Environmental factors affecting the start of pollen season and concentrations of airborne Alnus pollen in two localities of Galicia (NW Spain)

Alnus pollen is an early component of the annual atmospheric aerosol of the north-west regions of Spain, which causes the first occurrence of allergic symptoms. Seasonal and intra-daily variation of Alnus pollination, and the influence that main meteorological parameters exert, was studied in this paper. Monitoring was carried out from 1993–2002, by using two Lanzoni VPPS 2000 volumetric samplers. Once the atmospheric behaviour of this pollen had been identified, the final objective was to elaborate predictive models to determine the onset of the Alnus pollen season and its concentrations during the pollination period in two localities of north-west Spain (Santiago and Ourense). Winter chilling required to overcome the bud-dormancy period was similar in both cities, with around 800 Chilling Hours (C.H.) and 5.5ºC threshold temperature. Calculation of heat requirement for bud growth was carried out with maximum temperature, with around 50 Growth Degree Days (G.D.D.ºC) needed, with 6ºC threshold temperature. Data from 2002 were used in order to determine the real validity of the models. This year was not taken into account to establish the aforementioned models. The variation between the predicted start of the pollen season and the observed season was smallest in Ourense. Verifying the proposed models for predicting daily mean concentrations of Alnus pollen during the pollen season shows that the predicted curves fits the observed variations of daily mean concentrations.This work was funded by the XUGA-PGDIT01PAT38301PR projectS

Use of phenological and pollen-production data for interpreting atmospheric birch pollen curves

Although aerobiological data are frequently used as a fl owering sign in phenological research, airborne pollen counts are infl uenced by a number of factors affecting pollen curves. A study was made about the reproductive biology of birch and environmental factors infl uencing its pollen release and transport, in order to achieve a reliable interpretation of Betula pollen curves. Aerobiological data were recorded in 2002 and 2003 at two sites in NW Spain and phenological observations were carried out on 20 trees from four Betula populations (three Betula alba L. and one B. pendula Roth.). Pollen production was calculated for six Betula alba trees. Chilling and heat requirements for triggering development were calculated. Due to differences in the geographical location, budbreak and fl owering started fi rst in Betula pendula. The fl owering period lasted from 8-13 days. Reduced pollen output per anther and catkin in individual trees in 2003 prompted a marked decline in overall pollen production. Major differences observed in birch pollen curves were attributed to the infl uence both of weather conditions and pollen transport from areas where the fl owering occurs at a different time. Heat requirements calculated using phenological and aerobiological data were similar when the peak pollen-count date was used.S

Incidence of fungals in a vineyard of the denomination of origin ribeiro (Ourense - north-western Spain)

Knowledge about the fungal spores most abundant in the atmosphere of a vineyard is of great use since it allows development of prediction models of the spore concentration, and therefore application of phytosanitary treatments only when high levels of fungal propaguls are detected. In this study the concentration of phytopathogenic spores is related with the different phenological stages of the vineyard, and a prediction model developed for each fungal type using meteorological, phenological and spore concentrations variables. The study was carried out in a vineyard of the Ribeiro district during the year 2007. For the aerobiological study a volumetric Hirst type trap was used, while phenological observations were carried out on 20 plants of the three varieties monitored (Treixadura, Godello and Loureira) following the phenological scale standardized by the BBCH. Botrytis reached the highest annual total value with 16,145 spores, followed by Plasmopara with 747 spores and Uncinula with 578 spores. In order to forecast the concentration of the phytopathogenic fungal spores, equations of lineal regression were elaborated including as estimators, variables with high correlation coefficient. For Botrytis the regression equation explained 42.4% of the variability of spore concentration, 26.1% for Uncinula and 24.7% for PlasmoparaThis study was financed by the project PGIDIT07PXIB2000076PR sponsored by the “Xunta of Galicia”S

Prediction of biological sensors appearance with ARIMA models as a tool for Integrated Pest Management protocols

