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The paper describes time-domain simulation of gear pitting damage using animation program. Key frames have been used to create illusion of motion. The animation uses experimental results of high-cycle fatigue of material. The fatigue damage occurs in the nominal creep area on the side of the gear tooth sample loaded with variable-positioned Hertz pressure. By applying the force, the pressure cumulates between two convex surfaces. This phenomenon results in material damage under of curved surfaces in contact. Moreover, further damage has been registered on the surface. This is due to exceeding the elastic-plastic state limit and development of "tabs". The tabs serve as origin of surface micro cracks powered by shear stress and enclosed grease pressure as well. This deformation and extreme pressures of Pascal law contribute to elongation and growth of the surface micro crack. Non-homogenous parts of material volume support the initialization/development of the micro cracks as well. Resulting visualization of the tooth-side fatigue damage provides clear and easy-to-understand description of the damage development process right from the micro crack initialization to the final fragmentation due to pitting degradation.

Increasing demands of the present society lead to an effort to rationalize logging operations in forest management. Therefore, multi-function logging machines are increasingly used in the course of timber harvesting. Nevertheless, the economic effectiveness of these machines is affected not only by their productivity or environmentally friendly operations but also the quality of performed work. It can be evaluated by the assessment of the quality of produced assortments. Decreasing quality of produced logs can result in the reduction of marketability and wood price. Thus, the aim of this paper is to determine some defects originating at the harvester production of assortments and specification of their potential causes.

The response of tubers of nine varieties of potatoes to the bar impact have been evaluated. The proposed method enables to obtain force - time record. The response function is represented by the time history of the surface displacement. This function has been recorded using laser vibrometer technique. The main features of the force and displacement function have been found both in the time and frequency domain. It has been found that given method can be used for the detection of the potato tubers damage origin as well as for the differentiation among different varieties of the potatoes. There is also a chance to evaluate the main mechanical characteristics of the potato tubers by non - destructive way.

Defoliation of vineyard find between growers always wider exercise. The ground are ecological aspects and for ever growing title to qualitative character of production. Thrifty ablation of leaves from winegrapes zone, fulfilment in correct term highly effects on health of clusters and quantity of their contentual matters.
The aim of this work was monitoring of technic-economical parameters by 2 sets with defoliators. Furthemore was evaluated quality of their work in relation to quantity of involved bunches.

The yield of sugar beet is directly affected by LAI (leaf area index) and values of LAD (leaf area duration). The integral leaf area plays, except for other factors, an important role during the damage or reduction of leaf apparatus. There are many sources of leaf damage: natural disasters (hailstorm), diseases, pests (including game browsing) etc. The intensity of the root production and quality differs in relation to the growth stage of the damage plant. The aim of this study was to evaluate the extent of losses in the root yield and the quality of sugar beet upon gradual reduction of the leaf area. Two diploid varieties Monza and Compact were used in the small-plot trials conducted in years 2004 to 2006 (in the experimental station Žabčice - maize production region, zone K2, average altitude 184 m, soil type was classified as gley fluvisoil, soil is medium heavy to heavy, clay-loam to loam type). The leaf area was manually reduced by 25% and 50% at BBCH 18-19 growth phase (8-9 leaves unfolded). The results were statistically evaluated by analysis of variance and testing by Tukey test (at the significance level α = 5%). Reduction of the leaf area was reflected on the decrease of the root yield by 1 to 10% depending on the year of harvest. In addition, the stressful state of the plants after defoliation resulted in the decrease of the yield of polarization sugar per hectare, namely by 0.45 to 1.66 t.ha^-1. In 2005, the leaf area reduction caused a rise of the α-amino nitrogen content. The rise in the potassium and sodium cations content caused by the leaf area reduction also increased the sugar content in the treacle (by 0.1 to 0.16%). The increasing leaf area reduction lead to decreasing of yield of polarization sugar. However, this descent was statistically significant in harvest year 2006 only.

Grape phylloxera, Dactulosphaira vitifoliae Fitch., is one of most destructive insect pest of cultivated grapes (Vitis vinifera L.) worldwide. Phylloxera was the cause of incomparable structural changes in European viticulture. It also led to the usage of new biotechnology - rootstocks for grape varieties. The direct damage is related to phylloxera feeding of roots and leaves. Rootstocks bred solely with American Vitis spp. parentage allow little or none of phylloxera related root damage that is seen on Vitis vinifera. Rootstocks with partial Vitis vinifera parentage may also confer a high level of grape phylloxera resistance, but this resistance is not durable. Rootstock was evaluated under laboratory conditions and with pot trials. Resistance against phylloxera at roots and leaves was evaluated. Highest resistance degree was proved for variety Börner. Good resistance was found for most of tested rootstock varieties. Very good resistance have SO4 PO 0/7 and Craciunel 2 PO 0/6. It is interesting, that hybrid Kl×SO4 has also relatively good resistance. This promising franco-american needs further examination thanks to its good growing properties. After long time, this research offers new results about rootstock and phylloxera interactions under conditions of Southern Moravia. Results serve as a ground for further resistance breeding against phylloxera in Czech Republic.

As mentioned earlier, it is not true that some bulbous species from the family Orchidaceae are able to survive only mycotrophically, i. e. without formation of stalk. Our observations, especially of Ophrys apifera, have demonstrated (in the Czech Republic) that the durability of adult plants is very short so that their numbers are fluctuating. The dying can be caused by several factors. Frost damages followed by rotting of underground parts (roots and bulbs) are relatively frequent. The leaf rosette, which is the most resistant, dies as the last, usually later in the spring of the following year. This means that the frost damage is often not identified during the cursory visually control in the spring. We observated very extensive damaging and dying of the Orchidaceae after the winter of 2002/03 - on the turn of November and December 2002, there was a rapid onset of very strong black frost after a long, wet and relatively mild autumn. Consequently 80% of population perished. None specimens of Ophrys apifera and/or Himantoglossum adriaticum came into blossom in 2003 and other species were strongly damaged. Our observations document that the general increase in air temperatures need not result in the occurrence of generally expected better growing conditions for some thermophilous species. It is very probable that the extremes climatic conditions could show greater effects than the general increase in average temperatures. Such phenomena are well-known but in practice they are not noticed and/or are explained in a different way. Such risks can exist in the whole Central European region. Negative effects of frosts in winter 2002/03 were further intensified by long and extreme droughts in the growing season of the year 2003. Combination of these extremes was crucial for the species Gentianella bohemica: In average, 95% of specimens in each population perished. If the fluctuations in climatic conditions will be more frequent, some species can become extinct irreversibly very quickly.