Implementation of Integrated Pest Management by vegetable and salad growers in the UK

Abstract: In the UK, vegetable and salad crops are grown outdoors throughout the year, their seasonality dependent mainly on the ability of the crop to withstand low temperatures in winter. These crops are subject to infestation by a range of pests, most of which have caused concern for growers for many years. Control of pest insects on outdoor vegetable and salad crops in the UK is highly reliant on insecticides and growers are fortunate that they continue to have access to a range of insecticides with different modes of action. Even so, some pests and/or the viruses they transmit are difficult to manage with the tools available at present and for some species a very limited range of modes of action are available. Despite the potential availability of different modes of action, pyrethroid insecticides are used widely and it is of concern that incidences of pyrethroid resistance in pest species are increasing. The selection pressure from use of pyrethroids, and potentially other insecticide groups, is exacerbated by the fact that many pest species infest both arable and horticultural crops. Vegetable and salad growers have access to information and tools to forecast infestations and monitor a number of key pests to optimise insecticide use. However, without undertaking a very detailed study it is difficult to gauge the impact of this information, both in terms of any potential reduction in insecticide use and improved levels of control. Other management tools such as fine mesh netting crop covers, host plant resistance and biopesticides are used on a relatively small scale. It appears that one of the main reasons why Integrated Pest Management is not being taken up more widely is because of a lack of alternative tools and management practices that are both effective and cost-effective and there is a considerable need for these to be developed and transferred to growers in a form that they can use. They include: reliable, cost effective and simple monitoring and decision support systems; control strategies with less side effects on beneficial organisms; more knowledge about spraying technology and alternative ways of applying insecticides; more effort to breed for pest resistance; alternative control strategies such as those using pheromones. Finally, although functional biodiversity is not easy to implement and manage, and its efficacy is neither proven nor predictable, it needs to be investigated in more detail and it undoubtedly needs to be coordinated at a landscape scale.