Introduction and objectives: Powdery mildew caused by Uncinula necator and Downy mildew produced by Plasmopara viticola are the most common diseases in the North-West Spain vineyards. Knowledge of airborne spore concentrations could be a useful tool in the Integrated Pest Management protocols in order to reduce the number of pesticide treatments, applied only when there is a real risk of infection. Material and Methods: The study was carried out in a vineyard of the D. O. Ribeiro, in the North-West Spain, during the grapevine active period 2004–2012. A Hirts-type volumetric spore-trap was used for the aerobiological monitoring. Results: During the study period the annual total U. necator spores amount ranged from the 578 spores registered in 2007 to the 4,145 spores sampled during 2008. The highest annual total P. viticola spores quantity was observed in 2010 (1,548 spores) and the lowest in 2005 (210 spores). In order to forecast the concentration of fungal spores, ARIMA models were elaborated. Conclusions: The most accurate models were an ARIMA (3.1.3) for U. necator and (1.0.3) for P. viticola. The possibility to forecast the spore presence 72 hours in advance open an important horizon for optimizing the organization of the harvest processes in the vineyardThe study was financed by the Proyects INOU12-08 of the University of Vigo and the AGL2014-60412-R supported by the Ministry of Economy and Competitiveness of the Spanish GovernmentS

Estudio de los niveles de los principales fitopatógenos para la optimización de cosechas de Vitis vinifera en Valdeorras, Ourense (1998)

RODRÍGUEZ RAJO, F.J., SEIJO COELLO, M.C. & JATO RODRÍGUEZ, M.V. 2002. Estudio de los niveles de los principales fitopatógenos para la optimización de cosechas de Vitis vinifera en Valdeorras, Ourense (1998). Bot. Complutensis 26: 121-135. Las características climatológicas de Galicia, favorecen la aparición en los viñedos de enfermedades producidas por hongos como el mildiu, el oidio o la podredumbre gris que ponen en peligro la producción de uva llegando a provocar pérdidas millonarias. Con el fin de conocer el nivel de propágulos fúngicos se ha ubicado un captador volumétrico tipo Hirst en un viñedo de la provincia de Ourense. De los tres hongos patógenos estudiados, se han encontrado cantidades importantes de esporas de Botrytis que suman un total de 12.303 esporas, siendo entre las 19-20 horas el momento del día en el que se alcanza su mayor concentración. Los valores totales registrados para Uncinula y Plasmopara son muy inferiores (1.456 y 242 esporas respectivamente). Las variables meteorológicas que poseen una mayor influencia positiva sobre las concentraciones de esporas en el viñedo son la temperatura de rocío para Botrytis cinerea, la temperatura máxima para Uncinula necator y la humedad para Plasmopara viticola. Finalmente los modelos ensayados para la predicción de infecciones que además de los valores meteorológicos tienen en cuenta la cantidad de inóculo de patógeno existente, poseen una capacidad de predicción mayor.RODRÍGUEZ RAJO, F.J., SEIJO COELLO, M.C. & JATO RODRÍGUEZ, M.V. 2002. Study of the main phytopatogenic level’s in order to optimize the harvest of Vitis vinifera in Valdeorras, Ourense (1998). Bot. Complutensis 26: 121-135. Estudio de los niveles de los principales fitopatógenos para la optimización de cosechas de Vitis vinifera en Valdeorras (1998). The peculiar climatological characteristics of Galicia favours the appearance in the vineyards of the diseases produced by fungus as grey mould, powdery mildew or downy mildew that endangers the grape production provoking millionaire losses. With the aim to know the level of fungal spores, it was placed an Hirst type volumetric sampler in a vineyard of Ourense. Of the tree pathogenic fungus studied, it was found important quantities of Botritys fungal spores, that amount a total of 12303 spores. The moment of the day with highest concentrations are the 19-20 hours. The total values registered by Uncinula and Plasmopara were minor (1456 y 242 spores respectively). Dew temperature for Botrytis cinerea, maximum temperature for Uncinula necator and external humidity for Plasmopara viticola, were the meteorological variables that exert the highest positive influence in the spore concentrations of the vineyard. Finally the models attempted for the prediction of the infections that takes into account the meteorological variables in addition with the quantity of pathogenic spores existing, have the best prediction capacity

