Toxicidade do extrato orgânico de sementes de Annona muricata L. (Annonaceae) sobre Tetranychus evansi (Baker & Pritchard, 1960) (Acari: Tetranychidae) em tomateiro

The aim of this study was to evaluate the toxicity of the seed organic extract of Annona muricata L. (Annonaceae) against nymphs and adult females of Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) on tomato leaves (Lycopersicon esculentum Mill. (Solanaceae)). Experimental design was completely randomized in a factorial scheme (3x5), consisting in three time periods of mortality evaluation (24, 48 and 72 hours), five concentrations of A. muricata seed organic extract (0.0; 0.5; 1.0; 2.0 and 5.0%) and five replications. For the immature forms, each replicate comprised ten protonymphs; for the adult stage, it comprised ten adult females. The effect of the extracts was assessed by direct observation of mortality of immature individuals and adult females of T. evansi for 24, 48 and 72 hours. The results were subjected to regression analysis. In protonymphs and adult females, after 24 hours application of the A. muricata seed extract at concentration 5.0%, a mean efficiency of 98% mite mortality was reached. Concentration 5.0% of the organic extract was capable of causing 100% nymph mortality after 48 hours. Such mortality rate was found among the adults, after the same period, from concentration 1.0% on of the A. muricata extract.O objetivo deste trabalho foi avaliar a toxicidade do extrato orgânico de sementes de Annona muricata L. (Annonaceae) sobre ninfas e fêmeas adultas de Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) em folhas de tomateiro, Lycopersicum esculentum Mill. (Solanaceae). O delineamento experimental foi inteiramente casualizado em esquema fatorial (3x5), composto por três tempos de avaliação da mortalidade (24, 48 e 72 horas) e cinco concentrações do extrato orgânico da semente de A. muricata (0,0; 0,5; 1,0; 2,0 e 5,0%) e cinco repetições. Para as formas imaturas, cada repetição foi composta por dez protoninfas; e para a fase adulta, foi formada por dez fêmeas adultas. O efeito dos extratos foi avaliado através da observação direta da mortalidade das formas imaturas e fêmeas adultas de T. evansi durante 24, 48 e 72 horas. Os resultados foram submetidos à análise de regressão. Em protoninfas e em fêmeas adultas, após 24 horas da aplicação do extrato das sementes de A. muricata, a concentração 5,0%, atingiu uma eficiência média de 98% da mortalidade dos ácaros. A concentração de 5,0% do extrato orgânico foi capaz de ocasionar mortalidade de 100% das ninfas após 48 horas; sendo essa taxa de mortalidade encontrada, para os adultos, nesse mesmo período, a partir da concentração 1,0% do extrato de A. muricata

ENRAIZAMENTO DE ESTACAS DE INHAME (Dioscorea spp.)

A cultura do inhame (Dioscorea spp.) apresenta grande importância para toda a população brasileira, principalmente a nordestina, seja por seu valor nutricional ou comercial. O presente trabalho objetivou estudar um novo método de produção de mudas comerciais de inhame por a estaquia, utilizando ramos de plantas com idade de 120 dias. O experimento foi conduzido no CECA/UFAL, em estufa com nebulização intermitente. Adotou-se o delineamento experimental em blocos inteiramente casualizados com um fatorial 3×2×2, 12 tratamentos e 4 repetições. Foram avaliados três fatores: altura da estaca na planta (topo, centro e base), posição da estaca no ramo (proximal e distal) e concentração de ácido Indolbutírico (AIB) aplicado (0 e 1 mg/L). As estacas foram postas para enraizar em bandejas plásticas alveoladas de 32 células, contendo substrato comercial Bioplant®. Após 30 dias avaliou-se a presença, o número e o comprimento de raízes por estaca. Todas as variáveis foram submetidas à análise de variância e as médias comparadas pelo teste Tukey. Os resultados obtidos neste trabalho evidenciaram que a utilização de AIB (1g/L) não influenciou o enraizamento das estacas. Estacas coletadas no terço basal das plantas na posição proximal dos ramos, independente da concentração de AIB, apresentaram os melhores resultados para a percentagem de enraizamento, número de raízes, e comprimento de raízes por estaca

