INVESTIGADORES
MADDONNI Gustavo Angel
congresos y reuniones científicas
Título:
Post-flowering leaf senescence progress in stable and non-stable maize hybrids under nitrogen stress
Autor/es:
VALENTINUZ; O., D´ANDREA, K.; MADDONNI, G.A.; PAPAROTTI, O.F
Lugar:
Seattle, Washington
Reunión:
Congreso; ASA, CSSA, SSSA Annual Meeting; 2004
Institución organizadora:
ASA CSSA SSSA
Resumen:
Delayed leaf senescence has been associated with superior performance of newer
and stable maize hybrids. In this study ten maize hybrids varying in release year
and grain yield stability were compared in terms of the progress of visual symptoms
of leaf senescence when grown under low (0 kg ha-1) and high (200 kg ha-1)
nitrogen (N) rates. Regardless of hybrids and N, leaf senescence initiated around
500 GDD (base temperature of 8ºC) after sowing. Before silking, rates of
senescence increased under low N. After silking, all hybrids presented a leaf
senescence progress that fit to a bi-linear model with the breakpoint (i.e. thermal
time when rate of senescence increases) occurring around 400 GDD. At low N,
rates of senescence of first and second phases were greater and lower, respectively,
than those observed at high N. Newer and stable hybrids showed an increased rate
of leaf senescence of the second phase of model when grown at high N.
