Nitrogen and environmental factors influencing macadamia quality

Applications of nitrogen fertiliser in macadamia orchards remain high, despite indications that optimum yields and quality are obtained at a lower rate. This 6-year study examined the effect on quality of 230, 690 and 1150 g nitrogen/tree . year, applied in April (floral initiation), in April and June (inflorescence development), in April, June and November (rapid nut growth and premature nut drop), in April, June, November and January (nut maturation/oil accumulation) or monthly. Higher rates of nitrogen increased kernel recovery by 1% in 5 years out of 6. In 1 year only, 4 or more split applications of the medium and high rates of nitrogen increased kernel recovery by up to 1.6%. These increases were insufficient to compensate for depressed yields (17% lower) at high nitrogen. In good years, when yields were above average, kernel recovery tended to be high and in years with poor yields, kernel recovery tended to be low except when nuts were small. Moderate summer—early autumn rainfall of about 100 mm/month was associated with high kernel recovery whereas very heavy rainfall (>200 mm/month) during this period was detrimental. The percentage of first grade kernels was influenced most by season but was negatively correlated with the rate of nitrogen. Impurities, including immature, deformed, mouldy and insect-damaged kernels, were lowest at low rates of nitrogen and highest during wet harvest seasons. Time of nitrogen application had no significant effect on yield, kernel recovery, the percentage of first-grade kernels or impurities. For sustained high yield and quality, 355 g nitrogen, or 0.8 kg urea/tree.year, applied in April—June is indicated. Agronomic and economic advantages of reducing rates of nitrogen applied to macadamia orchards are enhanced by increasingly important environmental considerations. Multiple regression analyses indicated that the rate, strategy and timing of nitrogen application, rainfall, temperature, flushing and litterfall were correlated with kernel recovery and first-grade kernels but more work is needed to elucidate the significance of these factors

Paleostress field reconstruction and revised tectonic history of the Donbas fold and thrust belt (Ukraine and Russia).

In the WNW-ESE Donbas fold belt (DF), inversion of 3500 microtectonic data collected at 135 sites, in Proterozoic, Devonian, Carboniferous, and Cretaceous competent rocks allowed reconstruction of 123 local stress states. Accordingly, four successive paleostress fields reveal the tectonic evolution of the DF. At the numerous sites that have been affected by polyphase tectonics, the chronology between local paleostress states (also paleostress fields) was established using classical criteria (crosscutting striae, pre- or post-folding stress states, stratigraphic control). The oldest event is an extensional stress field with NNE-SSW σ<inf>3</inf>. It corresponds to the rifting phases that generated the basin in Devonian times and its early Visean reactivation. Later, the DF was affected by a transtension, with NW-SE σ<inf>3</inf> characterizing Early Permian tectonism, including the development of the "Main Anticline" of the DF and the pronounced uplift of its southern margin and Ukrainian Shield. Two paleostress fields characterize the Cretaceous/Paleocene inversion of the DF, which was accompanied by folding and thrusting. Both are compressional in type but differ by the trend of σ<inf>1</inf>, which was first NW-SE and subsequently N-S. The discrete paleostress history of the DF allows a revised interpretation of its tectonic evolution with significant implications for understanding the geodynamic evolution of the southern margin of the East European Craton. Copyright 2003 by the American Geophysical Union

Examining Periodic Solar Wind Density Structures Observed in the SECCHI Heliospheric Imagers

We present an analysis of small-scale, periodic, solar-wind density enhancements (length-scales as small as \approx 1000 Mm) observed in images from the Heliospheric Imager (HI) aboard STEREO A. We discuss their possible relationship to periodic fluctuations of the proton density that have been identified at 1 AU using in-situ plasma measurements. Specifically, Viall, Kepko, and Spence (2008) examined 11 years of in-situ solar-wind density measurements at 1 AU and demonstrated that not only turbulent structures, but also non-turbulent periodic density structures exist in the solar wind with scale sizes of hundreds to one thousand Mm. In a subsequent paper, Viall, Spence, and Kasper (2009) analyzed the {\alpha} to proton solar-wind abundance ratio measured during one such event of periodic density structures, demonstrating that the plasma behavior was highly suggestive that either temporally or spatially varying coronal source plasma created those density structures. Large periodic density structures observed at 1 AU, which were generated in the corona, can be observable in coronal and heliospheric white-light images if they possess sufficiently high density contrast. Indeed, we identify such periodic density structures as they enter the HI field of view and follow them as they advect with the solar wind through the images. The smaller periodic density structures that we identify in the images are comparable in size to the larger structures analyzed in-situ at 1 AU, yielding further evidence that periodic density enhancements are a consequence of coronal activity as the solar wind is formed.Comment: 15 pages, 12 figures. The final publication is available at http://www.springerlink.co

Geology of the Newtonmore-Ben Macdui district : Bedrock and superficial geology of the Newtonmore-Ben Macdui district : description for sheet 64 (Scotland)

This report provides an account of the geology of the Newtonmore-Ben Macdui district in the Grampian Highlands of Scotland, which extends from the Cairngorm massif in the north-east, west across to the Upper Spey valley and south into the upper parts of Glen Tilt and Glen Fearnach. The district is nearly all remote countryside with steep-sided glens between upland plateaus with relatively few distinct mountain peaks. The entire area lies within the Cairngorm National Park and much of the land is covered by large estates run for game conservation and recreational sports. The bulk of the rocks are metasedimentary and most of these are assigned to the Neoproterozoic Dalradian Supergroup (Figure 1). In the north-west near Newtonmore, a ridge or ‘palaeohigh’ of older metasedimentary rocks, the Glen Banchor Subgroup, is considered to lie below the Dalradian. The Dalradian Supergroup forms a thick succession of originally clastic, carbonate and pelitic rocks. Much of the latter is graphitic and pelagic in origin. The metasedimentary rocks were intruded by relatively minor basic igneous and granitic bodies as the Rodinian palaeocontinent broke up. At about 470 Ma the Laurentian continental margin collided with an island arc causing the Grampian Event of the Caledonian Orogeny. The orogeny is mainly manifest in four deformation phases which included early large nappe-like folds, ductile shear-zones and prograde Barrovian regional metamorphism. Most of the rocks in this district lie within the kyanite zone but, because most of the rocks are siliceous, this index mineral is scarce. Semipelitic rocks are locally migmatitic. The earlier Precambrian metamorphism in the Glen Banchor Subgroup is overprinted by the Grampian metamorphism

Measurement of the Remaining In-Plane Polarization Transfer Coefficients for the 10-B(p,p') 10-B Reaction at 200 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Late Cretaceous to Paleocene oroclinal bending in the central Pontides (Turkey)

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Medium Effects in the Normal Component Polarization Observables for the 13-C(p,p')13-C, (1/2)- → (9/2)+ Reaction at 200 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY-931478