scholarly journals Different types of N nutrition and their impact on endogenous cytokinin levels in Festulolium and Trifolium pratense

2011 ◽  
Vol 57 (No. 8) ◽  
pp. 381-387 ◽  
Author(s):  
M. Neuberg ◽  
D. Pavlíková ◽  
E. Žižková ◽  
V. Motyka ◽  
M. Pavlík

This study aims to reveal and to compare effects of two different systems of nitrogen (N) nutrition (sidedress application or injection application) on toxicity of NH<sub>4</sub><sup>+</sup> and mixed nutrition. We investigated whether NH<sub>4</sub><sup>+</sup> or mixed (NH<sub>4</sub>NO<sub>3</sub>) application causes significant changes in the endogenous levels of cytokinins (CK), whole plant N and their effects on yield of selected plants. Ammonium sulphate or ammonium nitrate were used as N source in the pot experiment. The yield of Festulolium and Trifolium pratense L. above-ground biomass and roots was more substantially enhanced after sidedress application of both ammonium sources in comparison with injection application. Our results confirmed that the accumulation of CKs in plants is in correlation with their N content (R<sup>2</sup> = 0.66&ndash;0.98). Proportions between individual CK forms remained relatively steady and their dynamics exhibited similar trends after N application. Our results indicate that the negative effect of the application of NH<sub>4</sub><sup>+</sup> on the growth of Festulolium and clover plants could be effectively modulated by the presence of NO<sub>3</sub><sup>&minus;</sup>.

1991 ◽  
Vol 71 (4) ◽  
pp. 1039-1046 ◽  
Author(s):  
Lucius Belzile

Red clover (Trifolium pratense L.) was grown for seed production after the seeding year on two different types of soils, in the same climatic area. An important difference in yield which was often related to cultivar and sometimes to year was observed between the two soils — the light soil, Saint-André gravelly loam, produced more seed than the heavy Kamouraska clay. Seed yield differed between cultivars with Florex and Arlington producing the most. On an annual basis, the thousand-grain weight was higher on Kamouraska than on Saint-André. The percent germination was not influenced by soil type and cultivar but variation between years was observed. The production of heads per plant was higher on Saint-André. The number of seeds produced per plant and per head was, as for yield, higher on Saint-André than Kamouraska. The influence of cultivars and years was not always visible on these last parameters. Therefore these results demonstrate that generally the success of red clover seed production depends not only on cultivar and climatic conditions, but that within the same climatic area the type of soil is a major factor. Key words: Red clover, seed production, soil effect, year of harvest, cultivar, yield components


Crop Science ◽  
1965 ◽  
Vol 5 (5) ◽  
pp. 425-428 ◽  
Author(s):  
R. J. Bula ◽  
R. G. May ◽  
C. S. Garrison ◽  
C. M. Rincker ◽  
J. G. Dean

Author(s):  
Frowin Fasold ◽  
Benjamin Noël ◽  
André Nicklas ◽  
Fabian Lukac ◽  
Stefanie Klatt

Throwing a ball is a primary skill in team-handball and can be directly influenced by the properties of different types of balls. Therefore, the use of different balls (i.e., methodic ball) recommended by the handball federations (e.g., IHF) and the education guidelines, are important in teaching throwing. Previous studies have shown that movement patterns and throwing velocity can be influenced by different ball types and sizes. However, the influence of these factors on throwing accuracy has not been investigated in detail yet. This study aims to replicate the findings of previous studies on increasing throwing velocity in children by comparing the use of a soft methodic ball with a size 0 handball. Furthermore, this study investigates the influence of these balls on throwing accuracy. In an experimental study, participants (10-years of age) threw a soft methodic ball and a size 0 ball at target areas in a handball goal. For all the throws, throwing velocity and accuracy were measured. Commensurate with previous research, throwing velocity was higher for the soft methodic ball compared to a size 0 ball. No difference was found in accuracy, although, it is worth mentioning that the participants were only experienced in throwing using the size 0 ball. Moreover, only one-third of the children favored throwing with a size 0 ball, which is what they are used to in training and competition. The results of our study, therefore, confirm that using soft methodic balls additionally, positively influences the throwing velocity and has no negative effect on the accuracy in throwing among young handball beginners.


2009 ◽  
Vol 4 (6) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Aldo Tava ◽  
Daniele Ramella ◽  
Maris Grecchi ◽  
Paolo Aceto ◽  
Renato Paoletti ◽  
...  

The composition of the volatile fraction of two important forage legumes from Italian sub-alpine N.E. pastureland, namely Trifolium pratense L. subsp. pratense (red clover) and T. repens subsp. repens (white clover) were investigated. The volatile oil was obtained from the fresh aerial parts by steam distillation and analyzed by GC/FID and GC/MS. The oil yield was 0.018 and 0.021% (weight/fresh weight basis) for T. pratense and T. repens, respectively. Several classes of compounds were found in both the oils, including alcohols, aldehydes, ketones, terpenes, esters, hydrocarbons, phenolics and acids. Qualitative and quantitative differences were found.


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