Potential predation and fecundity of Amblyseius aerialis fed two-spotted spider mite

The mites of the Phytoseiidae family stand out for the biological control of pest mites. The species Amblyseius aerialis (Muma, 1955) is a generalist mite, which can contribute to the natural regulation of pest mites. The objective of this study was to evaluate the potential for predation and fecundity of A. aerialis on the different phases of Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae). A female of A. aerialis was confined on dish (3.0 cm in diameter) of jack bean leaves, Canavalia ensiformis (L.) DC. The discs were left in petri dish with water. Each T. urticae phase was offered individually to A. aerialis at densities: 2, 5, 10, 15, 20 and 30 mites / arena. The number of prey consumed and eggs laid by A. aerialis were evaluated every 24 hours for seven days, with removal of laid eggs by phytoseiid and dead prey and replacement of prey in the initial amount. The data were submitted to analysis of variance and the means were compared by Tukey test, applying the factorial (4x6). It was observed that with the increase of the density of T. urticae offered there was an increase in the predation of A. aerialis. When offered the nymph and adult the average number of eggs per day was higher, differing from egg and larva. Thus, A. aerialis can be a biological control agent of the T. urticae, reducing the population of the pest and maintaining its fecundity in all phases and densities offered

CRESCIMENTO VEGETATIVO E PRODUTIVIDADE DE MAMONEIRA EM FUNÇÃO DA VARIEDADE E DA ADUBAÇÃO FOSFATADA

Having to evaluate the effect of varieties and phosphorus fertilization on growth and productivity of castor beans, is an experiment conducted at the Center for Agricultural Sciences, located in Rio Largo- AL. The paper was a 5 x 2 factorial, consisting of five doses of P2O5 (0, 45, 90, 135 e 180 kg ha-1) using triple superphosphate as source, and two varieties of castor bean, (BRS 149 Nordestina and BRS 188 Paraguaçu), with the treatments distributed in a randomized block design with four replications. We determined leaf area (LA) and plant height (PH) 30, 60, 90 and 120 days after transplanting (DAT), the length of the primary racemes (LPR) and subsequent (LSR), the number of racemes throughout the cycle (NR), the seed yield (SY) and dry matter accumulation in shoot (DM). The P fertilization increased the leaf area only at 30 and 120 DAT, while for plant height, the effect was only observed at 30 DAT. There was a quadratic effect of phosphorus for the LPR, NR, SY and DM. The variety BRS 188 Paraguaçu produced more racemes, but on the other side of the racemes BRS 149 Nordestina were longer

Toxicity and application of neem in fall armyworm

Aqueous extracts of neem, Azadirachta indica A. Juss., leaf and seed cake were tested for toxicity in Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) utilizing different methods of application (foliar and systemic). Probit analysis was used to determine the LC50 and regression analysis for mortality at different concentrations of the extracts (0.5%, 1.0%, 1.5%, 2.0% and control treatment). Two caterpillar morphometric variables (larval length and cephalic capsule width) and the scale of damage of attacked plants were measured and, analyzed using the Kruskal-Wallis test (P<0.05). The LC50 values for neem seed cake and leaves were 0.13% and 0.25%, respectively. For larval length and cephalic capsule width, the larvae were more affected to the seed cake extract than leaf extract, however there was no significant difference between the methods of application for these variables. There was no difference in the scale of damage by the extracts and the methods of application analyzed. Both methods of application provided similar results and, the main differences were associated with more efficient of the seed cake extract.  Aqueous extracts of neem, Azadirachta indica A. Juss., leaf and seed cake were tested for toxicity in Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) utilizing different methods of application (foliar and systemic). Probit analysis was used to determine the LC50 and regression analysis for mortality at different concentrations of the extracts (0.5%, 1.0%, 1.5%, 2.0% and control treatment). Two caterpillar morphometric variables (larval length and cephalic capsule width) and the scale of damage of attacked plants were measured and, analyzed using the Kruskal-Wallis test (H=16.93; P=0.0304). The LC50 values for neem seed cake and leaves were 0.13% and 0.25%, respectively. For larval length and cephalic capsule width, the larvae were more affected to the seed cake extract than leaf extract, however there was no significant difference between the methods of application for these variables. There was no difference in the scale of damage by the extracts and the methods of application analyzed. Both methods of application provided similar results and, the main differences were associated with more efficient of the seed cake extract

