Efeito de defensivos agrícolas naturais e extratos vegetais sobre parâmetros biológicos de AbstractThis study was carried out aiming to evaluate the effect and compatibility of vegetal and Pycnoporus sanguineus basidiocarps extracts and alternative products on biological parameters of Metarhizium anisopliae fungus. Extracts (solution in water 10%) and natural products (AR = average field recommendation; 0.5 AR and 2.0 AR) are applied on PDA culture media surface previously inoculated with fungi conidia. The effect of the treatment on conidia germination, vegetative growth and conidiogenesis was compared. Most alternative products were compatible to the fungus, and only Bordeaux mixture AR and 2.0 AR were moderately toxic to M. anisopliae. Although some significativally negative effect there were observed on conidial viability (reduction of 50 to 80% by alcoholic extracts), all extracts were compatible. This point to the necessity to be careful with application, avoiding mixtures or subsequent use of products less than 48 hours after fungi application.
Paraguay tea is a native crop of southern Brazil and is also socioeconomically important in Paraguay and Argentina. One of the main pests of this crop is Gyropsylla spegazziniana (Hemiptera: Psyllidae). As there are no registered insecticides for this pest in Brazil, the use of entomopathogenic fungi is an alternative method for its control. This study aimed to evaluate and characterize isolates of the entomopathogenic fungi Beauveria spp., Metarhizium anisopliae, Isaria spp. and Lecanicillium spp. on G. spegazziniana. For this purpose, 5 th instar nymphs were transferred to Paraguay tea seedlings, followed by spraying of conidial suspensions (1 × 10 9 conidia mL -1 ) and then placing the seedlings in polyvinyl chloride (PVC) cages and maintaining them in a temperature-controlled room (26 ± 1°C, 12h00 photophase, 60 ± 10% R.H.). Insect mortality was evaluated daily for 10 days, and the selected isolates were characterized according to their vegetative growth, conidial production in synthetic culture medium and rice and insecticidal activity as well as through molecular analyses, including sequencing the rDNA-ITS region and RAPD analysis. The genus Beauveria spp. was the most efficient, particularly the Unioeste 44 isolate, which caused the greatest total mortality of G. spegazziniana (81.7%) and showed among the highest conidial production levels on rice, indicating a significant potential to be used in an integrated management program for this pest. Molecular analysis of the rDNA-ITS region allowed the isolates to be identified as B. bassiana and B. brongniartii, and RAPD markers were found to be associated with virulence. Key words: Biological control, Ilex paraguariensis, rDNA-ITS ResumoA erva-mate (Ilex paraguariensis St. Hil.) é uma cultura nativa do Sul do Brasil, tendo grande importância socioeconômica também para o Paraguai e Argentina. Uma das principais pragas da cultura é a Gyropsylla spegazziniana (Hemiptera: Psyllidae), e pelo fato de não existirem inseticidas registrados para essa praga no Brasil, o uso de fungos entomopatogênicos pode ser uma alternativa para o seu controle. O objetivo desse trabalho foi caracterizar isolados dos fungos entomopatogênicos Beauveria spp., Metarhizium anisopliae, Isaria spp. e Lecanicillium spp. sobre G. spegazziniana. Para tal, ninfas de 5 o ínstar foram transferidas para mudas de erva-mate, seguido da pulverização das suspensões de conídios (1 × 10 9 conídios mL -1 ), e então as mudas foram acondicionadas em gaiolas de PVC (cloreto de polivinila), e mantidas em sala climatizada (26 ± 1°C; 12h00 de fotofase e U.R. 60 ± 10%). A mortalidade dos insetos foi avaliada diariamente, por 10 dias, e os isolados selecionados foram comparados entre si por meio do crescimento vegetativo, produção de conídios em meio sintético e em arroz, atividade inseticida e análises moleculares, utilizando-se o sequenciamento da região rDNA-ITS e marcadores RAPD. O gênero Beauveria spp. foi o mais eficiente, em especial o isolado Unioeste 44 que apresentou a maior mortalidade total s...
