the effect of nitrogen (n) levels on n uptake by high weed densities at early growth stages of corn (zea mays l., cv. double cross 370) was investigated for two years (2008-2009) at the agricultural research station of shiraz university. the experiment was arranged in a split-plot arrangement in the randomized complete blocks design with three replications. two levels of weed control (weedy and...

weeds in wheat (triticum aestivum l.) fields have always been a big problem in iran and worldwide and must be managed by non-chemical especially cultural methods. a field experiment as factorial based on a randomized complete block design with four replications in a 1000 m2 field in research farm of shirvan college of agriculture was conducted during 2007-2008. treatments included wheat densiti...

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...

a field experiment was conducted to investigate the spatial distribution of weeds at the sari agricultural sciences and natural resources university in 2011. field was divided into 42 grids (1.5×1.5 feet) then all samples were taken from grids intersection points before corn planting, after harvesting and ear emergence stage. weed maps and semi variance analysis carried out using rw99 and gs+ s...

a two year field experiment was carried out to evaluate the competitive effects of wild mustard densities growing with rapeseed (cultivar talaye) under different nitrogen rates. treatments were wild mustard densities (0, 10, 20, 30, and 40 plant m-2) and nitrogen (n) rates (0, 50, 100, 150, and 200 kg n ha-1). the factorial set of treatments was arranged into a randomized complete block design ...

ٍearly watergrass (echinochloa oryzicola (ard) fisher) is an aggressive specie of echinochloa and have mimicry chareterstics of rice . in order to evaluate competitive effect of aggressive specie of echinochloa on rice, an experiment was conducted at the rice research institute of rasht during 2007. the experimental design was complete randomized block with three replications. the treatment incl...

A user-friendly computerized decision model has been developed for selecting profitable site-specific herbicide applications in winter wheat. The model is based on six years of field research in southeastern Washington State, USA. The model calibrates herbicide applications to management unit weed densities, soil organic matter, soil moisture, and preceding management, as well as to expected in...

The cropping of perennial wildflower mixtures to produce biomass for use in biogas plants is one option breaking maize’s dominance as a bioenergy feedstock. aim this study was investigate the development weeds commercially produced mixtures. Weed control during establishment very difficult manage and raises issue new weed problems when In three-year field experiment with staggered starts four s...

Biological weed management is a system that incorporates the use of diverse biological organisms and biologically-based approaches including allelopathy, crop competition, and other cultural practices to significantly reduce weed densities in a manner that is similar to use of chemical herbicides alone. Interest in developing effective biological weed management systems continues to increase be...