Prediction of Grapevine Yield Based on Reproductive Variables and the Influence of Meteorological Conditions

Climate has a direct influence on crop development and final yield. The consequences of global climate change have appeared during the last decades, with increasing weather variability in many world regions. One of the derived problems is the maintenance of food supply in this unstable context and the needed changes in agricultural systems, looking for sustainable and adaptation strategies. The study was carried out from 2008 to 2017. Aerobiological data were obtained with a Lanzoni VPPS-2000 volumetric sampler, following the Spanish Aerobiological Network protocol. The pollen and flower production was studied on ten vines of the Godello grapevine cultivar. A HOBO Micro Station and a MeteoGalicia station were used to obtain meteorological information. We observed the detrimental effect of rain on airborne pollen presence, and we statistically corroborated the negative effect of high temperatures on fruit set and ripening. We developed an accurate multiple regression model to forecast the grape yield, applying a Spearman’s correlation test to identify the most influential variables. The use of aerobiological and meteorological studies for crop yield prediction has been widely used in different crops that suppose important engines for economy development. This enables growers to adapt their crop management and adjust the spent resourcesThis work was funded by Xunta de Galicia CITACA Strategic Partnership (Reference: ED431E 2018/07), the AGL2014-60412-R Economy and Competence Ministry of Spain Government project and the VITICAST 20190020007473 project of the Agriculture, Fisheries and Food Ministry of Spain Government. González-Fernández E. was supported by the Ministry of Sciences, Innovation and Universities (FPU grant FPU15/03343). Piña-Rey A. was supported by Xunta de Galicia Pre-doctoral Period Support Program (ED481A-2017/xxx). Fernández-González M. was supported by FCT (SFRH/BPD/125686/2016) through the HCOP-Human Capital Operational Program, financed by “Fundo Social Europeu” and “Fundos Nacionais do MCTESS

Puccinia spore concentrations in relation to weather factors and phenological development of a wheat crop in northwestern Spain

Rust is one of the main diseases affecting wheat crops in Spain, causing significant yield and quality losses. Research on its identification and quantification in the air is a worldwide priority due to the importance of this crop as a source of food and feed. The objective of this study is to determine the temporal variation of airborne spores of Puccinia and their relationship with meteorological variables and the phenological development of a wheat crop in Northwestern Spain during two growing seasons. The study was conducted in A Limia, Ourense, located in Northwestern Spain, during the wheat growing seasons of 2021 and 2022. The Lanzoni VPPS 2010 spore trap was used to collect airborne spores, which were identified using optical microscopy. The wheat growing season was less than 95 days during both years, and wheat rust spores were detected during all phenological stages of the crop. Concentrations were higher than 100 spores/m3 from the booting stage to senescence, mainly in 2021. Statistical analyses showed that temperature was the meteorological variable that most influenced Puccinia concentrations in the air in both years. The modification of a prediction model proposed by other authors for wheat rust, which takes into account mean temperature (10–25 °C), dew point temperature (<5 °C), and nighttime temperature (10–20 °C), allowed us to tentatively predict the increase in Puccinia concentrations in the year 2022 when these conditions occurred for four or five consecutive days. This research is the first in Spain to report the presence of rust-causing Puccinia spores in the air during all phenological stages of the wheat crop and provides useful information for designing management strategies, considering temperature values

London plane tree pollen and Pla A 1 allergen concentrations assessment in urban environments

