DISCUSSIONGrain yield in the DS was

DISCUSSION
Grain yield in the DS was greater than in the WS because
there was higher solar radiation during the reproductive
and ripening phases and lower temperature during vegetative and reproductive stages in the DS than in the WS
(Tables 1 and 2, Fig. 1). The greater yield in the 2003 DS
than the 2004 DS and in the 2004 WS than the 2003
WS was probably due to the difference in solar radiation
during the ripening phase. Evans and De Datta (1979)
reported that high radiation during reproductive and ripening phases was closely associated with high grain yield.
Akita (1989) indicated that high temperature during the
vegetative stage reduced sink size due to reduced spikelet
production efficiency. Lower temperature during the vegetative stage and higher solar radiation during the ripening phase contributed to greater sink formation and better
grain filling in the DS than the WS (Fig. 1, Table 3).