A Novel Strategy for Controlling Damping-Off and Charcoal Rot Diseases of Sunflower Plants Grown Under Calcareous-Saline Soil using Spermine, Potassium and Zinc
2010
El-Metwally, M.A. | Sakr, M.T.
Two field experiments were carried out to investigate the role of Spermine (SP) as seed soaking and/or foliar application of K and/or Zn in reducing the harmful effects of charcoal rot caused by Macrophomina phaseolina and damping-off caused by Rhizoctonia solani as well as improving the productivity of sunflower plant in calcareous-saline soil. From five tested locations of Maryout region, Egypt, M. phaseolina and R. solani were isolated from infected plants. Both fungi were pathogenic and cause typical symptoms of damping-off. Macrophomina phaseolina showed to be highly virulent fungus. It gave the highest values of pre- and post-emergence damping-off compared with R. solani. Application of SP+Zn+K increased germination percentage and reduced damping-off by both fungi under greenhouse conditions. Under greenhouse and field conditions, all treatments of SP and/or K and/or Zn significantly reduced the incidence of damping-off disease compared with control treatment. Presoaking of seeds in SP and foliar spraying of K and/or Zn increased most of growth parameters, yield and its components and oil content of seeds, as well as the contents of K, Ca, P and Zn and K/Na ratio, whereas decreased Na concentration. All treatments significantly increased the activity of total peroxidase, ascorbic peroxidase, superoxide dismutase and catalase enzymes in plants, in addition to the improvements in the content of chlorophyll A, chlorophyll B, caroteinoids and total phenols compared with control plants in both seasons. Therefore, application of SP+Zn+K could be recommended to alleviate the harmful effects of damping-off and charcoal rot diseases in calcareous-saline soil by enhancing the tolerance of sunflower plant to these adverse conditions.
显示更多 [+] 显示较少 [-]