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• The effect of copper fungicides on the rate of photosynthesis and the transpiration of hop plants

  117-123

  Jaroslav Pokorny

  Josef Pulkrábek

  Karel Krofta

  Josef Ježek

  Views:

  114

  The paper evaluates the effect of copper fungicide spraying on the rate of photosynthesis and transpiration of hops, the influence of spraying on the elemental copper content in the leaves and cones hop variety Agnus. Photosynthetic rate was measured by LC pro+ (infrared analyzer) in the Hop Research Institute Saaz in the field in some periods of 2008, 2009 and 2010. Dry cones and leaf samples (taken before and after application of copper fungicides) were analyzed in an accredited laboratory for elemental copper.

• Comparative study of newly-bred black locust clones with regard to photosynthetic rate and water use efficiency: early evaluation

  5-10

  Tamás Ábri

  József Csajbók

  Views:

  288

  Black locust (Robinia pseudoacacia L.) is one of the most important tree species in Hungary, due to its positive economic impacts. Research to increase its yield, improve its stem quality and enhance its drought tolerance has been ongoing since the 1960s. Of the current research works in this field, the clone trial of the Forest Research Institute, University of Sopron, established in 2020 in the Nyírség region, is worth highlighting. In this experiment 4 newly-bred clones and a state-approved black locust cultivar ('Üllői') are being tested. In the summer of 2022, ‘on site’ measurements of assimilation parameters – net assimilation (A_n), transpiration (Tr) – were carried out using the LI-6800 portable photosynthesis system. From the data obtained, the water use efficiency (WUE) was calculated. The results of the statistical analysis (Kruskal-Wallis H test) have shown significant differences (p < 0.05) between the clones for all three parameters (A_n, Tr, WUE) tested. The NK2 clone has performed the highest value for all the parameters studied. However, no significant differences were found between clones NK2 and PL040 for Tr or between NK2 and control ('Üllői') for WUE. Studies of this kind contribute to the improvement of black locust growing through the production and selection of cultivars, which are relatively resistant to the negative effects (drought) of climate change.

• Water managed properties of apple and pear trees based on lysimeters

  129-132

  Péter Riczu

  Nikolett Szőllősi

  János Tamás

  József Zsembeli

  Views:

  176

  A significant proportion of the aboveground green and dry weight of the plant is constituted by foliage. The canopy is an important factor of plant growth. On the one hand, the canopy absorbs solar energy, which is necessary for photosynthesis; on the other hand, it accumulates the nutrients absorbed by the roots, and most of the water-loss occurs through the foliage. The determination of the full canopy is not an easy target. In our research, we developed a measurement method to determine the leaf area. With the parameters of the examined tree (leaf length and maximum width) and the data of the ADC AM 100 leaf area scanner, we determined the k-value, with which we can easily and fast evaluate the leaf surface. Furthermore, we defined from the water balance of compensation lysimeters the cumulative transpiration of fruit trees and the efficiency of water use of trees. From the examined trees were made a 3D depiction, which show the shape, branching and the location of trees.

• Evaluation of water balance in apple and pear trees

  193-198

  János Tamás

  József Zsembeli

  Péter Riczu

  Views:

  147

  A significant proportion of the aboveground green and dry weight of the plant constitutes the foliage. The canopy is an important factor
  of plant growth. On one hand the canopy absorbs the solar energy, which is necessary for the photosynthesis, on the other hand accumulates
  the absorbed nutrients by the roots, and the most of the water-loss happens through the foliages. The determination of the full canopy is not
  an easy target. In our research we developed a measurement method to determine the leaf area. With the parameters of the examined tree
  (leaf length and maximum width) and the data of ADC AM 100 leaf area scanner we determined the k-value, with which we can easily and
  fast evaluate the leaf surface. Furthermore we defined from the water balance of compensation lysimeters the cumulative transpiration of
  fruit trees and the efficiency of water use of trees.

• Analysis of the photosynthetic parameters, the yield and the quality of winter wheat

  101-106

  József Csajbók

  Erika Kutasy

  Péter Pepó

  Views:

  184

  The environmental adaptability of crop production is basically determined by the selection of biological background (plant species and
  varieties) suitable for the region and the site. The aim of our work is to parametrize the plant assimilation, its intensity, dynamics and the
  most important characteristics and the relationships to the quality in winter wheat trials. The measurements were carried out at the research
  site of the University of Debrecen in small parcel experiments. We measured the leaf net CO2 assimilation rate, stomatal conductance,
  intercellular CO2 level, the transpiration, the leaf temperature and the air temperature by the LICOR LI-6400 portable photosynthesis
  system in field trials on the nutrient supply. The soil of the experimental area is calciferous chernozem with favorable water regime.
  We have examined the photosynthetic activity, the productivity and yield stability of winter wheat varieties. We have compared the yield
  results, at similar agrotechnical conditions in seven cropyears. We also determined the quality parameters of the winter wheat varieties.
  Then we valued the yield stability of genotypes with the help of analysis of variance and linear regression equations. We have defined the
  connections between assimilation parameters, the yield stability and quality parameters of wheat varieties.