The London plane tree is frequently used in gardens, parks, and avenues in European urban areas for ornamental purposes with the aim to provide shade, and given its tolerance to atmospheric pollution. Nevertheless, unfortunately, over recent decades, bioaerosols such as Platanus pollen grains cause increasing human health problems such as allergies or respiratory tract infections. An aerobiological sampling of airborne Platanus pollen and Pla a 1 allergen was performed using two volumetric traps placed on the roof of the Science Faculty building of the city of Ourense from 2009 to 2020. A volumetric sampler Hirst–type Lanzoni VPPS 2000 (Lanzoni s.r.l. Bologna, Italy) was used for pollen sampling. Pla a 1 aeroallergen was sampled by using a Burkard Multi-Vial Cyclone Sampler (Burkard Manufacturing Co., Ltd., Hertfordshire, UK) and by means of the enzyme-linked immunosorbent assay (ELISA) technique. Data mining algorithms, C5.0 decision trees, and rule-based models were assessed to evaluate the effects of the main meteorological factors in the pollen or allergen concentrations. Plane trees bloom in late winter and spring months in the Northwestern Spain area. Regarding the trends of the parameters that define the Platanus pollen season, the allergen values fitted the concentrations of pollen in the air in most cases. In addition, it was observed that a decrease in maximum temperatures causes a descent in both pollen and allergen concentrations. However, the presence of precipitations only increases the level of allergens. When the risk of allergy symptomatology was jointly assessed for both the concentration of pollen and allergens in the study area, the number of days with moderate and high risk for pollen allergy in sensitive people increased with respect to traditional alerts considering only the pollen values.Xunta de Galicia | Ref. ED431C 2017/62 BV1Consellería de Sanidade, Xunta de Galicia | Ref. CO-0034-2021 00V

Forecasting ARIMA models for atmospheric vineyard pathogens in Galicia and Northern Portugal: Botrytis cinerea spores

Botrytis cinerea is the cause of the most common disease in the Galician and Portuguese vineyards. Knowledge of the spore levels in the atmosphere of vineyards is a tool for forecasting models of the concentration of spores in order to adjust the phytosanitary treatments to real risk infection periods. The presented study was conducted in two vineyards, one located in Cenlle (Spain) and other in Amares (Portugal), from 2005-2007. A volumetric trap, model Lanzoni VPPS-2000, was used for the aerobiological study. Phenological observations were conducted on 20 vines of three grape varieties in Cenlle (Treixadura, Godello and Loureira) and in Amares (Trajadura, Loureiro and Pedernã), by using the BBCH scale. The highest total spore concentrations during the grapevine cycle were recorded in 2007 in both locations (Cenlle:16,145 spores; Amares:1,858 spores), and the lowest, in 2005 in Cenlle (1,700 spores) and in Amares (800 spores) in 2006. In Cenlle, the best adjusted model was an ARIMA (0,2,2), including the relative humidity four days earlier, while in Amares there was an ARIMA (1,2,3), considering the relative humidity three days earlier and rainfall two days earlier. The t-test showed no significant difference between observed and predicted data by the model.The study was partially supported by the University of Vigo (Bolsas de Estadías en centros de Investigación)S

Data mining methods to detect airborne pollen of spring flowering arboreal taxa

Variations in the airborne pollen load are among the current and expected impacts on plant pollination driven by climate change. Due to the potential risk for pollen-allergy sufferers, this study aimed to analyze the trends of the three most abundant spring-tree pollen types, Pinus, Platanus and Quercus, and to evaluate the possible influence of meteorological conditions. An aerobiological study was performed during the 1993–2020 period in the Ourense city (NW Spain) by means of a Hirst-type volumetric sampler. Meteorological data were obtained from the ‘Ourense’ meteorological station of METEOGALICIA. We found statistically significant trends for the Total Pollen in all cases. The positive slope values indicated an increase in pollen grains over the pollen season along the studied years, ranging from an increase of 107 to 442 pollen grains. The resulting C5.0 Decision Trees and Rule-Based Models coincided with the Spearman’s correlations since both statistical analyses showed a strong and positive influence of temperature and sunlight on pollen release and dispersal, as well as a negative influence of rainfall due to washout processes. Specifically, we found that slight rainfall and moderate temperatures promote the presence of Pinus pollen in the atmosphere and a marked effect of the daily thermal amplitude on the presence of high Platanus pollen levels. The percentage of successful predictions of the C5.0 models ranged between 62.23–74.28%. The analysis of long-term datasets of pollen and meteorological information provides valuable models that can be used as an indicator of potential allergy risk in the short term by feeding the obtained models with weather prognostics.Xunta de Galicia | Ref. CO-0034-2021 00VTUniversidad de Vigo | Ref. INOU 2021Universidad de Vigo | Ref. OUR1 131H 64