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\hypersetup{pdftitle={Non"=destructive Measurements of Leaf Area and Total Dry Weight of Banana Intercropped in Coffee Agroforestry Systems},pdfauthor={Christian Dold, Charles Staver, Pablo Siles, Oscar Bustamante, Paulo Dos Santos Faria Lichtemberg, Luis Pocasangre, Jürgen Burkhardt},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Banana cultivar, circumference, dry matter, smallholder},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{Non"=destructive Measurements of Leaf Area and Total Dry Weight of Banana Intercropped in Coffee Agroforestry Systems\footnote{\textbf{Contact Address:} Christian Dold, University of Bonn, Institute for Crop Science and Resource Conservation, Gottfried-Kinkel-Str. 6, 53123~Bonn, Germany, \mbox{e-mail}: \email{neophyta960@gmail.com}}\\[0.8ex]}}
\normalsize{\textsc{Christian Dold$^{1}$, Charles Staver$^{2}$, Pablo Siles$^{2}$, Oscar Bustamante$^{2}$, Paulo Dos Santos Faria Lichtemberg$^{1}$, Luis Pocasangre$^{2}$, Jürgen Burk\-hardt$^{1}$}}
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\begin{itemize*}
\item[]{\small{\textit{$^{1}$University of Bonn, Institute for Crop Science and Resource Conservation, Germany}}}
\item[]{\small{\textit{$^{2}$Bioversity International, }}}
\end{itemize*}
\index[author]{Dold, Christian}
\index[author]{Staver, Charles}
\index[author]{Siles, Pablo}
\index[author]{Bustamante, Oscar}
\index[author]{Lichtemberg, Paulo Dos Santos Faria}
\index[author]{Pocasangre, Luis}
\index[author]{Burk\-hardt, Jürgen}
\begin{center}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
Aim of this work was to evaluate non"=destructive methods of leaf area and above ground dry weight estimation of banana. Therefore, smallholders intercropping coffee, banana (Musa spp.) and trees in Costa Rica and Nicaragua were intensively investigated for leaf area and dry weight measurements. Banana plants were in different development stages and several cultivars. On sixty farms most common banana cultivars were of subgroup AAA Gros Michel, AAA Cavendish and AAA Red Subgroup.



On 10 farms we cut all banana, and measured every leaf (length\,$\times$\,width\,$\times$\,0.8) in a plot 15 m\,$\times$\,\mbox{15\,m}. Turner (2003) proposed an equation to estimate leaf area by measuring the first leaf, the last leaf, and number of leaves. We used this equation with our measured leaf area data, and analysed the results. Linear regression analysis between destructive leaf area and non"=destructive leaf area estimation was conducted (R$^2$ = 0.96). Mean leaf area from real measurements has a \mbox{95\,\%} - Confidence Interval = [7.85 m$^2$; 9.18 m$^2$]. Mean leaf area estimated with Turner (2003) has a \mbox{95\,\%} - Confidence Interval = [6.51 m$^2$; 7.74 m$^2$]. This indicates that leaf area is underestimated. 



On 8 farms, we measured circumference and fresh weight of pseudostems and leaves. Stem and leaf samples were taken for dry weight measurements. A linear regression between above ground dry matter and circumference allows dry matter estimation (R$^2$ = 0.84). 



Dry matter and leaf area estimations are probably applicable for several cultivars since mixing data of several cultivars seemed not to influence results. For leaf area estimation, a factor derived by linear regression could adjust underestimations and allow better results. The two methods presented can be recommended for field work which facilitates data collection. Further research should analyse differences by cultivars and development stages.



}

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\noindent \textbf{Keywords:} Banana cultivar, circumference, dry matter, smallholder
\index[key]{Banana cultivar}
\index[key]{Circumference}
\index[key]{Dry matter}
\index[key]{Smallholder}
\end{document}