Cour Trap Research Articles

Integrating Phenological, Aerobiological and Weather Data to Study the Local and Regional Flowering Dynamics of Four Grapevine Cultivars

Phenological, aerobiological, and weather data are useful tools to study local and regional flowering dynamics in crops with economic importance. The present study focuses on four autochthonous grapevine cultivars, namely, ‘Treixadura’, ‘Godello’, ‘Loureira’, and ‘Albariño’ (Vitis vinifera L.), which belong to the Designation of Origin Ribeiro area (located in northwestern Spain) from 2015–2019. The aims of the work were to (1) compare the airborne pollen concentration in the vineyard collected by two different traps, (2) analyze the influence of the main meteorological variables on cultivar phenology and pollen concentration, and (3) test the contribution of the air masses on pollen concentrations in the vineyard. Phenological development has been assessed twice weekly, according to the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH) scale. Airborne pollen concentrations were monitored by using two traps during stage 6 (flowering), namely, a Hirst volumetric sampler and a Cour passive trap. The bioclimatic conditions affected the duration of flowering, ranging from 11 and 24 days. The highest seasonal pollen integral (SPIn) was registered in 2016 for the Hirst sampler, with 302 pollen, and in 2019 for the Cour trap, with 1,797,765 pollen/m2/day. The main variables affecting pollen concentrations were average temperature during the main pollen season, as well as, temperatures and dew points during the pre-peak period. The relationship between pollen data registered by both traps and the obtained harvest indicate that the Hirst trap may be more suitable for predicting a local production and that the Cour sampler is more appropriate for forecasting regional productions.

Modeling olive-crop forecasting in Tunisia

Tunisia is the world’s second largest olive oil-producing region after the European Union. This paper reports on the use of models to forecast local olive crops, using data for Tunisia’s five main olive-producing areas: Mornag, Jemmel, Menzel Mhiri, Chaal, and Zarzis. Airborne pollen counts were monitored over the period 1993–2011 using a Cour trap. Forecasting models were constructed using agricultural data (harvest size in tonnes of fruit/year) and data for several weather-related and phenoclimatic variables (rainfall, humidity, temperature, Growing Degree Days, and Chilling). Analysis of these data revealed that the amount of airborne pollen emitted over the pollen season as a whole (i.e., the Pollen Index) was the variable most influencing harvest size. Findings for all local models also indicated that the amount, timing, and distribution of rainfall (except during blooming) had a positive impact on final olive harvests. Air temperature also influenced final crop yield in three study provinces (Menzel Mhiri, Chaal, and Zarzis), but with varying consequences: in the model constructed for Chaal, cumulative maximum temperature from budbreak to start of flowering contributed positively to yield; in the Menzel Mhiri model, cumulative average temperatures during fruit development had a positive impact on output; in Zarzis, by contrast, cumulative maximum temperature during the period prior to flowering negatively influenced final crop yield. Data for agricultural and phenoclimatic variables can be used to construct valid models to predict annual variability in local olive-crop yields; here, models displayed an accuracy of 98, 93, 92, 91, and 88 % for Zarzis, Mornag, Jemmel, Chaal, and Menzel Mhiri, respectively.

A bioclimatic model for forecasting olive yield

SUMMARYThe aim of the present study was to develop a hierarchical bioclimatic model for forecasting olive crop yields in the Alentejo region of south-eastern Portugal. The model was estimated for three different developmental stages: (1) at flowering, using only the regional pollen index (RPI); (2) at fruit growth using RPI and a plant water requirements index (PWRI) and (3) at fruit maturing using RPI plus a water requirements index plus a phytopathological index (PPI). Olive airborne pollen was sampled from 1999 to 2007, using a Cour trap installed in Reguengos de Monsaraz. The meteorological parameters used in the calculation of the post-flowering indices corresponded to data from a meteorological station located near the airborne sampling point. At the flowering stage, 0·66 of the regional olive yield can be explained by the RPI with an average deviation between observed and predicted production of 0·15 for the forecast model internal validation and of 0·19 for the cross-validation. The addition of the variable PWRI to the forecasting model explained an additional 0·26 of the variation, while the PPI explained an additional 0·05. The final bioclimatic model, with all the three variables tested, explained 0·97 of the regional olive fruit yield being the average deviation between observed and predicted production of 0·04 for the internal validation of the model and of 0·07 for the external validation. The hierarchical nature of this bioclimatic model, along three different development stages, enabled the prediction to be updated as the growing season progressed.

