اثر آرايش كاشت و تراكم بوته بر شاخص‎هاي رشد و كارآيي مصرف تابش دو رقم كلزاي بدون گلبرگ و گلبرگ‎دار

Effect of planting pattern and plant density on growth indices and radiation use efficiency of apetalous flowres and petalled flowers rapeseed (Brassica napus L.) cultivars

In order to evaluate the effects of plant density and planting pattern on yield, yield components of apetalous flowers and petalled rapeseed, a field experiment was conducted in Rice Research Institute of Iran located in Rasht in 2005- 2006. The experimental design was arranged as a split plot-factorial in a randomized complete block with three replications in which, planting pattern (rectangular and square) assigned to main plot and two rapeseed cultivars (petalled = Hyola 401 and apetalous = Hylite 201) and plant densities (33, 67 and 133 plants per unit area) as factorial in sub-plots. Results showed that there were significant differences between cultivars, plant density and planting patterns in growth indices and radiation use efficiency (RUE). At the flowering, the leaf area index in apetalous cultivar was 3% greater than the petalled rapeseed (3.22 and 3.12, respectively). Dry Matter of apetalous rapeseed was 11% higher than the petalled rapeseed (1441 and 1280 g/m2, respectively). Similar results were obtained for crop growth rate (CGR) and net assimilation rate (NAR) (1.5 and 23%, respectively). Maximum LAI and TDM were obtained earlier with the high plant density. Leaf area index, Dry Weight, CGR and NAR in square planting pattern were higher than the rectangular planting pattern. Radiation use efficiency in apetalous rapeseed was 9.2% higher than the petalled cultivar (2.38 and 2.16 g/Mj) which caused 14.6% increase in grain yield.