The consequences of aphid infestation on fruit production become evident in a multi-year perspective: Insights from a virtual experiment
Résumé
Aphids are commonly considered major agricultural pests because of their ability to severely alter hostplant physiology. However, their effects on fruit tree yield have not received wide attention and fewexisting works considering plant-aphid interaction and its consequences have only been conducted overa single year. We modified an existing process based model for the peach tree Prunus persica − greenaphid Myzus persicae pathosystem, explicitly considering interactions between the two species underthe influence of cultural practices (i.e. winter pruning and nitrogen fertilization), in order to simulatemulti-year dynamics. The new model indicates that fertilization affects plant growth more than aphidinfestation and the consequences of aphid infestation over fruit yield only emerge when considering theentire tree life span (ca. 10 yr). In fact, in a given year, aphid infestation mainly impairs shoot growth and,as fruits are borne on 1-yr old wood, its effects on fruit production are delayed in time. Our results are inaccordance with the few existing experimental studies and highlight the need of considering multi-yeardynamics, both via modelling and field observations, when dealing with perennial crops as fruit trees.