Multi-farm operational evaluation of a leaf area index-based approach to optimize fungicide distribution in vineyards

Optimizing fungicide distribution is essential for the environmental and economic sustainability of viticultural systems, mainly because traditional (ground-area-based) spraying strategies frequently lead to overapplications, especially during early phenological stages, with up to 70% of the fungicide dispersed in the environment. In this study, we tested a recent approach that uses LAI estimates – acquired using a smartphone – to define spray volumes and fungicide doses according to the canopy characteristics and to possible limits declared in the fungicide label. An exploratory on-farm demonstration of the method was carried out in four vineyards in Northern Italy during 2024, by comparing LAI-based applications with farmer-defined volumes. Results highlighted reductions in spray volume and fungicide dose (mean values: − 9.8% and − 9.4%), and no obvious deterioration in yields or increase in disease severity were observed under the conditions explored. Moreover, mean reductions in copper residues in must and wine samples (–8.6% and − 18.1%, respectively) were observed, and a 37.3% decrease in a stained-area drift index was estimated during one application at one farm. The approach is implemented in a mobile application, thus opening to new opportunities to transfer LAI-based methods to optimized fungicide distribution in operational farming contexts.