Growth indices variations of wheat in response to various density and sowing dates of wild oat

Subject Areas : crop production

farshad abrahimpour ¹ ( payame noor university )

Received: 2010-07-01 Accepted : 2011-07-30 Published : 2010-10-09

Keywords: Interference, Leaf Area Index, Leaf Area Ratio, Net Assimilation Rate and Relative Growth Rate.,

Abstract :

To study the effect of sowing date and density of wild oat on growth and development of wheat an experiment was conducted in randomized complete block in four replications in forms of split-plot in frame of basic design in 2004-2005 and 2005-2006 at Farm Experimental-Research Islamic Azad University of Shooshtar, Khouzestan. Treatments including sowing date of wild oat (16, 22, 26 November, 1, 6, 11, 16, 22, and 26 December) as main plot, and six densities (0, 20, 40, 60, 80 and 100 plants m-2) as subplot was conducted in competition with winter wheat on December 6th . The results analysis of growth indices of wheat indicated that with increase growth day degree (GDD), the best status of total dry matter (TDM), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area index (LAI), leaf area ratio (LAR), specific leaf area (SLA) and leaf weight ratio (LWR) belonged to free plots and the latest sowing date (26 December). In addition, by increasing of density or sowing date of wild oat before wheat decreased total dry matter 61 and 70%, crop growth rate 45 and 58%, relative growth rate 57 and 89%, net assimilation rate 92 and 100%, and leaf area index 97 and 100% than density 0 plant m-2 and the later sowing date

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