scholarly journals Effect of growth temperature levels on photosynthetic ability and fruit quality of ‘KU-PP2’, a new low-chill peach cultivar

2021 ◽  
Vol 35 (3) ◽  
pp. 233-241
Author(s):  
Panawat Sikhandakasmita ◽  
Ikuo Kataoka ◽  
Tsuneo Ogata ◽  
Ryosuke Mochioka ◽  
Kenji Beppu

Temperature is a crucial factor in growing plants in a forcing system. Our goal was to introduce low-chill peach cultivars into a forcing culture for early-season peach production with high fruit quality. However, the effects of growth temperature on plant growth and fruit quality during fruit development of the ‘KU-PP2’ peach cultivar have not yet been evaluated. ‘KU-PP2’ trees were grown in containers and transferred to phytotrons after fruit set in April 2019. The air temperature was set at 20, 25, and 30°C until harvest. Photosynthetic ability, leaf characteristics, and fruit quality under each treatment were determined. Long exposure to lower growth temperatures did not cause a change in leaf characteristics or a reduction in photosynthetic ability and fruit quality in the ‘KU-PP2’ peach cultivar. In contrast, the 30°C was found to be associated with a decrease in leaf size and thickness, stomatal density, photosynthesis, chlorophyll content, and fruit size. Conversely, the high-temperature condition enhanced coloration of the fruit peel and hastened the harvesting period, compared with the lower-temperature treatments. These results indicated that long-term exposure to the moderately high temperature of 30°C negatively affected plant growth and fruit productivity through changed leaf characteristics and a disrupted photosynthesis.

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 928
Author(s):  
Yong Du ◽  
Zhenzhen Kong ◽  
Muhammet Toprak ◽  
Guilei Wang ◽  
Yuanhao Miao ◽  
...  

This work presents the growth of high-quality Ge epilayers on Si (001) substrates using a reduced pressure chemical vapor deposition (RPCVD) chamber. Based on the initial nucleation, a low temperature high temperature (LT-HT) two-step approach, we systematically investigate the nucleation time and surface topography, influence of a LT-Ge buffer layer thickness, a HT-Ge growth temperature, layer thickness, and high temperature thermal treatment on the morphological and crystalline quality of the Ge epilayers. It is also a unique study in the initial growth of Ge epitaxy; the start point of the experiments includes Stranski–Krastanov mode in which the Ge wet layer is initially formed and later the growth is developed to form nuclides. Afterwards, a two-dimensional Ge layer is formed from the coalescing of the nuclides. The evolution of the strain from the beginning stage of the growth up to the full Ge layer has been investigated. Material characterization results show that Ge epilayer with 400 nm LT-Ge buffer layer features at least the root mean square (RMS) value and it’s threading dislocation density (TDD) decreases by a factor of 2. In view of the 400 nm LT-Ge buffer layer, the 1000 nm Ge epilayer with HT-Ge growth temperature of 650 °C showed the best material quality, which is conducive to the merging of the crystals into a connected structure eventually forming a continuous and two-dimensional film. After increasing the thickness of Ge layer from 900 nm to 2000 nm, Ge surface roughness decreased first and then increased slowly (the RMS value for 1400 nm Ge layer was 0.81 nm). Finally, a high-temperature annealing process was carried out and high-quality Ge layer was obtained (TDD=2.78 × 107 cm−2). In addition, room temperature strong photoluminescence (PL) peak intensity and narrow full width at half maximum (11 meV) spectra further confirm the high crystalline quality of the Ge layer manufactured by this optimized process. This work highlights the inducing, increasing, and relaxing of the strain in the Ge buffer and the signature of the defect formation.


2021 ◽  
Author(s):  
Nadia S Arias ◽  
Fabián G Scholz ◽  
Guillermo Goldstein ◽  
Sandra J Bucci

Abstract Low temperatures and drought are the main environmental factors affecting plant growth and productivity across most of the terrestrial biomes. The objective of this study was to analyze the effects of water deficits before the onset of low temperatures in winter to enhance freezing resistance in olive trees. The study was carried out near the coast of Chubut, Argentina. Plants of five olive cultivars were grown out-door in pots and exposed to different water deficit treatments. We assessed leaf water relations, ice nucleation temperature (INT), cell damage (LT50), plant growth and leaf nitrogen content during summer and winter in all cultivars and across water deficit treatments. Leaf INT and LT50 decreased significantly from summer to winter within each cultivar and between treatments. We observed a trade-off between resources allocation to freezing resistance and vegetative growth, such that an improvement in resistance to sub-zero temperatures was associated to lower growth in tree height. Water deficit applied during summer increased the amount of osmotically active solutes and decreased the leaf water potentials. This type of legacy effects persists during the winter after the water deficit even when treatment was removed, because of natural rainfalls.


1992 ◽  
Vol 280 ◽  
Author(s):  
K. S. Chandra Sekhar ◽  
A. K. Ballal ◽  
L. Salamanca-Riba ◽  
D. L. Partin

ABSTRACTHeteroepitaxial growth of indium arsenide films on indium phosphide substrates is being actively pursued since the electronic properties of these films make them promising materials for optoelectronic and other high speed devices. The various structural aspects of the film that affect their electronic properties are structural defects like dislocations, film-substrate interface roughness and chemical inhomogeneities. In InAs films, electrons accumulate at the film-air interface, making surface morphology an important factor that decides the electronic properties. The InAs films used in this study were grown on InP substrates by metal organic vapor deposition, at different temperatures. A higher growth temperature not only resulted in poor surface morphology of the film, but also created a rough film-substrate interface. However, at all deposition temperatures, the film-substrate interfaces are sharp. At lower growth temperature, the interfaces were flat. Films grown at lower temperatures had good surface morphology and a flat and shaip heterointerface.


