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\hypersetup{pdftitle={Weed Community Response to Environmental Factors and Soil Properties in Field Condition},pdfauthor={Leila Alimoradi, Mohammad Hasan Rashed Mohassel, Hamid Reza Khazaee, Amir Ahmadian Yazdi},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={PCA, Sugarbeet. , Weed},pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
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\begin{center}
\Large{\textbf{Weed Community Response to Environmental Factors and Soil Properties in Field Condition\footnote{\textbf{Contact Address:} Leila Alimoradi, Islamic Azad University - Mashhad Branch, Department of Agronomy, Azadi Square, 91775-1163~Mashhad, Iran, \mbox{e-mail}: \email{lealimoradi@yahoo.com}}\\[0.8ex]}}
\normalsize{\textsc{Leila Alimoradi$^{1}$, Mohammad Hasan Rashed Mohassel$^{2}$, Hamid Reza Khazaee$^{3}$, Amir Ahmadian Yazdi$^{4}$}}
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\begin{itemize*}
\item[]{\small{\textit{$^{1}$Islamic Azad University - Mashhad Branch, Department of Agronomy, Iran}}}
\item[]{\small{\textit{$^{2}$Ferdowsi University of Mashhad, College of Agriculture, Department of Agronomy, Iran}}}
\item[]{\small{\textit{$^{3}$Ferdowsi University of Mashhad, College of Agriculture, Department of Agronomy, Iran}}}
\item[]{\small{\textit{$^{4}$Agriculture and Natural Resources Research Center, Plant Protection, Iran}}}
\end{itemize*}
\index[author]{Alimoradi, Leila}
\index[author]{Rashed Mohassel, Mohammad Hasan}
\index[author]{Khazaee, Hamid Reza}
\index[author]{Ahmadian Yazdi, Amir}
\begin{center}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
Weeds have a greater genetic diversity than crops. Consequently, if a resource such as light, water and nutrients changes within the environment, it is more likely that weeds will show a greater growth and reproductive response. Factors found to act on the buildup of weed communities include abiotic factors such as climate, agricultural practices, soil properties and landscape heterogeneity. Biotic factors such as competition from the crop or other weed species. Correlation between weed population in sugar beet fields and climate were studied in 178 fields in Iran, by PCA method. The results showed that Torbate-Heydarieh, Torbate-Jam and Chenaran were classified in one group and there was a correlation between these cities and Venice mallow (Hibiscus trionum L.) Lamb's"=tongue (Plantago Lanceolata L.), Burdock (Xanthium strumarium L.), Jimson weed (Daturea stramonium L.), Russian knapweed (Acroptilon repens L.), Turnesole (Chrozophora tinctoria L.), Barnyard grass (Echinochloa crus"=galli L.). Both Khauf and Jajarm were in one group and species such as Russian thistle (Salsola kali L.), Caltrop (Tribulus terrestris L.), Winter grass (Poa annua L.), Knot weed (Polygonum aviculare L.), Common lambs quarters (Chenopodium album L.) had correlation with this group. Results also showed that Russian knapweed, Turnesole, Turnip weed (Rapistrum rugosum L.) and Barnyard grass had adaptation with warm climate, and had more abundance in Torbate"=jam(warm climat). Burdock, Foxtail millet (Setaria glauca L.),  Redroot pigweed (Amaranthus retroflexus L.), Venice mallow, Turnip weed, Lamb's"=tongue, Barnyard grass were more when rain(mm), silt (percent), P(ppm) were increased. Grass and Smooth sowthistle (Sonchus oleraceus L.) density were seen more with increasing in N (\%), clay (percent). There was a positive correlation between species such as Common lambs quarters, Jimson weed, Russian knapweed ,Turnesole and sand (percent), K (ppm) and EC. }

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\end{abstract}
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\noindent \textbf{Keywords:} PCA, Sugarbeet. , Weed
\index[key]{PCA}
\index[key]{Sugarbeet. }
\index[key]{Weed}
\end{document}