Thrips can severely affect strawberry crop quality and yield during summer months, favouring temperatures between 20 - 30°C and continually reproducing during a life-cycle that lasts two to three weeks.
As a result, they are a significant issue for field growers during the summer, and longer for greenhouse growers. RSK ADAS crop consultant, Robert Irving, advises how to successfully control these challenging pests in strawberry crops.
“Thrips numbers increase rapidly in summer,” says Mr Irving. “They attack the yellow centre of strawberry flowers. Depending on the species, berries develop severely misshapen or with a ‘bronzed effect’ roughened skin, rendering it unsaleable.
“Damage from thrips can result in losing over half of strawberry crops if left uncontrolled. Preventative measures are essential,” Mr Irving explains.
“Get ahead of thrips, before they get ahead of you,” says Mr Irving. “Monitor flowers at least once a week for their presence. Once you see an average of three thrips per flower, act fast.
“Check the yellow flower centres with a hand lens. Blowing hard into the centre will make them run around and easier to spot.
“Also, consider the wider landscape. All forms of grass and weed cutting, including hay making, harvesting cereals, and strimming field margins and road verges near crops cause thrips to fly out of vegetation due to having their food source desiccated. In these instances, increase crop monitoring to at least twice a week.”
“Western flower thrips (WFT) are mostly resistant to insecticides. Successful control consists of a prolonged sequence of biological measures, such as Neoseiulus (previously Amblyseius) cucumeris and/or Orius laevigatus; both being predatory insects,” suggests Mr Irving.
“However, unlike WFT, other thrips can be successfully treated with insecticides. Always read the label to check guidelines and maintain awareness of bee activity,” Mr Irving emphasizes.
Mr Irving provides his top tips for controlling thrips in strawberries:
Further information can be found in AHDB’s factsheets; Integrated control of thrips on strawberries and Western flower thrips control in strawberries.
For more information about the control options available for thrips at various stages of the pest lifecycle, visit the Certis website, or contact us.