Early detection and management of important grapevine diseases (RESENS-VITIS)

Viticulture is one of the most profitable agricultural industries in Slovenia, with approximately 16.000 ha of vineyards entered in the register of grape and wine producers. In a year, 800.000 to 1.000.000 litres of wine are produced. Optimal implementation of protection measures has a significant impact on the economics of production. Grapevines are capable of sustained production for 30 years or more, their long lifespan depends on nutrition and protection against diseases and pests. Most grapevine diseases are caused by phytoplasmas, fungi and viruses. Among these, most damage is caused by grapevine yellows (Flavescence dorée), grapevine fanleaf virus (GFLV) and the group of fungal diseases known as esca. All of these lead to severe yield losses and plant death. Two of these diseases are being spread by vectors grapevine yellows by the American grapevine leafhopper, (Scaphoides titanus, which are controlled with insecticides) and GFLV by the nematode Xiphinema index. The effectiveness of such control measures, however, is limited and disease foci remain present or spread. An example is the rapid spread of grapevine yellows in the wider area of Ormož, leading to the adoption of an action plan with measures to control grapevine yellows. Regardless of the chosen plant disease management method, preventive measures remain crucial. Detection of the disease is of utmost importance, as there is no real cure for infected plants, we can only remove them from the vineyard. Therefore, it is necessary to assess the health status of all plants in an individual vineyard, which is time consuming and costly. Visible signs of infections are not necessarily specific to a particular disease, so molecular analyses are applied, further increasing the effort and cost. These limitations can be circumvented by using spectral imaging to obtain spatially accurate data on the health status of plants, before the appearance of visible symptoms. The proposed project addresses these issues. We will obtain reliable health status data of all plants in each selected vineyard in two wine-growing regions (Primorska and Štajerska). By capturing hyperspectral data with a drone and an aircraft in a time series, we will be able to develop methods for early detection of the diseases. In cooperation with local growers and experts from KGZS Zavod Nova Gorica and KGZS Zavod Maribor, we will find vineyards scheduled to be cut down after autumn 2023. In these vineyards, we will carry out the evaluation of esca, which will provide reliable data for remote sensing disease detection models. We will also test different methods to mitigate the influence of the selected diseases. These experiments will take place in a greenhouse, where we will test, for example, the use of bionematicides, fungi and bacteria from vineyard soil to suppress nematodes. The results of the project will be directly applicable to real world scenarios. The spectral libraries that will be established within the framework of this project will encourage further development of models for the determination of other vine diseases. Newly developed disease management will be able to be used or lead to the development of new products. Due to the nature of esca’s development, we will monitor this disease in selected vineyards even after this project ends, within the framework of expert integrated pest management activities at the Agricultural institute of Slovenija, KGZS-Nova Gorica and KGZS-Maribor. A Precision agriculture Living Lab will also be established, which will facilitate implementation of remote sensing, further education activities, and enhance cooperation between different stakeholders. By combining multi-year work outside the time limits of this research project, we will gain better understanding of esca and further improve the reliability of the methods developed in the project.