Improving knowledge and experience of integrated pest control of soft fruit in Wales to reduce pesticide application and wastage

Project Description:

Biological pest control has become standard practice for many larger horticulture farms supplying supermarkets, but it is not yet common practice for many smaller fruit growers in Wales. Biological control is the use of natural predators, parasites, bacteria, and sometimes plants to control pests and weeds as part of an integrated pest management programme, mainly in greenhouses and polytunnels. Many small scale fruit growers are interested in utilising this method to reduce their use of conventional pesticides and reduce the chance of pests developing resistance to these pesticides. The main hurdle for the small scale growers is the lack of knowledge and understanding on how to recognise pests, what biological controls are available, how best to use them, and how to integrate them into an existing pest and disease control programme. This project will trial the establishment of different biological pest control strategies on two commercial fruit farms in south west Wales, with a combined growing area of about 1.3ha. 

The growers, will work closely with experts to develop a programme that will suit their growing systems. The exact methods used will be identified on the basis of what pests are present on each site, however a minimum of four pests are expected to be targeted. The growers will receive training on pest identification, monitoring methods, and biological control options on an ongoing basis.  At the end of the project, best practice recommendations for the wider sector will be produced.

Project objectives;

• Does biological pest control provide significant benefits in terms of pest control over conventional systems?
• Is biological pest control a cost effective investment compared with conventional control?
• What adaptations are necessary for effectively implementing a biological pest control programme in a soft fruit business?
• What are the common problems/pitfalls of implementing a biological control programme, and how can these be resolved or avoided?

Executive Summary:

Growers’ crops are increasingly vulnerable to damage from mite, aphid and thrips pests due to reducing pesticide efficacy and availability. As the industry tries to move away from pesticide interventions some new challenges face the industry in Wales. Biological pest control has become standard for larger farms supplying into supermarkets, particularly in response to loss of chemical actives and emerging resistance, but these benefits have yet to be realised by some of the fruit 
growing sites in Wales in an effective way. A range of biological controls (e.g. Aphidius, Amblyseius, Phytoseiulus and nematodes) are commercially available and can offer comparable if not greater pest control than chemical methods. Effective biological control can enable growers to reduce wastage, reduce pesticide application and future proof against further reductions in pesticide availability. 

Biological pest control is also integral to organic production, allowing growers to achieve a market premium on organic fruit. It should also be noted that conventional pest control is not a simple process, as pesticides can be difficult to apply and calibrate and are never 100% effective. Small quantities are not available to suit growers with fewer production facilities and sharing between growers is not permitted. Often large quantities have to be purchased and stored and these may be 
withdrawn at short notice leaving growers to dispose of expensive pesticides. 

Effective biological pest control requires a significant base knowledge of both pest and bio control biology, and how this interacts with the environment and other (e.g., chemical) control methods in a site-specific fashion due to growing habit, cultivars and marketing model. Grower uptake of biological control has been historically hindered by a lack of understanding and knowledge. Few of the smaller farms producing soft fruit in Wales are specialist and most have several other enterprises all competing for depth of knowledge and monitoring. Long season picking by using several techniques from sequential planting of cold stored plants to use of everbearer varieties in both raspberries and strawberries is a challenge for management. In-depth understanding of both pest and control species’ lifecycles is required to ensure sufficient populations of control agents can be established. New biological control agents are being made available commercially, and the regulatory environment is constantly evolving as actives are deregulated or become available through new registrations or short-term Extension of Authorisation for Minor Use (EAMUs) for off-label use. The existing suppliers of biological control often list tables of the relative safety of pesticides on the introduced beneficials, but this is quite complex for growers to use and become familiar with and some interpretation will be key to getting success and confidence going forward.

Such understanding is often lacking among smaller producers and this project seeks to take the knowledge of the larger scale producers and transfer it to the smaller growers who sometimes struggle to keep abreast of technological advancements within the industry. This results in an ongoing challenge for growers looking to combine chemical and biological control to implement an effective integrated pest and disease (IPDM) programme.

Best practice recommendations:

• Being fastidious in keeping the crop clean as well as the wider site can go a long way to reducing pest numbers or keeping them low. 
• Remove any waste from the plants and dispose of properly far from your crop – pests will leave this waste and go back into the crop!
• A clean and disinfection at the end of the season will go a long way to helping prepare for the new season. 
• Regular monitoring is invaluable for effective decision making. Keep a log of common areas you are observing pests, these can be useful for future years at your site. 
• Consider the environmental variables, temperature and relative humidity, and their impact on the pest and predator levels and survival. Low temperatures typically mean slower development of pests but also predators.
• Consider using data loggers in tunnels to monitor the conditions and help inform you when the benchmark temperatures for predators have been reached (e.g. 15®C for Orius).
• Buying good plant stock is important, pests often arrive on these plants if ordered from a less reputable propagator. These can be expensive initially but save a lot of issues. Sometimes new plants are the primary method for the introduction of new pests onto an otherwise clean site. 
• Make sure to check the new plants for pests and disease immediately.
• Containerised growing media can be replaced, a useful option when compared to soil grown crops. This is useful for ‘re-setting’ pest levels each year to avoid a yearly steady build up especially if you are buying new plants.
• When placing new cropping areas investigate and consider the local environment for pests and where they may come from. Alex and Tom Higgs have had a lot of success from their new tunnels centrally placed in a field where it is harder for pests to come in. 
• Cold winters are a useful free way of reducing pest numbers, this is obviously not entirely reliable and so clean up sprays at the start of the season has been seen to be useful in this project.

Future work:

This work has primarily focused on the use of biological controls for pest reduction within an integrated pest management (IPM) programme. The use of bio protectants for the treatment of pests, diseases and weeds is similarly challenging and there is a lot of scope for future work to help support the development of these schemes within Wales. Further specialised mentoring and guidance on the recognition of pests and diseases is another area that can be developed further. 

IPDM Factsheet June 2021.pdf

[.PDF, 295.77 KB]