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Evaluation of Potential Sources of Allelochemicals in Lalang

Aqueous leachates from fragmented lalang (I. cylindrica (L) Raeuschel var. major) dead leaves in situ, caused delayed germination in biossays of all six species of pasture legumes tested, while radicle and shoot growth were inhibited in two of the test species. Phytotoxicity was dependent on the q...

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Main Authors: Rajan, Amarthalingam, Lovett, J. V., Andrews, A. C.
Format: Article
Language:English
English
Published: 1988
Online Access:http://psasir.upm.edu.my/id/eprint/2596/1/Evaluation_of_Potential_Sour~es_of_Allelochemicals_in_Lalang.pdf
http://psasir.upm.edu.my/id/eprint/2596/
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spelling my.upm.eprints.25962013-05-27T07:02:09Z http://psasir.upm.edu.my/id/eprint/2596/ Evaluation of Potential Sources of Allelochemicals in Lalang Rajan, Amarthalingam Lovett, J. V. Andrews, A. C. Aqueous leachates from fragmented lalang (I. cylindrica (L) Raeuschel var. major) dead leaves in situ, caused delayed germination in biossays of all six species of pasture legumes tested, while radicle and shoot growth were inhibited in two of the test species. Phytotoxicity was dependent on the quantity of plant residues available in the proximity of germinating phytometer species. Leachates from rhizome and root fragments exhibited strong inhibitory activity even at the 5% (w/v) level while leaf leachates were inhibitory at the 10% level and higher. In pot experiments with soil containing living lalang tillers or incorporated with rhizome or root fragments, phytotoxicity development in the soil extracts was evident at four weeks of growth or decay. In soils with decaying roots or rhizomes there was a sub-sequent loss in activity over the eight week incubation period. Extracts of soils with living tillers showed loss of activity at six weeks of growth followed by a significant stimulatory response at eight weeks. The use of two controls (control-soil extract and distilled water control) enabled detection of inherent stimulatory activity in the control soiL Comparison with both controls to eliminate such influences showed only living tillers, and decaying rhizomes and roots as major potential sources of inhibitory substances. The common soil organism, Bacillus cereus (Frankland & Frankland), Alcaligenes faecalis Castellani & Chalmers) and a Trichoderma sp. were found to be associated with the decay of rhizomes resulting in an initial stimulatory growth reponse in the phytometer species followed by inhibition and subsequent loss in activity. The nature of these organisms suggest that the release ofPhytotoxins through decay of rhizomes as a common, natural phenomenon in most soils. The dead leaves accumulating as litter in mature lalang vegetation may serve as an additional source of water leachable allelochemicals if sufficient quantities were available in contact with the soil. 1988 Article PeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/2596/1/Evaluation_of_Potential_Sour~es_of_Allelochemicals_in_Lalang.pdf Rajan, Amarthalingam and Lovett, J. V. and Andrews, A. C. (1988) Evaluation of Potential Sources of Allelochemicals in Lalang. Pertanika, 11 (2). pp. 175-189. English
institution Universiti Putra Malaysia
building UPM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Putra Malaysia
content_source UPM Institutional Repository
url_provider http://psasir.upm.edu.my/
language English
English
description Aqueous leachates from fragmented lalang (I. cylindrica (L) Raeuschel var. major) dead leaves in situ, caused delayed germination in biossays of all six species of pasture legumes tested, while radicle and shoot growth were inhibited in two of the test species. Phytotoxicity was dependent on the quantity of plant residues available in the proximity of germinating phytometer species. Leachates from rhizome and root fragments exhibited strong inhibitory activity even at the 5% (w/v) level while leaf leachates were inhibitory at the 10% level and higher. In pot experiments with soil containing living lalang tillers or incorporated with rhizome or root fragments, phytotoxicity development in the soil extracts was evident at four weeks of growth or decay. In soils with decaying roots or rhizomes there was a sub-sequent loss in activity over the eight week incubation period. Extracts of soils with living tillers showed loss of activity at six weeks of growth followed by a significant stimulatory response at eight weeks. The use of two controls (control-soil extract and distilled water control) enabled detection of inherent stimulatory activity in the control soiL Comparison with both controls to eliminate such influences showed only living tillers, and decaying rhizomes and roots as major potential sources of inhibitory substances. The common soil organism, Bacillus cereus (Frankland & Frankland), Alcaligenes faecalis Castellani & Chalmers) and a Trichoderma sp. were found to be associated with the decay of rhizomes resulting in an initial stimulatory growth reponse in the phytometer species followed by inhibition and subsequent loss in activity. The nature of these organisms suggest that the release ofPhytotoxins through decay of rhizomes as a common, natural phenomenon in most soils. The dead leaves accumulating as litter in mature lalang vegetation may serve as an additional source of water leachable allelochemicals if sufficient quantities were available in contact with the soil.
format Article
author Rajan, Amarthalingam
Lovett, J. V.
Andrews, A. C.
spellingShingle Rajan, Amarthalingam
Lovett, J. V.
Andrews, A. C.
Evaluation of Potential Sources of Allelochemicals in Lalang
author_facet Rajan, Amarthalingam
Lovett, J. V.
Andrews, A. C.
author_sort Rajan, Amarthalingam
title Evaluation of Potential Sources of Allelochemicals in Lalang
title_short Evaluation of Potential Sources of Allelochemicals in Lalang
title_full Evaluation of Potential Sources of Allelochemicals in Lalang
title_fullStr Evaluation of Potential Sources of Allelochemicals in Lalang
title_full_unstemmed Evaluation of Potential Sources of Allelochemicals in Lalang
title_sort evaluation of potential sources of allelochemicals in lalang
publishDate 1988
url http://psasir.upm.edu.my/id/eprint/2596/1/Evaluation_of_Potential_Sour~es_of_Allelochemicals_in_Lalang.pdf
http://psasir.upm.edu.my/id/eprint/2596/
_version_ 1643822365300228096
score 13.211869

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