Studies On Root Rot Disease Of Soybean (Glycine Max.) In Upper Egypt

Abstract

The present investigation was planned to study the causal pathogens of soybean root-rot and damping- off disease as well as factors affecting disease incidence and resistance such as soybean cultivars, preceding crops, control of the disease throughout soil solarization, stratification and biological control by using plant extracts and biocontrol agents.

Results of this work can be summerized as follows:

1- Six isolates of Rhizoctonia solani (Kuhn), seven isolates of Fusarium moniliforme (Sheldom), eight isolates of Fusarium solani (Mart.), seven isolates of Fusarium oxysporum Schlech. ex Fremend-Snyda • Hans.), seven isolates of Macrophomina phaseolina (Tassi) Goid, one isolate of Chaetomium cupreum (Ames) and two isolates of Phoma exigua were isolated from naturally diseased soybean plants, collected from different localities of Assiut Governarte, Egypt. Rhizoctonia, Fusarium, Macrophomina, chatomium and Phoma isolates caused pre­ and post-emergence damping-off, root-rot and external root discoloration symptoms. Rhizoctonia solani was the most serious pathogen m infecting Clark soybean variety followed by Macrophomina phaseolina, Fusarium moniliforme, ('usarium solani and Fusarium oxysporum, whereas Phoma exigua and Cheaetomium cupreum were the least hazardous ones.