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\hypersetup{pdftitle={Effect of \textit{Azotobacter} Inoculation, Dry Bread Yeast Suspension and Varying Levels of Urea on Growth of Potato cv. Desiree},pdfauthor={Taha Sarhan, Omar Khaleda Abdullah},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Azotobacter, bread yeast, potato},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{Effect of \textit{Azotobacter} Inoculation, Dry Bread Yeast Suspension and Varying Levels of Urea on Growth of Potato cv. Desiree\footnote{\textbf{Contact Address:} Taha Sarhan, University of Duhok, College of Agriculture, Horticulture, Zakho, 00964~Duhok, Iraq, \mbox{e-mail}: \email{t_sarhan@yahoo.com}}\\[0.8ex]}}
\normalsize{\textsc{Taha Sarhan$^{1}$, Omar Khaleda Abdullah$^{2}$}}
\end{center}
\begin{itemize*}
\item[]{\small{\textit{$^{1}$University of Duhok, College of Agriculture, Horticulture, Iraq}}}
\item[]{\small{\textit{$^{2}$University of Mosul, College of Agriculture and Forestry, Iraq}}}
\end{itemize*}
\index[author]{Sarhan, Taha}
\index[author]{Khaleda Abdullah, Omar}
\begin{center}
\vspace{1.1cm}
\textbf{Abstract}
\begin{abstract}
\normalsize{
The present study was carried out at the research field of the Agriculture Research station, Zakho, Duhok Governorate during 2005 and 2006 growing season. A factorial randomised complete block design was selected for the experiment which contained 24 treatments with three replicates to test the effect of \textit{Azotobacter} inoculation, dry bread yeast suspension and different levels of urea on the growth of potato (\textit{Solanum tuberosum}) cv. Desiree. Duncan multiple test at 0.05 level was used to detect differences among means. The experiment counted three factors: un"=inoculation and inoculation with \textit{Azotobacter}, four levels of dry bread yeast suspension (0, 2, 4 and 6\,g\,ml\textsuperscript{-1} and utilisation of nitrogen mineral fertilisation (urea) at rates of (0, 25, and 50\,kg\,donum\textsuperscript{-1}; 1 donum equals 2\,500 m\textsuperscript{2}).



The results showed that the vegetative growth was significantly increased in terms of plant height, areal stem number, leave area, total chlorophyll content of leaves and dry matter percentage as a result of \textit{Azotobacter} inoculation, bread yeast suspension, and the application of urea as compared to the control during both growing seasons.



The dual interaction between \textit{Azotobacter} inoculation and bread yeast suspension, \textit{Azotobacter} with urea, and yeast suspension with urea improved the vegetative growth of potato during both growing seasons.



Inoculating potato plants with \textit{Azotobacter} in combination either with a suspension of bread yeast at a rate of 6\,g\,ml\textsuperscript{-1} or fertilising them with \mbox{50\,kg} urea donum$^{-1}$, appeared to be the most effective treatments in improving the vegetative growth traits of potato.



}

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\noindent \textbf{Keywords:} \textit{Azotobacter}, bread yeast, potato
\index[key]{Azotobacter@\textit{Azotobacter}}
\index[key]{Bread yeast}
\index[key]{Potato}
\end{document}