The fungus Beauveria bassiana is naturally found in poultry houses and causes high rates of mortality in Alphitobius diaperinus. Laboratory and field experiments have shown the potential of this fungus as an insect control agent. However, in poultry houses, bacteria as Salmonella, can be found and have been studied alternative control methods for this pathogen. Thus, this study aimed to evaluate the effect of plant extracts and a disinfectant on the fungus Beauveria bassiana (strain Unioeste 4). Conidial viability, colony-forming unit (CFU) counts, vegetative growth, conidia production, insecticidal activity of the fungus and compatibility were used as parameters in the evaluation of the effect of these products on the fungus. Alcoholic and aqueous extracts of jabuticaba (Myrciaria cauliflora (Mart.), guava (Psidium guajava (L.)), and jambolan (Syzygium cumini (L.), at concentrations of 10% as well as the commercial disinfectant, Peroxitane 1512 AL, were evaluated at the recommended concentrations (RC), 1:200 (RC), 0.5 RC and 2 RC. There was a negative influence of alcoholic and aqueous extracts of jabuticaba, guava and three dilutions of Peroxitane on the viability of conidia. The CFUs and vegetative growth of the fungus were affected only by the Peroxitane (all dilutions). For conidial production, the aqueous extract of guava had a positive effect, increasing production, while the Peroxitane at the R and RC concentrations resulted in a negative influence. The mortality of A. diaperinus, caused by the fungus after exposure to these products, was 60% for the peracetic acid at 0.5 RC, and above 80% for the extracts. Thus, the results showed that all the extracts and Peroxitane at RC 0.5 are compatible with the fungus B. bassiana Unioeste 4, however only the extracts had a low impact on inoculum potential. Keywords: Myrciaria cauliflora), na concentração de 10% e também o desinfetante comercial Peroxitane 1512 AL na concentração recomendada -1:200 (CR), 0,5 CR e 2CR. Foram avaliados a: germinação dos conídios, unidades formadoras de colônias (UFC), crescimento vegetativo, produção de conídios e efeito sobre a atividade inseticida do fungo contra adultos de A. diaperinus, bem como a compatibilidade entre produtos e o fungo. Verificou-se influência negativa dos extratos alcoólico e aquoso de jabuticabeira, goiabeira e das três diluições de Peroxitane sobre a viabilidade dos conídios. Já, a UFC e o crescimento vegetativo foram afetados apenas com Peroxitane (em todas as diluições). Para produção de conídios, o extrato aquoso de goiabeira teve efeito positivo, elevando a produção, enquanto as diluições recomendada e o dobro de Peroxitane mostraram influência negativa. Observou-se ainda que a mortalidade de A. diaperinus causada pelo fungo após a exposição aos produtos foi de 60% para o ácido peracético na 0,5 CR, já para os extratos foi acima de 80%. Assim, os resultados demonstraram que todos os extratos e o Peroxitane na 0,5 CR são compatíveis com o fungo B. bassiana Unioeste 4, porém apenas os extratos...
This study was performed under laboratory conditions to identify isolates of the fungus Beauveria spp. that can control Polyphagotarsonemus latus in the greenhouse and field. Thirty Beauveria spp. isolates were tested by spraying 1 mL conidia (1 × 10 8 conidia/mL) on pepper leaf discs containing 15 mites. Evaluations were performed on the 3rd and 6th day post application by counting the number of dead mites. Vegetative growth and conidial production were measured from the selected isolates, and bioassays were conducted in the greenhouse on bean seedlings in plastic pots. The isolate Unioeste 53 was selected, and a conidial suspension (1 × 10 8 conidia/mL) was applied with a backpack sprayer. The evaluation consisted of pre-and post-treatment counts of the number of live mites on ten leaflets in both the plots treated with the fungus and control plots, and the same procedure was followed for the field experiment. In the laboratory, the Unioeste 53 isolate resulted in total and confirmed mortality rates of 70% and 57.7%, respectively. In the greenhouse, the population decreased by 76.71% by the 16th day after application. In the field, the population decreased by 66% by the 12th day after application, demonstrating the potential of this fungus for mite management.Keywords: microbial control, entomopathogenic fungi, broad mite. Seleção e caracterização de isolados do fungo ResumoEste trabalho teve por objetivo selecionar isolados do fungo Beauveria bassiana em condições de laboratório com potencial de uso em casa de vegetação e campo no controle do ácaro branco. Foi realizada uma seleção com 30 isolados de Beauveria spp. através de pulverização direta de conídios (1 × 10 8 conídios/mL) sobre discos foliares de pimenta contendo 15 ácaros. As avaliações foram realizadas no terceiro e sexto dia contando-se o número de mortos, e confirmação do patógeno em câmara úmida. Parâmetros de crescimento vegetativo e produção de conídios foram avaliados. No bioensaio em casa de vegetação foram preparados vasos com plantas de feijão e fez-se a aplicação do Unioeste 53 (1 × 10 8 conídios/mL), utilizando pulverizador costal, a avaliação constou da contagem prévia e posterior à aplicação do número de ácaros vivos em 10 folíolos, tanto nas parcelas destinadas ao tratamento com fungo, quanto na testemunha. A fase de campo seguiu os mesmos padrões, porém, com área experimental total de 225 m 2 , com oito parcelas de 10,24 m 2 , sendo 4 testemunhas e 4 onde foi aplicado o isolado Unioeste 53 seguindo metodologia de aplicação e avaliação já descritas para casa de vegetação. Em laboratório o isolado Unioeste 53 causou mortalidade total de 70% e 57,7% de mortalidade confirmada. Em casa de vegetação, apresentou redução da população de 76,71% 16 dias após aplicação, já em campo, a redução da população foi de 66% após 12 dias da aplicação, demonstrando o potencial do ácaro pelo fungo.Palavras-chave: controle microbiano, fungos entomopatogênicos, ácaro branco.
This work aimed to evaluate the effects of the products Biogermex®, Agro-mos®, Soil-Set® and Planta Clean® on the development of white muscardine in Bombyx mori. Products have been tested at two stages for effects on biology of caterpillars and on silk production (1), and then they were evaluated to know their potential in the prevention/control of white muscardine (2). Products were sprayed on mulberry leaves (preventive treatment) and also on the integument of silkworms (curative treatment). At the first stage, the products were applied on four consecutive days, in one of the daily feeds. Planta Clean® - curative treatment - and Soil-Set® - preventive treatment - caused mortality in 63.3% and 30% of silk worms, respectively. The fungus Beauveria bassiana was inoculated at the concentration 5 × 107 conidia/mL on the leaves and insects. The products were applied three hours after application on the fungus, in a single application, and also for four days in the other groups. A group of silkworms sprayed only with the fungus served as control. Biogermex® - curative treatment applied once and for four times - was the most effective, reducing mortality by 25 and 26.7%, respectively, as compared with the control group. None of the evaluated products acts preventively against white muscardine.
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