Mortality of Plutella xylostella larvae treated with Aspidosperma pyrifolium ethanol extracts Mortalidade de larvas de Plutella xylostella tratadas com extratos etanólicos de Aspidosperma pyrifolium

The objective of this work was to assess the effects of Aspidosperma pyrifolium ethanol extracts on cabbage moth (Plutella xylostella) larvae. The ethanol extracts of the stem bark, fruits and roots of A. pyrifolium were obtained by classical phytochemical methods, and the resulting subfractions were tested on P. xylostella, using 4 and 5 mg L-1. The crude ethanol extract of the stem bark was more lethal. The alkaloid-rich aqueous subfraction derived from the stem bark extract caused 100% larval mortality at 4 mg L-1. Insecticidal activity was associated with the presence of the monoterpenoid indole alkaloids aspidofractinine, 15-demethoxypyrifoline, and N-formylaspidofractinine. These alkaloids presented excellent insecticidal properties against P. xylostella.<br>O objetivo deste trabalho foi avaliar os efeitos dos extratos etanólicos de Aspidosperma pyrifolium sobre lagartas da traça-das-crucíferas (Plutella xylostella). Os extratos etanólicos da casca do caule, do fruto e da raiz de A. pyrifolium foram obtidos pelos métodos fitoquímicos clássicos, e as subfrações resultantes foram testadas contra P. xylostella, nas dosagens 4 e 5 mg L-1. O extrato bruto etanólico da casca do caule foi mais letal. A subfração aquosa rica em alcalóides, derivada do extrato da casca do caule, causou 100% de mortalidade larval a 4 mg L-1. A atividade inseticida foi associada à presença dos alcalóides monoterpenóides indólicos aspidofractinina, 15-demetoxipirifolina e N-formilaspidofractinin. Estes alcalóides apresentaram excelente propriedade inseticida contra P. xylostella

Effect of anonaceous extracts on Aphis gossypii (Glover, 1887) (Hemiptera: Aphididae) and selectivity to Eriopis connexa (Germar, 1824) (Coleoptera: Coccinellidae)

<div><p>ABSTRACT. The effects of ethanolic and hexanic extracts of soursop and sugar apple (EES, EHS, EESA and EHSA, respectively) on Aphis gossypii (Hemiptera: Aphididae) and its natural enemy Eriopis connexa (Coleoptera: Coccinellidae) by contact exposure, residual effect and ingestion tests were evaluated. The estimated LC50 and LC99 values for A. gossypii were 0.39% and 5.47% for (EESA); 0.23% and 1.19% for (EES); 0.47% and 4.39% for (EHSA); and 0.42% and 6.38% for (EHS), respectively. Considering contact exposure, EES at 0.23% was innocuous, and EHS at 0.42% was slightly harmful; for adult ladybugs, only EESA (5.47%) was classified as slightly harmful, with the other treatments classified as harmless. The results were similar for the residual effect. For selectivity in ingestion tests, EES and EHS at the LC50 did not affect the survival rate of the predator, but EESA (0.39% and 5.47% for the LC50 and LC99, respectively) reduced the survival rate to zero in less than 7 days, resembling chemical treatment with Decis®. Extracts applied to the eggs of an alternative prey reduced the consumption of eggs and therefore the predatory capacity of the ladybug, which led to a decrease in oviposition, egg viability and ultimately a reduction in predator fecundity. EES at a concentration of 0.23% was effective in the control of A. gossypii and was selective and did not affect the survival rate of the its natural enemy E. connexa.</p></div