نتایج جستجو برای: weed density

تعداد نتایج: 420665  

2018
Ilias S. Travlos Nikolina Cheimona Ioannis Roussis Dimitrios J. Bilalis

Weeds pose a major threat to world agriculture by reducing detrimentally crop yield and quality. However, at the same time, weeds are major interacting components of the agroecosystems. Abundance and diversity of weeds vary significantly among the several communities. In order to evaluate each community’s structure and the interactions among them, several population indices are used as key tool...

A. Woźniak, M. Soroka

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...

2012
Dionisio Andújar Martin Weis Roland Gerhards

Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is...

2010
Jacob Weiner Sven B Andersen Wibke K-M Wille Hans W Griepentrog Jannie M Olsen

Evolutionary theory can be applied to improve agricultural yields and/or sustainability, an approach we call Evolutionary Agroecology. The basic idea is that plant breeding is unlikely to improve attributes already favored by millions of years of natural selection, whereas there may be unutilized potential in selecting for attributes that increase total crop yield but reduce plants' individual ...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2003
M S Heard C Hawes G T Champion S J Clark L G Firbank A J Haughton A M Parish J N Perry P Rothery R J Scott M P Skellern G R Squire M O Hill

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...

Journal: :حفاظت گیاهان 0
خانجانی خانجانی محمودی محمودی

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...

Journal: :پژوهش های زراعی ایران 0
سید حسین ترابی محمد بازو بندی جواد باغانی

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...

Journal: :تولید گیاهان زراعی 0

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...

2005
Randy L. Anderson

L.) are now grown with winter wheat and fallow. Integrating crop diversity with other cultural tactics enabled No-till systems have enabled producers to change crop rotations in producers to effectively control weeds with 50% less the semiarid Central Great Plains. Previously, winter wheat (Triticum aestivum L.)–fallow was the prevalent rotation; now producers grow herbicide inputs compared wit...

Journal: :تولید گیاهان زراعی 0
علی قنبری استادیار دانشگاه فردوسی مشهد، ابراهیم کازرونی منفرد استادیار دانشگاه جامع علمی- کاربردی محمدتقی آل ابراهیم استادیار دانشگاه محقق اردبیلی سجاد میجانی دانشجوی کارشناسی ارشد دانشگاه فردوسی مشهد مهدی افشاری دانشجوی دکتری دانشگاه فردوسی مشهد جواد شباهنگ کارشناس آموزشی گروه زراعت، دانشگاه فردوسی مشهد

in order to evaluate competition among some weed species and canola, a field experiment in astan ghods razavi's field in mashhad was done on 2007-2008. thirty 50×50 cm quadrates were used in two times (stem and flower production) to measure the canola dry weight, leaf area index and canola and weeds density with destruction and thirty similar quadrates were used for counting weed species a...

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