The response of bananas to plant spacing in double rows in north Queensland

Bananas cv. Williams were grown at a range of plant spacings in double rows in north Queensland using a continuously variable design. Increasing the plant density from 930 to 3980 plants/ha increased the yield (t/ha/yr) of the plant crop by 200% and the first ratoon by 50%. These increases resulted from the greater number of bunches per unit area despite a 16% reduction in average bunch weight in the plant crop and a 43% reduction in the first ratoon. The duration of each of the two crop cycles increased with increasing density; from the lowest to the highest density there was an increase of 60 days in the plant crop and 125 days in the first ratoon. Plant spacings, giving acceptable yield and fruit quality, best suited to double rows were those with a distance between the two rows of the double row of 1 to 1.5 m and an intra-row distance of 1.2 to 1.8 Density in this range was 1710 to 2780 plants/ha

Soil water stress at bunch emergence increases maturity bronzing of banana fruit

Banana plants cv. Williams which had bunches emerge during a period of soil water stress before rewatering developed significantly more severe maturity bronzing than the unstressed control. Maturity bronzing began developing on fruit at a much thinner finger diameter on water stressed bunches. There was a constant difference in finger diameter between the treatments for all maturity bronzing ratings. Water stress also reduced the greenlife of fruit at harvest. Soil water stress, while contributing, was not the only factor responsible for bronzing

Effects of bunch covering and bunch trimming on bananas in north Queensland

The effect on yield and fruit quality of polyethylene bunch covers applied one week after abscission of the last female flower bract was investigated with plant crop bananas in north Queensland. Bunch trimming by removal of the distal one or two hands of the bunch was investigated in conjunction with bunch covering in one experiment. In a second experiment the same bunch trimming treatments were applied in a ratoon crop without bunch covering treatments. Bunch covering increased fruit weight per bunch by 4% and decreased the period from bunch emergence to harvest by 5 days. Bunch covering increased finger length of_ fruit at the proximal end of the bunch only. Yield was reduced by 5% by trimming one hand per bunch in both experiments and by 15% and 13% by trimming two hands in Experiments 1 and 2 respectively. These yield declines occurred without an accompanying improvement in fruit grades. Thus bunch trimming was unprofitable in north Queensland

Banana stew and brew on Uganda's menu

Ugandans eat more bananas than anyone else, drink banana beer and have a word for a banana variety which also means “food”. Jeff Daniells of Queensland’s Department of Agriculture, Fisheries and Forestry (QDAFF) attended an international banana workshop in Uganda. He provided this report with Deborah Karamura of Bioversity International, Uganda

Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements

Measurement of the branching ratio Γ(Λb⁰ → ψ(2S)Λ0)/Γ(Λb⁰ → J/ψΛ0) with the ATLAS detector

An observation of the $\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0$ decay and a comparison of its branching fraction with that of the $\Lambda_b^0 \rightarrow J/\psi \Lambda^0$ decay has been made with the ATLAS detector in proton--proton collisions at $\sqrt{s}=8\,$TeV at the LHC using an integrated luminosity of $20.6\,$fb$^{-1}$. The $J/\psi$ and $\psi(2S)$ mesons are reconstructed in their decays to a muon pair, while the $\Lambda^0\rightarrow p\pi^-$ decay is exploited for the $\Lambda^0$ baryon reconstruction. The $\Lambda_b^0$ baryons are reconstructed with transverse momentum $p_{\rm T}>10\,$GeV and pseudorapidity $|\eta|<2.1$. The measured branching ratio of the $\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0$ and $\Lambda_b^0 \rightarrow J/\psi \Lambda^0$ decays is $\Gamma(\Lambda_b^0 \rightarrow \psi(2S)\Lambda^0)/\Gamma(\Lambda_b^0 \rightarrow J/\psi\Lambda^0) = 0.501\pm 0.033 ({\rm stat})\pm 0.019({\rm syst})$, lower than the expectation from the covariant quark model.Comment: 12 pages plus author list (28 pages total), 5 figures, 1 table, published on Physics Letters B 751 (2015) 63-80. All figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2013-08

Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

Search for strong gravity in multijet final states produced in pp collisions at √s=13 TeV using the ATLAS detector at the LHC

A search is conducted for new physics in multijet final states using 3.6 inverse femtobarns of data from proton-proton collisions at √s = 13TeV taken at the CERN Large Hadron Collider with the ATLAS detector. Events are selected containing at least three jets with scalar sum of jet transverse momenta (HT) greater than 1TeV. No excess is seen at large HT and limits are presented on new physics: models which produce final states containing at least three jets and having cross sections larger than 1.6 fb with HT > 5.8 TeV are excluded. Limits are also given in terms of new physics models of strong gravity that hypothesize additional space-time dimensions