02091naa a2200241 a 450000100080000000500110000800800410001910000180006024500800007826000090015852014910016765000130165865000120167165000100168365000170169365000130171065300170172365300120174065300100175265300150176270000190177777300530179610520762010-07-09       1988    bl ---       0--  u    #d1 aHOLLEY, R. N.  aStalk quality and stalk rot resistance of tropical hybrid maize derivaties.  c1988  aTemperate-adapted, 100% tropical maize inbreds were evaluated as inbreds and in hybrid combination with corn belt germ plasm for stalk quality and resistance to two stalk rot pathogens, Stenocarpella maydis and Colletotrinchum graminicola. Plants were inoculated with one of the two pathogens and evaluated for stalk rot resistance via internode discoloration and lodging ratings. There was a wide range of resistance among the tropical inbreds to internode discoloration caused by the two pathogens. Most tropical inbreds had relatively high levels of resistance to S. maydis but were relatively susceptible to C. graminicola. Several experimental 50% tropical hybrids were superior to the commercial checks for stalk-lodging resistance. There was no correlation between internode discoloration ratings of the inbreds or hybrids and lodging resistance. The late-season internode discoloration data were limited, however, by a natural infestation of Pythium sp. that was associated with de sintegration of pith in many plants. The importance of rind strength in lodging resistance was evident by the consistency of experimental hybrid performance over different pathogen tests. Poor stalk quality has been one of the major factors limiting the use of exotic maize germ plasm. The strong performance of some tropical inbreds used in this study, however, suggests that major progress has been made in some tropical breeding programs. No significant root lodging was observed in the study.  aDiplodia  aDoença  aMilho  aResistência  aZea Mays  aAnthrancnose  aDisease  aMaize  aResistance1 aGOODMAN, M. M.  tPlant Diseasegv.72, n.4, p.321-324, Apr., 1988.