28 research outputs found

    Produção de batata-doce em função de doses de P2O5 em dois sistemas de cultivo Yield of sweet potato affected by P2O5 levels in two planting systems

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    Com o objetivo de avaliar o efeito da adubação fosfatada e de sistemas de plantio na produção total e comercial de raízes de batata-doce, cv. Rainha Branca, conduziu-se um experimento, de fevereiro a julho de 2003, na UFPB, em Areia (PB). O delineamento experimental foi de blocos casualizados com os tratamentos distribuídos em esquema fatorial 5 x 2, com os fatores doses de fósforo (0; 100; 200; 300 e 400 kg de P2O5 ha-1) e sistemas de plantio (uma e duas ramas por cova), em quatro repetições. As produções total e comercial de raízes de batata-doce, em resposta as doses de fósforo no sistema de plantio com uma rama por cova, foram de 21,6 e 18,7 t ha-1, obtidas com 237 e 210 kg de P2O5 ha-1, respectivamente. No sistema de plantio com duas ramas por cova, essas produções foram de 23,5 e 18,9 t ha-1, alcançadas com 259 e 231 kg de P2O5 ha-1, respectivamente, enquanto as doses econômicas para a produção de raízes comerciais, foram 173 e 194 kg de P2O5 ha-1, para os sistemas de plantio com uma e duas ramas, respectivamente. No sistema de plantio com uma rama e dose econômica correspondeu a 82% daquela para a máxima eficiência técnica (MET) e para o sistema de duas ramas a 84% da MET, constituindo um indicativo da viabilidade econômica do emprego de fósforo no cultivo da batata-doce. As doses de fósforo estimadas que resultaram nas máximas produções de raízes comerciais e retornos econômicos, quanto ao sistema de plantio com uma e duas ramas por cova corresponderam, respectivamente, com 21 e 19 mg de P disponível dm-3, extraído pelo extrator de Melich 1. Em solos semelhantes ao deste estudo, a adubação fosfatada na batata-doce poderá ser dispensada, quando os teores de fósforo disponível forem superiores a 19 e 20 mg dm-3 de solo, respectivamente, para os sistemas de plantio com uma e duas ramas por cova.<br>The influence of phosphate fertilization and planting systems were evaluated on the yield and quality of sweet potato roots, Rainha Branca cv. The experiment was carried out from February to July/2003 in a Quartz Psamment soil in Paraiba State, Brazil. The experimental design was of randomized blocks with four replications. Treatments were distributed in a 5 x 2 factorial design, with five levels of P2O5 (0; 100; 200; 300 and 400 kg ha-1 ) and two planting systems (one and two stems/hole). Total and commercial sweet potato roots production, in response to P2O5 levels with one stem/hole, were 21.6 and 18.7 t ha-1 obtained with 237 and 210 kg ha-1 of P2O5, respectively. Using two stems/hole, 23.5 and 18.9 t ha-1 were obtained when 259 and 231 kg of P2O5, were employed, respectively. Levels of 173 and 194 kg of P2O5 applied for one and two stems/hole, respectively, were economically viable for the commercial roots production. The economical level in the planting system using one stem/hole, was 82% of the technical maximum efficiency (TME) and for two stems/hole was 84% TME being an indicative of economical viability of phosphorus application in sweet potato. P2O5 levels that resulted in maximum production and economical returns for commercial roots for planting systems with one and two stems/hole were 21 and 19 mg dm-3 of phosphorus available, using Melich-1 extractor. In similar soil types for commercial roots production, the phosphate fertilization will be dispensed, when available phosphorus levels were higher than 19 and 20 mg dm-3 of soil in planting systems with one and two stems/hole

    Características produtivas da batata-doce em função de doses de P2O5, de espaçamentos e de sistemas de plantio Yield characteristic of sweet potato affected by P2O5 levels, in the spacings and planting systems

