Growers get extra spray to control bruchid beetle in beans

Bean growers now have a new spray available to them, for controlling bruchid beetle in crops, following the authorisation of the insecticide, Biscaya.

After a surge in beetle problems over the past five years, the new approach will come as welcome news to growers, many of whom would have suffered from the widespread downgrading of field beans last season.

Biscaya (thiacloprid) is a fast-acting insecticide, which is used to reduce the damage from insects in a number of crops including oilseed rape, potatoes and carrots.

Andy Bury, pulse manager for agronomy and trading group Frontier, explains 2017 was an extremely difficult year for bean growers in terms of bruchid beetle damage, with the export market for human consumption far below the average figure of 280,000t.

“Last year, UK exports wouldn’t have reached 100,000t, with bruchid beetle responsible for 80% of downgrading,” he said.

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Mr Bury also highlights the timing of spray is crucial to the control of the problem, claiming beans are at risk from attack when pods are present on the lowest node and temperatures reach 20C plus on two consecutive days.

For the reduction of bruchid beetle damage, two sprays are recommended to be applied within the 1 May and 31 June window, with a minimum of 10 days between applications. The recommended dose of spray is 0.4 litre/ha, with a suggested water volume of between 200 and 400 litres/ha.

Becky Howard, principal technical officer at the Processors and Growers Research Organisation, says the above average temperatures this time last year made bruchids very active, but believes Biscaya will be more persistent than the pyrethroid sprays previously used.