scholarly journals Evaluation of Pear Rootstocks for the Cultivar ‘Suvenirs’ in the Baltic Region

Author(s):  
Jānis Lepsis ◽  
Līga Lepse ◽  
Darius Kviklys ◽  
Neeme Univer

In 2001, investigations were carried out on the Latvian origin cultivar ‘Suvenîrs’ grafted on seven pear rootstocks (MA, MC, BA29, Pyrodwarf, Brokmal, Kirchensaller Mostbirne and Kazrauðu bumbiere) in Polli (Estonia), Pûre (Latvia) and Babtai (Lithuania). The aim of the investigation was to evaluate pear rootstocks in different climatic conditions in the Baltic region. In Polli, all trees were planted in a dense planting, and therefore, trunk cross section area did not differ significantly between trees on different rootstocks. The most vigorous tree habit was observed in Lithuania for trees grafted on the rootstocks Kirchensaller Mostbirne and Brokmal, but in Latvia on Kirchensaller Mostbirne and Kazrauðu bumbiere. The highest dwarfing effect was observed for rootstock MC in both places. The highest cumulative yield from the orchard area was found for trees grafted on rootstocks of the quince group in all three locations of investigation. Nevertheless, the winter hardiness of the quince group rootstocks was not sufficient for Baltic climatic conditions. Good overwintering in Latvia and Lithuania was observed for trees on Pyrodwarf. Survival rate of trees grafted on Pyrodwarf in Estonia was unsatisfactory. The worse overwintering in Lithuania was observed for trees grafted on Brokmal. There was a dwarfing effect on trees and better yield on the vegetative propagated rootstocks included in the investigation, but none one of them can be recommended as perspective for commercial orchards in Baltic agro-climatic conditions.

2012 ◽  
Vol 29 (No. 1) ◽  
pp. 23-25 ◽  
Author(s):  
J. Kosina

Dwarf apple rootstocks M 9, M 27, Pajam 1, Pajam 2, Jork 9, J-TE-E, J-TE-F, J-TE-G and J-OH-A were evaluated in a trial conducted in an experimental orchard with cultivars Golden Delicious, Gloster and Melrose. The experimental plantation was established in 1990. Data on: yield (kg/tree), yield efficiency (kg/cm2), trunk cross-section area and suckering were recorded during the period 1991–2000. The cumulative yield per tree was highest on Jork 9 and Pajam 2. Trees on Pajam 1 and M 9 also had good productivity. Yield efficiency was highest on Jork 9, followed by M 27 and J-TE-G. Trees on Pajam 2 were most vigorous. The tree size on M 9 was similar like on Pajam 1. Trees on J-TE-E and J-TE-F grew less than those on M 9. The weakest growth was observed on rootstocks M 27 and J-TE-G. Among the tested rootstocks, J-OH-A produced the highest number of suckers. Suckering was more intensive with Melrose followed by Gloster and Golden Delicious.


1993 ◽  
Vol 118 (2) ◽  
pp. 170-172 ◽  
Author(s):  
C.G. Embree ◽  
B.H. Lesser ◽  
A.D. Crowe

The 30 apple (Malus domestica Borkh.) rootstock candidates selected for cold hardiness, known as the Kentville Stock Clone (KSC), with `McIntosh' and `Delicious' as scion cultivars, were compared at 11 years of age for tree size, weight, fruit yield, and crop efficiency under field conditions. Trunk cross-section area and tree weight were highly correlated. Tree size was similar for the two cultivars in most cases and ranged in size from semidwarf to very vigorous. Cumulative yield efficiencies varied by nearly two-fold and were not correlated with tree size. The most efficient rootstocks were KSC 28, KSC 7, and KSC 6 in the semidwarf, semivigorous, and vigorous size classifications, respectively.


Author(s):  
Alexis Giauque ◽  
Maxime Huet ◽  
Franck Clero ◽  
Sébastien Ducruix ◽  
Franck Richecoeur

Indirect combustion noise originates from the acceleration of nonuniform temperature or high vorticity regions when convected through a nozzle or a turbine. In a recent contribution (Giauque et al., 2012, “Analytical Analysis of Indirect Combustion Noise in Subcritical Nozzles,” ASME J. Eng. Gas Turbies Power, 134(11), p. 111202) the authors have presented an analytical thermoacoustic model providing the indirect combustion noise generated by a subcritical nozzle when forced with entropy waves. This model explicitly takes into account the effect of the local changes in the cross-section area along the configuration of interest. In this article, the authors introduce this model into an optimization procedure in order to minimize or maximize the thermoacoustic noise emitted by arbitrarily shaped nozzles operating under subsonic conditions. Each component of the complete algorithm is described in detail. The evolution of the cross-section changes are introduced using Bezier's splines, which provide the necessary freedom to actually achieve arbitrary shapes. Bezier's polar coordinates constitute the parameters defining the geometry of a given individual nozzle. Starting from a population of nozzles of random shapes, it is shown that a specifically designed genetic optimization algorithm coupled with the analytical model converges at will toward a quieter or noisier population. As already described by Bloy (Bloy, 1979, “The Pressure Waves Produced by the Convection of Temperature Disturbances in High Subsonic Nozzle Flows,” J. Fluid Mech., 94(3), pp. 465–475), the results therefore confirm the significant dependence of the indirect combustion noise with respect to the shape of the nozzle, even when the operating regime is kept constant. It appears that the quietest nozzle profile evolves almost linearly along its converging and diverging sections, leading to a square evolution of the cross-section area. Providing insight into the underlying physical reason leading to the difference in the noise emission between two extreme individuals, the integral value of the source term of the equation describing the behavior of the acoustic pressure of the nozzle is considered. It is shown that its evolution with the frequency can be related to the global acoustic emission. Strong evidence suggest that the noise emission increases as the source term in the converging and diverging parts less compensate each other. The main result of this article is the definition and proposition of an acoustic emission factor, which can be used as a surrogate to the complex determination of the exact acoustic levels in the nozzle for the thermoacoustic shape optimization of nozzle flows. This acoustic emission factor, which is much faster to compute, only involves the knowledge of the evolution of the cross-section area and the inlet thermodynamic and velocity characteristics to be computed.


2013 ◽  
Vol 365-366 ◽  
pp. 1211-1216
Author(s):  
Fan Zhang ◽  
Peng Yun Song

The cross-section area of straight fin is often considered to be equal in the thermal analyses of straight fin, but sometimes it is unequalin actual situation. Taking a straight fin with two unequal cross-sectional areas as an example,an analytical method of heat conduction for unequal section straight fin is presented. The analytical expressions of temperature field and heat dissipating capacity about the fin,which has a smaller cross-section area near the fin base and a larger one, is obtained respectively. The calculation results of the unequal cross-section are fully consistent with the equal area one, so the method is proved right. The results show that the larger the cross section areanear the base,the better is the heat transfer, and the temperature at the base with larger cross-section area is lower than that with smaller cross-section area when the amount of heat is fixed.


1976 ◽  
Vol 30 (2) ◽  
pp. 179-183 ◽  
Author(s):  
R. S. Hickman ◽  
A. E. Kassem ◽  
L. H. Liang

The rotational temperature at pressures near 1 atm and at room temperature has been successfully measured using spectra obtained in an intracavity Raman scattering experiment. The accuracy of the method is sufficient to allow local temperature measurement of multicomponent gases with no disturbance in the temperature field. The advantage of the method lies in the fact that it does not require knowledge of the relative scattering cross-section area of the component gases.


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