الفهرس 
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Abstract
• Twenty nine isolates of fungi belonging to six genera were isolated from pea plants naturally infected with leaves and pods spots, collected from Minia and Matai districts, Minia Governorate. These isolates were as follows, five isolates of Alternaria alternata, two isolates of A. tenuissima, three isolates of Septoria pisi, six isolates of Aspergillus niger, four isolates of each Penicillium sp. and two isolates of Rhizopus stolonifer, two isolates of Fusarium solani, one isolate of each F. moniliforme, F. sp. and one isolate of unidentified fungus.
• Pathogenicity test revealed that all isolates of Alternaria spp., Septoria pisi and that non-identified fungus infected leaves and pods of Masster B cv. of pea causing spots with different degrees of severity ranged between 12.2 -39.4% on leaves and 15.0 – 48.9% on pods. Whereas, except the isolate P3 of Penicillium sp., the other fungi infected pods of pea causing 2.2 – 17.8% disease incidence and 1.1- 6.8% disease severity. Septoria pisi produced the highest percentages of disease incidence 55.6 – 71.1, 60.0- 89.6 in leaves and pods and 28.9- 39.4 and 27.2 – 48.9% disease severity in leaves and pods, respectively.
• master B, Qena 1 and Qena 3 cultivars of pea were the highly susceptible appearing the highest degrees of susceptibility whereas Jaguar and Palmoral were more resistance showing the least degrees of disease incidence and disease severity. Isolate S1 of S. pisi was more aggressive than other isolates of the fungus.
• Chlorophyll a, b and carotenoids were significantly reduced in diseased master B and Palmoral cvs. in comparing with healthy plants. The reduction percentages were more in master B (the highly susceptible cv) than Palmoral cv.
• The concentration of total soluble sugars was reduced in seeds collected from infected master B and Palmoral cvs. than that obtained from healthy plants. Total protein concentration was increased in seeds of diseased plants than control.
• The optimum temperature for growth and pycnidia formation of S. pisi was 21±2oC for both tested isolates. The fungus grew at a wide range of temperature ranged between 10 and 27oC. The fungus failed to grow at 5 and 30oC.
• Oat meal, malt, pea dextrose and Czapek’s media were the best favorable media for growth and pycnidia formation of the fungus, followed by V-8 juice and potato dextrose media. The poorest growth was obtained on basil and garlic media. No pycnidia formed on garlic and onion media.
• Excellent growth and pycnidia formation of S. pisi were obtained when simple sugars, i.e. fructose, glucose, maltose and sucrose, represented as the sole carbon source, followed by raffinose, dextrin and starch. Pectin, sorbitol and manitol proved to be the poorest sources of carbon for growth of tested fungus.
• The maximum growth and pycnidia formed on media contained sodium and potassium nitrate, followed by peptone or threonine. Minimum growth was obtained when urea or asparagine was used as a sole nitrogen source. No growth and pycnidia were formed when sodium nitrite or amino acids Cystine and Cysteine were used as a sole nitrogen sources,
• Trichoderma viride and Bacillus subtilis reduced the growth of S. pisi isolates. Isolate S3 of S. pisi showed the highest inhibition in the growth and forming pycnidia when comparing with isolate S1. T. viride was moor effect than B. subtilis
• The growth of S. pisi was reduced affecting by treatment with salicylic acid, ascorbic acid or humic acid in vitro. Salicylic acid followed by humic acid were the most affected compounds against the two tested isolates of S. pisi. Salicylic acid at 600 ppm complete inhibited the growth and maximum reduced pycnidia formation of S1 isolate. Humic acid reduced the growth of S1 and S3 by 65.8 and 63.0%, respectivity. Whereas, formation of pycnidia was completely inhibitedat 600 ppm of humic acid of S3 and reduced pycnidia formation for isolate S1 by 98.7%.
• The fungicides Anadol 80, Duett M 73 and Nativo 75 reduced the growth and pycnidia formation of Septoria pisi. Growth and formation of pycnidia of isolate S1 was completely inhibited at 300 ppm of Nativo and 400 ppm of Duett M 73, while isolate S3 was failed to grow at 200 ppm of Nativo, 300 ppm Duett and 400 ppm of Anadol.
• Field experiments were carried out to study the effect of antagonistic agents; Trichoderma viride and Bacillus subtilis, two chemical antioxidant compounds; Salicylic acid and Humic acid, and two fungicides; Nativo and Duett-M, on controlling the disease and on plant characters and yield components, under field conditions.
• Trichoderma viride or Bacillus subtilis reduced the disease incidence and disease severity on leaves and pods of pea caused by S.pisi. The reduction of leaf spots incidence ranged between 20.0 and 31.23% for isolate S1 and between6.50 and 33.3% for isolate S3, whereas pod spot incidence was reduced by14.05– 34.84% for isolate S1 and 9.87- 37.8 % for S3 isolate. Pod severity was reduced by 39.6% when B. subtilis was foliar applied at the first season.
• Disease incidence and severity were significantly reduced post-treatments with either humic or salicylic acids. The percentages of decrease were more when SA was foliar sprayed on pea plants than humic acid. Pod infection was reduced by14.23 -59.31%, at the first season and by 27.96 and 50.0% at the second season when SA or HA were applied.
• All tested concentrations of fungicides Nativo 75 and Duett M 73 were reduced both disease incidence and disease severity caused by isolates S1 or S3 of S. pisi. The maximum reduction in both disease incidence and severity was recorded when Nativo 75 (at 31.25 g /100 Ll water) was applied. Nativo 75 was more affected than Duett M.
• Plant height, plant fresh and dry weights and number of branches/plant were reduced by infection with S.pisi. Foliar application with T. viride or B. subtilis significantly increased all tested growth characters of infected pea plants. Whereas no significant differences were recorded, in all determined growth parameters, when healthy plants treated with antagonistic agents compared with untreated pea plants.
• Yield components, i.e. number of pods/plant, weight of pods/plant and weight of seeds/plant, were reduced due to infection with any of Septoria pisi isolates when compared with control. All yield components studied were improved when plants were sprayed with T. viride or B. subtilis on infected plants. The best results were obtained when T. viride was used to control the disease comparing with either B. subtilis or the control.
o Foliar application with humic acid and salicylic acid improved all growth parameters tested if compared with untreated infected or non-infected plants. Yield components were significantly increased when either humic acid or salicylic acid was foliar applied comparing with untreated plants.
o Plant fresh weight, plant dry weight, plant height and number of branches/plant were increased by fungicides treatment comparing with untreated infected plants. Also, fungicides treatment improved the yield components in plants infected with either S1 or S3 isolates of S. pisi.