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

Subject Areas : crop production

farshad abrahimpour ¹

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

References:

 Anafjeh, Z., Gh. Fathi., F. Ebrahimpour., E. Zand., and A. Chaab. 2010. Study on Competitiveness of Wild oat (Avena fatua L.) With Wheat (Triticum aesativum L.) Chamran Cultivar. Weed Science. 4 (1): 35-46. (In Persian).
 Chaab, A., G. Fathi., A. Siadat., E. Zand., and Z. Anafjeh. 2010. The interference effects of natural weed population on growth indices of corn (Zea mays L.) at different plant densities. Iranian Journal of Crop Research. 2(7): 391-400. (In Persian).
 Cousens, R., A.G. Barnett., and G.C. Barry. 2003. Dynamics of competition between wheat and oats. I. Effects of changing the timing of phonological events. Agronomy Journal. 95.
 Cousens, R., N.C.B. Peters., and C.J. Marshall. 1984. Models of yield loss- weed density relationship. International Symposium on Weed Biology, Ecology and Systematic. PP. 367-374.
 Cudeny, D.W., L.S. Jordan., J.S. Holt., and J.S. Reints. 1989. Competitive interactions of wheat (Triricum aesitvum) and wild oat (Avena fatua) grown at different densities. Weed Science. 37: 538- 543.
 Cudney, D.W., L.S. Jordan., and A.E. Hall. 1991. Effect of wild oat (Avena Fatua) infestations on light interception and growth rate of wheat (Triricum aestivim). Weed Science. 39: 175- 179.
 Hasanzadeh Dlouie, M., H. Rahimian Mashhadi., Nassiri M. Mahallati., and G. Nour-Mohamadi. 2002. The competitive effects of wild oat (Avena ludoviciana L.) on winter wheat (Triticumm aestivum L.) at differnt densities. Iranian Journal of Crop Science. 2(4): 116-128. (In Persian).
 Iqbal, J., and D. Wright. 1997. Effects of nitrogen supply on competition between wheat and three annual weed species. Weed Science. 37: 391- 400.
 Jafar-Nejad, A. and H. Rahimian. 2003. Study of competition between wheat (Triticumm aestivum) cultivars, wild oat (Avena fatua) and Rocket (Eruca sativa). Journal Agricultural. Science. Natural Resource. 1: 39-55. (In Persian).
 Kennet, J., and K.J. Kirkland. 1993. Spring wheat (Triticum aestivum) growth and yield as influenced by duration of wild oat (Avena fatua) competition. Weed Technology. 7: 890- 893.
 Rastgoo, M., A. Ghanbari., M. Banaian Aval., and H. Rahimian. 2002. Investigation of growth indices of wild mustard and autumn wheat in response to amount and time nitrogen consume. Journal of Agricultural Science. 1: 51-63. (In Persian).
 Rooney. J.M. 1991. Influence of growth from of Avena fatua L. on the growth and yield of Triticum aestivum L. Journal of Applied Biology. 118: 411-416.
 Satorre, E.H. and R.W. Snaydon. 1992. A comparison of root and shoot competition between spring cereals and Avena fatua L. Weed Research. 32: 45- 55.
 Spandi, E., B.R. Durgan., and D.W. Miller. 1997. Wild oat (Avena fatua) control in spring wheat (Triticum aestivum) and barely (Hordeum vulgare) with reduced rates of post emergence herbicides. Weed Technology. 11: 591- 597.
 Van Heemst. J.D.J. 1988. Plant data values required for simple crop growth simulation models: review and bibliography. Simulation Report CABO- TT no. 17, Agricultural University, Wageningen, the Netherlands.