Current Status of Powdery Mildews Diseases on Cucurbits in The Northeast of Syria

Omran Youssef(1) Alan  Ramo*(1) and Sultan Shekhmus (1)

(1). Al Qamishly Agriculture Research Center. General Commission for Scientific Agriculture Research (GCSAR), Al Qamishly, Syria.

(*Corresponding author: Dr. Alan Ramo. E-Mail: alanremo123@hotmail.com).

Received: 06/06/ 2015                                     Accepted: 07/08/ 2015

Abstract

This study aimed to investigate the spread of powdery mildews diseases on cucurbits in the northeast of Syria during 2011. This study included 36 fields of cucurbits. The percentage and severity of infection was recorded. The infected samples were transported and tested in the lab. The fungus species were identified. Results showed that the spread of these diseases was 48.2% of the planted fields. The infection percentage and its severity varied from one region to another. The highest infection percentage (91.7%) was recorded in Almalekya region in Zone1-A. The average highest infection percentage was (50%) and the severity (9), recorded in Cucumis sativus L. Next were Al Qamishly region fields in Zone1-B, where the percentage of infected fields was 41.7% with an average highest infection percentage of 15% and a severity of 3. However, the lowest infection percentage was 25% in Rasalayn regions in Zone2. Here, the average highest infection percentage was (10%) and the average highest severity was (4). The plants of cucurbits were found to be infected by two species of fungi: Erysiphe cichoracearum and Sphaerotheca fuliginea. E.cichoracearum was found to infect three plant species (Cucumis sativus L., Citrullus vulgaris L., and Cucumis melo L.) and E.cichoracearum and S. fuliginea were able to infect together  three plant species (Cucumis sativus L., Cucurbita pepo L. and Cucurbita maxima Duch.). Results also showed that the presence of the two fungus species on all their plant hosts was only in the conidial phase. The sexual phase was absent and the fruits of Cleistothecium were not found.

Key words: Cucurbitaceae, Powdery mildew, Erysiphe cichoracearum, Sphaerotheca fuliginea, Syria.

Full paper in Arabic: الحالة الراهنة لأمراض البياض الدقيقي على القرعيات في شمال شرقي سورية.