weed's behaviors differ in a multiweed-crop competition system compare to a mono weed-crop competition system. the present investigation was carried out in mashhad, iran, to study the effect of weeds, which emerged naturally in a multi species community along side with melon, on quantitative and qualitative characteristics of the crop during 2007. thirty five plots were selected randomly in a g...

Returns of an individual enterprise in the short term are usually measured through a gross margin budget, which is determined by subtracting factors such as the cost of weed control (both herbicide and non-herbicide) and other inputs (eg seed and fertiliser) from gross income (calculated as crop yield multiplied by grain price). Crop yield is directly influenced by weed density, which itself is...

in order to compare different weed management methods in sugar beet, an experiment was conducted at the agricultural research station, ferdowsi university of mashhad, iran, during 2006-2007 and 2007-2008. the experiment designed as a complete randomized block with three replications. the treatments including: metamitron + fenmedifam, metamitron + fenmedifam + rotation, metamitron + cultivation,...

abstract use of empirical competition models is one of approaches in integrated weed management strategies. in order to investigation of this approach in simulation of yield loss of bean (phaseolus vulgari. l.) caused by jimson weed (datura stramonium l.) interference, an experiment was conducted in national bean research station, in khomein, in 2007. the experiment design was randomized comple...

this study was carried out to evaluate empirical models of competition, as two separated experiments based on a randomized complete block design with 3 replications at agricultural faculty of bu-ali sina university, in 2008-2009. in both experiments, alvand and sayson cultivar were planted with densities of 450 plants m-2. in the 1st experiment, feral rye (secale cereale) with densities of 0, 2...

A strict field experiment with crops sown in crop rotation and monoculture wascarried out in the years 1988-2012 at the Experimental Station Uhrusk belonging tothe University of Life Sciences in Lublin, south-eastern Poland. The study wasaimed at evaluating the structure of weed communities occurring in crop rotationand monoculture of cereals. The highest weed density m-2 was determined inthe s...

A general model of crop yield response to herbicide application is proposed. The model includes three components: the effect of herbicide dosage on weed density, the effect of surviving weed density on crop yield and the effect of herbicide directly on the crop. The model is used to estimate the response of wheat yield to application of diclofop-methyl to control ryegrass .(Lolium rigidum) in A...

Cover crops are a suite of non-marketable plant species grown to improve soil quality. They may have additional benefits including reduced weed pressure and enhanced habitat for beneficial arthropods, but they do not provide direct revenue. Integrating sheep grazing for cover crop termination could make the use of cover crops more economically feasible. However, if grazing shifts biological com...

in order to investigate the effects of composted manure and zeolite on efficacy of trifluralin in control of weed natural population in sunflower under different irrigation regimes, an experiment conducted in 2009 in tarbiat modares university, tehran, iran. a randomized complete block design in factorial arrangement with three replications was used. first factor was irrigation regimes that inv...

to determine the optimum weed management method and plant population density on chickpea yield, a split plot experiment based on rcbd with four replications was carried out at the university of tehran research farm (located in karaj) during 2010-2011. the main factor consisted of nine treatments including: 1. trifluralin pre-plant, 2. pendimethalin pre-plant, 3. complete weeding, 4. imazethapyr...