02278naa a2200253 a 450000100080000000500110000800800410001910000200006024501030008026000090018352015700019265000090176265000300177165000170180165000100181865000120182865000130184065300330185370000180188670000210190470000170192570000190194277300630196119594872013-10-18       2013    bl uuuu     u00u1 u    #d1 aMONDO, V. H. V.  aEffect of seed vigor on intraspecific competition and grain yield in maize.h[electronic resource]  c2013  aHigh-vigor seeds result in faster emergence of seedlings and crop establishment than low-vigor seeds. Th ese characteristics could enhance plant competitive ability and could have direct eff ects on maize (Zea mays L.) grain yield. Th is study examined the hypothesis that seed vigor heterogeneity in maize seed lots could increase intraspecifi c competition and negatively aff ect crop grain yield. A 2-yr experiment was executed combining two hybrid maize seed lots, possessing high-vigor and low-vigor seeds, in seven diff erent distributions in the sowing row. Th e distributions of the plants originating from high- and low-vigor seeds were evaluated at harvest for dry mass accumulation, prolifi cacy, number of grains per row, number of rows per ear, 1000-grain mass, and grain yield. A replacement series design for data analysis of two homogeneous populations and fi ve seed mixture populations was applied. We concluded that, in plant populations originating from heterogeneous seed lots, intraspecifi c competition was intensifi ed, resulting in losses of dry mass accumulation and grain yield. Plants originating from low-vigor seeds had less competitive ability and reduced plant dry mass accumulation and grain yield than those originating from high-vigor seeds and were responsible for crop yield losses. Plants originating from high-vigor seeds had a dominant eff ect on those originating from low-vigor seeds and had no compensatory eff ects. Th e major production component aff ected by intraspecifi c competition was the number of grains per row.  aCorn  aIntraspecific competition  aErva daninha  aMilho  aSemente  aZea mays  aCompetencia intraespecífica1 aCICERO, S. M.1 aDOURADO-NETO, D.1 aPUPIM, T. L.1 aDIAS, M. A. N.  tAgronomy Journal, Madisongv. 105, n. 1, p. 222-228, 2013.