For an important and expensive crop such as corn, the resistance of Spodoptera frugiperda J.E. Smith to various pesticides has led to research throughout the world for a potential insecticide from a natural source. For the management of pest resistance, natural compounds associated with synthetic insecticides can be a promising tool because they can reduce the application of the synthetics molecules while maintaining their effectiveness and promoting the control of the pests. Linalool is a potential insecticide that is easily obtained because it is found in high concentrations in the essential oil of Ocimum basilicum L. Therefore, the present study aimed to evaluate the toxicity of this essential oil and its combination with deltamethrin to control S. frugiperda. Through dose response assays, the acute toxicities (LD 50 ) of the essential oil and deltamethrin were estimated. Additionally, the combination of these materials was also assessed, attaining a reduction of 80% of the LD 50 of deltamethrin while obtaining the same result as when the pyrethroid was administered alone. From these results, it is expected that the combination of natural compounds and synthetic insecticides will be a promising practice, helping to manage resistance while reducing the environmental impact of toxic compounds.Index terms: Natural insecticides; linalool; fall armyworm; pyrethroid; synergism. RESUMOPara uma cultura importante e expressiva como o milho, a resistência de Spodoptera frugiperda J.E. Smith a vários inseticidas atraiu a atenção no mundo para pesquisar o potencial inseticida de compostos naturais. Para o manejo da resistência, os compostos naturais associados a inseticidas sintéticos podem ser uma ferramenta promissória por reduzirem a aplicação das moléculas sintéticas para que não percam sua eficácia, além de promover o controle das pragas. O linalol é um terpenoide considerado como inseticida potencial, pode ser facilmente obtido naturalmente uma vez que é encontrado em alta concentração no óleo essencial de Ocimum basilicum. Portanto, o presente estudo teve como objetivo avaliar a toxicidade deste óleo essencial e sua combinação com deltametrina no controle de Spodoptera frugiperda. Através do ensaio de dose-resposta, foi estimada a toxicidade aguda (DL50) do óleo essencial e da deltametrina. Adicionalmente, foi também avaliada a combinação entre ambos, alcançando uma redução de 80% da DL 50 de deltametrina para se obter o mesmo resultado quando o piretroide foi administrado sozinho. A partir dos nossos resultados, espera-se que uma combinação de uso de compostos naturais e inseticidas sintéticos possa ser uma prática promissora, auxiliando no manejo da resistência de pragas e principalmente reduzindo os impactos ambientais de compostos tóxicos.

-Yellow passion fruit has conquered a significant position in the agribusiness of tropical fruits; therefore, farmers have been interested in expanding their groves, and technical information that guarantees the high yield of the farmings is needed. Aiming to observe factors related to the propagative material targeted at quality and maximization of the genetic potential, the objective of the study consisted in assessing germination and emergence of passion fruit seeds collected in three positions in the fruits and submitted to different methods of mucilage removal (aryl). The passion fruits were split in three parts: distal, medial and proximal and the contents of each part was divided in two. The content of each part of the fruit was submitted to mechanical and by fermentation methods for removal of aryl. It is concluded that the seed position in the fruit does not interferes with the germination. The aryl removal method by mechanical extraction affects the germination and seedling emergence.Index terms: Passiflora edulis, mechanical extraction, fermentation, propagation, mucilage. Métodos de remoção do arilo e posições das sementes no fruto de maracujá:Germinação e emergência RESUMO -O maracujá-amarelo conquistou significativa posição no agronegócio de frutas tropicais, com isso, produtores despertaram interesse para expandir seus pomares, sendo necessárias informações técnicas que garantam a alta produtividade das lavouras. No intuito de observar fatores relacionados ao material propagativo visando a qualidade e a maximização do potencial genético objetivou-se avaliar a germinação e a emergência de sementes de maracujá coletadas em três posições nos frutos e submetidas a métodos de retirada da mucilagem (arilo). Os frutos de maracujá foram seccionados em três partes: distal, mediana e proximal. Cada um destes conteúdos foi submetido aos métodos mecânico e de fermentação para remoção do arilo. Podendo concluir que a posição da semente no fruto do maracujazeiro não interfere na germinação e o método de remoção do arilo por extração mecânica prejudica a germinação e a emergência de plântulas.Termos para indexação: Passiflora edulis, extração mecânica, fermentação, propagação, mucilagem.

