Format: ORAL

Mara Fernndez-Gonzlez1, Eva Navascus2, Laura Montero2, Dominique Roujou2, Xose Manuel Lourido2, Dbora Franco3, Jos David Rey3, Kenia C. Snchez-Espinosa1, Guillermo Guada1, Luca Carrera1, F. Javier Rodrguez-Rajo1

1 Department of Vegetal Biology and Soil Sciences, Faculty of Sciences, University of Vigo, 32004 Ourense, Spain 2 Viña Meín · Emilio Rojo. Lugar de Meín s/n · 32420 · Leiro, Ourense, Spain 3 Monet Tecnología e Innovación SL., Rúa Das Pontes 4, 36350 Nigrán, Pontevedra, Spain

Knowledge of the phenology and concentration of phytopathogical fungi in a vineyard is a useful tool to estimate when a phytosanitary treatment is necessary, since today the high use of pesticides leads to subsequent soil contamination that can negatively affect the soil biodiversity and the vine itself. Our aim was to understand how environmental conditions can influence the Guignardia bidwellii, causal agent of grape black rot. The study was carried out in two vineyards (Via Mein and Emilio Rojo) belonging to the DO Ribeiro (Northwest Spain) during 2023 campaign. Phenological study was carried out on 20 selected vines following BBCH scale. To monitor the spores, two Lanzoni VPPS-2010 volumetric samplers are used, one in each study plot. The identification and counting of airborne spores have been carried out following the methodology proposed by the Spanish Aerobiology Network. Meteorological variables have been provided by two meteorological stations, located near the spore trap. The concentration of G. bidwellii spores was higher in Via Mein (2912 spores) than in Emilio Rojo (656 spores). The peak of spore concentration occurred on May 28 with 438 spores/m3 in Via Mein coinciding with the end of flowering stage (S-6), and 84 spores/m3 on June 23 in Emilio Rojo coinciding with fruit development stage (S-7). When analyzing intraday behavior of G. bidwellii spores in both plots, we observed that the highest concentrations occur at dawn (01:008:00 a.m.). The meteorological variables that exert the greatest influence on the concentration of G. bidwellii were the minimum temperature, dew point, relative humidity and precipitation. Knowledge of the phenological, phytopathological and meteorological variables of a certain region can provide us a valuable tool to know the phytosanitary status of a crop and thus be able to make appropriate decisions regarding the application of different phytosanitary treatments.