TITLE:
Modeling Leaf Area Estimation for Arabica Coffee (Coffea Arabica L.) Grown at Different Altitudes of Mana District, Jimma Zone
AUTHORS:
Zerihun Misgana, Gerba Daba, Adugna Debela
KEYWORDS:
Coffea arabica L., Modeling, Leaf Area Estimation
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.6,
May
30,
2018
ABSTRACT: This study was aimed at
establishing allometric models for estimating LA (Leaf Area) of eight Coffea arabica genotypes in Mana
district of Jimma Zone Oromia Regional State, South Western Ethiopia (7°46'N,
36°0'E). Many Methodologies and instruments have been devised to facilitate
measurement of leaf area. However, these methods are destructive, laborious and
expensive. For modeling leaf area, leaf width, leaf length and leaf area of
1200 leaves (50 leaves for each genotype) was measured for model calibration
and the respective measurements on 960 leaves were used for model validation.
Linear measurement was taken from leaves and branch diameters of eight
genotypes of C. arabica, cultivated
in field following a randomized complete blocks design at three altitudes (High,
Medium and Low) were evaluated to identify best option for input in the models,
and to validate the method to estimate the leaf area. Linear and non-linear
models were tested for their accuracy to predict leaf area of the eight C. arabica genotypes. The use of linear
model resulted in high accuracy for all of the eight C. arabica genotypes. No significant effect of growing altitude and
genotype was obtained among the slopes of the models. Therefore, one single
model was fitted to the combined data of all genotypes at all altitudes (LA =
0.6434LW). Comparison between observed and predicted leaf area was made using
this model in another independent dataset, conducted for model validation,
exhibited a high degree of correlation (r = 0.98 - 0.99, P C.
arabica genotypes. Hence, this
model can be proposed to be reliably used and with this developed model,
researchers can estimate the leaf area of newly released eight genotypes of C. arabica at different altitudes accurately.