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Influence of Air Temperature on the Release of Ascospores of Venturia inaequalis
Author(s) -
Rossi V.,
Giosuè S.,
Bugiani R.
Publication year - 2003
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1046/j.1439-0434.2003.00680.x
Subject(s) - ascospore , venturia inaequalis , spore , biology , orchard , biological dispersal , horticulture , leaf wetness , botany , atmospheric sciences , fungicide , population , demography , sociology , geology
The influence of air temperature on the release pattern of Venturia inaequalis ascospores was studied by volumetric spore samplers in two spore sampling periods. In the first period (1991–1996; Passo Segni, Ferrara), 15 ascospore dispersal events were considered occurring in daylight, with high spore counts (168–5892 ascospores per m 3 air per event), at an average temperature between 8.4 and 20.3°C. Both the length of the ascospore release period and distribution of airborne spores over time were significantly influenced by temperature. A logistic regression model was used to fit the proportion of ascospores trapped from the orchard air as a function of time after the beginning of the discharge event and air temperature. The accuracy of this equation was tested against data collected in the second spore sampling period (1997–2000; Sala Bolognese, Bologna, and Castelfranco, Modena); 16 dispersal events were considered, triggered by rainfall that occurred both in the dark and in daylight, with low to high spore counts (29–458 ascospores per m 3 air per event), at an average temperature between 2.8 and 14.3°C. There was a general agreement between the proportion of ascospores trapped from the orchard air during these events and that estimated by using the logistic equation – in most cases, actual and estimated values showed a high coincidence. Statistical comparison showed a significant correlation (r=0.93, P < 0.01) between observed and estimated data.