Peach orchard protection strategies and aphid communities: Towards an integrated agroecosystem approach

Summary in the original language of the document

Aphid populations, including a widespread pest, Myzus persicae, are known to be affected by cultural practices, plant growth and natural regulation, but their control in orchards most frequently relies on regular treatments aiming to avoid direct damage and virus transmission. This study aimed first at characterising farmers’ management strategies towards aphids and, secondly evaluating them in terms of efficiency and impact on aphid natural enemies from 19 organic and conventional fruit farms in south-eastern France. Comprehensive variables made it possible to differentiate four strategies: intensive, optimised, input-substitution and integrated. The more integrated the strategy, the more diverse and abundant the aphids. The two most effective strategies were dominated by chemical treatments, whereas the other two, less detrimental to aphid antagonists, were mostly carried out by organic farmers. Unexpectedly, the structures of aphids communities were not related to the number of treatments, management of tree vigour or of the surrounding environment. The four strategies identified can be further interpreted as steps towards a redesign of orchard protection where integrated organic farming would be the most advanced stage. However, the paradox between effective protection strategy and biodiversity conservation still remains, casting doubts on the agroecological concept of sustainability.