Airborne pollen concentration in Seville (Spain), 1993–1996. First results obtained with Hirst’s method

The data presented constitute the longest historical series of results obtained in Seville with a Hirst-type sampler, and are a further contribution to earlier aerobiological studies carried out in the city with a Cour trap. This work supplies an updated pollen calendar of the city, together with pollen counts and other aerobiological parameters for the 14 most important types in the 4-year period of sampling. These werePlatanus hispanica, Olea europaea, Quercus, Cupressaceae, Poaceae, Urticaceae, Moraceae, Chenopodiaceae/ Amaranthaceae,Plantago, Pinaceae,Rumex, Myrtaceae, Compositae, andCasuarina.

Aerobiology of Vigo, North-Western Spain: atmospheric pollen spectrum and annual dynamics of the most important taxa, and their clinical importance for allergy

Vigo is a city located in the northwest of the Iberian Peninsula. Influenced by the Atlantic climate, it is surrounded by a Eurosiberian-type vegetation, modified by the introduction of forestry and ornamental species. Different ruderal vegetation types, resulting from human influence, grow in the area. The study of the pollen content of the air of Vigo started in 1989, with a Cour trap. Average results for the period 1989–1995 are presented in this paper, together with the lowest and highest values found. The representativeness of the mean values is analysed by calculating the coefficient of variation of the data series. Most pollen types in the atmosphere of Vigo are from tree species (54.2%); an important proportion comes from herb species (43.9%) and very few (1.8%) correspond to shrub species. A total of 73 different pollen types have been identified. The most abundant, listed in decreasing order of mean annual values for the period, are:Pinus (25.1%), Poaceae (21.1%), Urticaceae (14.6%),Quercus (8.5%),Castanea (3.7%),Betula (3.6%),Eucalyptus (3.4%),Plantago (3.2%),Alnus (2.1%), Cupressaceae (2.1%), Oleaceae (1.6%;Olea 1.3%),Platanus (1.3%),Rumex (1.3%), Chenopodiaceae/Amaranthaceae (1.0%), Ericaceae (0.8%), Asteraceae (0.6%;Artemisia 0.1% andTaraxacum type 0.2%) andMercurialis (0.5%). A pollen calendar showing the annual dynamics of all these pollen types is presented in this paper. A parallel study of the clinical importance of respiratory allergies in Vigo was also conducted. From a sample of 2750 patients, 87.2% suffered from rhinoconjunctivitis, 26.0% of these due to pollen, and 78.3% from asthma, 17.2% due to pollen. The pollen types responsible for these allergies, listed in decreasing order, are: Poaceae (78%),Parietaria (12%),Chenopodium (11%),Plantago (9%), Oak (4%),Artemisia (3%),Pinus (3%),Eucalyptus (3%),Olea (2%),Platanus (2%),Castanea (2%),Taraxacum (2%),Rumex (2%),Betula (1%),Cupressus (1%) andMercurialis (1%).

Forecasting olive (Olea europaea) crop production by monitoring airborne pollen

Forecasting harvests of olives destined for the production of olive oil can be based on counts of airborne olive pollen, and meteorological and agronomic observations. This study was carried out during six consecutive years (1990–1995) in the Campina Alta (an olive-producing region in the province of Cordoba, south-west Spain). Olive pollen totals are the annual sum of the concentrations recorded for the periods that the filters of a Cour trap were exposed. The meteorological data are the values of accumulated rainfall between 1 September and the following 15 April (a date prior to the beginning of olive flowering). The agronomic data are the forecast and actual productions for the province of Cordoba, supplied by the Board of Agriculture of the Andalusian government, and the actual production of the Campina Alta, supplied at the end of harvest by private olive-growing co-operatives. The data were combined, and four mathematical equations were obtained to forecast the crop 6 months in advance, with varying degrees of reliability. The reliability was very high for an appropriate agricultural area. The most accurate equation isY=−1.90×104+2.35X+53.94 (which forecasts the production of the Campina Alta), whereY is the olive production (MT),X the olive pollen count,Z the rainfall prior to flowering, anda, b andc are constants. The least accurate equation is that relating olive pollen concentrations with olive production in the province of Cordoba.

