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During the ageing in barrels, the contact with the fine lees triggers several processes in wine. Lees has a reductive effect by absorbing dissolved oxygen and reducing the amount, which will remain in the wine. At present, minimizing the addition of sulphur dioxide is the trend in all viticultural areas. In this study, the effect of various sulphur dioxide levels was monitored in presence of the lees to determine which dose is appropriate to provide the protection of susceptible white wine against oxidation.

Without SO2 protection, the rH and redox potential changed slightly, so the level of dissolved oxygen seemed to be controlled during the ageing period by the lees, though the antioxidant effect of lees in itself was not appropriate to protect the polyphenol content from chemical oxidation, which led to considerable browning. With the addition of a lower amount of SO2 — 40 mg l2, the lees is already able to protect the white wine samples in all aspects.

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Basil has traditionally been used for a long time in medicine and gastronomy. Essential oil is the most important active substance of the drug, which influences the aroma and the effect of the plant. Although the compositions of essential oils vary in different basil cultivars, the main components are oxygenated monoterpenes and phenylpropane derivates. The high chemical variation is most likely caused by interspecific hybridization. Various factors, like genetic background, ontogenesis, morphogenesis, abiotic factors, essential oil extraction method, drying, and storage, are responsible for the variant essential oil composition.

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A new process, bilateral band compression has been used to increase the sensitivity of detection of minor components of a mixture. After band-shaped sample application, fully off-line OPLC separation, and drying, the separated bands were compressed bilaterally, in parallel, perpendicular to the direction of development, by use of a strong eluent and capillary driven chromatography. To introduce the eluent on to the layer for band compression a simple manual tool equipped with parallel foam strips was constructed. A mixture of xanthine standards (caffeine 0.998 mg mL −1 , theophylline 1 μg mL −1 , and theobromine 1 μg mL −1 ) and black tea leaf extract were used to test the efficiency of detection after bilateral band compression. After band compression 20 ng theophylline and theobromine could be detected by densitometry in the xanthine standard mixture at a loading of 20 μg/10 mm whereas they were not visible in the original, uncompressed chromatogram.

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Abstract  

The method is based on the difference of the half-lives of two dififerent radionuclides, having similar -energies. Using the method it is possible to determine the two components in the peaks also in that cases, if the difference between the energies is less, than the energy resolution of the detector. The main point is the perform only one irradiation, but use two different clock times before counting. The criterion of the method can be used when there is significant difference between the half-lives of the radionuclides.

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The dependence of winter wheat production on spring temperature and precipitation was analysed on the basis of historical meteorological data. Production was found to be a linear function of temperature, so increasing temperatures resulted in lower yields. The dependence of yield on precipitation could be described with a quadratic function, and the yield decreased above the optimal precipitation amount. The results of regression analysis are presented using 30-year data for Fejér County. Simulation modelling was used to analyse the suitability of future climates for growing winter wheat in Hungary. The locations chosen were heterogeneous in terms of meteorological conditions, but were all relatively flat and of great importance for Hungarian winter wheat production: Győr-Moson-Sopron County in W. Hungary, which is well supplied with precipitation, Hajdú-Bihar County in the east, where the weather is warmer and drier, and Pest County in the middle of the country. Evaluations were made using the Ceres-Wheat model and a modified version of AFRCWHEAT2. An analysis of the simulation results revealed that agricultural productivity is close to the upper limit of what can be achieved using conventional methods, so decreased yields and an increase in production risks are probable in the future in all three regions.

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The purpose of this work was to further investigate the regulatory interplay between pyrophosphate:fructose 6-phosphate 1-phosphotransferase (PFP) and its positive effector, fructose 2,6-bisphosphate (Fru-2,6-P 2 ), in the storage organs of cold- and drought-stressed plants. Since there is no detectable cytoplasmic fructose-1,6-bisphosphatase (cytFBPase) activity in the taproots of carrot plants, PFP is the only enzyme that can replace its function when stored starch is converted to transportable sucrose. The working hypothesis was that PFP is likely to be involved in the mobilisation of energy reserves and might have a special role in storage organs such as carrot taproots upon stress. Both cold and drought stress resulted in a marked increase in the endogenous Fru-2,6-P 2 levels. It is suggested that the significant changes in photosynthate allocation are the direct results of the stimulation of PFP activity by elevated Fru-2,6-P 2 levels. PFP stimulated by Fru-2,6-P 2 operated in the gluconeogenic direction in the taproots of stressed carrot plants, whereas the glycolytic direction was dominant in the non-stressed controls. This suggests that the metabolic status determining the net activity of PFP depends on the physiological stress situation, making PFP an important sensor of environmental changes. The experimental data indicated that PFP is involved in the mobilisation of energy reserves during unfavourable environmental changes by promoting the re-synthesis of transportable sucrose in taproots.

