Epsilon Archive for Student Projects

Abstract

The rate of biodiversity loss has in the last decades increased by rates unseen in the history of the humankind. Agricultural intensification has been one of the main contributors to biodiversity loss. In modern agricultural production, the concentration of land devoted to single crops causes several challenges. In the pest management, specialist crop herbivores have larger area of suitable host plants in monocultures, while the lack of plant diversity reduces environmental opportunities for natural enemies. Synthetic pesticides commonly used for controlling pests over the last decades are gradually losing their effectiveness due to increasing pesticide resistance of insects. Moreover, many pest control technologies have been linked to problems of pollution, high costs, or deregistration of insecticides because of safety concerns. Since January 2014, all fruit growers in EU are required to follow the Integrated Pest Management (IPM) standards, which incorporate a wide array of pest management practices and tactics for long-term pest control. Currently, the IPM still heavily relies on the use of pesticides but tries to promote prevention and alternative environmentally friendly pest management strategies. Functional agrobiodiversity (FAB) has been acknowledged as one of the methods for suppression of the insect pests in agro-ecosystems. The benefits of high diversity on agroecosystems have been discussed for almost decades. However, there is still lack of evidence about the real effects of different FAB practices. Apples are crops with the second highest pesticide use per hectare in Europe after grapes. Organic apple growers have access to less harmful pesticides with lower efficacy that often provide insufficient pest suppression. Therefore, the organic growers need to focus on preventive measures and alternative practices than application of pesticides. This thesis investigates effects of functional agro-biodiversity (FAB) in intensive organic apple production. It aims to understand whether end-user adapted monitoring methods for insect pests and their arthropod natural enemies used by farmers and advisors can support implementation of FAB practices for pest management. Moreover, this work investigates whether flower strips, as one of FAB practices, promote biological pest control in modern apple production. This is achieved through combination of qualitative and quantitative research, participatory research and field trials. This thesis is conducted under the umbrella of the EcoOrchard project that aims to assess how far functional biodiversity can reduce pest damage and pesticide use in organic apple orchards. During the EcoOrchard project, four approaches to FAB were identified. These approaches were adopted and further examined in this thesis. The approaches were interpreted by the growers as an increasing scale of action from observations and avoidance of harming beneficials until active promotion of them by introduction of specific FAB strategies. The participants suggested to create a program for a growing season, to introduce different tasks, and gradually learn through collaboration between research, advisors and growers. The tasks could include a recommended schedule of management practices that promote beneficial insects or recommended dates for use of specific monitoring methods. The economic aspect was of crucial importance for the implementation of FAB practices. This thesis also underlines the importance of monitoring of natural enemies in apple production for participatory development of more resilient and sustainable apple orchards. Better knowledge of biological processes can help growers to change their attitude towards more sustainable production. Functional agrobiodiversity is a complex approach to improve agroecosystems that requires understanding, knowledge and expertise in biological process of specific species and in agricultural production. While the results of the field trials failed to deliver convincing arguments for use the flower strips, as one of FAB practices for pest regulation, the study uncovered several benefits of the monitoring for the growers and the advisors. Further research is required to find plant species with desirable traits that could be applied for FAB in different conditions and for different crops.