Evaluating the Competitive Ability of Maize (Zea mays L.) Genotypes against Weeds under Different Nitrogen Rates

Document Type : Research Article

Authors

Shoushtar Branch, Islamic Azad University

Abstract

Introduction: Maize is among the world's three most important cereal crops. Weeds are one of the most important factors that reduce maize production. They cause important yield losses worldwide with an average of 12.8% despite weed control applications and 29.2% in the case of no weed control. Weeds compete with crops when they remove a portion of a resource from a shared resource pool, leaving the crop with less of the resource than is needed for optimum growth. Competition may occur for water, creating or exacerbating water stress. It may occur for nutrients such as nitrogen, leading to chlorosis, leaf senescence and yield loss. Increasing the ability of a crop to compete with weeds has been considered an approach to improving weed management in recent years. The importance of weed competition in maize depends on the maize genotype, weed species, crop growth stage, the weed density, the level of water, and nutrient stress. Some crops can significantly suppress weeds by their ability to grow faster than weeds or to endure greater sowing densities. The plant competitive ability can be expressed in the following two modes: First, the crop weed suppressive ability (WSA) that results in the reduction of weed biomass and second, the crop tolerance ability (CTA) to tolerate weed effects and to have high yields at the same time. Crop tolerance to weed interference aims to improve stability of yield and quality in weedy fields, whereas weed-suppressive ability targets the long-term management of weed populations by reducing seedbank size. Several traits, including the growth intensity in the initial developmental stages, rapid development of a high leaf structure, the plant height, maximum LAI, rate of canopy closure, height of LAI, and leaf architecture, may improve weed-suppressive ability and dent maize tolerance to weed interference. Therefore, the objective of this experiment was to evaluating the competitive ability of maize (Zea mays L.) genotypes against weeds under different nitrogen rates.
Materials and Methods: Experiments were carried out on clay loam soil with low organic matter content (less than 1%) and a pH of 2.9 at south west Iran in 2011-2012 growing season. The experiment site had a hot climate with a moderate winter and dry and hot summer. Treatments consisted of a split-plot with randomized complete blocks design and three replicates. Nitrogen rates (0, 90, 180 and 260 kgNha-1) were the main plots and four dent maize hybrids Sc.704, DKC6589, Mobeen and Sc.640 were planted in sub-plots. DKC6589, Mobeen and Sc.640 are an early-season hybrids, whereas Sc.704 is relatively late-season hybrid. Plots consisted of 6 maize rows (distance between and within the rows 75 and 18 cm, respectively) and 6 m long. Maize hybrids were sown on 1st Jun. Fields received 100 kgPha-1 and 150 kg K ha-1. The P and K were supplied in the form of single superphosphate and potassium sulfate, respectively. Nitrogen treatments were applied in two equal splits as urea (46% N) at two and six weeks after planting by side placement. Each plot was divided into two parts hypothetical. One part was maintained weed-free and another weedy for the all maize duration growth stages. In weed-free parts, weed removal was started immediately after crop emergence and the plots were kept weed-free for different growth stage durations until physiological maturity of maize. The experiment was properly monitored and irrigated whenever water was needed. Weed plants were harvested at the R1 (silking) growth stage of maize using 0.5×0.5m quadrate, and weed biomass obtained by drying tissues at 68 C to constant mass. Weed density and species also, determined. Interference of maize and weed was quantified by calculating weed index (WI), weed interference tolerance index (WITI) and competition index (CI(. Statistical analysis was made using the SAS statistical software. Differences between traits means were assessed using Duncan's Multiple Range Test.
Results and Discussion: The percent loss of grain yield, 100 grain weight, biological yield and grain number per rows under weed interference conditions were 21.7, 5.3, 24 and 10%, respectively. Grain yield reduction in weedy plots was resulted from decreasing grain number per rows and biological yield. Negative impact of weeds on maize yield was enhanced under higher rates of nitrogen. When maize competed with weeds, the reduction of grain yield at 260 kg N ha-1 treatment was more compared to 180 kg N ha-1maize. Maize genotypes were different in response to weed competition. The highest weed tolerance interference index was obtained in DKC6589 line due to higher grain yield in both weedy and weed-free plots. Competition index was higher in Sc. 704 and DKC6589 than other genotypes. Although Mobeen and Sc.640 hybrids had lower grain yield reduction trend under weed competition conditions, but DKC6589 and Sc.704 showed a high grain yield potential and high ability to withstand weed competition.

