الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 132 |  |  |
| | | from | 132 | | |
Abstract
Roselle (Hibiscus sabdariffa L.) is one of the most crucial medicinal plants all over the world. The present study was carried out with the intention of solving some problems related to soil-borne diseases and to study the use of microorganisms in enhancing crop production. Fusarium oxysporum is associated with wilt disease of roselle plant. The application of some microbiota i.e., a mixture of Pseudomonas fluorescens (PSR-11), Bacillus subtilis (BSR-8), Pleurotus ostreatus and mycorrhizeen® individually or in combination were investigated for controlling wilt disease, growth, and yield of roselle plant. The study was conducted in sandy textured soil under sprinkler irrigation of Ismailia Agricultural Research Station, Ismailia, Egypt. Under greenhouse conditions, all the tested bioagents reduced wilt incidence and increased the percentage of survived plants. The conglomeration of the bacterial mixture of Pseudomonas fluorescens and Bacillus subtilis, Pleurotus ostreatus and mycorrhizeen® was more effective in controlling wilt disease than using any of them individually. The application of the investigated bioagents showed a significant increase in phenol, photosynthetic pigments, and dehydrogenase contents, as well as root colonization percent. The obtained results showed the ability of B. subtilis and P. fluorescens to produce lytic enzymes such as β-1-3 glucanase, β-1-4 glucanase, chitinase and protease, in addition to their production of siderophore and HCN. The consortium of all microbiota gave the best results for growth and yield parameters of roselle plant. A field experiment was implemented to inspect the impact of the bacterial mixture (Bacillus subtilis (BSR-8) and Pseudomonas flourescens (PSR-11)), Pleurotus ostreatus and mycorrhizeen® individually and /or in combination on the growth and yield of roselle plant and their impact on newly sandy soil. The tested bioagents significantly increased the growth and yield of roselle plant in comparable to the untreated plants. Also, inoculation increased soil dehydrogenase activity, root colonization and photosynthetic pigments. Significant enhancement in soil fertility properties was occurred, where the soil NPK availability improved. The NPK concentrations and uptake increased in calyx and shoot in response to bioagents. Soil organic matter content and soil aggregates increased while EC and pH decreased. Generally, the application of microbial mixtures modified physio-chemical soil properties and consequently reflected on roselle yield production.