Measurement of Oil Palm LAI by Manual and LAI-2000 Method

In this study, accurate Leaf Area Index (LAI) of different palm age groups were determined by manual (direct) method. Optical methods for quantifying variation in LAI of different palm ages were evaluated using LAI-2000 Plant Canopy Analyser (PCA) as an indirect method. In the manual method, LAI val...

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Main Authors: Awal, Md. Abdul, Wan Ismail, Wan Ishak
Format: Article
Language:English
English
Published: Asian Network for Scientific Information 2008
Online Access:http://psasir.upm.edu.my/id/eprint/7883/1/49-56.pdf_k.pdf
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author Awal, Md. Abdul
Wan Ismail, Wan Ishak
author_facet Awal, Md. Abdul
Wan Ismail, Wan Ishak
author_sort Awal, Md. Abdul
collection UPM
description In this study, accurate Leaf Area Index (LAI) of different palm age groups were determined by manual (direct) method. Optical methods for quantifying variation in LAI of different palm ages were evaluated using LAI-2000 Plant Canopy Analyser (PCA) as an indirect method. In the manual method, LAI values obtained were 0.69, 1.11, 2.38, 2.49, 3.41, 3.83, 4.05 and in the indirect method LAI values obtained were 1.75, 1.4, 1.14, 1.42, 2.87, 1.89, 3.05 for 2, 3, 6, 7, 9, 12 and 16 year old palms, respectively. Results showed that the PCA LAI values were overestimated for immature palms but underestimated for mature palms. The PCA LAI values were overestimated by 30.8-153% for 2 to 3-year old palms and underestimated by 24-52% for beyond 6-year old palms as compared to manual measurement. The relationship between palm age and LAI was also established in this study. A strong linear relationship between direct LAI and palm age was observed with a correlation coefficient, R = 0.90. However, the relationship between PCA LAI and palm age was weak and not significant. A relationship was observed between PCA LAI and direct LAI with a correlation coefficient of R = 0.57. The study shows that it was possible to rapidly determine LAI using the LAI-2000 Plant Canopy Analyser. This rapid and non-destructive method saves labour when compared to manual measurements. However, this instrument gave inconsistent of LAI values in respect to oil palm age.
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spelling upm.eprints-78832013-05-27T07:36:58Z http://psasir.upm.edu.my/id/eprint/7883/ Measurement of Oil Palm LAI by Manual and LAI-2000 Method Awal, Md. Abdul Wan Ismail, Wan Ishak In this study, accurate Leaf Area Index (LAI) of different palm age groups were determined by manual (direct) method. Optical methods for quantifying variation in LAI of different palm ages were evaluated using LAI-2000 Plant Canopy Analyser (PCA) as an indirect method. In the manual method, LAI values obtained were 0.69, 1.11, 2.38, 2.49, 3.41, 3.83, 4.05 and in the indirect method LAI values obtained were 1.75, 1.4, 1.14, 1.42, 2.87, 1.89, 3.05 for 2, 3, 6, 7, 9, 12 and 16 year old palms, respectively. Results showed that the PCA LAI values were overestimated for immature palms but underestimated for mature palms. The PCA LAI values were overestimated by 30.8-153% for 2 to 3-year old palms and underestimated by 24-52% for beyond 6-year old palms as compared to manual measurement. The relationship between palm age and LAI was also established in this study. A strong linear relationship between direct LAI and palm age was observed with a correlation coefficient, R = 0.90. However, the relationship between PCA LAI and palm age was weak and not significant. A relationship was observed between PCA LAI and direct LAI with a correlation coefficient of R = 0.57. The study shows that it was possible to rapidly determine LAI using the LAI-2000 Plant Canopy Analyser. This rapid and non-destructive method saves labour when compared to manual measurements. However, this instrument gave inconsistent of LAI values in respect to oil palm age. Asian Network for Scientific Information 2008 Article PeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/7883/1/49-56.pdf_k.pdf Awal, Md. Abdul and Wan Ismail, Wan Ishak (2008) Measurement of Oil Palm LAI by Manual and LAI-2000 Method. Asian Journal of Scientific Research, 1 (1). pp. 49-56. ISSN 1992-1454 http://scialert.net/abstract/?doi=ajsr.2008.49.56 10.3923/ajsr.2008.49.56 English
spellingShingle Awal, Md. Abdul
Wan Ismail, Wan Ishak
Measurement of Oil Palm LAI by Manual and LAI-2000 Method
title Measurement of Oil Palm LAI by Manual and LAI-2000 Method
title_full Measurement of Oil Palm LAI by Manual and LAI-2000 Method
title_fullStr Measurement of Oil Palm LAI by Manual and LAI-2000 Method
title_full_unstemmed Measurement of Oil Palm LAI by Manual and LAI-2000 Method
title_short Measurement of Oil Palm LAI by Manual and LAI-2000 Method
title_sort measurement of oil palm lai by manual and lai 2000 method
url http://psasir.upm.edu.my/id/eprint/7883/1/49-56.pdf_k.pdf
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