Fig. 1. Incident solar radiation (diamonds, dotted line), maximum temperature (circles,
solid line), minimum temperature (triangles, solid line) and rainfall (bars)
during the two experiments: 2003 (open symbols) and 2004 (closed symbols) in
Pergamino. Values aremeans (radiation and temperature) or total (rainfall) of 10-day
periods.
Daily fraction of PAR intercepted between measurements was
obtained by linear interpolation and applied to the corresponding
daily values of PAR to estimate IPAR. To calculate daily incident PAR,
the incident total solar radiation was measured with a standard
weather station 200 m from the plots and then multiplied by 0.45
(Monteith, 1965). Daily values were summed from emergence for
each plot to obtain cumulative IPAR.