الفهرس 
introductionيوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
Potato (Solanum tuberosum L.) is one of the most important crops in Egypt as well as all over the world; increased importance of the potato in Egypt due to increasing Egypt’s export of potatoes. The total amount of Egypt potatoes approved for export to foreign destinations has reached 427907 tonnes2013 (Anonymous, 2013). Stem canker and black scurf caused by Rhizoctonia solani Kuhn is considered by far the most destructive disease and reduce productivity of potato. Occurrence of stem canker and black scurf diseases during 2013/2014 and 2014/2015 recorded different percentage of disease infection in two surveyed Governorates El-Sharkiya (New El–Salhia region)and Ismaillia (El-Shabab region). Pathogenicity test of 12 isolates of R.solani (selected from 140 isolates) revealed that all isolates were pathogenic, isolate No.RS7 was the most virulent isolates in the events of the stem canker and black scurf disease. Molecular technique applied to determine anastomosis group for this isolate showed that isolate belong to AG3. Five potato cultivars were tested against the most pathogenic R. solani, the resistance was Diamant cv., the moderately susceptible were cultivar; Spunta and Mondial, while susceptible one was Lady Rosetta cv.Biological control in vitro by using two fungal agents, Trichoderma harzianum and Aspergillus niger have been tested for their ability to antagonize the R. solani.Results showed that both tested fungal isolates were found to be antagonistic to R.solani. Trichoderma harzianum was found to be the most potent antagonistic to R. solani. Experiment of chemical control in vitro by using two funicides(Rizolex-T and Topsin M) showed that growth of R. solani decreased with increasing the concentration of Topsin M, while Rizolex-T inhibited completly the growth of R. solani at all tested concentrations.
Key words: Potato - Black scurf and stem canker disease - Anastomosis group - Molecular technique - Rhizoctonia solani - Pathogenicity test- Trichoderma harzianum
- Biological control- Chemical control