Cientifica最新文献

{"title":"Allelopathic effect of aqueous extract of Cyperus rotundus on Lactuca sativa and Solanum lycopersicum","authors":"Eduardo Fernando Bispo, N. B. Meneses, G. O. Sousa, F. D. M. Sousa, E. Costa","doi":"10.15361/1984-5529.2020v48n1p36-40","DOIUrl":"https://doi.org/10.15361/1984-5529.2020v48n1p36-40","url":null,"abstract":"The demand for vegetables was reinforced by the search for healthier foods, favoring increased sales of fresh products. Lettuce ( Lactuca sativa L.) and tomato ( Solanum lycopersicum L.) are the most cultivated vegetables in Brazil, thus being economically important. This study evaluates the allelopathic effect of aqueous extract of nutgrass ( Cyperus rotundus ) on lettuce ( Lactuca sativa ) and tomato ( Solanum lycopersicum ) plants, aiming to ana­lyze its influence on species development. Two trials were conducted in the premises of the Taquaritinguense Institute of Higher Education (ITES) in Taquaritinga city, Sao Paulo State, under temperatures ranging from 14 oC to 28 oC, in a greenhouse. The variables analyzed were: fresh shoot and root weight (g), using a semianalytical scale; and root length (cm), using a ruler. Cyperus rotundus leaf extract at higher concentrations positively affected the early growth of vegetables. Studies on allelopathic effects between plants are extremely important because the use of this extract can contribute to seedling growth. The 200% concentration of Cyperus rotundus extract increased root and shoot development in tomato crop.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46311352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Análisis del impacto del intervalo de tiempo de transmisión sobre la latencia en la red de acceso radio de sistemas 5G","authors":"Andrés Castro-Delgado, V. Quintero-Flórez","doi":"10.46842/ipn.cien.v24n1a03","DOIUrl":"https://doi.org/10.46842/ipn.cien.v24n1a03","url":null,"abstract":"Los Sistemas de Comunicaciones Móviles de Quinta Generación (5G, Fifth Generation) soportarán servicios de Comunicación Ultra Confiable de Baja Latencia (URLLC, Ultra-Reliable Low-Latency Communication), que imponen requerimientos exigentes en términos de latencia y confiabilidad. La Unión Internacional de Telecomunicaciones (ITU, International Telecommunications Union) ha considerado reestructurar la trama de datos de nivel físico en Sistemas 5G para adaptar el Tiempo de Intervalo de Transmisión (TTI, Time Transmission Interval) y cumplir con los requerimientos definidos para los servicios URRLC. El presente artículo analiza el impacto del TTI sobre la latencia de la Red de Acceso Radio (RAN, Radio Access Network) de Sistemas 5G. Para esto, se estudia la estructura de trama de nivel físico de Sistemas 5G y se diseñan escenarios de simulación teniendo en cuenta la latencia en el nivel físico. Estos escenarios son implementados en la herramienta software ns3, utilizando el módulo mmWave para sistemas 5G. Los resultados muestran que el TTI influye significativamente sobre la latencia en la RAN, sin embargo, es necesario considerar las características de la red y los servicios a desplegar.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70596132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelado de Orden Fraccional de la dinámica de robots manipuladores de 1, 2 y 3 GDL","authors":"Israel Ceron-Morales","doi":"10.46842/ipn.cien.v24n2a06","DOIUrl":"https://doi.org/10.46842/ipn.cien.v24n2a06","url":null,"abstract":"Este documento presenta el modelado de orden fraccional de la dinámica de robots manipuladores de 1, 2 y 3 grados de libertad (GDL). Se presenta la demostración de estabilidad del modelo de orden fraccional mediante el segundo método de Lyapunov. Se considera un parámetro físico básico, la inercia de masa de los eslabones empleados. Se utiliza el software Freecad para el diseño mecánico. Se simula el modelo dinámico y en el caso de los manipuladores de 2 y 3 GDL se presentan trayectorias en el plano (x, y) y en el espacio (x, y, z) respectivamente. Los modelos se programan en una tarjeta de desarrollo basada en un microcontrolador, la ventaja de la tarjeta de desarrollo se encuentra en sus periféricos de salida debido a que cuenta con dos canales analógicos de salida, y estos se envían a un osciloscopio, los resultados obtenidos están de acuerdo con los modelos presentados.