Map-based zonal dosage strategy to control yellow spider mite (Eotetranychus carpini) and leafhoppers (Empoasca vitis &Jacobiasca lybica) in vineyards

Abstract

The particularly high incidence of yellow spider mite and leafhoppers in southern European viticulture means that between 1 and 4 interventions are required each year for their effective control. In vineyards with spatial variability in vigour, decision support systems such as DOSA3D (www.dosa3d.cat/en) have proven useful to adjust dose rates according to vigour classes delimited in on-board monitor prescription maps. However, there remain some doubts as to whether this variable dosage allows pests to be controlled when reducing conventional doses in vines with low vegetative development. To check the efficacy of using variable dose rates according to two vigour classes (low and high), field trials were carried out against the aforementioned pests in vineyards located in Raïmat (Catalonia, Spain). After classifying vigour through multispectral images, doses were reduced by 16.6%–24.8% in low vigour areas without losing control efficacy. Biological efficacy was always higher in low vigour areas, reducing the initial pest population below the corresponding economic damage threshold. In areas of high vigour, subsequent applications will probably be necessary to avoid exceeding the economic threshold, as there is normally a higher pest population density in vines with more vegetative development.