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RESUMO -A lagarta-do-cartucho (Spodoptera frugiperda) é uma praga-chave na cultura do milho, e aplicações de inseticidas têm sido necessárias para reduzir a população do inseto. O controle desta praga tem sido difícil porque a lagarta encontra-se comumente protegida no interior do cartucho, o que pode reduzir a deposição e eficácia do inseticida. Portanto, este trabalho objetivou avaliar o efeito de taxas de aplicação, pontas de pulverização e inseticidas no controle de S. frugiperda no milho. O experimento foi conduzido em delineamento em blocos casualizados, em esquema fatorial 2 x 2 x 2 + 1 com quatro repetições. Os fatores foram duas taxas de aplicação (100 e 200 L ha -1 ), duas pontas de pulverização (jato plano com e sem com indução de ar) e dois inseticidas (triflumuron e fenpropatrina). Também se utilizou um tratamento controle correspondente à aplicação de clorpirifós utilizando a ponta jato plano simples na taxa de 200 L ha -1 . As características avaliadas foram espectro de gotas, deposição de calda, eficácia biológica e produtividade da cultura. A taxa de aplicação de 100 L ha -1 produziu maior deposição de calda do que a 200 L ha -1 para ambas as pontas de pulverização e não reduziu a eficácia dos inseticidas. Ambos os inseticidas tiveram eficácias semelhantes no controle da lagarta-do-cartucho aos 10 dias após a aplicação (DAA), embora a eficácia do inseticida fenpropatrina tenha sido maior do que a do triflumuron aos 3 DAA. Palavras-chave: lagarta-do-cartucho, Zea mays, ponta de pulverização, taxa de aplicação, manejo de pragas. INSECTICIDE APPLICATION TECHNOLOGY ON FALL ARMYWORM CONTROL IN CORNABSTRACT -The fall armyworm (Spodoptera frugiperda) is a key pest in corn, and insecticide applications have been needed to reduce the insect population. The fall armyworm has been difficult to control because its larvae is commonly protected in the whorl of corn, which may reduce insecticide deposition and its efficacy. Therefore, this research aimed to evaluate the effects of application rate, nozzle type and insecticide on control of S. frugiperda in corn. Experiment was conducted in a randomized complete block design and a 2 x 2 x 2 + 1 factorial scheme with four replications. The factors were two application rates (100 e 200 L ha -1 ), two hydraulic nozzles (standard and air induction flat-fan) and two insecticides (triflumuron and fenpropathrin). An additional treatment was also included, composed of chlorpyrifos sprayed at 200 L ha -1 using a standard flat-fan nozzle. Parameters of interest were droplet spectrum, spray deposition, biological efficacy and crop yield. A 100 L ha -1 application rate produced greater spray deposition than at 200 L ha -1 for both nozzle types and did not reduce the insecticide efficacy. At 10 days after application (DAA) both insecticides provided similar efficacy on fall armyworm control, although it was greater using fenpropathrin than triflumuron at 3 DAA. Keywords: fall armyworm, Zea mays, spray nozzle, spray volume, pest management. A tecnologia de aplicação, contudo...

Coffee plants (Coffea arabica L.) present dense foliage that obstruct the entering of pesticides inside the plant canopy uniformly. Adjust the application rate concerning the plant canopy volume can be a way to make the pesticide applications more efficient. The objective of this study was to evaluate the deposition of spray solution on coffee leaves with different volumes of plant canopy and different application rates; additionally, to determine the specific volume indexes for different coffee phenological stages. The studies of coffee leaf deposition were performed on commercial fields of C. arabica - Topázio MG 1190 and Catuaí Vermelho IAC 99 cultivars, in different months. Three volumes of vegetation ranging from 8.572 to 16.200 m3 ha-1 - obtained from the calculation of tree-row volume (TRV) performed in 20 plants - and five application rates (200, 300, 400, 600 and 800 L ha-1) and in each phenological stage (maturation, post-harvest, grain filling) were evaluated in a randomized block design with five replications. A bright blue marker was added to the spray solution to be detected by spectrophotometry in order to study the spray deposition and losses to the soil. After the treatment applications, ten coffee leaves corresponding to the 1st pair of leaf from an orthotropic branch of each third of the coffee plant (upper, middle, lower) were randomly collected. Petri dishes were used to evaluate the losses to the soil. The TRV and leaf density should be considered together in the definition of the application rate for coffee protection. It is also possible to reduce the application rate to values close to 200 L ha-1. The volume indexes for each coffee phenological stage were defined for proper canopy wetting and low losses to the soil.

