Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development

This study aimed to evaluate the insecticides resistance development of diamondback moth (DBM), Plutella xylostella L. in relation to insecticide application practices. A study was initiated with a survey to assess the current insecticides application practices for controlling DBM in the highland an...

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Main Author:	Chia, Meei Kee
Format:	Thesis
Language:	English English
Published:	2010
Subjects:	Insecticides - Malaysia. Insecticide resistance - Malaysia. Diamondback moth - Control - Malaysia.
Online Access:	http://psasir.upm.edu.my/id/eprint/19507/1/FP_2010_12_F.pdf
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spelling	my-upm-ir.195072013-04-08T04:06:38Z Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development 2010-10 Chia, Meei Kee This study aimed to evaluate the insecticides resistance development of diamondback moth (DBM), Plutella xylostella L. in relation to insecticide application practices. A study was initiated with a survey to assess the current insecticides application practices for controlling DBM in the highland and lowland areas in Malaysia. Survey data were analyzed with SPSS statistical software using Independent-samples T-test and Pearson correlation where appropriate. The survey showed complete reliance on insecticide mixtures to control DBM. A total of 11 and 14 active ingredients of insecticides were found to be commonly used in the lowland and highland respectively. The percentage of highland farmers used indoxacarb, spinosad, pyridalyl and fipronil was higher than lowland farmers, while lowland farmers recorded higher usage of chlorfenapyr than highland farmers. Besides that, a comparative usage for emamectin benzoate was reported, with slight greater use in the lowland (53%) than highland (41%). Highland farmers were found to apply significantly higher spray volume at 3.8-fold greater than lowland farmers (t = 7.361; P<0.05). Majority of insecticides were applied at tank concentrations below recommended doses. Highland farmers were found to apply significantly lower doses of emamectin benzoate compared to lowland farmers. A leaf-dip bioassay was conducted to investigate the susceptibilities of two DBM field strains to the six selected commonly used insecticides among the cruciferous vegetable farmers namely emamectin benzoate, spinosad, indoxacarb, fipronil, pyridalyl and chlorfenapyr. Results from the bioassays showed inter-population genetic variation in susceptibility between the two field strains of DBM. Higher LC values for all the insecticides except chlorfenapyr were reported on the Highland strain indicating that the Lowland strain is more susceptible to most of the insecticides tested. Comparison of LC50 values between the two strains showed that the Highland strain is significantly (P<0.05) less susceptible to spinosad and pyridalyl than lowland strain. On the other hand, Lowland strain was significantly (P<0.05) less susceptible to chlorfenapyr. The reported higher LC50 values were consistent with greater uses of the insecticides in respective location and the inter-population variation in susceptibility of DBM is due to local insecticide selection. With a lower usage but significantly higher LC90 for emamectin benzoate, the results suggested that reduced doses of emamectin benzoate practiced by the highland farmers accelerated the rate of resistance development in DBM. Insecticides - Malaysia. Insecticide resistance - Malaysia. Diamondback moth - Control - Malaysia. 2010-10 Thesis http://psasir.upm.edu.my/id/eprint/19507/ http://psasir.upm.edu.my/id/eprint/19507/1/FP_2010_12_F.pdf application/pdf en public masters Universiti Putra Malaysia Insecticides - Malaysia. Insecticide resistance - Malaysia. Diamondback moth - Control - Malaysia. Faculty of Agriculture English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Insecticides - Malaysia. Insecticide resistance - Malaysia. Diamondback moth - Control - Malaysia.
spellingShingle	Insecticides - Malaysia. Insecticide resistance - Malaysia. Diamondback moth - Control - Malaysia. Chia, Meei Kee Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development
description	This study aimed to evaluate the insecticides resistance development of diamondback moth (DBM), Plutella xylostella L. in relation to insecticide application practices. A study was initiated with a survey to assess the current insecticides application practices for controlling DBM in the highland and lowland areas in Malaysia. Survey data were analyzed with SPSS statistical software using Independent-samples T-test and Pearson correlation where appropriate. The survey showed complete reliance on insecticide mixtures to control DBM. A total of 11 and 14 active ingredients of insecticides were found to be commonly used in the lowland and highland respectively. The percentage of highland farmers used indoxacarb, spinosad, pyridalyl and fipronil was higher than lowland farmers, while lowland farmers recorded higher usage of chlorfenapyr than highland farmers. Besides that, a comparative usage for emamectin benzoate was reported, with slight greater use in the lowland (53%) than highland (41%). Highland farmers were found to apply significantly higher spray volume at 3.8-fold greater than lowland farmers (t = 7.361; P<0.05). Majority of insecticides were applied at tank concentrations below recommended doses. Highland farmers were found to apply significantly lower doses of emamectin benzoate compared to lowland farmers. A leaf-dip bioassay was conducted to investigate the susceptibilities of two DBM field strains to the six selected commonly used insecticides among the cruciferous vegetable farmers namely emamectin benzoate, spinosad, indoxacarb, fipronil, pyridalyl and chlorfenapyr. Results from the bioassays showed inter-population genetic variation in susceptibility between the two field strains of DBM. Higher LC values for all the insecticides except chlorfenapyr were reported on the Highland strain indicating that the Lowland strain is more susceptible to most of the insecticides tested. Comparison of LC50 values between the two strains showed that the Highland strain is significantly (P<0.05) less susceptible to spinosad and pyridalyl than lowland strain. On the other hand, Lowland strain was significantly (P<0.05) less susceptible to chlorfenapyr. The reported higher LC50 values were consistent with greater uses of the insecticides in respective location and the inter-population variation in susceptibility of DBM is due to local insecticide selection. With a lower usage but significantly higher LC90 for emamectin benzoate, the results suggested that reduced doses of emamectin benzoate practiced by the highland farmers accelerated the rate of resistance development in DBM.
format	Thesis
qualification_level	Master's degree
author	Chia, Meei Kee
author_facet	Chia, Meei Kee
author_sort	Chia, Meei Kee
title	Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development
title_short	Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development
title_full	Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development
title_fullStr	Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development
title_full_unstemmed	Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development
title_sort	insecticide application practices among lowland and highland cruciferous vegetable farmers and their relationship upon plutella xylostella l. resistance development
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Agriculture
publishDate	2010
url	http://psasir.upm.edu.my/id/eprint/19507/1/FP_2010_12_F.pdf
_version_	1747811398750044160

Insecticide Application Practices Among Lowland and Highland Cruciferous Vegetable Farmers and Their Relationship Upon Plutella Xylostella L. Resistance Development

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