Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide

Controlled-release formulations of diuron were prepared in the laboratory using the concept of physical matrix utilizing sodium alginate and kaolin. The release rates of diuron from the formulations were determined by chemical assay and bioassay. In the chemical assay, using high performance chro...

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Main Author: Mazlan, Norida
Format: Thesis
Language:English
English
Published: 1999
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/10444/1/FP_1999_22_A.pdf
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spelling my-upm-ir.104442011-04-14T08:30:55Z Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide 1999-05 Mazlan, Norida Controlled-release formulations of diuron were prepared in the laboratory using the concept of physical matrix utilizing sodium alginate and kaolin. The release rates of diuron from the formulations were determined by chemical assay and bioassay. In the chemical assay, using high performance chromatography with UV detector, significant differences in release rates between formulations were observed from 3 to 7 days after the granules were placed into distilled water. The formulation having a 1:1 ratio of alginate to kaolin with 1 mm granule size showed the fastest release of diuron while release from the 2 mm granules was slower. The release of diuron from the formulations reached a maximum level of 27% at 30 days after placement in water this same rate of release was maintained up to 60 days after the treatment. Increasing the proportion of kaolin to sodium alginate in the controlled-release formulation reduced the release rate of active agent. Bioassays were conducted in the glasshouse to study the release rates of diuron using Brassica rapa seedlings as bioindicator. The controlled-release formulations showed slower release than the conventional formulation at the beginning of the treatments. At 3 weeks after treatment, there was no significant difference in the mortality of the seedlings between the conventional formulation and controlled-release formulations. However, the controlled-release formulations gave significantly higher seedling mortality compared to the conventional formulation at 16 weeks after the treatments. The same results were observed up to 24 weeks after the treatment when the controlled-release formulations caused between 40 to 70% mortality, while the conventional formulation treatment caused only 6% mortality. Among the controlledrelease formulations, the A K-2 formulation (1:1, alginate to kaolin) was found to give the best control with the highest percentage mortality of the seedlings. Plants, Effect of diuron on Diuron Plants, Effect of herbicides on 1999-05 Thesis http://psasir.upm.edu.my/id/eprint/10444/ http://psasir.upm.edu.my/id/eprint/10444/1/FP_1999_22_A.pdf application/pdf en public masters Universiti Putra Malaysia Plants, Effect of diuron on Diuron Plants, Effect of herbicides on Faculty of Agriculture English
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
English
topic Plants
Effect of diuron on
Diuron
Plants
Effect of diuron on
spellingShingle Plants
Effect of diuron on
Diuron
Plants
Effect of diuron on
Mazlan, Norida
Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide
description Controlled-release formulations of diuron were prepared in the laboratory using the concept of physical matrix utilizing sodium alginate and kaolin. The release rates of diuron from the formulations were determined by chemical assay and bioassay. In the chemical assay, using high performance chromatography with UV detector, significant differences in release rates between formulations were observed from 3 to 7 days after the granules were placed into distilled water. The formulation having a 1:1 ratio of alginate to kaolin with 1 mm granule size showed the fastest release of diuron while release from the 2 mm granules was slower. The release of diuron from the formulations reached a maximum level of 27% at 30 days after placement in water this same rate of release was maintained up to 60 days after the treatment. Increasing the proportion of kaolin to sodium alginate in the controlled-release formulation reduced the release rate of active agent. Bioassays were conducted in the glasshouse to study the release rates of diuron using Brassica rapa seedlings as bioindicator. The controlled-release formulations showed slower release than the conventional formulation at the beginning of the treatments. At 3 weeks after treatment, there was no significant difference in the mortality of the seedlings between the conventional formulation and controlled-release formulations. However, the controlled-release formulations gave significantly higher seedling mortality compared to the conventional formulation at 16 weeks after the treatments. The same results were observed up to 24 weeks after the treatment when the controlled-release formulations caused between 40 to 70% mortality, while the conventional formulation treatment caused only 6% mortality. Among the controlledrelease formulations, the A K-2 formulation (1:1, alginate to kaolin) was found to give the best control with the highest percentage mortality of the seedlings.
format Thesis
qualification_level Master's degree
author Mazlan, Norida
author_facet Mazlan, Norida
author_sort Mazlan, Norida
title Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide
title_short Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide
title_full Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide
title_fullStr Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide
title_full_unstemmed Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide
title_sort formulation and evaluation of controlled-release diuron as pre-emergence herbicide
granting_institution Universiti Putra Malaysia
granting_department Faculty of Agriculture
publishDate 1999
url http://psasir.upm.edu.my/id/eprint/10444/1/FP_1999_22_A.pdf
_version_ 1747811123358334976