An agro-ecological model of the peach tree-Myzus persicae aphid system and its use to evaluate and design integrated management scenarios

We addressed the question of crop-pest management on the Prunus persica (L.) Batsch - Myzus persicae (Sulzer) (Hemiptera: Aphididiae) biological system. Firstly, we developed an agro-ecological model describing (i) peach-green aphid interactions as controlled by winter pruning and nitrogen fertilization, (ii) aphid insecticide induced-mortality, (iii) development of Harmonia axyridis Pallas (Coleptera: Coccinellidae) used as a biological control agent, and corresponding predation of aphids, (iv) and fruit quality. Secondly, we simulated management scenarios that combined different levels of cultural management with theoretical pest control strategies, and studied the relationships between management variables and system performances. We showed that (i) agronomical performances were largely controlled by cultural practices, while pest pressure was largely controlled by pest control strategies, and (ii) the way nitrogen and winter pruning influence pest numbers depended on the pest control strategy. Thirdly, we used a multi-objective optimization approach to design new management scenarios for three virtual grower production profiles. The selected scenarios using the conventional (chemical) pest control strategy were the best whatever the grower profile, but the selected scenarios using other pest control strategies had good performances. This study demonstrated that agro-ecological and multi-criteria crop-pest simulation models, associated with simulation-based evaluation and multi-objective optimization, have high potential for the implementation of integrated fruit production