Study of light extinction coefficient and leaf area index affecting in photosynthesis on delay planting in genus Brassica (B. napus, B. rapa and B. juncea)

摘要

An experiment was conducted in 2006 at the Agricultural Research Station, Isfahan. The purpose of this study was to evaluate the effects of delay planting on light absorption properties and the effect on yield in canopy of Brassica. A split-plot layout within randomized complete block design with three replications was used. Main plots were two planting dates (27 September was normal cropping and 11 November was delay cropping), sub-plots were inclusive of species B. napus (Option 500, Hyola 330, Hyola 401, Sargol and RGS 003 were spring types and Modena, SLM 046, Opera and Zarfam were winter types), two varieties of B. rapa (Echo and Park land) and one variety of B. juncea (Land race). The results showed that effect of cropping date on K, LAI and LAIp was decreased significantly. Effect of variety on K, LAI and LAIp was more significant. Reaction of cropping date and variety was more significant on K, LAI and LAIp. Positive and significant correlation was observed between the amount of K with LAI, LAIp and biological yield; also there was positive and significant correlation between the amount of LAIp with grain and biological yield. The varieties, namely, SLM 046 and RG 003 were found best for delay cropping due to their high quantity of K, LAI, LAIp, seed and biological yields.