An experiment was conducted in Gonbad, Iran between
2005 and 2007 to study the variation in flower and pod number under high
temperature stress and supplemental irrigation. The experiment was a randomized
complete block design arranged in split plot. Two cultivars of spring
type canola (Hyola401 and RGS003) as subplots and 5 sowing dates as main
plots were used. The number of flowers on the main racemes that produced
pods was 57 and 49% for Hyola401 and RGS003, respectively. Seed yield
was positively related to pods per plant in the two cultivars with 38
and 64% of the variation for Hyola 401 and 71 and 84% of that for RGS003
under irrigation and rainfed conditions, respectively. The relationship
between the number of flowers and pods in the main racemes was positively
strong with 88 and 72% of the variation for Hyola401 and 88 and 78% of
that for RGS003 under irrigated and rainfed conditions, respectively.
High temperature; particularly in the late sowing dates accelerated the
rate of plant development and reduced the length of the flowering period
and also the number of flowers and pods. With a delay in sowing date;
flowers and pods per main raceme decreased from 53 to 12 flowers and 34
to 2 pods over two years. Obtained results showed that a great proportion
of the variations in flower and pod formation were related to environmental
stress during the flowering. Quantitative relationships between flower
and pod number with seed yield, crop phenology and temperature pattern
during the critical period of flowering could be useful for crop modeling.
Abolfazl Faraji, Nasser Latifi, Afshin Soltani and Amir Hossain Shirani Rad, 2008. Effect of High Temperature Stress and Supplemental Irrigation on Flower and Pod Formation in Two Canola (Brassica napus L.) Cultivars at Mediterranean Climate. Asian Journal of Plant Sciences, 7: 343-351.