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• Eco-friendly methods to control infection of Botrytis cinerea during propagation of grapevines

  53-56.

  B. L. Farkas

  L. Kocsis

  Views:

  332

  Grey mould (Botrytis cinerea Pers.) is a pathogenic fungus which causes damage to the production of grapevine nursery plant materials especially on the stored canes or on graftings during the callusing period. The conditions, increased temperature and humidity, are ideal for the pathogen during the pre-forcing stage and in the storage Botrytis cinerea can easily infect the outbursting buds as large amounts of grapevine canes are stored in a relatively small place. The fungicide-based management is general in the prevention of gray rot infection but the palette of authorised chemical compounds is narrowed year by year due to the regulations of the European Union. Our aim is to develop an eco-friendly method which combines the use of natural materials with techniques used in organic farming. Effect of the ultraviolet-c light on the Botrytis cinerea was studied. The development characteristics of the pathogen were examined under daylight and dark conditions and experiments were set up with cow’s milk and acetic acid. UV-C light destroyed the developed conidia, however, the radiation stimulates the development of immature propagules. Larger quantities of conidiophores and conidia were formed in daylight compared to culture in the dark, while different conditions did not signifi cantly change the mycelial growth characteristics. The developed bacteria prevented the spread of pathogen mycelia during the test with cow’s milk in Petri dishes, although the smooth development of propagules that occurred did not change the vitality of the fungal colony. Furthermore the growth of Botrytis cinerea fungus mycelia was strongly inhibited by acetic acid.

• Change of Thiamine concentration and amino acid composition during sparkling wine base Production

  62-66.

  B. Pühra (Böröczki)

  M. Kállay

  K. Korány

  Views:

  156

  It has been established, that thiamin content added in 3 mg/I concentration to musts before fermentation resulted in the enhanced storability of sparkling wine base at lower SO2 levels. Fermentation rate is not increased by this concentration and it causes no "thiamine taste" in organoleptic evaluation.

• Investigation of the Relationship between the SO2 Production of Different Yeast Strains and Thiamine Concentration

  57-62.

  B. Pühra (Boróczki)

  M. Kállay

  K. Korány

  Views:

  162

  Our general conclusion was that the thiamine amounts of 0,6 and 3,0 mg/1 added prior to wine fermentation, resulted in higher free-S0₂ level in comparison to the control. Furthermore, among the yeast strains examined in our experiments, Uvaferm BC strain produced the highest free-S0₂ content under the conditions mentioned before. As regards the dynamics of reductone and SO, production, the concentration of the previous one was practically identical in the middle and at the end of the fermentation while the SO₂ content — both free- and total — was lower at the end. Thiamine addition did not cause any difference in the organoleptic properties of wines as proved by sensory analysis.

• Enzym Methods in Wine Analysis

  67-70.

  M. Kállay

  Gy. Bárdi

  K. Korány

  Views:

  146

  In our laboratory for special determinations BOERINGER-MANNHEIM's enzyme-test combinations have been used for 10 years. Our present work deals with the practical aspects of the enzymatic determination of so important wine components like L-malic, L-lactic and citric acid, glycerol, D-gluconic acid, D-sorbitol, acetic aldehyde and D-glucose to D-fructose (G/F) ratio. Whenever possible, the results arc compared to the results of other methods (spectrophotometry, gas chromatography, polarimetry) used at our department.

• Results with the establishment of in vitro culture of Leucojum aestivum

  67-71.

  E. Kohut

  M. Ördögh

  E. Jámbor-Benczúr

  Á. Máthé

  Views:

  275

  Leucojum aestivum is a native, protected ornamental and medicinal plant in Hungary and in Ukraine too. The aim of our work was to establish in vitro cultures of this bulbous plant. Prior to surface sterilisation the old leaves and roots were dissected from the bulbs and they were stored in a refrigerator (2-3°C) for different periods (1 week for the first starting experiment and 5 weeks for the second one). After sterilisation, bulbs, bulb scales and leaves of the bulbs were placed on Murashige and Skoog's (1962) medium with 1 mg/1 benzyl-adenine (BA) and 0,1 mg/1 naphthalene acetic acid (NAA). At the first starting experiment 81,3%, and at the second one 92,3% of the explants turned to be sterile. Bulblets and roots were developed on the explants in the case of using bulb plates together with bulb scales and leaves as inoculua. The best result was achieved after 5 weeks chilling and it was possible to gain little bulbs from the bulb leaves too.