two new threats to their crops that are expected to be the worst to hit for some time.
The spread of Tuta absoluta and Nesidiocoris tenius has so far kept the production industry guessing, but preliminary research was shared with the sector at the Tomato Growers’ Association Conference in Coventry last Thursday.
Dr Rob Jacobson, director of consultancy RJC Ltd, is leading studies on the two pests, which were not even on the radar until last year.
His presentation, Pest Control in Evolving Growing Systems, looked at how Tuta in particular had spread from South America to Spain in 2006, before spreading around the Mediterranean by 2008 and crossing over to the UK this year.
There have been nine recorded incidences of Tuta in UK crops, starting in week nine, but with tow in the last fortnight but Jacobson stressed that they were “low levels of infection”.
However, he warned that losses as a result of the pest could exceed more than £300,000 per hectare per season.
Jacobson told the trade that much of the marketing advantage enjoyed by the UK tomato industry over rival sources is a result of the sector’s consideration for the environment and its reputation for the reduction of pesticides, so the pests must be tackled in a way that is compatible with IPM principles.
He said: “The UK tomato business has achieved a 93 per cent reduction in pesticides since 1995 and the tomato industry has lead the world in integrated pest management (IPM), so this research into new threats is something that we should be part of…
“The Spanish have bee using broad spectrum treatments but most of them are not compatible with our IPM, so we have to look at it differently.”
The industry is looking at control options using IPM-compatible chemicals, including Indoxacarb and Spinosad, as well as pheromone traps and mating disruption. And in the case of organics, a project led by Dr Phil Morley of Wight Salads Group is developing contingency plans.
Nesidiocoris tenuis, which is similar to predator Macrolophus but half as big again, has only seen one outbreak in the UK so far, close to a packing facility that had been handling Spanish produce.
Jacobson suggested that Nesidiocoris could actually be the best predator to tackle Tuta, in the same way that Macrolophus is used as an important biocontrol.
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