scholarly journals Photosynthetic activity of selected genotypes of hops (Humulus lupulus L.) in critical periods for yield formation

2011 ◽  
Vol 57 (No. 6) ◽  
pp. 264-270 ◽  
Author(s):  
J. Pokorný ◽  
J. Pulkrábek ◽  
P. Štranc ◽  
D. Bečka

This paper evaluates the influence of genotype on the photosynthetic activity of hops in the period critical for generating yield. Results over three years from measuring the photosynthesis rate statistically show an increase in the photosynthetic activity of hop plants in the flowering stage. The average photosynthetic rates from measurements on the second date (BBA 65) in the years 2007, 2008, and 2009 increased by 17.9%, 45.6%, and 49.2%, respectively. Different photosynthesis curve trends during the final stage of ontogenesis of the plants indicate the maturity level of each hop genotype. As regards the genotypes for which photosynthesis did not reduce significantly, it may be assumed that such plants had not reached technical maturity. The results from the three-year study also show that any promising genotype, with respect to the photosynthesis rate and yield, is the result of breeding of new varieties with greater resistance to drought and high temperatures. Very good results in photosynthetic activity were reached by the new varieties exhibiting high yield and a similar chemical composition to Saaz hop and those sharing the same origins to Saaz, showing a higher content of bitter substances. In 2008 and 2009, all three new forms reached yield levels of 2.35 to 3.12 t/ha of dry hops.

Author(s):  
А. А. Fadeev ◽  
Z. А. Nikonova

The results of study of the 12 year cycle of studies on the only in Russia collection of hops ordinary (Humulus lupulus L.), which contains 250 samples from different regions of Russia and 17 foreign countries. The number of process varieties, composition and origin, it is unique and corresponds to world level. A collection of accessions of hops is a population of female plants with a set of phenological, morphological and economic importance of signs. In the article, the estimation of the collectible varieties of hops at different ripeness groups according to phenological and morphological characteristics according to the method of test for distinctness, uniformity and stability. As the result of the research the Common Hop (Humuluslupulus) sorts were classified in accordance with their maturity time as early maturity (less than 100 days) – 10%, middle-early (101…110 days) – 14, middle duration (111…120 days) – 40, middle-late (121…130 days) – 10% and slow-maturing (more than 130 days) – 26%. Each group has a phenotypic and morphologies features. The early maturity, middle-early and middle duration varieties with vegetative season approximately 120 days are more adaptive to the conditions of the Chuvashia and central part of the Russia and provide obtaining high yield of the hop cones.


1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.


ChemInform ◽  
1990 ◽  
Vol 21 (51) ◽  
Author(s):  
C. H. ZAMBRANO ◽  
A. K. MCMULLEN ◽  
L. M. KOBRIGER ◽  
P. E. FANWICK ◽  
I. P. ROTHWELL

2001 ◽  
Vol 24 (2) ◽  
Author(s):  
Taichi Nakano ◽  
Sigeyuki Nöda ◽  
Nao-aki A-ihara ◽  
Hirohide Yamashita ◽  
Takashi Miyamoto ◽  
...  

RSC Advances ◽  
2012 ◽  
Vol 2 (4) ◽  
pp. 1292-1295 ◽  
Author(s):  
Chun-Xia Zhao ◽  
Lei Yu ◽  
Anton P. J. Middelberg

1976 ◽  
Vol 31 (5) ◽  
pp. 558-564 ◽  
Author(s):  
Marianne Baudler ◽  
Burkhard Carlsohn ◽  
Wolfgang Böhm ◽  
Goswin Reuschenbach

The weak resonances at + 22 and + 49 ppm appearing in the 31P NMR spectrum of melts or solutions of (PPh)5 that have been attributed previously in the literature to “dimeric” and “monomeric phenylphosphorus” are caused by (PPh)6 and (PPh)4, respectively. This was proved by comparison with the 31P NMR parameters of related compounds and by 31P NMR spectroscopic investigation of authentic samples of (PPh)6 and (PPh)4, the latter of which was prepared in high yield from (Me3Si)PhP–PPh–PPh(SiMe3) and PhPCl2. (PEt)4 and mixed-substituted phenyl-ethyl-cyclotetraphosphanes exhibit similar chemical shifts as (PPh)4, corresponding mixed-substituted cyclohexaphosphanes have similar chemical shifts as (PPh)6. Generally, cyclophosphanes establish an equilibrium between (PR)n-species of different ring-size. Probably, the ring-interconversion proceeds via a multi-center mechanism. No 31P NMR spectroscopic evidence for the existence of free PPh or P2Ph2 under the conditions described could be detected. On thermolysis of (PEt)4 the existence of (PEt)3 was proved for the first time.


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