Physical properties of soybean seeds damaged by fungi and a virus

Physical properties of soybean [Glycine max (L.) Merr.] seeds with symptoms caused by Alternaria sp., Fusarium graminearum, Phomopsis Longicolla, and soybean mosaic virus (SMV) were measured. These properties included seed density, volume, weight, shape, breakage susceptibility, and surface area. The properties were compared with those of asymptomatic seeds. The physical properties of soybean seeds were altered by the three fungi studied but not by the virus. The effects of fungal infection on the properties varied with the fungus. The properties of seeds with symptoms caused by P. longicolla were most severely affected. Density of seeds infected by this fungus was 4% lower, volume and weight were 13% lower, and breakage susceptibility 20 times higher than those of asymptomatic seeds. Physical properties of seeds showing symptoms caused by SMV were found to be better than those of the control.