Sour rot is an emerging disease affecting stone fruit. In the last few years, its incidence has increased, and the losses it causes can be similar to those caused by Monilinia spp., the main pathogen affecting stone fruit. For its control, the synthetic chemical products available on a commercial scale that are currently applied in the field and/or post-harvest are not effective. Moreover, it is already known that this disease is not only caused by Geotrichum spp. but also by a consortium of microorganisms which also includes yeasts of the genus Pichia spp. This fact complicates its control even more, since, on the one hand, the epidemiology and, on the other, the effectiveness of the products must be studied in parallel, due to both types of microorganisms. This project will study the epidemiology of the disease in depth, both in the field and post-harvest, and will focus on control strategies both in the field and post-harvest, including alternative products and systems. In addition, cultural practices to be applied in the field will be studied to determine their effectiveness in controlling sour rot. Finally, all the knowledge generated and control tools that have become effective will be integrated into a single control strategy that will be validated at commercial level.

The general objective is to control in a sustainable way the acid rot affecting stone fruit caused by Geotrichum spp. and yeasts of the genus Pichia. In order to achieve this general objective, the following secondary objectives are proposed:

1. To determine the epidemiological factors affecting the incidence and severity of the disease in stone fruit caused by the microorganisms that cause sour rot (Candidum and Pichia spp.).
2. To study the consortium of micro-organisms causing sour rot.
3. To assess the risk of infection of healthy fruit arriving at the packing house due to the presence of inoculum in the packing lines.
4. Evaluate the effectiveness of new products on a commercial scale or reported as effective in the most recent literature, in ‘in vivo’ laboratory studies.
5. Study the field scale-up of the potentially most effective products for the control of sour rot.
6. Determine the efficacy and feasibility of cultural practices applied in the field for the control of sour rot.
7. Study the most effective technology to apply the potentially effective products for the control of sour rot in stone fruit postharvest.
8. Study the heat treatment, hot water bath, to control acid rot in stone fruit.

Design and study the efficacy of a control strategy in accordance with all the knowledge generated, integrating the most effective field and postharvest actions to control acid rot.