Research upon the Influence of Climatic Conditions on Microsphaera Abbreviata L. Atack in Oak Forests

Ioan Oroian, Ilie Covrig, Antonia Odagiu, Petru Burduhos, Ioan Brașovean, Constantin Șulea, Cristian Iederan


The threat represented by powdery mildew attack is an important issue that must be taken into consideration by all that area dealing with forest management, especially due to drying phenomena, which could be intensified in whole tree, and also in both thin and thick branches. Our study aims to emphasize the comparative evolution of the Microsphaera abbreviata L. attack against mixed oak and durmast forests in climatic conditions of the county of Cluj in Transylvania, Romania, and to hierarchize the importance of considered climatic factors in pathogen intensity and frequency of attack. The trial was placed in oak and durmast forests from two Forest Offices, located in the county of Cluj, and the following parameters were monitored: Microsphaera abbreviata L. attack degree, temperature, dew point, humidity, pressure, rain regimen, wind velocity, and visibility. The data were statistically processed with IM SPSS office. Basic statistic, significance of differences (ANOVA), and Principal Components Analysis were taken into consideration. The average attack degrees of powdery mildew (progressively increased from 2012 (AD = 20.52%), up to 2014 (GA = 26.34%). The averages of dew point, pressure, wind velocity, visibility and rain regimen, during all three experimental years, discontinuous evolved. The average temperature continuously decreases from 2012 to 2014, from18.780C to 17.230C while average humidity progressively increases from 63.77% in 2012, to 69.40% in 2014.  According to PCA, humidity and temperature are the most important factors in manifestation of the powdery mildew average attack degree, during experimental period 2012 - 2014, being responsible for majority of variance - 69.82 respectively.


powdery mildew, basic statistics, ANOVA, Principal Components Analysis.

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