Competitive ability of canola cultivars (Brassica napus L.) against their natural weed populations

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Research Paper 01/03/2013
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Competitive ability of canola cultivars (Brassica napus L.) against their natural weed populations

Hashem Aminpanah, Saeed Firouzi, Abouzar Abbasian
Int. J. Biosci.3( 3), 121-128, March 2013.
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To determine the competitive ability of canola cultivars against natural weed populations, a field experiment was conducted in northern Iran, Mazandaran province, during 2010–2011 growing season. The experiment was arranged as a factorial randomized complete block design with three replications. Factors were four canola cultivars (Hayola-420, Hayola-308, RGS-003 and PF) and two weed management regimes (weed-free condition and weedy condition). Averaged across weed management regimes, grain yield of RGS-003 was significantly higher than that of other canola cultivars. Weed interference significantly reduced canola grain yield and yield components, regardless of canola cultivar. The reduction in grain yield by weed competition was 15.5% for Hayola-308, 11.1% for RGS-003, 9.8% for PF and 6.6% for Hayola-420. This indicates that canola cultivar had different ability to withstand competition, which Hayola-420 had the highest (43.39) ability to withstand competition, followed by PF (40.28), RGS-003 (38.94) and Hayola-308 (34.54). The rank order of competitive ability of the canola cultivars was RGS-003 = Hayola-420 > PF = Hayola-308. Canola grain yield was positively (P < 0.01) correlated with silique number on main stem, grain number in silique of main stem, silique number on side branches, 1000 grain weight, and canola biomass, but negatively (P < 0.01) correlated with weed biomass, and not correlated with grain number in silique of side branches, plant height and harvest index. In conclusion, these results confirmed that there was a significant difference among canola cultivars for competitive ability against weeds.


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