الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 221 |  |  |
| | | from | 221 | | |
Abstract
Chrysanthemum is 2nd cut flower plant of high economic, cosmetic, and medicinal importance, worldwide. Alternaria leaf spot and leaf blight is one of the most important causes that reduce the production of flowers and transplants. The aim of this study was to investigate the possibility of using plant extracts, essential oils, biological agents, and soil amendments as one element in an integrated control program to control Alternaria leaf spot and blight of chrysanthemum plants in Egypt. The disease was collected from three different regions in Egypt {Heliopolis (Cairo), Ezbet Al-Ahali and Darwah in Al-Qanater Al-Khairiya (Qalyubia)}, where the symptoms were typical in the form of brown spots and blight on the leaves and peduncles, in addition to the presence of rot on the flower cluster. The disease incidence was also calculated (%) in those areas and they were (87.15-61.44-38.72%), respectively. 102 different fungal isolates were isolated and the frequency (%) of Alternaria spp. was (95%). In vitro, the pathogenicity was tested by detached leaf inoculation using a single droplet technique during two periods of 7-14 days, where the frequency of the high pathogenic isolates was (19.6%). In vitro, The six highest pathogenic isolates were molecularly identified through rDNA ITS using a pair of primers ITS1/ITS4 and the result was five isolates belonging to Alternaria alternata and one isolate to Cordyceps memorabilis. The three highest pathogenic isolates that were identified molecularly {(HelCa - FWhd2(1-1), MGQa–FYhd2(1-3), MYQa - FLMhd5 (5-3)} were culturally and morphologically defined to confirm the molecular identification. The result was Alternaria alternata. In vitro, These isolates were tested with ten methanolic plant extracts, five essential oils, and two different fungicides (reference treatment), and the result was based on the calculation (EC50, EC90), which are extracts of Clove (281.64) and Cinnamon (10356.19), Spearmint (10.62) and Camphor (16951.18) oils. The five
bio-agents also showed a positive effect, as the best treatments in terms of inhibition of mycelium growth were Trichoderma harzianum (71.39%) and Bacillus subtilis (69.41%). Under greenhouse conditions, the best treatments were tested in the laboratory in addition to soil amendments (Compost and Vermicompost) on transplants of the chrysanthemum plant (Chrystal Fresh White cultivar) (80 days old) against isolate MGQa-FYhd2(1-3) in the form of curative and protective treatments, as the result was that treatment with compost and vermicompost, bio-agents, Spearmint and Camphor oils in their curative form, as well as treatment with compost, vermicompost, some bacterial biological agents, Spearmint and Camphor oils, Clove and Cinnamon extracts in their protective form with their three concentrations (the concentration, its half and its double based on the calculation of EC90) led to a decrease in the severity of the disease and an increase in the growth parameters of the plant in terms of Plant height, number of leaves, chlorophyll content, peroxidase and polyphenol oxidase enzymes were different significant degrees at the end of the experiment (after 150 days from cultivation of plant cuttings).