How to optimize the deployment of biocontrol products for carrot?

Today, producers are urged to choose the most environmentally friendly production practices in order to produce high quality vegetables while maintaining a good yield but it requires that they have the choice among efficient alternative solutions! Among these practices, the use of biocontrol products is growing rapidly, but very few products are available for carrot and none are registered to control Alternaria dauci, the most damaging carrot foliar disease in the world. The deployment of these products requires an optimization of their use which relies, among other things, on the understanding of their mode of action in order to be able to combine them efficiently with other control methods such as varietal resistance. For this purpose, we have adapted the qPDF® chip, already available on apple and some other species, to carrot in order to screen effective bio plant protection products (BioPPPs) against A. dauci. Among these bioPPPs, some plant resistance inducers proved to be very effective under controlled conditions. However, as expected, their efficacy is very dependent on environmental conditions but also on the treated cultivar. In order to optimize the plant protection method, these elements must be considered to efficiently combine varietal resistance, bioPPPs and all this in a context of climate change.