Investigation of seed moisture content at harvest time as an empirical index for improving viability and seed vigor of two oil-seed rape cultivars.

In order to evaluate the role of seed moisture content (SMC) at harvest time of two oil-seed rape cultivars (Hyola 401 and Hyola 308) in seed viability and vigour, a laboratory investigation was conducted at Seed and Plant Certification and Registration Institute (SPCRI) in Karaj, Iran. Seed samples provided from 2007 and 2008 growing season of a trade oil-seed rape field which is located at Dezful region, Khuzestan province, Iran. Enough seed samples were prepared from each cultivar contained 10, 15, 25 and 35 percent of moisture at harvest time and studied for several germination indices. Experimental data were arranged in a 2×4 factorial experiment based on completely randomized design with three replications. Results showed that the highest primary and final germination percent for both cultivars were earned at 15% of SMC. Also the highest rate of mean daily germination, seedling fresh weight, seedling dry weight and seedling vigour index were obtained at 15% of seed moisture content. Meanwhile it was found that Hyola 401 cultivar was superior to Hyola 308 in all treatments and both year for primary and final germination percent. Altogether Since the seed quality has been affected by experimental condition, harvesting two investigated cultivars of oil-seed rape with 15% of SMC is recommended.