in order to evaluate the efficiency of empirical competition models for simulation of sugar beet (beta vulgaris l.) yield at interference with redroot pigweed (amaranthus retroflexus l.), a factorial experiment based on randomized complete block design with three replications was carried out. factors were weed densities (d1=1, d2= 4, d3= 8, d4=12 and d5=16 plants m-1 of row) and relative time o...

Martin M. Williams II Corresponding author. U.S. Department of Agriculture—Agricultural Research Service, Invasive Weed Management Research, University of Illinois, 1102 S. Goodwin Ave., Urbana, IL 61801; [email protected] The critical period for weed control (CPWC) identifies the phase of the crop growth cycle when weed interference results in unacceptable yield losses; however, the effect of ...

A field experiment was conducted for two consecutive years (2003 and 2004) to study the effect of row spacing (75, 65 and 55cm) and different weed competition durations (0, 15,30,45,60 days after emergence and throughout the growth period) on weeds density and biomass and growth and yield of maize. Reducing row spacing significantly suppressed the weed density and biomass. The maximum reduction...

an experiment was conducted in 2011 to evaluate the effect of weed interference on sunflower yield in deficit irrigation and to study the grass and broadleaf weeds growth at different moisture condition. the experiment was arranged as factorial, randomized complete blocks with four replicates per treatment. treatments included different moisture conditions [40%, 60%, 80%, and 100 percent of cro...

in order to study the effect of mallow weed competition and nitrogen (n) rates on grain yield and yield components of wheat cv. chamran, a field experiment was conducted in 2009. the experiment was designed as a split-plot with three replications and additive series. the n application rates were assigned in the main-plots (50, 100, 150 and 200 kg.n.ha-1) and sub-plots consisted of target common...

introduction the lentil or masoor (lens culinaris l.) is a brushy annual plant of the legume family, grown for its lens-shaped seeds. lentil has been one of the first crops domesticated in the near east. with 26% protein, lentil is the vegetable with the highest level of protein other than soybeans, and it is an important part of people’s diet in many parts of the world. it is reported that the...

to investigate the effect of sowing density and growth habit on yield, yield components and weed community of red bean an experiment was conducted at research farm of zanjan university, during 2009. the experiment carried out using factorial-split plot design in completely randomized block arrangement with three replications. the main plots, included three red bean cultivars (goli, sayyad and d...

Use of efficient methods of weed control with as regards environmental sustainability as well as increased crop yield and also weed resistance to herbicides is essential. In order to, an experiment was conducted in 2012 in the Damavand jaban in Iran. Experiment treatments were compared in a split plot design by a randomized completely block design with 3 replication. The used variety of maize w...

ABSTRACT-Several herbicides are registered for selective weed control in sugar beet; however, no single chemical herbicide can control all weeds in beet fields. Frequently, two or more herbicides may have to be combined sequentially or as tank mixed to achieve adequate broad-spectrum weed control. In order to evaluate the effects of some combinations of broadleaf herbicides on sugar beet yield ...