Corn yield with reduction of insecticidal sprayings against fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

The ideal time is more important than amount of insecticidal spraying to adequate the control of Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae) in corn. This study aimed to evaluate lufenuron sequential sprayings effect and its rotation with other active ingredients on the population, damage caused by S. frugiperda and the impact on corn yield. The experiment was carried out in the field with six treatments: (1) one lufenuron spraying, (2) two lufenuron sprayings, (3) three lufenuron sprayings (4) four lufenuron sprayings, (5) sprayings with spinosad, lufenuron, thiamethoxam+lambdacyhalothrin and deltamethrin (in sequence, at ten days intervals) (6) control treatment. Sprayings started twenty days after the seedling had emerged and then every ten days for a maximum of four sprays. Both caterpillar population (20.9-21.7 larvae/plot) and index of damage (1.2-1.7) observed in corn plants were significantly lower in treated plots compared to control (untreated) (31.7 larvae/plot and index of damage 2.7), regardless of spraying amount. The results showed that multiple insecticide applications to control S. frugiperda do not guarantee higher yields in corn, ranging from 6375.2 to 7650.1 kg ha -1. Only one spraying of lufenuron was enough to prevent significant reduction in corn yield (6749.9 kg ha -1). © 2012 Asian Network for Scientific Information.

Influence of optimized lubrication-cooling and minimum quantity lubrication on the cutting forces, on the geometric quality of the surfaces and on the micro-structural integrity of hardened steel parts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tolerância de Espécies de Mucuna a Herbicidas Utilizados na Cultura da Cana-de-Açúcar

The emergence of Mucuna species in sugarcane plantations, even after herbicide spraying for weed management, allowed us to elaborate the hypothesis that these plants are tolerant to the herbicides commonly used in the culture. Thus, to prove this hypothesis, this work was carried out to study the tolerance of Mucuna aterrima, Mucuna cinerea and Mucuna deeringiana to application of herbicides with different mechanisms of action in pre- and postemergence. The experiment was arranged in a randomized block design with 9 treatments and five replications in a factorial 3 × 3, plus controls. At pre-emergence, the first factor was constituted by the herbicides sulfentrazone (800 g ha-1), imazapic (245 g ha-1), and amicarbazone (1,400 g ha-1), and the second factor by the Mucuna species, besides the additional control for each species studied. At post- emergence, the herbicides tested were clomazone (1,100 g ha-1), ametryn+trifloxysulfuronsodium (1,463 + 37 g ha-1), and 2,4-D (1,209 g ha-1). In the chemical management at pre-emergence, the species were sensitive to amicarbazone, followed by sulfentrazone, and tolerant to imazapic. At post-emergence, all species were sensitive to ametryn + trifloxysulfuron-sodium and 2,4-D, but tolerant to clomazone.

Efeito de produtos químicos sobre a mancha bacteriana (xanthomonas perforans) e na ativação de proteínas relacionadas à patogênese em tomateiro

The present study aims to evaluate the effect of fungicides and antibiotics to control bacterial spot (Xanthomonas perforans) in tomato, and the activation of pathogenesis-related proteins. Hybrid tomato AP 529 was used to assess the severity of disease. The treatments consisted of spraying with acibenzolar-S-methyl, fluazinam, pyraclostrobin, pyraclostrobin + methiran, copper oxychloride, copper oxychloride and mancozeb + oxytetracycline, and inoculated and non-inoculated controls. After three days of treatment, all plants were inoculated with X. perforans (10 6 CFU / mL). Leaf discs were collected for assessment of peroxidase, polyphenol oxidase, β-1,3 glucanase, phenylalanine ammonia lyase and protease. The area under the disease progress curve (AUDPC) was calculated with the data of severity. All treatments had reduced AUDPC compared to the inoculated control. Fungicides acibenzolar-S-methyl, pyraclostrobin, and pyraclostrobin + methiran had more satisfactory results in reducing the severity of bacterial spot on tomato. The products based on pyraclostrobin together with acibenzolar-S-methyl induced enzymatic activities of peroxidase, polyphenoloxidase and β-1,3 glucanase, indicating that these products may be related to the induction of resistance to bacterial spot on tomato plants.

Continuous production of metal matrix composites from the semisolid state

Continuous strip metal matrix composite (MMC) casting of 0.3 mm diameter hard-drawn stainless steel (316L) wire in a quasi-eutectic SnPb (64Sn36Pb) matrix was performed by a two-roll melt drag processing (TRMDping) method, with the wire being dragged through a semisolid puddle with a fibre contact time of approximately 0.2 s. A slag weir placed at the nozzle contained two wire guide holes: one located near the upper roll, and the other located between the rolls. A successful continuous composite strip casting with good fibre alignment was achieved by inserting and embedding the wire into the matrix using the guide hole between the rolls. Degeneration of eutectic/dendrite structures led to the formation of globular structures. The occurrence and formation mechanisms of cracks, de-lamination and voids in the matrix were discussed. TRMDping is economically viable and has significant benefits over other MMC fabrication methods. © (2013) Trans Tech Publications, Switzerland.

