The main objectives of this work were to isolate and identify the causal agents of sudden death syndrome (SDS) from samples collected in different Argentinean localities, to quantify its incidence, and to estimate yield losses. Two hundred and fifteen roots from plants with typical SDS foliar symptoms were analyzed. In order to perform pathogenicity tests, two bioassays were conducted in the greenhouse. Yield losses were estimated in a field trial located in Pergamino by quantification and comparison of yield of paired samples. Thirty-six percent of total roots (78 roots) presented signs of Fusarium, compatible with signs caused by SDS. Morphological studies allowed the identification of 35 isolates as F. tucumaniae and 18 as F. virguliforme. Other eight isolates could not be identified. All isolates that were inoculated reproduced typical SDS foliar symptoms. Significant differences were observed between healthy and diseased plants for 1000-grain weight and between potential and real yield (p<0.05). Average yield loss was 1514 kg/ha (range 192-3770 kg/ha). These results corroborated the distribution and predominance of F. tucumaniae and F. viguliforme in the area under study and its destructive potential.
Glycine max; Fusarium tucumaniae; Fusarium virguliforme; SDS
