scholarly journals Comparing the Effects of Four Propagation Methods on Hybrid Chestnut Seedling Quality

2021 ◽  
pp. 100157
Author(s):  
Taylor Evans ◽  
Dr. Heather Griscom
Agriculture ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 321 ◽  
Author(s):  
Julie Oustric ◽  
Radia Lourkisti ◽  
Stéphane Herbette ◽  
Raphaël Morillon ◽  
Gilles Paolacci ◽  
...  

Current climatic upheavals reduce water availability which impacts the growth and fruit quality of plants. In citrus crops, scion/rootstock combinations are used to ensure high fruit production and quality and a stress tolerance/resistance. Our objective was to assess the effect on the clementine scion (C) under natural mild water deficit of (i) polyploid rootstocks by comparing the allotetraploid FlhorAG1 (C/4xFLs; trifoliate orange + Willowleaf mandarin) with its diploid parents, trifoliate orange (C/2xTOs), and Willowleaf mandarin (C/2xWLs), and with a diploid genotype used as reference (Carrizo citrange, C/2xCCs), (ii) rootstock propagation methods by comparing trifoliate orange seedling (C/2xTOs) with cutting (C/2xTOc). A mild water deficit observed under orchard conditions during the summer period (July–August) induced a significant change in yield (except in C/2xTOs), fruit size, and quality. C/2xCCs, C/2xTOs, and C/2xWLs appeared less affected by water deficit as indicated by their lower reduction of predawn leaf water potential (Ψpd), relative water content (RWC), transpiration (E), and photosynthetic parameters (Pnet and gs). Their greater redox balance was probably due to their better antioxidant efficiency. Seedling rootstocks lead to a better adaptation of clementine scions to water deficit than cutting or allotetraploid rootstock. Improving the tolerance to water deficit requires taking into consideration the rootstock genotype, propagation method, and ploidy level.


Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 298
Author(s):  
Juan Martinez-Carranza ◽  
Tomasz Kozacki ◽  
Rafał Kukołowicz ◽  
Maksymilian Chlipala ◽  
Moncy Sajeev Idicula

A computer-generated hologram (CGH) allows synthetizing view of 3D scene of real or virtual objects. Additionally, CGH with wide-angle view offers the possibility of having a 3D experience for large objects. An important feature to consider in the calculation of CGHs is occlusion between surfaces because it provides correct perception of encoded 3D scenes. Although there is a vast family of occlusion culling algorithms, none of these, at the best of our knowledge, consider occlusion when calculating CGHs with wide-angle view. For that reason, in this work we propose an occlusion culling algorithm for wide-angle CGHs that uses the Fourier-type phase added stereogram (PAS). It is shown that segmentation properties of the PAS can be used for setting efficient conditions for occlusion culling of hidden areas. The method is efficient because it enables processing of dense cloud of points. The investigated case has 24 million of point sources. Moreover, quality of the occluded wide-angle CGHs is tested by two propagation methods. The first propagation technique quantifies quality of point reproduction of calculated CGH, while the second method enables the quality assessment of the occlusion culling operation over an object of complex shape. Finally, the applicability of proposed occlusion PAS algorithm is tested by synthetizing wide-angle CGHs that are numerically and optically reconstructed.


2013 ◽  
Vol 2 (1) ◽  
Author(s):  
Jonathan Andreasen ◽  
Miroslav Kolesik

AbstractThis work demonstrates an improved method to simulate long-distance femtosecond pulse propagation in highcontrast nanowaveguides. Different from typical beam propagation methods, the foundational tool here is capable of simulating strong spatiotemporal waveform reshaping and extreme spectral dynamics. Meanwhile, the ability to fully capture effects due to index contrast in the transverse direction is retained, without requiring a decomposition of the electric field in terms of waveguide modes. These simulations can be computationally expensive, however, so cost is reduced in the improved method by considering only the waveguide core. Fields in the cladding are then properly accounted for through a boundary condition suitable for the case of total internal reflection.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 597
Author(s):  
Jacob A. Reely ◽  
Andrew S. Nelson

Environmental conditions and seedling quality interact to produce complex patterns of seedling survival and growth. Root growth potential (RGP) is one metric of seedling quality that can be rapidly measured prior to planting, but the correlation of RGP and seedling performance is not consistent across studies. Site factors including microsite objects that cast shade and competing vegetation can also influence seedling performance. We examined the effects of RGP, presence/absence of a microsite object, and competition cover on the survival and growth of three native conifers to the Inland Northwest, USA, over 5 years. We found that RGP had no effect on the survival or growth of western larch (Larix occidentalis), Douglas fir (Pseudotsuga menziesii var. glauca), and grand fir (Abies grandis) at a mesic north aspect site and a xeric south aspect site. Comparatively, the presence of a microsite increased the odds of survival by 37% for western larch and 158% for grand fir, while the absence of forb cover increased the odds of survival of western larch by 72% and of grand fir by 26%. Douglas fir was less sensitive to microsites and competition. The strong effects of neighborhood conditions around seedlings help inform silvicultural practices to enhance the establishment of western larch and grand fir, including planting seedlings near shading objects and competition control, while these practices may not be as important for Douglas fir.


2021 ◽  
pp. 1-19
Author(s):  
Pierre Lemerle

Abstract Viscoelastic materials are widely used for vibroacoustic solutions due to their ability to mitigate vibration and sound. Wave propagation methods are based on the measurement of the waveform pattern of a transitory pulse in one-dimensional structures. The time evolution of the pattern can be used to deduce the material elasticity and damping characteristics. The most popular propagation methods, namely Hopkinson bar methods, assume no dispersion, i.e. the complex elasticity modulus is not frequency-dependent. This is not significant for resilient materials such as elastomers. More recent approaches have been developed to measure frequency-dependent properties from a pulse propagating in a slender bar. We showed in previous works how to adapt these techniques for shorter samples of materials, representing a real advance, as extrusion is a cumbersome process for many materials. The main concept was to reconstruct the time history of the wave propagating in a composite structure composed of a long incident bar made of a known material and extended by a shorter sample bar. Then the viscoelastic properties of the sample material were determined in the frequency domain within an inverse method held in the time domain. In industry, most isolation solutions using mounts or bushings must support structural weights. This is why it is particularly interesting to know the viscoelastic properties of the material in stressed state. Here, we show how to overcome this challenging issue. The theoretical framework of the computational approach is detailed and the method is experimentally verified.


2010 ◽  
Vol 5 (3) ◽  
pp. 139-141
Author(s):  
Meng Zhang ◽  
Dan Wang ◽  
Shao-Xiong Ren ◽  
Li-Zhang Fan ◽  
Ren-Dao Liu
Keyword(s):  

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Piergiorgio Gherbin ◽  
Simone Milan ◽  
Giuseppe Mercurio ◽  
Antonio Scopa

The increasing interest in<em> Arundo donax,</em> a perennial lignocellulosic species only reproducing by propagation, requires the setup of cheap, simple and reliable techniques. Considering these targets, stem cutting offers considerable advantages. The present investigation aimed to compare: i) plants obtained by different propagation methods (by rhizome and micropropagation mother plants); ii) plants obtained by stem cuttings from basal, central and apical parts of the stem; iii) different planting periods (spring, summer, autumn). The obtained results showed that the number of new shoots from stem buds was: i) higher in the spring and lower in the summer planting period; ii) higher from cuttings obtained by micropropagated than rhizome mother plants, both in spring and summer plantings; iii) decreasing passing from the basal to the apical stem portion; iv) partly unexpressed in the autumn planting period; v) lower from one-year stem cuttings as compared to two-year stem cuttings.


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