to study the effects of applied nitrogen levels and wild mustard densities on the growth of wheat and wild mustard, a field experiment was conducted at re-search and experimental field of islamic azad university of ahvaz-iran. the effects of three nitrogen levels namely 90, 150 and 210 kg.ha-1 and four wild mustard densities such as 0, 5, 10 and 15 plants.m-2 were evaluated in split plot arrang...

Mapping weed densities within crops has conventionally been achieved either by detailed ecological monitoring or by field walking, both of which are time-consuming and expensive. Recent advances have resulted in increased interest in using Unmanned Aerial Systems (UAS) to map fields, aiming to reduce labour costs and increase the spatial extent of coverage. However, adoption of this technology ...

If an herbicide application fails to control a targeted weed community sufficiently, farmers may try to eliminate surviving weeds with a follow-up application (hereafter ‘‘respray’’). Despite the implications of resprays on the spread of herbicideresistant weeds, respray frequencies and causal factors are poorly understood. A two-part survey of glyphosate-resistant soybean fields and custom app...

Weed control through crop rotation has mainly been studied in a nonspatial context. However, weed seeds are often spread beyond the crop field by a variety of vectors. For weed control to be successful, weed management should thus be evaluated at the landscape level. In this paper we assess how seed dispersal affects the interactions between crop rotation and landscape heterogeneity schemes wit...

Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with t...

Weed infestations and associated yield losses require effective weed control measures in soybean and sugar beet. Besides chemical weed control, mechanical weeding plays an important role in integrated weed management systems. Field experiments were conducted at three locations for soybean in 2013 and 2014 and at four locations for sugar beet in 2014 to investigate if automatic steering technolo...

Management of nitrogen fertilization in crops is one of the most important components of integrated weed management. A two-year field experiment was conducted to determine the direct effects of wild mustard aboveground biomass and N content of wild mustard on oilseed rape yield. A set of factorial treatments was arranged in a randomized complete block design with four replications. Treatments w...

In order to study the effects of wild mustard competition and different levels of nitrogen on effective traits of wheat yield, this research was conducted in Ahvaz, south west of Iran. The study was consisted of a split plot experiment, on the basis of Randomized Complete Blocks Design with three replications. Different levels of nitrogen (90, 150 and 210 kgN.ha-1) were assigned in the main plo...

jimsonweed (datura stramonium l.) is an important weed in bean fields in iran. in order to investigate the effect of density and relative time of emergence of jimsonweed on yield and yield components of chitti bean, a field study based on factorial experiment was conducted at farm bean research national station in khomein in 2006. treatments were chosen to provide four different weed densities ...

We compared the seedbanks, seed rains, plant densities and biomasses of weeds under two contrasting systems of management in beet, maize and spring oilseed rape. Weed seedbank and plant density were measured at the same locations in two subsequent seasons. About 60 fields were sown with each crop. Each field was split, one half being sown with a conventional variety managed according to the far...