An investigation of effect of Latana camara, Tephrosia vogelii and Zingiber officinale applied at 5%, 10% and 25% concentrations on flea beetle of cabbage was conducted on the Teaching and Research Farm of the Ladoke ...An investigation of effect of Latana camara, Tephrosia vogelii and Zingiber officinale applied at 5%, 10% and 25% concentrations on flea beetle of cabbage was conducted on the Teaching and Research Farm of the Ladoke Akintola University of Technology Ogbomoso in the early seasons of 2011 and 2012. The experiment consisted of 11 treatments laid in a Randomized Complete Block Design （RCBD） with three replications. Data were subjected to analysis of variance and significant means were compared using the Least Significant Difference （LSD） at p〈0.05. All the tested plant extracts exhibited moderate efficacy in the control of flea beetle. The treatment plant extracts performed as well as synthetic insecticides （0.76±0.05 and 0.76±0.05, respectively）. It was discovered that 25% w/v of Z. officinale gave the best yield of 0.50 kg · hm-2. The result showed that extract of T. vogelii （0.71±0.00） and L. camara （0.96±0.23） could suppress flea beetle population at different hours of spraying, while Z. officinale showed an effect at 48 HAS （0.71±0.00） and 72 HAS （0.76±0.05） alter spraying.展开更多
Cotton bollworm(Helicoverpa armigera) is an important agricultural pest that causes severe yield loss to crops,particularly to cotton.Transgenic Bt crops have been successful in
Background To control the boll weevil Anthonomus grandis grandis(Coleoptera:Curculionidae),a key pest of cotton in the Americas,insecticides have been intensively used to manage their populations,increasing selection ...Background To control the boll weevil Anthonomus grandis grandis(Coleoptera:Curculionidae),a key pest of cotton in the Americas,insecticides have been intensively used to manage their populations,increasing selection pressure for resistant populations.Thus,this study aimed to detect insecticide resistance and assess insecticide control failure likelihood of boll weevil populations exposed to malathion,profenophos+cypermethrin,and fipronil insecticides.Results Twelve populations of the boll weevil were collected from commercial cotton fileds of the state of Bahia,northeastern Brazil.These populations were exposed to malathion,profenophos+cypermethrin mixture,and fipronil,at their respective maximum label dose for field applications.Three replicates of 10 adult beetles were exposed to the insecticides and mortality was recorded after 24 h treatment.The control failure likelihood was determined after 48 h.Highest median lethal times(LT_(50))were observed for malathion and the profenophos+cypermethrin mixture.Resistance to at least one insecticide was detected in 11 populations;three populations were resistant to malathion and profenophos+cypermethrin;seven were resistant to all insecticides tested.The resistance levels were low(<10-fold)for the three insecticides.Among 12 populations tested,58%of them exhibited significant risk of control failure for the insecticides malathion and profenophos+cypermethrin.The insecticide fipronil was efficient for the control of the boll weevil in 83%of the populations.Conclusions The results confirm the significant risk of insecticide control failure in the boll weevil populations to the main compounds used in the region.Thus,proper insecticide resistance management plans are necessary for the boll weevil in the region,particularly for malathion and profenophos+cypermethrin insecticides.展开更多
文摘An investigation of effect of Latana camara, Tephrosia vogelii and Zingiber officinale applied at 5%, 10% and 25% concentrations on flea beetle of cabbage was conducted on the Teaching and Research Farm of the Ladoke Akintola University of Technology Ogbomoso in the early seasons of 2011 and 2012. The experiment consisted of 11 treatments laid in a Randomized Complete Block Design （RCBD） with three replications. Data were subjected to analysis of variance and significant means were compared using the Least Significant Difference （LSD） at p〈0.05. All the tested plant extracts exhibited moderate efficacy in the control of flea beetle. The treatment plant extracts performed as well as synthetic insecticides （0.76±0.05 and 0.76±0.05, respectively）. It was discovered that 25% w/v of Z. officinale gave the best yield of 0.50 kg · hm-2. The result showed that extract of T. vogelii （0.71±0.00） and L. camara （0.96±0.23） could suppress flea beetle population at different hours of spraying, while Z. officinale showed an effect at 48 HAS （0.71±0.00） and 72 HAS （0.76±0.05） alter spraying.
文摘Cotton bollworm(Helicoverpa armigera) is an important agricultural pest that causes severe yield loss to crops,particularly to cotton.Transgenic Bt crops have been successful in
基金supported by Foundation for Research Support of the State of Bahia(FAPESB)the CAPES Foundation(Brazilian Ministry of Education+1 种基金Finance Code 001)for financial supportBahia Association of Cotton Producers。
文摘Background To control the boll weevil Anthonomus grandis grandis(Coleoptera:Curculionidae),a key pest of cotton in the Americas,insecticides have been intensively used to manage their populations,increasing selection pressure for resistant populations.Thus,this study aimed to detect insecticide resistance and assess insecticide control failure likelihood of boll weevil populations exposed to malathion,profenophos+cypermethrin,and fipronil insecticides.Results Twelve populations of the boll weevil were collected from commercial cotton fileds of the state of Bahia,northeastern Brazil.These populations were exposed to malathion,profenophos+cypermethrin mixture,and fipronil,at their respective maximum label dose for field applications.Three replicates of 10 adult beetles were exposed to the insecticides and mortality was recorded after 24 h treatment.The control failure likelihood was determined after 48 h.Highest median lethal times(LT_(50))were observed for malathion and the profenophos+cypermethrin mixture.Resistance to at least one insecticide was detected in 11 populations;three populations were resistant to malathion and profenophos+cypermethrin;seven were resistant to all insecticides tested.The resistance levels were low(<10-fold)for the three insecticides.Among 12 populations tested,58%of them exhibited significant risk of control failure for the insecticides malathion and profenophos+cypermethrin.The insecticide fipronil was efficient for the control of the boll weevil in 83%of the populations.Conclusions The results confirm the significant risk of insecticide control failure in the boll weevil populations to the main compounds used in the region.Thus,proper insecticide resistance management plans are necessary for the boll weevil in the region,particularly for malathion and profenophos+cypermethrin insecticides.
