Editor’s Choice 56:4 – A worm in the apple

Issue 56:4’s Editor’s Choice, Management trade-offs on ecosystem services in apple orchards across Europe: Direct and indirect effects of organic production highlights the need for more environmentally friendly pest control approaches in order to keep up with increasing production demands and avoid damage to pollination services.

Associate Editor, Juan Corley, comments on the article.

Photo by Ulrika Samnegård.

Strategy to minimize the negative effects of pests and weeds is an essential part of food production. One approach to suppress pests is integrated pest management (IPM) –a broad-based approach that integrates several different practices. While IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems, the practice often relies on fertilizers and chemical pesticides to reduce crop losses.

In apple production, which is by far the most important fruit crop grown in temperate regions worldwide, pests and weeds can lead to economically significant losses if no control strategy is used. Moreover, intensification in apple orchards to increase production inevitably leads to an increased use of chemical pesticides, in turn increasing production costs and negatively affecting ecosystem services such as those provided by pollinators and insect natural enemies. Alternative methods, such as agri-environmental schemes and organic management are yet to show overall benefits in apple orchards.

Ulrika Samnegård and colleagues shed some light on the issue through a labour-intensive study that quantified natural enemies, pollinators, pollination success, pest abundance and damage, and fruit production in apple orchards in three different European countries. The authors compared these indicators as well as landscape composition affecting diversity at three spatial scales in 28 or 30 apple orchards in each country. Half of these were managed following standard IPM guidelines and the other half were certified organic farms.

In this spotless study, the authors found that, when looking at the combined direct and indirect effects of management on fruit production, organic orchards had on average a much lower fruit production compared to IPM orchards. However some organic orchards were individually more productive. Furthermore, beneficial arthropod species richness was up to 38% higher in the organic orchards.

While the study clearly shows that management (IPM vs. organic) affects fruit production– directly due to pest damage and also by a variety of indirect effects – an additional important finding is that beneficial insect diversity and apple production are largely uncorrelated. In addition, the study found that a higher cover of apple orchards in the surrounding landscape can reduce species richness of beneficial arthropods within an orchard.

In conclusion, this study shows there are differences in the delivery of ecosystem services between organic and IPM apple orchards, with both natural enemy abundance and flower visitation rates higher in organic orchards. However, fruit production is not always the best. There is still very much a need for better-targeted, environmentally friendly pest control techniques if we do not wish to encounter a worm in the apple.

The Editor’s Choice article, Management trade-offs on ecosystem services in apple orchards across Europe: Direct and indirect effects of organic production is free to read in issue 56:4 of Journal of Applied Ecology.

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