A fungal disease caused by the highly specialized pathogen Septoria glycines Hemmi, which affects all above-ground plant organs. It is characterized by the appearance of angular rusty-brown spots with pycnidia, leading to premature leaf drop.
In the reference
21
varieties
crop Soybean,
where this is mentioned in the description.
The causative agent is the fungus Septoria glycines Hemmi of the Mycosphaerellaceae family, which forms pycnidia with conidia that are spread by raindrops and wind. The pathogen infects soybean cotyledons, leaves, stems, and pods. Initial symptoms on leaves appear as small, angular, rusty-brown spots measuring 1–5 mm, bounded by veins and often surrounded by a chlorotic halo. Characteristic black dots—pycnidia—form in the center of these spots.
On stems, the pathogen causes elongated dark-brown spots, while on pods it produces small dark lesions. With intense disease development, the spots coalesce, causing yellowing and premature leaf drop. A classification system for the pathogen into specialized races has not been described. Genes for immunity to the disease are absent; breeding efforts are focused on identifying quantitative resistance loci, particularly on chromosomes 14 and 17, to enhance field tolerance in varieties.
Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.