Cargando…

Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions

The efficacy of Bacillus thuringiensis (var. kurstaki) (Btk) against the diamondback moth (DBM) on cabbage was studied at Botswana College of Agriculture, Gaborone, Botswana. Using five concentrations of Btk: 2, 4, 6, 8, and 10 g/L, bioassays were conducted against DBM eggs and second instar larvae...

Descripción completa

Detalles Bibliográficos
Autores principales: Legwaila, Mitch M., Munthali, David C., Kwerepe, Baone C., Obopile, Motshwari
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Libertas Academica 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4722877/
https://www.ncbi.nlm.nih.gov/pubmed/26816488
http://dx.doi.org/10.4137/IJIS.S23637
_version_ 1782411424200392704
author Legwaila, Mitch M.
Munthali, David C.
Kwerepe, Baone C.
Obopile, Motshwari
author_facet Legwaila, Mitch M.
Munthali, David C.
Kwerepe, Baone C.
Obopile, Motshwari
author_sort Legwaila, Mitch M.
collection PubMed
description The efficacy of Bacillus thuringiensis (var. kurstaki) (Btk) against the diamondback moth (DBM) on cabbage was studied at Botswana College of Agriculture, Gaborone, Botswana. Using five concentrations of Btk: 2, 4, 6, 8, and 10 g/L, bioassays were conducted against DBM eggs and second instar larvae at 30°C ± 5°C. Each treatment was replicated three times. Probit analysis was used to determine the LD(50) and LD(90) values for the treatments against eggs and larvae. When the treatments were assessed at 72, 96, 120, and 144 hours, LD(90) values against larvae were 11.02, 10.22, 5.92, and 4.01 g/L, whereas they were 7.71, 6.94, and 6.24 g/L against eggs when assessed 48, 72, and 96 hours after the expected time of hatching. This indicated that Btk was effective against both eggs and larvae when exposed for long periods. The slopes of the probit lines for larvae assessed at 24, 48, 72, 96, 120, and 144 hours after application were 0.250, 1.064, 0.910, 0.383, 0.453, and 0.414, while those against eggs were 1.153, 1.246, and 0.933 when assessed 48, 72, and 96 hours after the expected time of hatching. This indicates a smaller change in mortality with increase in pesticide dosage for both eggs and larvae. Btk treatments achieved 85.7%–94.6% reduction in DBM damage on cabbage. Therefore, Btk can be used to achieve effective control of DBM eggs and larvae and reduce damage on cabbage under greenhouse conditions.
format Online
Article
Text
id pubmed-4722877
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Libertas Academica
record_format MEDLINE/PubMed
spelling pubmed-47228772016-01-26 Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions Legwaila, Mitch M. Munthali, David C. Kwerepe, Baone C. Obopile, Motshwari Int J Insect Sci Original Research The efficacy of Bacillus thuringiensis (var. kurstaki) (Btk) against the diamondback moth (DBM) on cabbage was studied at Botswana College of Agriculture, Gaborone, Botswana. Using five concentrations of Btk: 2, 4, 6, 8, and 10 g/L, bioassays were conducted against DBM eggs and second instar larvae at 30°C ± 5°C. Each treatment was replicated three times. Probit analysis was used to determine the LD(50) and LD(90) values for the treatments against eggs and larvae. When the treatments were assessed at 72, 96, 120, and 144 hours, LD(90) values against larvae were 11.02, 10.22, 5.92, and 4.01 g/L, whereas they were 7.71, 6.94, and 6.24 g/L against eggs when assessed 48, 72, and 96 hours after the expected time of hatching. This indicated that Btk was effective against both eggs and larvae when exposed for long periods. The slopes of the probit lines for larvae assessed at 24, 48, 72, 96, 120, and 144 hours after application were 0.250, 1.064, 0.910, 0.383, 0.453, and 0.414, while those against eggs were 1.153, 1.246, and 0.933 when assessed 48, 72, and 96 hours after the expected time of hatching. This indicates a smaller change in mortality with increase in pesticide dosage for both eggs and larvae. Btk treatments achieved 85.7%–94.6% reduction in DBM damage on cabbage. Therefore, Btk can be used to achieve effective control of DBM eggs and larvae and reduce damage on cabbage under greenhouse conditions. Libertas Academica 2015-07-16 /pmc/articles/PMC4722877/ /pubmed/26816488 http://dx.doi.org/10.4137/IJIS.S23637 Text en © 2015 the author(s), publisher and licensee Libertas Academica Ltd. This is an open-access article distributed under the terms of the Creative Commons CC-BY-NC 3.0 License.
spellingShingle Original Research
Legwaila, Mitch M.
Munthali, David C.
Kwerepe, Baone C.
Obopile, Motshwari
Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions
title Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions
title_full Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions
title_fullStr Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions
title_full_unstemmed Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions
title_short Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions
title_sort efficacy of bacillus thuringiensis (var. kurstaki) against diamondback moth (plutella xylostella l.) eggs and larvae on cabbage under semi-controlled greenhouse conditions
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4722877/
https://www.ncbi.nlm.nih.gov/pubmed/26816488
http://dx.doi.org/10.4137/IJIS.S23637
work_keys_str_mv AT legwailamitchm efficacyofbacillusthuringiensisvarkurstakiagainstdiamondbackmothplutellaxylostellaleggsandlarvaeoncabbageundersemicontrolledgreenhouseconditions
AT munthalidavidc efficacyofbacillusthuringiensisvarkurstakiagainstdiamondbackmothplutellaxylostellaleggsandlarvaeoncabbageundersemicontrolledgreenhouseconditions
AT kwerepebaonec efficacyofbacillusthuringiensisvarkurstakiagainstdiamondbackmothplutellaxylostellaleggsandlarvaeoncabbageundersemicontrolledgreenhouseconditions
AT obopilemotshwari efficacyofbacillusthuringiensisvarkurstakiagainstdiamondbackmothplutellaxylostellaleggsandlarvaeoncabbageundersemicontrolledgreenhouseconditions