Search
Search Results
-
Effect of water supply on nutrient transport in grapevine varieties
64-68.Views:117The effect of water supply on availability of macro nutrient elements (N, P, K) by the plants in the soil and their transport in the plants were examined. In a field experiment two grapevine varieties characterized by higher (White Riesling B 7) and lower (Kövidinka K 8) water requirement were compared on the basis of N, P, K concentrations of leaf blades, petioles and berries. A different water supply of the vineyard was achived by striped coverage of the soil with plastic foil to exclude rainfalls from the beginning of May to ripening. Humidity of the soil decreased as the vegetative phase advanced. Soil cover resulted in 25-30% decrease of the water content in the soil at flowering but this difference gradually disappeared till veraison (i.e. the start of intense growth of the berries). The water consumption in the White Riesling B 7 plantation was more intensive. Mobility and availability of N, P, K in the soil was restricted by water exclusion (i.e. plastic soil cover) at flowering. Nitrogen was slightly affected, whereas P and K were in a higher extent. Comparing the transport of nutrient elements in the two varieties, leaf blades of Kövidinka K 8 contained less N and more P and K than White Riesling B 7 at flowering and more N and P and less K at ripening. Water deficiency inhibited K accumulation in the berries of White Riesling B 7, while this effect did not appear in Kövidinka K 8.Water exclusion decreased the yield of White Riesling B 7 already at lower bud loading, the yield of Kövidinka K 8 was affected only at higher bud loading. The higher yields of the treatments in Kövidinka K 8 plantation support the superior performance of this variety under the hot and dry climate of the Hungarian Great Plain.
-
Atropine and scopolamine in leaf and flower of Datura arborea L.
61-64.Views:224Angel's trumpet (Danira = Brugmansia arhorea) is a common, popular ornamental plant in Hungary. On the basis of thin layer chromatographic and densitometric alkaloid studies of leaf and flower samples collected from several places in Somogy and Baranya counties it can be stated that in samples of cultivars with different flower colour, taken approximately at the same time, the atropine and scopolamine content varies: there are samples free of alkaloids, but most of them are rich in alkaloids. Although the means do not reflect the extremes, they are suitable for determining the alkaloid accumulating capacity of flowers. Generally the amount of atropine and scopolamine is significant both in the leaf and the flower. It is conspicuous that the flower can be characterised by an extremely high scopolamine content (mean in mg/g dry matter of leaf: atropine 0.34, scopolamine 0.31; of flower: atropine 0.26, scopolamine 0.85). Thus it can be stated that the leaf, and especially the flower of angel's trumpet is a potential hallucinogen, just like in the case of Datura stramonium.
-
Water consumption of the wine grape varieties Kövidinka K.8 and White Riesling B.7
25-30.Views:120In the Carpathian Basin Kövidinka and White Riesling are promising wine grape varieties. As in the region continental climate dominates and dry years are not uncommon it was natural to study the water requirement and consumption of the two varieties. Morphological characters affecting transpiration were observed including leaf area, hairiness, number and type of stomata. The amount of water transpired per unit leaf area and time and rate of water consumption were measured in a model trial in cuttings with known water supply.
The water consumption of vine cuttings depends on varieties and is determined by the genotype but it is also affected by environment. Kövidinka requires little water and uses it to its advantage White Riesling requires more water and uses it rather lavishly. The results of our model trial could be introduced directly into viticulture practice.
-
The effect of cluster thinning, cluster tipping, cluster shredding and defoliation at the flowering on the vegetative and generative vine performance from Kékfrankos Cv.
63-68.Views:202The cluster thinning is a method of the yield regulation.With the removal one part of the clusters, the yield pro leaf area will be lower, hereby the grape and wine quality will be improved. The regulation of the yield can lead to further advantages: the ratio of the vegetative and generative performance of the vines will improve, the condition of the plants will better, the number of the physiological diseases can be reduced and the growth of the shoots and roots can be promoted. The grape growers make the cluster thinning almost exclusive by creating one cluster shoots. Usually the upper clusters are removed, because the sugar content of these second or third clusters will be lower. The cluster thinning is an easy task, can be done without special skills. It is an effective method improving wine quality, but its use can lead to other problems. The grapes try to compensate the removed clusters. Therefore the clusters will be bigger and thicker, but more sensitive to bunch rot. Moreover the treatment is expensive, because it needs manual work. It is worth to get acquainted and try the new yield regulation methods, which can help to avoid the occurring problems. Our aim is to show the results of our experiment, which was carried out in Eger, examining the red grape cultivar Kékfrankos. During our 4 years long experiment we compared the effects of cluster thinning, cluster shredding, cluster tipping and defoliation at the flowering, on the vegetative and generative vine performance.