Yield and crop cycle time of peaches cultivated in subtropical climates and subjected to different pruning times.

<p>The cultivation of peaches in regions of subtropical and tropical climate is currently achieved through a set of practices such as using less demanding cultivars in cold conditions, applying plant growth regulators to break dormancy, and performing specific pruning, like production and renewal pruning. Research on the climate adaptation of cultivars is of great importance in establishing a crop in a given region. Therefore, the objective of this study was to evaluate the agronomic performance of three cultivars subjected to different production pruning times in Botucatu/SP, where 2-year old peach trees were evaluated, grown at a spacing of 6.0 x 4.0 meters. The experimental design was a split plot design with four blocks, using the cultivars Douradão, BRS Kampai and BRS Rubimel, and the subplots corresponded to pruning times in May, June, July and August. Ten plants were used per plot, with the four central plants considered useful and the remaining considered as margins. Pruning in June and July showed the best results in terms of percentage of fruit set and production. The cultivar BRS Rubimel showed the best percentage of fruit set when pruned in June (44.96%), and best fruit production when pruned in July (18.7 kg plant-1). Pruning in May anticipated the harvest of cultivar BRS Rubimel by 13 days whereas pruning carried out in July and August provided late harvests for cultivars Douradão and BRS Kampai.</p

Double Layer Metasurface for Enhanced Photon Up Conversion

We present a double-layer dielectric metasurface obtained by stacking a silicon nanodisc array and a silicon photonic crystal slab with equal periodicity on top of each other. We focus on the investigation of electric near-field enhancement effects occurring at resonant excitation of the metasurface and study its optical properties numerically and experimentally. We find that the major difference in multi-layer metasurfaces when compared to conventional single-layer structures appears to be in Rayleigh-Wood anomalies: they are split into multiple different modes which are themselves spectrally broadened. As a proof of concept we cover a double-layer metasurface with a lanthanide-doped up-conversion particle layer and study its interaction with a 1550 nm photoexcitation. We observe a 2.7-fold enhancemed up-conversion photoluminescence by using the stacked metasurface instead of a planar substrate, although only around 1% of the up-conversion material is exposed to enhanced near-fields. Two mechanisms are identified explaining this behavior: First, enhanced near-fields when exciting the metasurface resonantly, and second, light trapping by total internal reflection in the particle layer when the metasurface redirects light into high-angle diffraction orders. These results pave the way for low-threshold and, in particular, broadband photon up-conversion in future solar energy and biosensing applications.Comment: 14 pages, 6 figure

Breaking Dormancy of &quot;Tupy&quot; Blackberry in Subtropical Conditions

Abstract In subtropical or tropical conditions, the insufficient winter chill accumulation is often a limiting factor to break the dormancy of temperate-climate species such as the blackberry, which requires using products to help break dormancy. This study evaluates the efficacy of compounds in breaking dormancy of blackberry and its consequent influence on phenology and crop yields. The experiment was conducted in São Manuel, State of São Paulo, Brazil, in the 2011/2012 production cycle. The plants used were two-year-old &quot;Tupy&quot; blackberry (Rubus spp.), with 0.6 × 4.0 m spacing (4.166 plants·ha −1 ). Pruning was performed in August, followed by the application of these treatments: control (water); hydrogen cyanamide (Dormex ® ); nitrogen fertilizer (Erger ® ) and mineral oil (Assist ® ). The concentrations of each compound used were: 2.0%, 4.0%, 6.0% and 8.0%. The compounds used influenced the budding, flowering and fruit harvest stages, in addition to providing increased yields depending on the concentration used. For hydrogen cyanamide the recommended concentration is of 4.2% and 5.4% for nitrogen fertilizer; doses above these concentrations may cause phytotoxic effects. For mineral oil the dose recommended is of 8.0%