Forecasting olive crop production based on ten consecutive years of monitoring airborne pollen in Andalusia (southern Spain)

This work describes a predictive model for the harvest of olives destined for olive oil, using olive groves in the province of Seville (southern Spain). The study was carried out between 1987 and 1996, monitoring airborne olive pollen with a Cour trap, and using agronomic data (size of harvest expressed in kg/ha) and meteorological observations (rainfall before and after olive pollination, days of rainfall during harvesting, and maximum temperatures during pollination). The data were subjected to simple and multiple regression analysis. Eight equations were obtained, enabling the olive harvest to be forecast with a high degree of reliability: five equations for use at the beginning of July (the end of flowering, and six months before fruit picking), another two at the end of November (immediately before picking), and the remaining one at the end of January, once picking was over.

Airborne grass (Poaceae) pollen in southern Spain. Results of a 10‐year study (1987–96)

This work reports an exhaustive study of the aerobiology of the Gramineae in Seville, Spain, which is typical of coastal Mediterranean areas. Sampling was done with a Cour trap installed on the roof terrace of the School of Pharmacy, Seville, from 1987 to 1996, both inclusive. The climatic pattern of that period was characterized by two exceptionally wet years (1989 and 1996), between which were 5 consecutive years of drought (1990-5). This typically Mediterranean climate affects grass aerobiology. The annual amounts of total grass pollen are low, never exceeding 2500 grains/m3. The start, length, and intensity of the pollen season are significantly correlated with preseasonal meteorologic factors (precipitation and temperature), but intraseasonal meteorologic conditions have no effect on the three variables. The relationships are stated by three equations that, while further years of observations are anticipated, can be considered models to forecast the characteristics of the pollen season: the starting date depends on the mean temperatures of January and February, and the length and intensity of the season depend on the rainfall between the beginning of January and the starting date of the season. For the study period, the weekly concentrations (pollen curves) throughout the year showed no typical pattern of variation over the years, so that it was impossible to make mid- and long-term forecasts of the variation in weekly concentration. The most noteworthy aspects of grass pollen curves are a long pollen season, which starts in February or March and lasts until September or October; peaks of higher concentration (> 100 grains/m3) in May and June, associated with increases in temperature and absence of precipitation; and other peaks in the summer months that may be as high as the spring peaks.

The pollen spectrum of trees and shrubs in SW Spain (1987–1996)

A Cour trap was used to sample the air of Seville of continuously from 1987 to 1996. The most important climatological feature recorded during that period was the drought that began in 1990 and which was at its most severe in the first half of 1995. The behaviour of a total of 20 pollen types was studied: those exceeding 0.01% of the total pollen collected during the ten‐year period. These were Quercus, Olea Cupressaceae, Platanus Myrtaceae, Pinaceae, Palmae, Moraceae, Fraxinus Ericaceae, Citrus, Pistacia, Acer, Casuarina Salicaceae, Ulmus, Alnus, Castanea Cistaceae, and Viburnum. The following aspects are described and analysed: the spectrum of tree and shrub types identified in the air, and their possible significance for allergies; the relationship between the woody vegetation of the region and the composition of the pollen spectrum in quantitative terms; and the possible effect of the drought on annual variations total pollen concentrations. A detailed study of olive pollen, aimed at finding applications in allergy and agriculture is also given. In particular, the possibility of forecasting both the date of olive pollination from observations of preceding mean temperatures, and the size of the crop from palynological and agronomical data.

