Document Type : Research Paper
Key Laboratory of Agricultural Water Resources, Centre for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Hebei 050021.
Crop depends on its canopy to intercept solar radiation to drive both assimilation
and water, nutrient absorption for its growth. Field experiments, involving three
sowing time and three sowing rate, were conducted at Luancheng Station to
investigate the effects of canopy size and development on crop growth and radiation
use efficiency (RUE) of winter wheat during 2009/2010 and 2010/2011 growing
seasons. The results showed that the maximum effects of sowing time on the
phenological development occurred between emergence and elongation, and which
was 186.0 and 162.3 doC thermal time difference during 2009/2010 and 2010/2011,
respectively. Sowing time and sowing rate significantly affected above-ground
biomass accumulation and RUE. Results showed that optimized sowing time and
sowing rate has the potential to improve yield of winter wheat and radiation use
efficiency. RUE during pre-anthesis was lower than that during post-anthesis,
especially for the delayed sowing treatments which was mainly caused by the lower
dry matter mobilization (DMM) and dry matter mobilization efficiency (DMME).
Compared with the normal sowing time treatment, the delayed sowing time
treatments had the lower DMM and DMME which indicated that the different
sowing date would affect the duration of growth and then the RUE.