02503naa a2200373 a 450000100080000000500110000800800410001910000230006024500820008326000090016552016100017465000120178465000160179665000100181265000120182265000160183465000100185065000170186065000160187765000120189365000090190565300120191465300140192665300080194065300180194865300090196665300120197565300100198765300150199765300210201265300080203370000160204177300720205714446292017-05-22       1989    bl uuuu     u00u1 u    #d1 aFRANCA NETO, J. B.  aProblems in evaluating viability of soybean seed infected with Phomopsis spp.  c1989  aThe detrimental effects of Phomopsis spp. on seed germination of soybean [Glycine max (L.) Merrill] are broadly recognized. Rolled paper toweling is the most widely used method for testing germination of soybean seed. The validity of the rolled-paper-towel test to determine the actual viability of soybean seed infected with Phomopsis spp. was examined. Seventy-three seed samples of 23 soybean cultivars produced in Florida in 1986 were analyzed for germination, vigor [tetrazolium (TZ) test], and pathogens. Phomopsis spp. were the fungi most frequently associated with soybean seed (up to 77% seed infection). Infection by these microrganisms was mainly restricted to the seedcoat. Deep-seated infection was rare (mean 0.5%). Viability, as obtained by the standard germination test (rolled paper toweling) was drastically reduced by high (&gt 33%) levels of Phomopsis spp. These detrimental effects were not observed when germination was examined in sand, if conditions were adequate for fast emergence. When seed were tested in sand, the infected seedcoats remained in or on the sand upon emergence, thus the seedlings escaped much of the detrimental effects of infected seedcoats. Therefore, rolled paper toweling was not the best substrate to evaluate germination of soybean seed infeced with high levels of Phomopsis spp. Emergence in sand or the TZ test provided more realistic estimates of viability for seed lots infected with these fungi. Nevertheless, it was noted that as the vigor level expressed by the TZ test decreased, the level of infected seedlings and damping-off tended to increase.  aFlorida  agermination  avigor  aDoença  aEmergência  aFungo  aGerminação  aGlycine Max  aSemente  aSoja  aDisease  aEmergence  aEUA  aPhomopsis spp  aSeed  aSoybean  aTeste  aTetrazolio  aTetrazolium test  aUSA1 aWEST, S. H.  tJournal of Seed Technology, Beltsvillegv.13, n.2, p.122-135, 1989.