Tank mixture of pesticides and foliar fertilizes for Triozoida limbata control in guava trees (Psidium guajava L.) 1Although the tank mixture of pesticides and foliar fertilizers is common practice in agriculture, further clarification and scientific support is needed to be regulated. Thus, the objective of this work was to evaluate the effect of tank mixture of an organosilicon adjuvant and manganese foliar fertilizer throw the insecticide imidacloprid effectiveness over Triozoida limbata control in guava trees. The experimental plot was considered with four trees followed in the same cultivation line subdivided into 4 quadrants. The experiment followed a randomized block design with split plots, with four replications. Treatments were T1 -Imidacloprid (Imid.); T2 -Imid. + Polyether-polymethyl siloxane copolymer (Sil.); T3 -Imid. + MnSO 4 ; T4 -Imid. + Sil. + MnSO 4 ; T5 -Control (no application). Physical-chemical characteristics, spray deposition over the leaves and losses to the soil, guava psyllid percentage of infestation and nymph's number were evaluated. The addition of foliar fertilizer on the mixture reduced the pH and surface tension and increased the electric conductivity and viscosity of the insecticide solutions. The silicon adjuvant reduced the surface tension and increased the viscosity and the pH. The tank mixture of organosilicon adjuvant and manganese foliar fertilizer do not influence the efficacy level of the insecticide.

ABSTRACT:Nowadays, few studies have been conducted to evaluate the effect of tank mixture of pesticides on pest chemical control in maize crops, however the farmers are often using these mixtures, without any technical support. The current study focused on assessing some pesticide mixtures to control Spodoptera frugiperda with triflumuron in a conventional corn hybrid. Moreover, this experiment aimed to assess likely plant physiological effects, as well as physical-chemical characteristics of these tank mixes. To this end, four treatments were carried out in a randomized block design with five replications, being repeated in two seasons. Treatments consisted of different pesticide mixtures, such as insecticide (INS) + adjuvant (ADJ); INS + ADJ + fungicide (FUN); INS + ADJ + FUN + foliar fertilizers (FF); control (Ctrl). The treatments underwent analyses of mixture physical-chemical characteristics, sampled caterpillar number and size, leaf gas exchange (IRGA), and amount of chlorophyll a and b. Spray liquid characteristics changed with used mixture. Fertilizer addition caused major changes in spray liquid properties as increasing pH and electrical conductivity. No effect was observed by mixing azoxystrobin, cyproconazole, zinc oxide and manganese sulfate to triflumuron concerning control effectiveness of Spodoptera frugiperda in the corn plants. Conversely, each pesticide mixture had a distinct effect on plant physiological variables.

Among the pests that attack the maize, the maize leafhopper, which causes direct damages by sap-sucking and indirect ones, stands out as being a vector of pathogens and viruses, and can cause losses of up to 100% of the production. An alternative to improve the chemical control of this pest is the use of electrostatic spraying technology. However, there is no research support. This study aimed to evaluate the deposition of spray in the maize crop and the effectiveness in the chemical control of the maize leafhopper, using the electrostatic spraying system, at different application rates, compared to the conventional spraying system. The experiment was conducted in a randomized block design with five treatments, in a 2x2 + 2 factorial scheme: presence or absence of electrostatic spraying system, two application rates (35 and 50 L ha-1), an additional treatment using a hydraulic spray nozzle and a rate of 100 L ha-1, and other additional treatment without the application of insecticide, in order to support the study of pest infestation. Each treatment consisted of eight replicates, in which the spray deposition in the maize canopy and the efficiency in the control were evaluated. For the insecticide applications, a boom sprayer with induction electrostatic spraying system was used with indirect electrification. To evaluate the deposition, the Brilliant Blue FCF marker was added to the spray to be detected by absorbance in spectrophotometry. For the biological efficacy of the maize leafhopper, the insecticide composed of thiamethoxam and lambda-cyhalothrin was used compared with the control without the application. There was a significant increase in the spray deposition, both in the upper and lower maize leaves, with the use of electrostatic spray technology compared to the conventional spray system. The control of the maize leafhopper was also superior. The electrostatic spraying also made it possible to reduce the application rate by approximately three times in relation to that used in conventional hydraulic spraying.