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70596243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biological control of Pseudomonas syringae pv. garcae in coffee crop with Bacillus spp. isolates","authors":"Fabrício J. Silva, B. S. Vieira, A. Siquieroli","doi":"10.15361/1984-5529.2019v47n4p364-370","DOIUrl":"https://doi.org/10.15361/1984-5529.2019v47n4p364-370","url":null,"abstract":"Among the diseases that affect the coffee crop, bacterial blight caused by Pseudomonas syringae pv. garcae (Psg) stands out due to production losses. This study evaluates the antagonistic effect of Bacillus spp. against Psg both in vitro and in coffee seedlings. In vitro antagonism was evaluated by the double layer method for the inhibition of Psg growth. Subsequently, in vitro selected antagonists were tested for their ability to inhibit bacteriosis in coffee seedlings (cv. Mundo Novo) under greenhouse conditions. It was evaluated nonspecific met­abolic production by antagonistic bacteria and identified the isolates that stood out in the in vitro experiment. Iso­lates considered as the most promising in vitro experiments (23% of the total) were chosen for the antagonistic efficiency test in a greenhouse. Isolates B04, B05, B22, B31, B53, B202, B208, B264, B266, and B294 showed ammonia production. Isolates B04, B33, and B294 showed hydrocyanic acid production. Isolates B04, B05, B18, B22, B33, B53, B105, B202, B208, B264, and B294 showed siderophores production. In addition, isolates B18  ( B. subtilis ), B22 ( B. thuringiensis serovar israelensis ), B05 ( B. methylotrophicus ), B53 ( B. safensis ), B202          ( B. subtilis ), and B33 ( B. subtilis ) reduced more than 80% the severity of bacterial blight under greenhouse condi­tions. Field experiments should be conducted to confirm the potential of these isolates for bacterial blight man­agement.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49199395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macauba production estimated by regression models","authors":"J. Malaquias, L. D. H. C. S. Conceição, M. F. Braga, N. Junqueira","doi":"10.15361/1984-5529.2019v47n4p419-425","DOIUrl":"https://doi.org/10.15361/1984-5529.2019v47n4p419-425","url":null,"abstract":"Macauba has been shown to be the most promising native species for oil and biomass production. The first com­mercial crops have arisen mainly in Minas Gerais State, and estimates indicate a vegetable oil yield potential above 8 t ha -1 . In this context, research has acted strongly on technological advance for improvements in the pro­duction system and selection of superior genotypes, which requires the use of precise and less expensive meth­odologies. Thus, we built prediction models to estimate the weight of macauba bunches using easy-to-measure physical variables. Bunches of plants from five regions of Brazil were evaluated. The bunches were weighed, and length and diameter were measured along with four other variables. Based on the set of variables obtained, step­wise multiple regression analysis was used to build regression models for each region. The correlation between observed versus estimated data reached determination coefficients (R 2 ) above 0.90 in three of the models built. The main variables selected by the best models were bunch volume, bunch length/diameter ratio, and bunch square diameter.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44225804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Initial development of bottle gourd as a function of nitrogen rates","authors":"B. R. Oliveira, Aline dos Anjos Souza, Celicleide Quaresma Lobo, U. C. Oliveira, Anacleto Ranulfo Santo","doi":"10.15361/1984-5529.2019v47n4p441-446","DOIUrl":"https://doi.org/10.15361/1984-5529.2019v47n4p441-446","url":null,"abstract":"Bottle gourd ( Lagenaria siceraria ) is a little known cucurbit, which is well accepted by consumers and is used in cooking mainly in the northeastern and southern regions of Brazil. This study evaluates the behavior of bottle gourd subjected to nitrogen rates in a greenhouse. The experimental design was completely randomized with five treatments and six replicates. The treatments consisted of five nitrogen rates equivalent to 0, 70, 140, 210, and 420 mg L -1 . The following were evaluated: plant height, stem diameter, number of leaves, root dry mass, stem dry mass, leaf dry mass, total dry mass, root/shoot ratio, and chlorophyll a and b contents. Nitrogen rates influenced all studied variables. Greater plant height and stem diameter were obtained with 277 and 282 mg L -1 N, respectively. The highest nitrogen rate provided higher root growth. The results showed that the bottle gourd crop is very responsive to nitrogen fertilization during its initial growth.