Effect of Planting Date on Physiological and MorphologicalCharacteristics of Four Canola Cultivars in Yasouj

In order to study the physiological and morphological characteristics of canola cultivars at different planting dates, an experiment was carried out in 2008-2009 at the Agriculture Research Station of Yasouj. A factorial with Randomized Complete Block Design with four replications was conducted. Four planting dates (September 12, September 22, October 2 and October 12) and four cultivars (Zarfam, Okapi, Elite and SLM-046) were used in this study. Results showed that cultivars and planting dates had significant effects on more characteristics. In addition, interaction of planting date and cultivar was significant on plant height, height to lowest silique, number of branches, growth indices and grain yield. Zarfam and Elite cultivars had lower initial fluorescence (Fo) and higher maximum fluorescence (Fm) and photochemical capacity of photosystem II (Fv/Fm) than Okapi and SLM-046 cultivars. Elite cultivar at September 12 planting date had the highest plant height (173 cm) and height to lowest silique (87.5 cm) and Okapi cultivar at October 12 planting date showed the lowest plant height (91 cm) and height to lowest silique (43.7 cm). At September 12 planting date, Elite cultivar had the greatest leaf area index (5.21) and grain yield (5231 kg/ha). At other planting dates, Zarfam cultivar because of priority in leaf area index, crop growth rate and total dry matter have the greatest grain yield than other cultivars. In general, seems at September 12 planting date, Elite cultivar and for delayed sowing, Zarfam cultivar had better reaction than other cultivars.