WEATHER ANALYSIS WITH BILLING'S SPRING SYSTEM IN RELATION TO THE POTENTIAL RISK OF FIREBLIGHT OUTBREAKS IN ITALY.

C. Bazzi, M. Gasser, U. Mazzucchi
In evaluating the theoretical risks of potential fireblight infections in some Italian fruit-growing areas, the Billing's Spring system adapted to our situation was used. The modified system, advised by Dr. Billing, covered a period from the 1st March - 10th May. This was chosen as it comprises the main blossom period of pears in the Po Valley areas and apples in the Southern Tyrol. The maximum and minimum daily temperatures and rainfall records considered during the March-June period, concerned the last ten years in four areas of the Po Valley (Cadriano, Cesena, Ferrara, Verona), and five areas of the Southern Tyrol (Bressanone, Laimburg, Silandro, S. Michele all'Adige, Terlano).

On the basis of the corresponding PFA diagrams, the are as of the Po Valley had similar patterns for most years even if there are some differences in detail. It seems that in most years epidemic primary pear blossom infection is unlikely and the risk of any such infection appears to be low or moderate. Amongst the five areas of the Southern Tyrol, Silandro presents a low infection risk before, during and after the apple bloom. The assessment made in the other four areas suggests that they may present favourable conditions for potential outbreaks of fireblight following blossom infections and the risk tends to increase during the season and reaches high levels in the post-bloom periods. This latter trend is common to all the Po Valley areas considered.

Bazzi, C., Gasser, M. and Mazzucchi, U. (1984). WEATHER ANALYSIS WITH BILLING'S SPRING SYSTEM IN RELATION TO THE POTENTIAL RISK OF FIREBLIGHT OUTBREAKS IN ITALY.. Acta Hortic. 151, 97-106
DOI: 10.17660/ActaHortic.1984.151.12
https://doi.org/10.17660/ActaHortic.1984.151.12

Acta Horticulturae