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    Com o objetivo de avaliar a influência da adubação fosfatada, espaçamentos e sistemas de plantio na produção de raízes de batata-doce cv. Rainha Branca, conduziu-se um experimento no período de fevereiro a julho de 2004 em um NEOSSOLO REGOLÍTICO Psamítico típico, textura areia-franca, na Universidade Federal da Paraíba, Areia-PB. O delineamento experimental empregado foi de blocos casualizados em parcelas subdivididas com quatro repetições. Nas parcelas, foram testados vinte tratamentos formados por cinco doses de P2O5 (0, 100, 200, 300 e 400 kg ha-1), combinado fatorialmente com quatro espaçamentos entre plantas (0,20, 0,30, 0,40 e 0,50 m) por 0,80 m entre linhas; e nas subparcelas, dois sistemas de plantio (uma e duas ramas/cova). A maior produção de raízes comerciais/planta (662 g) foi obtida no sistema de plantio com uma rama/cova, no espaçamento de 0,80 m x 0,50 m (25.000 plantas ha-1), na dose estimada de 180 kg ha-1 de P2O5, enquanto que a menor (108 g), no espaçamento de 0,80 m x 0,20 m com duas ramas/cova, na ausência de P2O5. A produtividade comercial de raízes de batata-doce, em resposta às doses de fósforo no sistema de plantio com uma rama/cova, foi de 18,7 t ha-1, obtida com 210 kg de P2O5 ha-1. No sistema de plantio com duas ramas/cova, essa produtividade foi de 18,9 t ha-1, alcançada com 231 kg de P2O5 ha-1. A maior produtividade de raízes comerciais em função dos espaçamentos (19,64 t ha-1) foi obtida com 0,30 m entre plantas, no sistema de plantio com duas ramas/cova (83.330 plantas ha-1).<br>The influence of phosphate fertilization, spacing and planting systems were evaluated on the yield of sweet potato roots Rainha Branca cv. The experiment was carried out from February to July/2004 in Quartz Psamment soil, in the Universidade Federal of Paraíba, Areia-PB, Brazil. It was used experimental design of randomized blocks in sub divided plots in four replications. In the main plots, twenty treatments were tested forming five levels of P2O5 (0, 100, 200, 300 and 400 kg ha-1), combined factorially with four spacing among plants (0.20, 0.30, 0.40 and 0.50 m) for 0.80 m among lines; and in subplots, two planting for ms (one and two stems/hole). The largest production of commercial/plant roots (662 g) was obtained in planting system with a stems/hill, in the spacing of 0.80 m x 0.50 m (25.000 plants ha-1) with 180 kg ha-1 of P2O5. The commercial roots productivity of sweet potato roots, considering P2O5 levels at planting system with one stems/hole, were 18.7 t ha-1 obtained with 210 kg ha-1 of P2O5. The productivity in the planting system using two stems/hole were 18.9 t ha-1, and it was reached with 231 kg ha-1 of P2O5. The largest productivity on spacing function (19.64 t ha-1) was obtained with 0.30 m among plants, in the planting system with two stems/holes (83.330 plants ha-1)

    Search for high-mass exclusive diphoton production with tagged protons in proton-proton collisions at s= \sqrt{s} = 13 TeV