Keywords


1- Abouziena H.F., El-Karmany M.F., Singh M., and Sharma S.D. 2007. Effect of nitrogen rates and weed control treatments on maize yield and associated weeds in sandy soils. Weed Technol., 21:1049-1053.
2- Azeez J.O., and Adetunji M.T. 2007. Nitrogen use efficiency of maize genotypes under weed pressure in tropical Alfisol in northern Nigeria. Tropiculture, 25 (3): 174-179.
3- Barker D. C., Knezevic S. Z., Martin A. R., Walters D. T., and Lindquist J. L. 2006, Effect of nitrogen addition on the comparative productivity of corn and velvetleaf, Weed Science, 54: 354-363.
4- Blackshaw R.E., Brandt R.N., Janzen H.H., Entz T., Grant C., and Derksen D.A. 2003. Differential response of weed species to added nitrogen. Weed Science, 51: 532-539.
5- Booth B., Murphy S.D., and Swaton C.J. 2003. Weed ecology in influence threshold values of green publishing. Canada. P. 303.
6- Costa C., Dwyer L.M., Stewart D.W., and Smith D.L. 2002. Nitrogen effects on grain yield and yield components of leafy and non-leafy maize genotypes. Crop Science, 42: 1556–1563.
7- Gastal F., and Lemaire G. 2002. N uptake and distribution in crops: an agronomical and ecophysiological perspective. Journal of Experimental Botany, 53:789-799.
8- Gholamshahi M., Ghanbari A., Saffari M., Izadi Darbandi E., and Samaie M. 2016. Effect of nitrogen fertilizer on weeds growth and emergence and yield and yield components of corn (Zea mays L.). Journal of Plant Protection, 6: 416-425. (In Persian with English abstract)
9- Harbur M.M., and Owen M.D. 2006. Influence of relative time of emergence on nitrogen responses of corn and velvetleaf. Weed Science, 54, 917-922.
10- Inamullah N., Rehman N.H., Shah M., Arif M.S., and Mian I. 2011. Correlations among grain yield and yield attributes in corn hybrids in various nitrogen levels. Sarhad Journal of Agriculture, 27(4): 531-538.
11- Izadi F., Bagheri A.R., and Miri H.R. 2017. The effect of nitrogen and weeds interference on millet (Panicum miliaceum) yield and yield components. Journal of Plant Ecophysiology. 5 (12): 85-94. (In Farsi with English abstract)
12- Mirshekari B., Shahi Ahmad Abad H., Valad Abadi A., and Dabbage Mohammadi Nasab A. 2009. Response of yield related traits in three grain corn hybrids to weed competition periods. Crop Ecology, 5 (2): 89-99. (In Persian with English abstract)
13- Mirshekari B., Farahvash F., and Jvanshir A. 2010. Phenology and grain yield of maize cv. hybrid 604 at interference with Lambsquarters (Chenopodium album L.). Seed and Plant Production Journal, 4 (2-26): 365-385. (In Persian with English abstract)
14- Modhej A., and Kaihani A. 2013. Effect of nitrogen rates on canola (Brassica napus L.) and wild mustard (Sinapis arvensis L.) competition. Iranian Journal of Field Crop Research, 11 (2): 357-364. (In Persian with English abstract)
15- Mohammaddoust Chamanabad H., Hemmati K., Asghari A., and Barmaki M. 2014. Effect of nitrogen and weed interference on some agronomic traits, five cultivars wheat yield and yield components. Agriculture and Sustainable Production Science, 23 (4): 131-140. (In Persian with English abstract)
16- Mohammadi V., Kambouzia J., Zand E., Soufizadeh S., and Rahimi Moghaddam S. 2017. The effect of different levels of N fertilizer on yield and yield components of maize (Zea mays L.) under competition with different densities redroot pigweed (Amaranthus retroflexus L.) and millet (Panicum miliaceum L.). Iranian Journal of Field Crops Research, 47 (3): 437-449. (In Persian with English abstract)