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43358387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Induction of drought tolerance by inoculation of Bacillus aryabhattai on sugarcane seedlings","authors":"André May, B. R. D. A. Moreira, G. Mascarin, R. D. S. Viana, M. S. Santos, E. H. Silva, N. P. Ramos, I. S. Melo","doi":"10.15361/1984-5529.2019v47n4p400-410","DOIUrl":"https://doi.org/10.15361/1984-5529.2019v47n4p400-410","url":null,"abstract":"In twenty-first century, free-living endophytic and rhizosphere-competent microbes have become breakthrough strategies to meet global demands for sustainable foods and renewable fuelstocks owing to their great potential to produce stress-tolerant food and energy crops. Here, we investigate how Bacillus aryabhattai could mitigate water stress by drought in sugarcane seedlings. Briefly, the sugarcane genotypes, namely IAC91-1099 and RB85-5156, both exposed to cells-centrifuged B. aryabhattai suspension at 1x10 8 CFU mL -1 and non-treated were developed under irrigation regimes of 0, 7, 14 and 21 days to simulate different degrees of soil moisture content. The osmotolerant bacterium remarkably enhanced development of aboveground structures and root system, mainly in irrigated seedlings of IAC91-1099. Clearly noted that microbial metabolism depends on genotype and soil water potential to promote plant growth. This bacterium probably enabled sugarcane plants in early phenological stages to cope with water deficit by regulation of plant growth hormones along with solubilization of nutrients. Of particular importance, the bacterium exerted more pronounced effects by conferring drought tolerance at 7 and 14 days irrigation interval, irrespective of sugarcane genotype, which also translated into increased biomass of shoots and roots. Microbial degradation of ethylene precursors exuded in rhizosphere could reasonably explain why B. aryabhattai -associated seedlings developed deeper root systems to uptake water and nutrients and, conse­quently, allocating larger amounts of dry matter to shoots. Collectively, our findings provide relevant insights on the beneficial effects of the cacti-associated B. aryabhattai in alleviating the harmful effects of drought stress in seedlings and contribute to increasing our understanding of the phenotypic outcomes from the interaction be­tween sugarcane genotypes and a beneficial rhizobacterium. Hence, this bacterial inoculant forms a low-cost and ecologically sound strategy to enhancing drought stress tolerance in sugarcane crops planted in water-limited zones in Brazil.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46827108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of advanced selections of strawberry in southern Brazil","authors":"D. Zanin, A. F. Fagherazzi, Katiana Vanusa Tillwitz, Juliana Martins de Lima, A. Kretzschmar","doi":"10.15361/1984-5529.2019v47n4p388-399","DOIUrl":"https://doi.org/10.15361/1984-5529.2019v47n4p388-399","url":null,"abstract":"Strawberry cultivation is technically considered a complex activity, which demands high inputs in investment and manpower. One of the most relevant technical aspects of this crop is the choice of correct cultivars. A highly fea­sible way to obtain fully adapted genotypes with high production potential and fruit quality is to select the geno­types with best performance in the producing region itself. The objective of this work was to evaluate the ad­vanced selections of strawberry on productive performance, fruit quality and resistance to strawberry leaf spot, powdery mildew and anthracnose, under conditions of the municipality of Lages, Santa Catarina State. Eleven genotypes were evaluated, being one commercial cultivar - San Andreas - and ten advanced selections, namely: ITA 12,103-15; ITA 12,103-12; ITA 12,103-22; ITA 