01851naa a2200265 a 450000100080000000500110000800800410001910000180006024500830007826000090016152011260017065000170129665000090131365000100132265000120133265000180134465000170136265000230137965000230140265000170142565300180144270000250146070000250148577300750151012054602021-09-10       1996    bl uuuu     u00u1 u    #d1 aPRABHU, A. S.  aGenetic control of blast in relation to nitrogen fertilization in upland rice.  c1996  aSix upland rice cultivars were evaluated under two nitrogen levels (10 kg and 60 kg N/ha) for blast control based on slow leaf and panicle blast characteristics in field experiments conducted during three consecutive years. The criteria for measuring slow blasting resistance were area under disease progress curve (AUDPC), maximum severity during disease progress (Ymax) and the rate of increase until the disease reaches maximum ('ymax.). There was a high positive correlation among the criteria utilized. The control of leaf blast in improved rice cultivars (Cuiabana, Centro America, Guarani, Rio Paranaiba) ranged from 36 to 56% for 10 kg/ha of N and from 19 to 49% for 60 kg/ha of N over the susceptible checks (IAC 47, IAC 165). The effect of slow blasting resistance on panicle blast control was less than on leaf blast in most of the cultivars. Increasing the nitrogen level from 10 to 60 kg/ha resulted in a mean yield increase by only 12% corresponding to 258 kg/ha. The data suggest that the existing level os slow blasting resistance in the improved rice cultivars is efficient only under low nitrogen level.  aepidemiology  arice  aArroz  aCerrado  aEpidemiologia  aOryza Sativa  aPyricularia Grisea  aPyricularia Oryzae  aResistência  aSlow blasting1 aFILIPPI, M. C. C. de1 aZIMMERMANN, F. J. P.  tPesquisa Agropecuária Brasileiragv. 31, n. 5, p. 339-347, maio 1996.