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The drought tolerance of six green-and yellow-podded varieties of green beans with different genetic backgrounds was tested in the phytotron. During the week prior to flowering the plants were kept either at 25/15°C (day/night) or at high temperature (30/15°C), with RH 75% and optimum water supplies. The heat-stressed plants were then divided into three groups; the first was returned to the control (25/15°C) chamber (RH 75%, optimum water supplies), while the second and third were exposed to mild drought stress (RH 60%, 50% water) at temperatures of 30/15°C and 35/25°C, respectively, throughout the flowering period.The varieties survived the short period of heat stress (30/15°C) prior to flowering without damage provided the temperature during flowering was reduced to 25/15°C and the water supplies were optimum. There was a sharp increase in the carotene level in the leaves of drought-stressed plants when the temperature during flowering was 30/15°C, but in plants exposed to 35/25°C during flowering the level dropped to near the control level. The latter group exhibited considerable damage, with a reduction in the water-soluble antioxidant content (ACW: antioxidant capacity of water-soluble substances) and the chlorophyll b content compared with the control.The antioxidant content (ACW) in the dark green leaves of green-podded varieties was lower than in the yellow-podded varieties and did not change as the result of drought and heat stress. In yellow-podded varieties, however, there was a significant decline in ACW in response to stress. Differences between the varieties in their adaptability to drought and heat could be detected as changes in the chlorophyll and carotene contents of the leaves even at 30/15°C.

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Scree forest communities Mercuriali-Tilietum Zólyomi et Jakucs 1958 of Börzsöny Mts were not processed until the present. These lime-dominated forests develop on andesite base-rock, mainly on periglacial scree surfaces. Using the Braun-Blanquet-Soó method 15 sampling spots were studied and analysed based on floristical composition, cenological aspects and habitat characteristics. The stand's species stock consists of tree species like Acer platanoides, Carpinus betulus, Fraxinus excelsior, Tilia platyphyllos, shrubs like Cornus mas, Corylus avellana, Euonymus verrucosus, Ribes uva-crispa and herbs like Cystopteris fragilis, Dryopteris filix-mas, Galeobdolon luteum, Galium schultesii, G. odoratum, Hedera helix, Melica uniflora, Mercurialis perennis, Mycelis muralis, Poa nemoralis, Waldsteinia geoides. Rare Tilio-Acerion species are Adoxa moschatellina, Gagea minima, Geranium lucidum. Cenological categories, life forms, geoelement distribution, and Borhidi's Social Behaviour Types were studied on the basis of the synthetic table. Relative ecological T, W, R values according to Zólyomi, and Borhidi's continentality were also evaluated. Results were compared to Parietario-Aceretum (Horánszky 1964) Soó 1971 community belonging to alliance Tilio platyphylli-Acerion pseudoplatani. This andesitic gorge forest community where highly dominant species are Acer pseudoplatanus, Fagus sylvatica, Fraxinus excelsior is a closely related to the scree forests.

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Swertia L. with about 150 species worldwide is one of the most divers genera of the Gentianaceae. Based on previous work for morphological phylogeny of the family, Swertia can be considered as a primitive genus of the temperate subtribe Gentianinae Gilg. To explain diversity in Swertia, species number per 100,000 sq. km were calculated and mapped for important parts of the generic range, evolutionary advancement indices (AI) for 118 species were determined (based on morphological traits) and a correlation analysis, with ecological and phenotypical variables, was undertaken. Diversity centres are East Himalaja plus Chinese provinces of Yunnan and Sichuan (with diversity maximum of 16.3 in Nepal) and the East African Rift Valley Region (with highest diversity in Malawi, 6.8). Advancement indices of species range from 0.12 to 0.78 within 0 and 1, theoretically possible. The nine most primitive species (AI<0.25) are distributed in Asia and Africa, above an altitude of at least 2,500 m while in North America most species are highly advanced (AI≯ 0.65). Correlation analysis with ecological factors such as latitude, altitude, habitat type suggests that the genus originated in the moist montane or alpine zones.

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To raise the efficiency of plant regeneration we studied the important and necessary elements of the procedure. The embryogen capacity of 33 various grape genotypes were tested on four different induction media. We successfully obtained anther derived embryogenic calli in 27 genotypes with the range of 1–12%, this is the first reported protocol for embryogenesis from Korai bíbor, Odysseus, Orpheus and Pannon frankos cultivars. Two sorts of sterilization treatments were examined before inducing somatic embryos. For optimisation of grape regeneration system the propagation of calli was attempted in Richter 110 cultivar, there was no any significant differences in the measured values, but CPE medium proved more successful in maintaining embryogenic capacity of callus. We experienced high developmental differences between the propagated embryogenic culture of Richter 110, Teleki 5C and Chardonnay derived from MSNOA liquid medium and from MSE solid medium. Regenerated plants from embryogenic callus were obtained in 21 genotypes, in Chardonnay cultivar CP medium influenced more positively the plant regeneration than the MS/2 medium.

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