Host range and survival of powdery mildew of cucmber in Ghor El-Safi Area, Jordan

الملخص EN

The objcctivc of this sludy was lo determine the host range and inoculum sourccs of cucumber powdery mildew in Ghor El-Safi area, Jordan, using artificial inoculation on 15 sclccted cultivated crops and weed species.

Survival of the pathogen was also assessed on cultivated crops and weed species commonly found in the area.

Erysiphe cichoracearum and Sphaerotheca fuliginea arc identified in the area, where the second pathogen is reported for the first lime in Jordan.

It seems that E.

cichoracearum is adapted to Jordan University campus while S.

fuliginea is adapted lo Ghor El-Safi area.

Though no perfect stage of these fungi was found in this study, the imperfect stage (conidia) of powdery mildew was present throughout the year on cultivated crops and/or weed species in fields or in plastic houses ensuring inoculum supply during the year.

Out of 15 plant species tested for host range, E.

cichoracearum was able to produce disease symptoms on 7 of the species.

S.

fuliginea was a!so able to cause the disease on 8 out of 11 plant species tested.

While both pathogens failed to infect loofa and snapdragon, they were able to incite the disease on squash and cucumber but differ in tltcir reaction towards the rest of the specics tested.