Effect of sowing date and various seeding rate on some traits and growth of triticale in Rasht climate

To investigate the effect of sowing date and seeding rate on Triticale growth characteristics, a field experiment was carried out in the Rice Research Institute of Iran, during 2008-2009. The experiment was conducted as a RCBD based split-plot design with three replications. Experimental treatments included: Four sowing date (Sept. 21, Oct. 1, Oct. 10, and Oct. 20) as main plot and four plant density (275, 350, 425 and 500 plant/m2) composed of as sub plots, respectively. Measured traits, including yield, leaf and shoot dry weight and leaf area and growth Indicators as leaf area index (LAI), crop growth rate (GGR), relative growth rate (RGR) and net assimilation rate (NAR). Results indicated that interaction of sowing date × sampling time was significant effect on height, leaf dry weight and leaf area index. The Highest values of height (120.7 cm), leaf dry weight (11.21 g.m-2.day-1) were obtained in 21 Sept. in flowering time. Shoot dry weight significantly affected by triple interaction of sowing date × seeding rate × sampling time, and maximum shoot dry weight achieved in seeding rate 200 Kg.ha-1 in 21 Sept. The highest (23.5 g.m-2.day-1) and lowest crop growth rate (11.5 g.m-. day-1) were found on 21Sept. in seeding rate (200 Kg.ha-1) and 21 Oct. in seeding rate (110 Kg.ha-1), respectively.While, the relative growth rate and net assimilation rate reached their maximum with delay in sowing date and reduced seed rate (21 Oct. and 110 Kg.ha-1). In general, according to the results, The highest grain yield (5893 kg.ha-1) was obtained in the earlier sowing date and greater quantities of seed 21 Sept. and seeding rate 200 kg.ha-1) due to higher crop growth rate, leaf area index, shoot and leaf dry weight and plant height.