Abstract
Growth, yield and radiation use efficiency (RUE) of hybrid maize, in response to different nitrogen rates (150, 200,
250, 300, 350 kg ha-1) were analyzed for three different locations (Faisalabad, Sargodha and Sahiwal) in Punjab,
Pakistan during 2004 and 2005. The results depicted a large yearly variations mainly attributed to more rainfall
and incidence of solar radiation in 2005. Maize hybrids respond differently for all variable under study, at all sites
except IPAR and radiation use efficiency for total dry matter RUETDM at Faisalabad. Hybrid Bemasal-202 gave
more grain yield (23-35 %) than Monsanto-919 at different locations. Similar types of differences were noted in
CGR and Final TDM. Increasing nitrogen rates had significant effects on CGR, final TDM and grain yield and
RUE. The intercepted PAR, RUETDM and RUEGY were significantly affected by hybrid potential and nitrogen
application rates. On an average RUETDM varied from 2.45 to 2.73 g MJ-1 at different locations, while RUEGY was
recorded 1.12, 1.14, and 1.03 for Faisalabad, Sargodha and Sahiwal, respectively. Total dry matter and grain
yield of different treatments was linearly related to IPAR at all location and the common regression (R2
)
accounted for 94, 68, and 80 % for TDM & 64, 34, and 95 % for grain yield at the Faisalabad, Sargodha, and
Sahiwal, respectively. It was concluded that planting of hybrid Bemasal-202 with 300 kg N ha-1 is the best
recommendation for semi-arid areas of Pakistan.
