Kontext

In many places, scab is the most common disease in apple production. It is caused by the fungus Venturia inaequalis and its anamorph Spillocae pomi. The disease begins at the beginning of winter, caused by spores projected from the inoculum reservoir present in the fallen leaves affected the previous year, the so-called primary infections. Rain triggers the release of the spores and provides the conditions needed to germinate and infect the unripe tissues. From the first spots, new spores appear that spread the disease, affecting new leaves and fruits. Most currently produced apple varieties are susceptible to the fungus.
Disease control is achieved by applying fungicides to prevent primary infections from thriving. Ten to twenty treatments are often required during the most sensitive period, depending on weather conditions of the year. The current legislative framework for agricultural production in the European Union with regard to the use of plant protection products (Directive 91/414/EEC, Regulation 396/2005 and Directive 128/2009), the foreseeable new guidelines of the CAP (Green Deal in its strategic Farm to Fork proposal) and pressure from society are aimed at reducing pesticides, including fungicides, in apple production.
This innovative project has shown that two techniques, installing rain nets and removing inoculum from the orchard soil, are applicable to our production conditions. They improve the effectiveness of disease control and reduce or eliminate the need for fungicides. The innovation involving the use of rain nets in apple growing also affects the quality of the product obtained: negatively, causing loss of colour, and positively, reducing russeting and cracking of the fruit.