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    A search is presented for high-mass exclusive diphoton production via photon-photon fusion in proton-proton collisions at s= \sqrt{s} = 13 TeV in events where both protons survive the interaction. The analysis utilizes data corresponding to an integrated luminosity of 103 fb1 ^{-1} collected in 2016--2018 with the central CMS detector and the CMS and TOTEM precision proton spectrometer (PPS). Events that have two photons with high transverse momenta (pTγ> p_{\mathrm{T}}^{\gamma} > 100 GeV), back-to-back in azimuth, and with a large diphoton invariant mass (mγγ> m_{\gamma\gamma} > 350 GeV) are selected. To remove the dominant inclusive diphoton backgrounds, the kinematic properties of the protons detected in PPS are required to match those of the central diphoton system. Only events having opposite-side forward protons detected with a fractional momentum loss between 0.035 and 0.15 (0.18) for the detectors on the negative (positive) side of CMS are considered. One exclusive diphoton candidate is observed for an expected background of 1.1 events. Limits at 95% confidence level are derived for the four-photon anomalous coupling parameters ζ1 |\zeta_1| 100 GeV), back-to-back in azimuth, and with a large diphoton invariant mass (mγγ>m_{\gamma\gamma} \gt 350 GeV) are selected. To remove the dominant inclusive diphoton backgrounds, the kinematic properties of the protons detected in PPS are required to match those of the central diphoton system. Only events having opposite-side forward protons detected with a fractional momentum loss between 0.035 and 0.15 (0.18) for the detectors on the negative (positive) side of CMS are considered. One exclusive diphoton candidate is observed for an expected background of 1.1 events. Limits at 95% confidence level are derived for the four-photon anomalous coupling parameters ζ1<\lvert\zeta_1\rvert \lt 0.073 TeV4^{-4} and ζ2<\lvert\zeta_2\rvert \lt 0.15 TeV4^{-4}, using an effective field theory. Additionally, upper limits are placed on the production of axion-like particles with coupling strength to photons f1f^{-1} that varies from 0.03 TeV1^{-1} to 1 TeV1^{-1} over the mass range from 500 to 2000 GeV

    Search for high-mass exclusive diphoton production with tagged protons in proton-proton collisions at s\sqrt{s} = 13 TeV

    No full text
    International audienceA search is presented for high-mass exclusive diphoton production via photon-photon fusion in proton-proton collisions at s\sqrt{s} = 13 TeV in events where both protons survive the interaction. The analysis utilizes data corresponding to an integrated luminosity of 103 fb1^{-1} collected in 2016-2018 with the central CMS detector and the CMS and TOTEM precision proton spectrometer (PPS). Events that have two photons with high transverse momenta (pTγ>p_\mathrm{T}^\gamma > 100 GeV), back-to-back in azimuth, and with a large diphoton invariant mass (mγγ>m_{\gamma\gamma} \gt 350 GeV) are selected. To remove the dominant inclusive diphoton backgrounds, the kinematic properties of the protons detected in PPS are required to match those of the central diphoton system. Only events having opposite-side forward protons detected with a fractional momentum loss between 0.035 and 0.15 (0.18) for the detectors on the negative (positive) side of CMS are considered. One exclusive diphoton candidate is observed for an expected background of 1.1 events. Limits at 95% confidence level are derived for the four-photon anomalous coupling parameters ζ1<\lvert\zeta_1\rvert \lt 0.073 TeV4^{-4} and ζ2<\lvert\zeta_2\rvert \lt 0.15 TeV4^{-4}, using an effective field theory. Additionally, upper limits are placed on the production of axion-like particles with coupling strength to photons f1f^{-1} that varies from 0.03 TeV1^{-1} to 1 TeV1^{-1} over the mass range from 500 to 2000 GeV

    Proton reconstruction with the CMS-TOTEM Precision Proton Spectrometer

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    International audienceThe Precision Proton Spectrometer (PPS) of the CMS and TOTEM experiments collected 107.7 fb1^{-1} in proton-proton (pp) collisions at the LHC at 13 TeV (Run 2). This paper describes the key features of the PPS alignment and optics calibrations, the proton reconstruction procedure, as well as the detector efficiency and the performance of the PPS simulation. The reconstruction and simulation are validated using a sample of (semi)exclusive dilepton events. The performance of PPS has proven the feasibility of continuously operating a near-beam proton spectrometer at a high luminosity hadron collider

    Search for central exclusive production of top quark pairs in proton-proton collisions at s\sqrt{s} = 13 TeV with tagged protons

    No full text
    International audienceA search for the central exclusive production of top quark-antiquark pairs (ttˉ\mathrm{t\bar{t}}) is performed for the first time using proton-tagged events in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 29.4 fb1^{-1}. The ttˉ\mathrm{t\bar{t}} decay products are reconstructed using the central CMS detector, while forward protons are measured in the CMS-TOTEM precision proton spectrometer. An observed (expected) upper bound on the production cross section of 0.59 (1.14) pb is set at 95% confidence level, for collisions of protons with fractional momentum losses between 2 and 20%

