الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The objective of this study was to evaluate the antifungal activity of silver nanoparticles and some biocontrol agents against some cotton pathogenic fungi. Samples of seedlings infected with damping-off of cotton plants were collected from several locations of cotton-producing areas at Egypt. The samples yielded 7 highly pathogenic fungal isolates. Isolates were identified as Rhizoctonia solani, Fusarium spp. and Macrophomina phaseolina . The most pathogenic fungal isolates on Giza90 and Giza94 were F. fujikuroi F3, R. solani RS37(AG4) and M. phaseolina M4. All the tested Trichoderma isolates were effective as antagonists and caused inhibition of linear growth of all pathogenic fungal isolates in vitro. Especially T33 ,T23 and T1 were the most effective Trichoderma isolates. Combinations of seed dressing fungicides and Trichoderma isolates were evaluated for their effects on the susceptibility of cotton cultivars to F. fujikuroi (F3) under greenhouse conditions, and from the practical point of view, using of biocide Trichoderma T33 was the best one for both cultivars as it did not include chemical fungicides. The effect of culture filtrates of Trichoderma isolates on survival and radical length of cotton cultivars in vitro was evaluated. For both cultivars, none of Trichoderma isolates were effective in increasing the survival significantly compared to the control. Mycosynthesis of silver nanoparticles using Trichoderma harzianum, was reported in this work. The synthesized nanoparticles were characterized for their size, shape, charge and composition by visual analysis, UV–visible spectrometry, Zeta potential, DLS, TEM, SEM and EDX. The antifungal activity of the synthesized nanoparticles was evaluated in vitro and in vivo for their role in increasing the antifungal activity compared with two chemical fungicides (Moncut and Maxim XL) against F3, Rs37, and M4.