Study onPlatanus hispanica Miller pollen content in the air of Seville, southern Spain

The work was carried out using a Cour trap that sampled the air of the city for 8 consecutive years (1987–1994). The pollen ofPlatanus hispanica is the fourth most abundant in the air of Seville (a mean of 11.05% of the total pollen collected). The variation throughout the years in the sum of weekly concentrations ofPlatanus hispanica pollen presents a certain biennial rhythm, in which years of high and low collection of pollen alternate. The starting day of the main pollination period (MPP) is negatively related with the mean of the mean temperatures for February (r=0.73,r2=0.53,P=0.0398) and is earlier (at the beginning of March) when the mean temperature for February is high, and vice versa. The pattern of pollen variation inPlatanus hispanica remains constant through the years—pollen appears abruptly in high weekly concentrations (> 150 grains/m3) in March (sporadically at the beginning of April), with a week of maximum pollen emission (WMPE) in which more than 50% of the annual pollen is collected (in 6 of the 8 years), and a main pollination period (MPP) of 2 or 3 weeks (except in 1989 when it was 5 weeks). In every year (except 1989), weekly mean temperatures increased during the MPP, the duration of which depends on mean temperature and mean rainfall: mean temperatures > 16°C and absence of rainfall shorten the MPP, while lower temperatures and presence of rainfall lengthen it. The meteorological conditions most often found during the WMPE are mean temperatures > 15°C and rainfall absent or almost so.

A comparative study of atmospheric pollen concentrations collected with Burkard and Cour samplers, Seville (Spain), 1992–1994

A comparative study has been carried out of the relative efficiency of a Burkard sampler and Cour trap, by taking samples from the air of Seville (SW Spain) for two consecutive years (July 1992 to July 1994). The devices were subjected to identical conditions of installation. 16 specific pollen types were studied either because of their high presence in the regional atmosphere or because of their allergenicity. With both methods, the variations in weekly concentrations throughout the year were analysed. Then the data from the two traps was compared in order to compare the efficiency of the two methods. The Burkard sampler collects 1.42 times more total pollen than the Cour trap. Certain pollen types are found more frequently in the Burkard trap (Casuarina, Mercurialis, Olea, Platanus, Rumex and Urticaceae); some are approximately equal in the two traps (Amaranthaceae/Chenopodiaceae, Cupressaceae, Fraxinus, Pinaceae, Plantago, Poaceae and Quercus); and others are found more frequently in the Cour trap (Artemisia, Compositae and Myrtaceae). Qualitatively, the Cour trap (with 80 different pollen types identified) is more efficient than the Burkard (with 44 different pollen types identified), although the analysis with the Burkard is quicker, and therefore more practical for allergy studies. A Spearman correlation analysis between the two methods was carried out. It showed that there were no large statistical differences in the weekly concentrations through the year for 15 out of the 16 pollen types considered.

Aeropalynology ofFraxinus (Ash) in an urban area of southwestern Spain

The first observations from Huelva (southwestern Iberian Peninsula) on the phenology of Ash, based on an aeropalynological study over three years, are presented. Sampling was carried out with a Cour trap. The beginning of pollination is related to the moment of the lowest average temperature of the year, usually in January. Flowering occurs earlier if there are exceptionally low average temperatures (<10°C) in November. The amount of rainfall in autumn and winter affects the intensity of pollination.

Airborne fungal spores trend over a highly polluted area of south-west Spain using Cour's trap

This investigation was aimed at studying the mycoflora present in Huelva (South West Spain), a highly polluted region. The study was carried out using the Cour trap and it is worth pointing out that the chemical treatment performed following the Cour methodology might destroy a certain percentage of spores. We analyzed the presence and biannual changes (10 April 1989 to 8 April 1991) of fungal spores of three genera, seventeen form genera, and four groups lacking taxonomic category, looking at their morphology: ascospores, basidiospores, and unidentified unicellular and multicellular spores. Special attention was given to agriculturally interesting groups. The results obtained were correlated with meteorological parameters (rainfall, minimum temperature and humidity).