Growth parameters enhancing the competitive ability of corn (Zea mays L.) against weeds

Abstract

In order to determine which plant growth parameters enhanced the competitive ability of corn (Zea mays) against weeds, a field study was conducted at the Agricultural Research Farm, Razi University, Kermanshah, Iran. A factorial experiment based on a randomized complete block design with four replications was used. The factors consisted of weed treatments (including weedy and weed‐free during all of the growing season) and corn cultivars (including KSC 260, KSC 302, KSC 500, KSC 647, KSC 700, and KSC 704). The plant growth parameters under study consisted of height, plant dry weight, the number of tillers, leaf area index, specific leaf area, crop growth rate, relative growth rate, and net assimilation rate. The results indicated that the cultivars, KSC 700 and KSC 704, had the highest competitive ability and the cultivars, KSC 302 and KSC 260, had the lowest competitive ability. The competitive ability of the cultivars, KSC 500 and KSC 647, was intermediate. All of the growth parameters under study, except the number of tillers, indicated a positive and significant correlation with competitive ability, and the relative growth rate showed the highest correlation. Variable selection using the stepwise multiple linear regression method revealed that, among the growth parameters under study, both the relative growth rate and the specific leaf area were the best predictors of corn cultivar competitiveness.