scholarly journals Toxicidade de Extratos de Sementes de Jatropha curcas e Azadirachta indica à Plutella xylostella

2013 ◽  
Vol 7 (13) ◽  
pp. 73-76
Author(s):  
Paulo V. Sousa ◽  
Flávio G. Jesus ◽  
Márcio S. Araújo ◽  
Fábio S. Matos ◽  
Leandro Bacci

Avaliou-se a toxicidade de extratos de sementes de Azadirachta indica (Neen) e de Jatropha curcas (Pinhão manso) à Plutella xylostella (Traça das crucíferas). Discos foliares de couve (Brassica oleracea var. acephala) cultivar Portuguesa foram imersos nos extratos de Neen e Pinhão manso nas concentrações de 0,5 % e, depois, fornecidos como alimento para as lagartas. Após isso, acompanhou-se o seu ciclo biológico. Todas as fases de desenvolvimento do inseto investigadas foram afetadas pela aplicação de óleos vegetais de A. indica e J. curcas. A aplicação de óleos vegetais de A. indica e J. curcas reduz a sobrevivência da praga.

2011 ◽  
Vol 78 (2) ◽  
pp. 279-285
Author(s):  
F.G. Jesus ◽  
L.A. de Paiva ◽  
V.C. Gonçalves ◽  
M.A Marques ◽  
A.L. Boiça Junior

RESUMO Avaliou-se o efeito de Azadirachta indica A. Juss. (Nim), Sapindus saponaria L. (Sabão de soldado), Nim + Piretro + Rotenona, Dimorphandra mollis (Faveira) e Stryphnodendron adstringens (Mart) Coville (Barbatimão) em relação a não-preferência para oviposição e alimentação, atratividade e biologia de Plutella xylostella. Discos foliares de couve (Brassica oleracea var. acephala) cultivar Manteiga foram imersos em cada extrato à concentração de 10% (massa/volume) por 30 segundos para realização dos experimentos. Para o teste sem chance de escolha, os tratamentos que apresentaram menores atratividades foram os extratos de A. indica e D. mollis, e o menor consumo foi em A. indica. Os extratos de A. indica, S. saponaria D. mollis e S. adstringens proporcionaram efeito deterrente na oviposição de P. xylostella. Os tratamentos A. indica, S. saponaria e S. adstringens influênciaram negativamente os parâmetros biológicos da praga.


2012 ◽  
Vol 1 (2) ◽  
pp. 229 ◽  
Author(s):  
P. K. Baidoo ◽  
J. I. Adam

<p>The effects of ethanolic extract of neem, <em>Azadirachta indica</em> (Meliaceae), seeds and petroleum ether extract of <em>Lantana camara</em> leaves (Verbenaceae) on the populations of three cabbage pests, <em>Plutella xylostella</em>, <em>Brevicoryne brassicae</em> and <em>Hellula undalis</em> were studied. The study was conducted between January and April 2008. Extracts of the two plants were sprayed on cabbage plants to control these pests. A standard synthetic chemical insecticide (Mektin) was used as reference product. The experiment was conducted in a randomized complete block design and each treatment was replicated four times. The effects of plant extracts on the population dynamics of the pests’ species, the level of infestation and yield were assessed. Significantly more of the pests infested the control plants than the treated plants (<em>P</em>&lt; 0.01). The mean weight of cabbage heads on the sprayed plots was significantly heavier than that of the control unsprayed plots. The use of <em>A. indica</em> seeds and <em>L. camara</em> leaf extracts increased yield by 37.05% and 25.80%, respectively. Spraying the cabbage plants with the plant extracts significantly reduced the numbers of pests compared with the control plants. The use of these plant extracts can be incorporated into an overall control programme of these pests.</p>


2018 ◽  
Vol 44 (3) ◽  
pp. 274-277
Author(s):  
Alexandre Dinnys Roese ◽  
Walmes Marques Zeviani ◽  
Harley Nonato de Oliveira ◽  
Cesar José da Silva

ABSTRACT Jatropha curcas L. has been studied with the aim of attending the bioenergy demand in Brazil. In this study, the time of occurrence, the severity, and the control of powdery mildew and rust in a commercial crop were investigated. During the evaluation period, powdery mildew was first observed soon after the onset of the raining period in October. Rust was first observed in April. Metarhizium anisopliae. Azadirachta indica oil, J. curcas oil, and the fungicide triadimenol were efficient in controlling powdery mildew. None of these products nor potassium silicate did control rust.


2005 ◽  
Vol 95 (5) ◽  
pp. 457-465 ◽  
Author(s):  
D.S. Charleston ◽  
R. Kfir ◽  
L.E.M. Vet ◽  
M. Dicke

AbstractThe impact of three different doses of botanical insecticide derived from the syringa tree, Melia azedarach and the neem tree, Azadirachta indica was tested on the behaviour of the diamondback moth, Plutella xylostella (Linnaeus). Both botanical insecticides had a significant impact on larval behaviour. At higher doses the extracts showed feeding deterrent activity, with larvae preferring the untreated sides of cabbage leaves and consuming less of the treated half of cabbage leaves. The botanical insecticides had less of an effect on the oviposition behaviour of P. xylostella moths. In laboratory and glasshouse trials, significantly fewer eggs were oviposited on the plants that had been treated with syringa extracts. Therefore, the syringa extracts appear to have a repellent effect. In contrast, when exposed to the neem extracts the moths did not discriminate between control plants and treated plants. Behavioural observation indicated that, despite the lower number of eggs oviposited on cabbage treated with syringa extracts, the moths chose cabbage treated with the highest dose of syringa more often than they chose control cabbage plants. Similar observations were found in cabbage plants treated with neem, moths chose the medium dose more often than they chose the control. Oviposition and feeding deterrent properties are important factors in pest control, and results from this study indicate that botanical insecticides have the potential to be incorporated into control programmes for P. xylostella in South Africa.


Sign in / Sign up

Export Citation Format

Share Document