2008 ◽  
Vol 1068 ◽  
Author(s):  
Ewa Dumiszewska ◽  
Wlodek Strupinski ◽  
Piotr Caban ◽  
Marek Wesolowski ◽  
Dariusz Lenkiewicz ◽  
...  

ABSTRACTThe influence of growth temperature on oxygen incorporation into GaN epitaxial layers was studied. GaN layers deposited at low temperatures were characterized by much higher oxygen concentration than those deposited at high temperature typically used for epitaxial growth. GaN buffer layers (HT GaN) about 1 μm thick were deposited on GaN nucleation layers (NL) with various thicknesses. The influence of NL thickness on crystalline quality and oxygen concentration of HT GaN layers were studied using RBS and SIMS. With increasing thickness of NL the crystalline quality of GaN buffer layers deteriorates and the oxygen concentration increases. It was observed that oxygen atoms incorporated at low temperature in NL diffuse into GaN buffer layer during high temperature growth as a consequence GaN NL is the source for unintentional oxygen doping.


2021 ◽  
pp. 1-17
Author(s):  
Peter A. Roussos ◽  
Athanassios Tsafouros ◽  
Efstathios Ntanos ◽  
Nikoleta-Kleio Denaxa ◽  
Anna Kosta ◽  
...  

BACKGROUND: Kiwifruit plants are extremely sensitive to hail storms. Black anti-hail nets are the most frequently used in kiwifruit culture, to protect both the plant and current as well as future production. OBJECTIVE: The present trial aimed to assess if the black hail net could also serve as an amelioration agent against high temperature and irradiance during the summer months. METHODS: The photosynthetic capacity, the yield, and fruit quality (carbohydrates, organic acids, phenolic compounds, and antioxidant capacity) of “Hayward” kiwifruit cultivar, both at harvest and after three months of storage were evaluated. RESULTS: Photosynthetic capacity under the net was slightly higher compared to control, while leaf temperature was always lower during the summer and autumn. The yield was significantly enhanced under the net, while the fruits exhibited higher titratable acidity, organic acids, and ascorbic acid concentration. After the storage, fruits produced from vines grown under net still had higher organic acid content, as well as total soluble solids but lower antioxidant capacity compared to control. CONCLUSIONS: Net installation above kiwifruit canopy seems to alleviate the effects of high temperature and heat load on kiwifruit vines, under saturating light intensity, inducing higher yields with good fruit quality.


Fruits ◽  
2003 ◽  
Vol 58 (4) ◽  
pp. 221-227 ◽  
Author(s):  
Ram Roshan Sharma ◽  
Ved Prakash Sharma
Keyword(s):  

2021 ◽  
Author(s):  
David Maria Tobaldi ◽  
Valentina Triminì ◽  
Arianna Cretì ◽  
Mauro Lomascolo ◽  
Stefano Dicorato ◽  
...  

Wide band gap semiconductors are very attractive because of their broad applications as electronics and optoelectronics materials − GaN-based materials being by far the most promising. For the production of such nitride-based optical and power devices, metal-organic chemical vapour deposition (MOCVD) is routinely used. However, this has disadvantages, such as the large consumption of ammonia gas, and the need for high growth temperature. To go beyond such a limit, in this study we successfully developed a remote plasma assisted MOCVD (RPA-MOCVD) approach for the epitaxial growth of high-quality GaN/AlGaN heterostructures on 4H-SiC substrates. Our RPA-MOCVD has the advantages of lower growth temperature (750 °C) compared to conventional MOCVD route, and the use of a remote N2/H2 plasma instead of ammonia for nitrides growth, generating in situ the NHx (x = 0−3) species needed for the growth. As assessed by structural, morphological, optical and electrical characterisation, the proposed strategy provides an overall cost-effective and green approach for high-quality GaN/AlGaN heteroepitaxy, suitable for high electron mobility transistors (HEMT) technology.


2020 ◽  
Vol 8 (5) ◽  
pp. 551-557
Author(s):  
Gurjot Singh Pelia ◽  
◽  
A K Baswal ◽  

Prevalence of heavy soil is a major problem for fruit cultivation under Punjab conditions consequently leading to deficiency of several micro-nutrients including zinc (Zn), iron (Fe), and manganese (Mn) which adversely affects the growth and productivity. In this view, a study was planned to investigate the effect of foliar applications of zinc sulphate (ZnSO4), iron sulphate (FeSO4), and manganese sulphate (MnSO4) on vegetative growth, reproductive growth and fruit quality of papaya cv. Red lady. Plants sprayed with ZnSO4 (0.4 %) exhibited significantly highest plant height, plant girth, number of leaves, petiole length; initiated an earliest flowering and fruiting; and improved fruit quality viz., fruit weight, fruit length, titratable acidity, soluble solids concentrations, ascorbic acid content, total phenols content, and total carotenoids content as compared with the control and all other treatments. In conclusion, foliar application ZnSO4 (0.4 %) significantly improved plant growth and fruit quality in papaya cv. Red lady.


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