10,107-6; ITA 10,107-7; ITA 13,097-05; ITA 10,133-2; ITA 10,128-9; ITA 12,103-6 and ITA 10,107-12. The experimental design was in randomized blocks, with three repli­cations, and plots constituted by eleven plants. The cultivar San Andreas presented the best results for total (657.06 g plant -1 ) and commercial production (547.77 g plant -1 ), and number of commercial fruits per plant (30.81 fruits plant -1 ). The selections ITA 10,128-9; ITA 10,133-2; ITA 13,097-5; ITA 10,107-7 and ITA 10,107-12 obtained the highest values for soluble solids content, above to 8.5 °Brix, being superior than San Andreas cultivar for this variable. The genotypes ITA 12,103-15 and ITA 10,107-12, on the other hand, were the most resistant to the dis­eases evaluated.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47752194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of Echinochloa spp. populations resistant and susceptible to acetolactate synthase-inhibiting and auxin-mimic herbicides","authors":"D. Sanchotene, S. Dornelles, Leandro Lima Spatt, M. Peripolli, V. S. Trivisiol, Danubia Quadros, E. Müller","doi":"10.15361/1984-5529.2019v47n4p371-379","DOIUrl":"https://doi.org/10.15361/1984-5529.2019v47n4p371-379","url":null,"abstract":"This study evaluated the control of Echinochloa spp. collected in four irrigated rice producing regions of Rio Grande do Sul State, Brazil. We identified populations susceptible and resistant to the herbicides quinclorac (auxin mimic), bispyribac-sodium, penoxsulam, and imazethapyr (ALS inhibitors). The experiment was car­ried out in a greenhouse in a randomized block design with four replicates. Treatments were arranged in a 40x4x6 factorial scheme (40 populations, 4 herbicides, and 6 rates, corresponding to zero, one-half label rate, full label rate, and two, four, and eight times the label rate of each herbicide tested). Echinochloa spp. plants were counted and collected 25 days after emergence. Percent damage was analyzed as a function of plant dry mass. The dose-response curves showed different resistances between the populations collected in the different regions. The Central Depression region accounted for a higher number of populations re­sistant to ALS-inhibiting herbicides. Some Echinochloa spp. populations showed multiple resistance to ALS inhibitors and auxin mimics. Thus, the identification of resistant and susceptible populations and their regions of occurrence allows for more environmentally appropriate weed management.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49096504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Propriedades físicas do solo e produtividade de mandioca em diferentes manejos de coberturas do solo","authors":"A. Rós, A. C. S. Hirata","doi":"10.15361/1984-5529.2019v47n4p411-418","DOIUrl":"https://doi.org/10.15361/1984-5529.2019v47n4p411-418","url":null,"abstract":"A manutencao de coberturas vegetais na superficie do solo ou sua incorporacao e realizada devido aos beneficios a propriedades do solo. O objetivo deste trabalho foi avaliar o impacto de manejos de Crotalaria ochroleuca ou comunidade infestante na produtividade da mandioca, propriedades fisicas do solo e manejo de plantas daninhas. Os tratamentos consistiram no cultivo de mandioca sobre quatro manejos de coberturas do solo: 1- C. ochroleuca rocada e incorporada; 2 - C. ochroleuca rocada; 3 - comunidade infestante rocada e incorporada e 4 - testemunha capinada. A incorporacao da C. ochroleuca e da comunidade infestante melhorou propriedades fisicas do solo em relacao a C. ochroleuc a rocada e o solo sem cobertura. Nao houve diferenca de resistencia a penetracao no solo entre os tratamentos com incorporacao da cobertura vegetal. A C. ochroleuca rocada ou incorporada nao interferiu na densidade e acumulo de massa seca de plantas daninhas na cultura da mandioca, aos 60 dias apos o plantio. A produtividade comercial da mandioca nao diferiu entre os tratamentos (media de 30 t ha -1 ). Os resultados indicam que o manejo da C. ochroleuca ou comunidade infestante influencia as propriedades fisicas do solo, mas nao necessariamente a produtividade da mandioca.","PeriodicalId":35044,"journal":{"name":"Cientifica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43097108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}