02930naa a2200469 a 450000100080000000500110000800800410001910000230006024501070008326000090019052017440019965000160194365000100195965000240196965000290199365000120202265000160203465000100205065000170206065000160207765000200209365000140211365000120212765000090213965000150214865300160216365300120217965300140219165300180220565300110222365300180223465300190225265300220227165300120229365300090230565300120231465300100232665300150233665300210235170000160237277300720238814446272017-05-22       1989    bl uuuu     u00u1 u    #d1 aFRANCA NETO, J. B.  aEffects of Collectotrichum truncatum and Cercospora kikuchii on viability and quality of soybean seed.  c1989  aSeventy-three seed samples of 23 soybean [Glycine max (L.) Merr.] cultivars produced in Florida in 1986 were analyzed for germination, vigor [tetrazolium (TZ) test], and presence of seedborne pathogens. Thirty percent of the samples contained from 5 to 20% (high) infection by Colletotrichum truncatum (Schw.) Andrus & Moore. Infection was mainly restricted to the seed coat, but 50% of the seed lots with high levels of infection had embryo infection from 1 to 10%. Although C. truncatum infected fewer seeds than Phomopsis spp., it caused more damping-off, regardless of seed vigor level. As the pathogen incidence increased, the amount of damping-of also increased. These detrimental effects were observed on the standard germination test (rolled paper towels) which also was severely affected by high levels of Phomopsis spp. The TZ test values were not affected by the presence of these fungi, thus giving the highest percent germination. Sand emergence provided estimates of germination for seed lots with high incidence of infection by C. truncatum that more nearly simulated what would be expected in the field under ideal conditions. Seventeen percent o the samples contained high levels (7 to 33%) of infection by Cercospora kikuchii (Matsu. & Tomoyasu). This pathogen was almost exclusively restricted to the seedcoat. An antagonistic effect was observed between C. kikuchii and Phomopsis spp. infecting soybean seeds: the higher the level of seed infection by C. kikuchii, the lower the seed infection by Phomopsis spp. No detrimental pathogen effects of seed infection of this pathogen were observed on germination, emergence, and vigor of soybean seed with the natural levels of C. kikuchii infected seeds used in this study.  agermination  avigor  aCercospora Kikuchii  aColletotrichum Truncatum  aDoença  aEmergência  aFungo  aGerminação  aGlycine Max  aMancha Púrpura  aQualidade  aSemente  aSoja  aTombamento  aDamping-off  aDisease  aEmergence  aFitopatologia  aFungus  aPhomopsis spp  aPhytopathology  aPurple seed stain  aQuality  aSeed  aSoybean  aTeste  aTetrazolio  aTetrazolium test1 aWEST, S. H.  tJournal of Seed Technology, Beltsvillegv.13, n.2, p.136-149, 1989.