Epiphytic Population Dynamics Of Olive Knot Pathogen Pseudomonas savastanoi pv. savastanoi

الملخص

Dynamics of epiphytic population of Pseudomonas savastanoi pv. savastanoi the causal agent of olive knot disease on olive was studied all around the year in Jordan. The pathogen was recovered from washing leaves collected from healthy trees as well as diseased trees. The recovered population was found to fluctuate with fluctuation in temperature and relative humidity. The higher epiphytic population was recovered during spring and fall seasons, while the lower was during summer and winter seasons. The high est recovered population obtained during the first week of June coincided with average temperature of 21.5 oC and relative humidity of more than 52%. During field inspection through 2015 and 2016, a delay in the onset of the disease where the newly formed knots appeared late in June, followed the highest epiphytic population. The occurrence of this pathogen as epiphytic population on olive leaves brings new dimension in the epidemiology of disease as well as a source of primary disease inoculum.