عنوان مقاله [English]
نویسندگان [English]چکیده [English]
To evaluate the interaction of nitrogen rates and Nicosulfuron dosages on corn weeds and corn yield, a factorial experiment based on randomized complete blocks design was conducted at Research Fields of University of Tehran in 2009. The nitrogen application rates were 0, 180, 270 and 360 kg ha-1 with nicosulfuron herbicide being applied at 0, 20, 40, 60 and 80 g ai ha-1. Each treatment combination was replicated three times. The result illustrated that all weed spices, except Russian Knapeweed (Acroptilion repens) showed a positive response to the highest level of nitrogen fertilizer (i.e 360 kg ha-1) where weeds dry weights increased markedly. The lowest weed biomass production was observed with herbicide dosages of 60 or 80 g ai ha-1 and nitrogen application rate of 180 or 270 kg ha-1. The more nitrogen fertilizer used (i.e. 360 kg ha-1), the higher herbicide dosages needed to effectively control the weeds as more resource might be available for their growth. The responses of corn yield to N rate and herbicide dose were similar to those of weeds as there was a close relationship between weed biomass productions and corn yields. Overall, given the economical costs and environmental consequences of fertilizer and herbicide applications, one may recommend a N application rate of 270 kg ha-1 with 60 g ai ha-1 nicosulfuron in terms of both acceptable weed control ( almost 85%) and obtaining a high corn yield ( almost 11000 kg ha-1).in additional to achieve 11000 kg ha-1 should use 180 kg ha-1 N fertilizer with 70 g ai ha-1 or 360 kg ha-1N fertilizer with 80 g ai ha-1.
Ampong-Nyarko, K. and de Datta, S. K. 1993. Effects of nitrogen application on growth, nitrogen use efficiency and rice-weed interaction. Weed Res. 33:269–276.
Baghestani, M. A., zand, E., Soufizadeh, S., Eskandari, A., Pourazar, R., Veysi, M. and Nassirrzadeh, N. 2007. Efficacy evaluation of some dual purpose herbicide to control weeds in maize (Zea mays L.).Crop Protection.26:936-942.
Blackshaw, R. E. and Brandt, R. N. 2008. Nitrogen fertilizer rate effect on weed competitiveness is species dependent. Weed Sci. 56:743-747.
Blackshaw, R. E., O’Donovan,J. T. Harker,K. N. Clayton,G. W. and Stougaard, R. N. 2006. Reduced herbicide doses in field crops: a review. Weed Biol. Manag. 6:10–17.
Blackshaw, R. E., Brandt, R. N., Janzen, H. H., Grant,C. A. and Derksen, D. A. 2003. Differential response of weed species to added nitrogen. Weed Sci. 51:532–539.
Blackshaw, R. B., Semach,G. and Janzen, H. H. 2002. Fertilizer application method affects nitrogen uptake in weeds and wheat. Weed Sci. 50:634-641.
Carlson, H. L. and Hill.J. E. 1986. Wild out (Avena fatua) competition with spring wheat: Effects of nitrogen fertilization. Weed Sci. 34:29-33.
Cathcart, R. J. and Swanton, C. J. 2003. Nitrogen management will influence threshould values of green foxtail (Setaria viridis) in corn. Weed. Sci. 51:975-986.
Cathcart, R. J., Chandler, K. and Swanton, C. J. 2004. Fertilizer rate and response of weeds to herbicides. Weed Sci. 52:291–296.
DiTomaso, J. M. 1995. Approaches for improving crop competitiveness through the manipulation of fertilization strategies. Weed Sci. 43:491–497.
Kim, D. S., Marshall, E. J. P., Caseley, J. C. and Brain, P. 2006. Modeling interactions between herbicide and nitrogen in terms of weed response. Weed Res. 46:490–501.
Kim, D. S., Marshall, E. J. P., Caseley, J. C. and Brains, p. 2006. Modelling the effects of sub-lethal doses of herbicide and nitrogen fertilizer on crop–weed competition. Weed Res.46:492-502.
Kropff, M. J. and Van Laar, H. 1993. Crop weeds interaction. CAB international, wallingfond UK.
Kropff, M. J. and Lotz, L. A. P. 1992. Systems approaches quantify crop – weed interactions and their application in weed management Agricultural systems. Weed Sci. 40: 265-282.
Liebman, M. and Davis, A. S. 2001. Integration of soil, crop and weed management in low-external-input farming systems. Weed Res. 40: 27–47.
Liebman, M. 1989. Effect of nitrogen fertilizer, irrigation, and crop genotype on canopy relations and yields of an inter/weed mixture. Field Crops Res. 22:83-100
Loomis, R. J. and Connar, D. J. 1992. Soil management. Pages 319-348.in crop ecology. Productivity and management in agriculture system.Cambridag Univ.press, New York.
Mithila, J., Swanton, C. J. Blackshaw,R. E. cachcart, R. J. and Hall,J. C. 2008. Physiological bassis for reduced Glyphosate efficacy on weeds growth under low soil nitrogen. Weed Sci. 56.12-17.
Rajcan, I. and Swanton, C. J. 2001. Understanding maize-weed competition: resources competition, light quality and the whole plant. Field Crops. Res. 71:139–150.
Swanton, C. J., Shrestha, A., Roy, R. C., Ball-Coelho,B. R. and Knezevic, S. Z. 1999. Effect of tillage systems, N, and cover crop on the composition of weed flora. Weed Sci. 47:454–461.
Teyker, R. H., Hoelzer, H. D. and Liebl, R. A. 1991. Maize and pigweed response to nitrogen supply and form. Plant Soil. 135:287–292.