17- Oerke E.C., and Steiner U. 1996. Absch.tzung der Ertragsverluste im Maisanbau. In: Ertragsverluste und Pflanzenschutz Ð Die Anbausituation f.r die wirtschaftlich wichtigsten Kulturpflanzen-.German Phytomedical Society Series, Band, Eugen Ulmer Verlag, Stuttgart. 6: 63-79.
18- Safahani Langroudi A. R., and Kamkar B. 2009. Field screening of canola (Brassica napus) cultivars against wild mustard (Sinapis arvensis) using competition indices and some empirical yield loss models in Golestan Province, Iran. Crop Protection, 28 (7): 577-582.
19- Sarabi V., Nassiri Mahalati M., Nezami A., and Rashed Mohassel M.H. 2011. Effect of the relative time of emergence and the density of common lambsquarters (Chenopodium album) on corn (Zea mays) yield. Weed Biology and Management, 11 (3): 127-136.
20- Siadat A., Modhej A., and Esfahani M. 2013. Cereals. Jahad Daneshgahi Mashhad. Iran. Pp: 372. (In Farsi)
21- Silva P.S.L., Silva P.I.B., Silva K.M.B., Olivera V.R. and Pontes Filho F.S.T. 2011. Corn growth and yield in competition with weeds. Planta Daninha, Viçosa-MG, 29 (4): 793-802.
22- Soufizadeh S., AghaAlikhani M., Bannayan M., Zand S., Hoogenboom G., and Manschadi A. 2011. The effect of nitrogen on yield and yield components of maize (Zea mays L.) under competition with redroot pigweed (Amaranthus retroflexus L.) and proso-millet (Panicum miliaceum L.). Journal of Ecophysiology, 1 (2): 17-33. (In Persian with English abstract)
23- Thomas J.M., Weller S.C., and Ashton F.M. 2002. Weed Science. Principles and practices. 4th ed. United States of America.
24- Vafabakhs F. 1995. The effect of different control methods on weed competition, grain yield and yield component of grain corn. MSc thesis. Ferdousi Mashhad University. (In Persian with English summery)
25- Vengris J., Colby W.G., and Drake M. 1955. Plant nutrient competition between weeds and corn. Agronomy Journal, 47: 213-216.
26- Wall D. 1994. Weed research report. Morden, Manitoba: Agriculture and Agri-Food Canada. p.20.
27- Yim F.S., Williams M.M., Pataky J.K., and Davis A.S. 2009. Principal canopy factors of sweet corn and relationships to competitive ability with wild-proso millet (Panicum miliaceum). Weed Science, 57 (3): 296-303.
28- Williams M.M., Boydston R.A., Davis A.S., and Pataky Y.S. 2007. Competitive interactions between sweet corn (Zea mays) hybrids differing in canopy architecture and wild proso millet (Panicum iliaceum). Proceeding of 14th EWRS Symposium, Hamar, Norway, pp. 84.
29- Zand E., Kouchaki A. R., Rahimian Mashhadi H. R., Deyhimfard R., Soufizadeh S., and Nasiri Mahalati M. 2005. Studies on some ecophysiological traits associated with competitiveness of old and new Iranian bread wheat (Triticum aestivum L.) cultivars against wild oat (Avena ludoviciana L.). Iranian Journal of Field Crops Research, 2 (2): 160-174. (In Persian with English Abstract).
30- Zarei Z., Modhej A., and Lorzadeh S. 2014. Effect of integrated weed management (chemical+mechanical) on corn grain yield hybrid SC.700. Iranian Journal of Field Crops Research, 12 (1): 73-79. (In Persian with English abstract)
31- Zerner M.C., Gill G.S., and Vandeleur R.K. 2008. Effect of height on competitive ability of wheat with oats. Agronomy Journal, 100: 1729-1734.
32- Zimdhal R. L. 1993. Fundamentals of weed science. Academic Press, Inc. Colorado State University, Fort Collins, Colorado.