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...

Harrowing is often used to reduce weed competition, generally using a constant intensity across a whole field. The efficacy of weed harrowing in wheat and barley can be optimized, if site-specific conditions of soil, weed infestation and crop growth stage are taken into account. This study aimed to develop and test an algorithm to automatically adjust the harrowing intensity by varying the tine...

BACKGROUND One theoretical explanation for the relatively poor performance of Brassica rapa (weed) x Brassica napus (crop) transgenic hybrids suggests that hybridization imparts a negative genetic load. Consequently, in hybrids genetic load could overshadow any benefits of fitness enhancing transgenes and become the limiting factor in transgenic hybrid persistence. Two types of genetic load wer...

Weed management systems that rely less on chemical control are needed globally. Next to curative chemical weed control, there are other ways of tackling weed problems, such as (a) reduction of the weed seed bank in the soil, (b) reduced recruitment of weed seeds from the soil seed bank, and (c) strengthening the relative competitive ability of the crop. A number of case studies are presented in...

Plant-soil feedback (PSF) and plant competition play an important role in structuring vegetation composition, but their interaction remains unclear. Recent studies suggest that competing plants could dilute pathogenic effects, whereas the standing view is that competition may increase the sensitivity of the focal plant to PSF. In agro-ecosystems each of these two options would yield contrasting...

Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim th...

in this experiment which was conducted at a field of ramin agriculture and natural resources university (khouzestan, iran) in 2005, the effect of molinate at 0 (weedy check), 2.16, 3.6 and 5 kg/ha and seeding rate of 100, 120 and 140 kg/ha was evaluated on the competition between rice and barnyard grass (echinochloa crus-galli) in a split plot design with four replication. the interaction effec...

abstract- this experiment was carried out during the growing seasons of 2010 and 2011 at the agricultural research farm of bu-ali sina university, to study the effect of weed competition on subsequent germination and seed vigour of chickpea. 12 weed interference durations were evaluated in a randomized complete block design with three replications. experiments consisted of two sets of treatment...