Influência de pontas de pulverização e adjuvantes no potencial de redução de deriva em túnel de vento

The drift is intimately linked to inappropriate use of pesticides and an important factor for reducing it, is the correct selection of spray nozzles and adjuvants. The objective of this work was to evaluate the drift potential in wind tunnel with different spray nozzles and different concentrations of adjuvants. The experiment was composed by six spray solutions (vegetable oil (in three concentrations), mineral oil, surfactant and reducing drift), which were applied with two nozzles, one pre-orifice flat fan (DG 8003 VS) and other with air induction (AI 8003 VS), totaling 12 treatments, with three repetitions. The equipment used was a wind tunnel, where the drift collections were made at different points. The treatments averages were compared using Confidence Interval at 5% probability. The analysis of the percentage of drift showed that the treatments had different behaviors. The nonylphenol ethoxylate adjuvant presented the highest drift when applied with the nozzle of pre-orifice and the lowest drift when applied with the air induction. The behavior of these nozzles when the oil-based adjuvant was used showed apposite results to those obtained for the surfactant. For the DG nozzles the lowest percentage of drift, at all analyzed distances, was observed to the treatment with vegetable oil (1.0%) and with the AI nozzles the lower drift was found for the treatment with nonylphenol ethoxylate (0.0625%), for the four distances in the collection. The result showed that both the spray nozzles and adjuvants alter directly the drift potential. There was no proportionately between the concentration of the oil-based adjuvant and the drift percentage.

Effect of different methods of cutting fluid application on turning of a difficult-to-machine steel (SAE EV-8)

In this study, different methods of cutting fluid application are used in turning of a difficult-to-machine steel (SAE EV-8). Initially, a semisynthetic cutting fluid was applied using a conventional method (i.e. overhead flood cooling), minimum quantity of cutting fluid, and pulverization. A lubricant of vegetable oil (minimum quantity of lubricant) was also applied using the minimum quantity method. Thereafter, a cutting fluid jet under high pressure (3.0 MPa) was singly applied in the following regions: chip-tool interface, top surface of the chip (between workpiece and chip) and tool-workpiece contact. Moreover, two other methods were used: an interflow between conventional application and chip-tool interface jet (combined method) and, finally, three jets simultaneously applied. In order to carry out these tests, it was necessary to set up a high-pressure system using a piston pump for generating a cutting fluid jet, a venturi for fluid application (minimum quantity of cutting fluid and minimum quantity of lubricant) and a nozzle for cutting fluid pulverization. The output variables analyzed included tool life, surface roughness, cutting tool temperature, cutting force, chip form, chip compression rate and machined specimen microstructure. Among the results, it can be observed that the tool life increases and the cutting force decreases with the application of cutting fluid jet, mainly when it is directed to the chip-tool interface. Excluding the methods involving jet fluid, the conventional method seems to be more efficient than other methods of low pressure, such as minimum quantity of volume and pulverization, when considering just the cutting tool wear. © 2013 IMechE.

Different methods of cutting fluid application on turning of a difficult-to-machine steel

Different methods of cutting fluid application are used on turning of a difficult-tomachine steel (SAE EV-8). A semi-synthetic cutting fluid was applied using a conventional method, minimum quantity of cutting fluid (MQCF), and pulverization. By the minimum quantity method was also applied a lubricant of vegetable oil (MQL). Thereafter, a cutting fluid jet under high pressure (3.0 MPa) was singly applied in the following regions: chip-tool interface; top surface of the chip; and tool-workpiece contact. Two other methods were used: an interflow between conventional application and chip-tool interface jet and, finally, three jets simultaneously applied. In order to carry out these tests, it was necessary to set up a high pressure system using a piston pump for generating a cutting fluid jet, a Venturi for fluid application (MQCF and MQL), and a nozzle for cutting fluid pulverization. The output variables analyzed included tool life, surface roughness, cutting tool temperature, cutting force, chip form, chip compression rate and machined specimen microstructure. It can be observed that the tool life increases and the cutting force decreases with the application of cutting fluid jet, mainly when it is directed to the chip-tool interface. Excluding the methods involving jet fluid, the conventional method seems to be more efficient than other methods of low pressure. © (2013) Trans Tech Publications, Switzerland.

