Abstract
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 m3 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 m3 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.
Lingua originale | English |
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pagine (da-a) | 50-58 |
Numero di pagine | 9 |
Rivista | Journal of Phytopathology |
Volume | 151 |
DOI | |
Stato di pubblicazione | Pubblicato - 2003 |
Keywords
- air temperature
- apple scab
- ascospore discharge
- logistic model