Pathogenicity of Fusarium spp. Incidence on soybean seed quality

— Fusarium semitectum Berk & Rav. has been often cited as causal agent of soybean (Glycine max (L.) Merril) pod rot.Eighteen strains of different species belonging to the same genus (F.equiseti (Corda) Sacc., F. fusa- rioides (Frag.& Cif.) Booth, F. graminearum Schwabe, F. moniliforme Sheldon, F. sambucinum var.coeruleum Fuckel Wollenw., F. semitectum and F. solani (Mart.)Sacc.) isolated from soybean seeds were inoculated on soybean pods on the plant, wounded and unwounded, at developing stages R 5 , 5 and Rg to verify if their pathogenic capacity was identical to F. semitectum and to determine their incidence on injury frequency and seed quality according to the time of attack.Injury frequency was registered 20 and 40 days after inoculation.The two observation dates showed higher injury frequency on wounded pods for both developmental stages.On day 20, injuries were higher when inoculation had been performed at R 5 , 5 .However, difference rates were less on day 40.Hundred seed weight was more affected at R 5 , 5 than at R 6 , 5 .Germinative capacity was not greatly affected at both reproductive stages in unwounded pods; but it was almost non-existent in previously wounded pods.The frequent presence of F. semitectum is not attibuted to its particular pathogenicity, but to its capacity for wide- spread distribution.It should be pointed out that the method applied here may not resemble the processes in nature and that these artificial conditions may have favoured the development of certain species to the detriment of others., On conclut que si F. semitectum est trouvé le plus fréquemment sur le soja, ce n est pas dû principalement à un pou- voir pathogène particulier, mais plutôt à son aptitude à se disperser facilement.Notons que les techniques utilisées peuvent être différentes des processus naturels et que les conditions artificielles peuvent avoir favorisé certaines espèces.graines de soja -pouvoir pathogène -stade de développement -qualité des graines -pourriture des gousses