A 5-year study (2002-2006) was carried out in two pear orchards in northern Italy, by trapping air-borne ascospores of Venturia pirina. Characteristics of 155 ascospore discharge events (hour of the day, duration, ascospore number) and weather conditions of the hours preceding the beginning of the discharge (WD, wetness duration; R, rainfall; Tw, temperature during wetness) were analysed with the aim of better defining environmental conditions favouring ascospore discharge. Ascospore discharge showed a diurnal periodicity, with the 92% of total spores trapped in daylight. Thirty-seven percent of ascospore discharge events were triggered by rainfall, 55% by leaf wetness, while 8% occurred under dry conditions. The probability of ascospore discharge to occur was calculated using a logistic regression procedure with a stepwise selection of the independent variables. The variable ‘WD × Tw’ was selected as the most influential, while Tw, WD and R were not. The logistic equation provides the probability of an ascospore discharge to occur based on the combination of wetness duration and average temperature during the wet period preceding the beginning of the ascospore discharge. Probability was higher than 0.5 when ‘WD × Tw’ was higher than 197.5°C×h, while it was 0.9 when ‘WD × Tw’ was 585°C×h. This result showed that ascospore discharge in V. pirina is mainly influenced by wetness and temperature, while in V. inaequalis it depends mainly on rainfall. Calculation of the infection periods for controlling pear scab should take account of this difference.

Rossi, V., Giosue', S., Salinari, F., Bugiani, R., Weather conditions triggering ascosporedischarge in Venturia pirina, Abstract de <<9th International Congress of Plant Pathology>>, (Torino, 24-29 August 2008 ), <<JOURNAL OF PLANT PATHOLOGY>>, 2008; (2, supplement): N/A-N/A. 10.4454/jpp.v90i2Sup.706 [http://hdl.handle.net/10807/45914]

Weather conditions triggering ascosporedischarge in Venturia pirina

Rossi, Vittorio;Giosue', Simona;Salinari, Francesca;
2008

Abstract

A 5-year study (2002-2006) was carried out in two pear orchards in northern Italy, by trapping air-borne ascospores of Venturia pirina. Characteristics of 155 ascospore discharge events (hour of the day, duration, ascospore number) and weather conditions of the hours preceding the beginning of the discharge (WD, wetness duration; R, rainfall; Tw, temperature during wetness) were analysed with the aim of better defining environmental conditions favouring ascospore discharge. Ascospore discharge showed a diurnal periodicity, with the 92% of total spores trapped in daylight. Thirty-seven percent of ascospore discharge events were triggered by rainfall, 55% by leaf wetness, while 8% occurred under dry conditions. The probability of ascospore discharge to occur was calculated using a logistic regression procedure with a stepwise selection of the independent variables. The variable ‘WD × Tw’ was selected as the most influential, while Tw, WD and R were not. The logistic equation provides the probability of an ascospore discharge to occur based on the combination of wetness duration and average temperature during the wet period preceding the beginning of the ascospore discharge. Probability was higher than 0.5 when ‘WD × Tw’ was higher than 197.5°C×h, while it was 0.9 when ‘WD × Tw’ was 585°C×h. This result showed that ascospore discharge in V. pirina is mainly influenced by wetness and temperature, while in V. inaequalis it depends mainly on rainfall. Calculation of the infection periods for controlling pear scab should take account of this difference.
Inglese
Rossi, V., Giosue', S., Salinari, F., Bugiani, R., Weather conditions triggering ascosporedischarge in Venturia pirina, Abstract de <<9th International Congress of Plant Pathology>>, (Torino, 24-29 August 2008 ), <<JOURNAL OF PLANT PATHOLOGY>>, 2008; (2, supplement): N/A-N/A. 10.4454/jpp.v90i2Sup.706 [http://hdl.handle.net/10807/45914]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10807/45914
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