    Search for high-mass exclusive diphoton production with tagged protons in proton-proton collisions at s\sqrt{s} = 13 TeV

    No full text
    International audienceA search is presented for high-mass exclusive diphoton production via photon-photon fusion in proton-proton collisions at s\sqrt{s} = 13 TeV in events where both protons survive the interaction. The analysis utilizes data corresponding to an integrated luminosity of 103 fb1^{-1} collected in 2016-2018 with the central CMS detector and the CMS and TOTEM precision proton spectrometer (PPS). Events that have two photons with high transverse momenta (pTγ>p_\mathrm{T}^\gamma > 100 GeV), back-to-back in azimuth, and with a large diphoton invariant mass (mγγ>m_{\gamma\gamma} \gt 350 GeV) are selected. To remove the dominant inclusive diphoton backgrounds, the kinematic properties of the protons detected in PPS are required to match those of the central diphoton system. Only events having opposite-side forward protons detected with a fractional momentum loss between 0.035 and 0.15 (0.18) for the detectors on the negative (positive) side of CMS are considered. One exclusive diphoton candidate is observed for an expected background of 1.1 events. Limits at 95% confidence level are derived for the four-photon anomalous coupling parameters ζ1<\lvert\zeta_1\rvert \lt 0.073 TeV4^{-4} and ζ2<\lvert\zeta_2\rvert \lt 0.15 TeV4^{-4}, using an effective field theory. Additionally, upper limits are placed on the production of axion-like particles with coupling strength to photons f1f^{-1} that varies from 0.03 TeV1^{-1} to 1 TeV1^{-1} over the mass range from 500 to 2000 GeV

    Search for central exclusive production of top quark pairs in proton-proton collisions at s\sqrt{s} = 13 TeV with tagged protons

    No full text
    International audienceA search for the central exclusive production of top quark-antiquark pairs (ttˉ\mathrm{t\bar{t}}) is performed for the first time using proton-tagged events in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 29.4 fb1^{-1}. The ttˉ\mathrm{t\bar{t}} decay products are reconstructed using the central CMS detector, while forward protons are measured in the CMS-TOTEM precision proton spectrometer. An observed (expected) upper bound on the production cross section of 0.59 (1.14) pb is set at 95% confidence level, for collisions of protons with fractional momentum losses between 2 and 20%

    Search for high-mass exclusive diphoton production with tagged protons in proton-proton collisions at s\sqrt{s} = 13 TeV

    No full text
    International audienceA search is presented for high-mass exclusive diphoton production via photon-photon fusion in proton-proton collisions at s\sqrt{s} = 13 TeV in events where both protons survive the interaction. The analysis utilizes data corresponding to an integrated luminosity of 103 fb1^{-1} collected in 2016-2018 with the central CMS detector and the CMS and TOTEM precision proton spectrometer (PPS). Events that have two photons with high transverse momenta (pTγ>p_\mathrm{T}^\gamma > 100 GeV), back-to-back in azimuth, and with a large diphoton invariant mass (mγγ>m_{\gamma\gamma} \gt 350 GeV) are selected. To remove the dominant inclusive diphoton backgrounds, the kinematic properties of the protons detected in PPS are required to match those of the central diphoton system. Only events having opposite-side forward protons detected with a fractional momentum loss between 0.035 and 0.15 (0.18) for the detectors on the negative (positive) side of CMS are considered. One exclusive diphoton candidate is observed for an expected background of 1.1 events. Limits at 95% confidence level are derived for the four-photon anomalous coupling parameters ζ1<\lvert\zeta_1\rvert \lt 0.073 TeV4^{-4} and ζ2<\lvert\zeta_2\rvert \lt 0.15 TeV4^{-4}, using an effective field theory. Additionally, upper limits are placed on the production of axion-like particles with coupling strength to photons f1f^{-1} that varies from 0.03 TeV1^{-1} to 1 TeV1^{-1} over the mass range from 500 to 2000 GeV
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