The Effects of organic fertilizer complement by addition Biological control agents on Rhizoctonia solani Kühn Causing of Eggplant root rot Disease

Abstract

The research was aimed to study of some plant extracts, Trichoderma harzianium and Plant growth promoting rhizobacteria Azotobacter chroococcum and addition of organic fertilizer made of Date palm leaves in control Eggplant root rot disease caused by Rhizoctonia solani fungus. Results of the field survey showed the presence of Eggplant root rot disease in all the surveyed districts Baghdad, Babylon and Karbalaa province with disease incidence of 33.3-83.0% and severity of 16-60%. T. harzianium and A. chroococcum have highly antagonistic ability against of pathogenic isolates of R. solani under laboratory conditions. The plant extract that used in study (Cinnamon, ginger, Milk thistle, Crack willow) had against effect on the growth of pathogen on PDA. superior of Cinnamon extract which was prevent growth of pathogen. The results of the field experiment and lath house condition indicated that Integrated treatment with the T. harzianium and A. chroococcum caused significant reduction in disease severity to 33.33% and caused significantly enhanced eggplant growth parameters. The organic fertilizer of Date palm leaves increased the Efficiency of biological control agents. The integrated treatment between T. harzianium and A. chroococcum and organic fertilizer of Date palm leaves showed decreased in disease severity to 20.00% then increasing the plant growth parameters into 17.33 cm, 18.33 and 2.77g respectively. These results were appeared for the first time in Iraq that T. harzianium, A. chroococcum and organic fertilizer of Date palm leaves showed high antagonistic with R. solani and decreased severity of Eggplant root rot disease.