Common Cocklebur Competition in Forage Maize

Abstract

Common cocklebur is a new weed in irrigated maize grown for forage in the hot, dry region of northwest Pakistan. We conducted experiments in the Khyber Pakhtunkhwa Province, Peshawar, Pakistan, during 2006 and 2007 to evaluate the interaction of common cocklebur density and maize density on biomass, leaf area index (LAI), and plant height of forage maize. Seven common cocklebur densities (0, 2, 4, 6, 8, 10, and 12 plants m−2) in maize planted at four densities (5, 7.5, 10, and 12.5 plants m−2) were evaluated. An ANOVA for both years revealed significant main effects and interactions for all variables. Regression of measured variables against common cocklebur density showed that maize biomass declined linearly as common cocklebur density increased from 0 to 12 plants m−2, with an increasing rate of decline for high maize densities and low maize densities. Combined data for all maize densities revealed that the relationship between maize biomass and common cocklebur biomass fit a linear function, with 1.28 to 1.35 kg ha−1loss in maize biomass for each kilogram per hectare increase in common cocklebur biomass from about 1,500 to 3,200 kg ha−1. Above 8 to 10 common cocklebur plants m−2, weed biomass declined, presumably due to intraspecific competition. An increase in common cocklebur density decreased maize LAI about 0.15 to 0.3 units for each additional common cocklebur plant per square meter in 2006, and 0.11 to 0.24 units in 2007. Common cocklebur LAI increased in a linear fashion as density of the weed increased. Results suggest that the effect of common cocklebur interference on maize biomass was associated with a change in allocation of resources, resulting in increased crop height growth at the expense of a reduction in LAI and presumably potential light interception by the crop as common cocklebur density increased.

Comparison of Different Weedicides on Multi-cut Sorghum Sudan Grass Hybrid for Productivity Enhancement and Control of Grassy Weeds

“…Decrease in plant height at higher weeds intensity may be due to more revelry between inter-species for the same assets. These conclusions were in concurrent with that of Hussain et al, 2011 who reported that the height of maize fodder reduced by increased intensity (beyond 6 plant m -2 ) of Xanthium strumarium. Celebi et al, 2010 observed that alfalfa (Medicago sativa) height decreased with increase of weed intensity.…”

Wild sunflower interference in common bean fields in the Central Rift Valley of Ethiopia

“…As common bean density increased in both locations, the wild sunflower dry biomass decreased substantially, even at the highest wild sunflower density of 24 plants m −2 (Table 2). In maize, increasing maize seeding densities positively reduced Xanthium strumarium L. dry biomass (Hussain et al., 2011). In soybeans, increasing crop density significantly reduced Amaranthus palmeri biomass, particularly at early stages of the weed's establishment (Korres et al., 2019).…”

Mesotrione use for selective post-emergence control of glyphosate-resistant Conyza spp. in black oats

“…Herbicide usage represents an inexpensive, efficient option for weed management in crops and pastures, delaying the onset of the critical period of weed interference and increasing productivity (Hussain et al, 2011). Weed allelopathy and competition for resources are known to decrease biomass production in forage species, from establishment to regrowth stages.…”