الفهرس 
Pathogenicity studiesOnly 14 pages are availabe for public view
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Abstract
Faba bean (Vicia faba L.) is one of the important crops in Egypt. It is important source of human consumption as well as for animal feed. However, faba bean seedlings are subjected to the attack by numerous pathogens causing root-rot diseases which reduce the quantity and quality of the crop. The present investigation was planned to isolate and study the pathogenicity of soil-borne fungi associated with faba bean (Vicia faba L.) roots of many cultivars. The investigation includes also the study of the effect of some biological agents, plant oils and extracts, biofertilizers and fungicide were tested for controlling root-rot and determine activity of the enzymes involved in phenolic compounds. The following results were obtained:
Pathogenicity experiment
1- Causal agents were isolated from faba bean seedlings collected from different location in Egypt, purified and identified as: one isolate of Sclerotium rolfsii, six isolates of Rhizoctonia solani, six isolates of Fusarium solani, one isolate of F. moniliforme and one isolate of Macrophomina phaseolina.
2- The pathogenicity tests proved that all the tested fungi were pathogenic and able to reduce pre-emergence (PRD), and post-emergence (PTD) and incited root-rot on faba bean cultivars, namely; Giza 2, Giza 3, Giza 40, Giza 716, Sakha 2 and Mass 1.
3. The highest PRD values were obtained on Masser 1, Giza 3 and G 716, inoculated with S. rolfsii (43.85%, 41.54% and 41.54% respectively) and G 716 cv inoculated with M. phaseolina was (34.16%), moreover inoculated with R. solani and F. solani on G 2 cv (36.7% and 34.16%, respectively). whereas, S 2 cv was the least (21.25%) compared to control.
4. The highest PTD incidence ratios were obtained by S. rolfsii on G 2, G 3, G 40, G 716 (39.23%, 34.16%, 34.16% and 34.16% respectively, whereas, G 2 and G 40 inoculated with F. solani (34.16%) compared with control. In addition, high PTD value was realized by M. phaseolina on G 2 cv (31.63%).
5. Inoculation experiments using S. rolfsii led to significant reduction in SS values (26.56%) on G 2 and Masser 1 cvs. On the other hand, the highest SS (seedlings survival) values obtained from S 2, G 3, G 40 and M 1 cultivars inoculated with M. phaseolina (55.84%, 46.38%, 43.85% and 43.85% respectively and G 716, S 2 inoculated with F. solani (43.85%, 50.99% respectively).