Effect of reduced fungicide doses on control of soybean Asian rust and bean yield

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Plant-derived essential oils affecting settlement and oviposition of Bemisia tabaci (Genn.) biotype B on tomato

The silverleaf whitefly Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) is an economically important pest of tomatoes Solanum lycopersicum (L.), causing irregular ripening on fruits and transmitting several plant pathogenic geminiviruses. The management of this pest is commonly based on repetitive spraying with synthetic pesticides, causing serious environmental damages and increase of resistance by insect population. In the present study, essential oils from the leaves of Artemisia camphorata Vill., Ageratum conyzoides L., Foeniculum vulgare Mill., Lippia alba (Mill.) N. E. Br., Plectranthus neochilus Schltr., and Tagetes erecta L. were investigated for their possible repellent and oviposition-deterrent effects against B. tabaci biotype B on tomato. In a multi-choice assay, P. neochilus essential oil was the most active repellent and oviposition deterrent. Essential oils of A. conyzoides and T. erecta significantly deterred the female B. tabaci biotype B from laying eggs on treated tomato leaflets compared with the control. (E)-Caryophyllene (30.67 %) and the monoterpenes α-pinene (15.02 %) and α-thujene (11.70 %) were identified as the major constituents of the essential oil of P. neochilus. Our findings demonstrated the potential of essential oil of P. neochilus and other oils in the reduction of settlement and oviposition of B. tabaci biotype B on tomato. © 2012 Springer-Verlag Berlin Heidelberg.

Spray Nozzles, Pressures, Additives and Stirring Time on Viability and Pathogenicity of Entomopathogenic Nematodes (Nematoda: Rhabditida) for Greenhouses

The objective of this study was to evaluate different strategies for the application of entomopathogenic nematodes (EPN). Three different models of spray nozzles with air induction (AI 11003, TTI 11003 and AD-IA 11004), three spray pressures (207, 413 and 720 kPa), four different additives for tank mixtures (cane molasses, mineral oil, vegetable oil and glycerin) and the influence of tank mixture stirring time were all evaluated for their effect on EPN (Steinernema feltiae) viability and pathogenicity. The different nozzles, at pressures of up to 620 kPa, were found to be compatible with S. feltiae. Vegetable oil, mineral oil and molasses were found to be compatible adjuvants for S. feltiae, and stirring in a motorized backpack sprayer for 30 minutes did not impact the viability or pathogenicity of this nematode. Appropriate techniques for the application of nematodes with backpack sprayers are discussed. © 2013 Moreira et al.

Chemical control of pilea microphylla in euterpe oleraceae nurseries with oxyfluorfen

The açai palm is a Brazilian native species and economically important, grown for the hearts of palm and fruit extraction, as well as the seedling production for ornamental purposes. The weed control is one of the concerns observed in seedling production, which has the artillery plant (Pilea microphylla) with the major and widespread occurrence. Thus, the aim of this trial was to evaluate the selectivity and efficacy of oxyfluorfen in artillery plant control in açai (Euterpe oleracea) seedlings. The experimental design was completely randomized. The treatments were arranged in a 2 x 3 factorial scheme, using 2 types of herbicide application: broadcast spraying (sprayed over total area) and spot spraying (directed to the target) and 3 oxyfluorfen dosages (0, 72 and 144 g of active ingredient ha-1) with four replications. Each experimental unit consisted by one açai palm pot infested by artillery plant. They ere visually evaluated for seedling toxicity and the weed control percentage, at 7, 15, 30, 45 and 60 days after application (DAA). There was 100% control of artillery plant from 15 to 60 DAA for the two tested dosages, regardless of application type. However, 100% control was observed at 7 days, using 1.5 L ha-1 in the spot type. The effects of phytotoxicity from 30 to 60 days was moderate, regardless the application method or dosage.

Estimativa da área e capacidade de retenção foliar de calda em citros

This work was done to determine the maximum amount of liquid that the citrus leaves can hold back and compare alternative methods for estimating leaf area with the standard method of integrating electronic image. The alternative methods were leaf mirroring on paper and leaf digitalization and imagine analyzes. The spray retention capacity was evaluated with mitecide sprayed with cyhexatin (Sipcatin 500 CS) plus the treatments: combination of two adjuvants (mineral oil - Assist and vegetable oil - Veget'Oil) and two concentrations (10 and 15 mL of adjuvant L-1). The methods for estimating leaf area assessed do not differ between them. The maximum retention of liquids for the leaf occurred when vegetable oil in the application was used.

Assistência de ar e aplicação em volume baixo no controle da ferrugem asiática da soja (Phakopsora pachyrhizi Sydon & Sydon

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inoculação e adubação molíbdica no amendoim cultivado em semeadura direta sobre forrageiras

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)