الفهرس 
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Abstract
The causal organism of early blight disease and chocolate spot disease were
isolated from diseased samples of tomato and faba bean plants, respectively during
the growing season 2017/2018. Samples were collected from tomato fields in Giza
Govemorate and from faba bean fields in Menoufia Govemorate. 32 actinobacteria
isolates were isolated from the rhizosphere of tomato and faba bean plants.
Streptomyces nodosus was the most efficient in reducing the mycelial growth and
sporulation of Alternaria solani and Botrytis fabae, respectively.
Biomass production of S. nodosus as well as antagonistic activity were
optimized. The optimized medium was of the following composition (g/100ml): 2
(gm) starch, 0.2 (gm) of potassium nitrate, dipotassium hydrogen phosphate as
.” .
phosphorus source at 30°C and pH 6.5, that lead to the more production of
biomass and antagonistic substance(s). Cultures were incubated in a shaking
incubator at 180 rpm.
Streptomyces nodosus was significantly decreased the severity of early
blight and chocolate spot disease under greenhouse conditions in compared to the
control. Also, seeds of tomato and faba bean coated with S. nodosus showed a
reduction in severity of early blight and chocolate spot disease under greenhouse
conditions in compared with control.
The active antimicrobial compound has been identified as amphotericin B.
Separation, purification and identification were carried out using physical and
chemical characters. Extracted amphotericin B has high potential effective as a
biocontrol agent against A. solani and B. fabae.
The results revealed that spraying tomato and faba bean plants with
amphotericin B was significantly decreased the severity of early blight disease and
chocolate spot disease in compared to the control under greenhouse conditions.
Tests showed that clove oil was the best effective oil in the control of the
mycelial growth of A. solani and B. fabae. Also, the combination of clove oil with
extracted amphotericin B was more effective in disease control.
Additionally, Results showed that Dithane M-45 was the effective
fungicides in controlling the mycelial growth of A. solani and B. fabae. Also, the
combination of Dithane M-45 with extracted amphotericin B was more effective in
disease control.