The role of mycorrhizal fungi has special importance in the case of low soil moisture because the colonization of vine roots by mycorrhiza increases water and nutrient uptake and thus aids the avoidance of biotic and abiotic stresses of grape. Our aim was to investigate in the Eger wine region the changes of mycorrhizal colonization, water potential, and yield quality and quantity of grape roots at three altitudes, along a changing soil moist gradient. Our results show that the degree of mycorrhizal colonization is higher in drier areas, which supports the water and nutrient uptake of the host plant.

No abstract

The 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.

Intensive mechanical soil cultivation and herbicide treatment was often the preferred technology in vineyards in the second half of the 20 th century. In the last decades we increasingly experienced the disadvantages of these suboptimal technologies: soil degradation, erosion and deflation damages. Alternative cultivation methods were sought for research and practice, especially in organic viticulture. The use of well-adapted cover-crop mixtures in the vine inter-rows poses a possible solution for weed control, soil conservation and biodiversity development. The technology has a special importance on steep slopes: it helps to prevent erosion damages and provides easier cultivation circumstances. In 2012 the Hungarian Research institute of Organic Agriculture in collaboration with other experts and growers began to study three different species-rich cover crop mixtures (Biocont-Ecovin, Legume mixture, Grass-herb mixture) in Hungarian vineyards. Each mixture was sown in three neighbouring inter-rows at each experimental site. After sowing (March 2012) we studied vegetation composition (June 2012, 2013 and 2014), pruning weight and diameter of the second bearing spur of the stocks, yield quality and quantity. Most of the sown species established successfully and in 2012 we found that Biocont-Ecovin and the mixture of legumes were the most effective in weed suppression. For 2013 we detected lower weed coverage in the inter-rows sown with the grass-herb and legume mixtures, while in control and Biocont-Ecovin inter-rows we detected increasing weed coverage. In the third year (2014) we found in every plot? that the grass-herb mixture-covered inter-rows were the least weedy. The most successful species in the inter-rows are: Coronilla varia, Lotus corniculatus, Medicago lupulina, Onobrychis viciifolia, Plantago lanceolata, Trifolium repens, Trifolium pratense. Viticultural measurements (2014) show a 10-13 % decrease of yield in case of covered inter-rows, and a 26 and 21 % reduction in pruning weight (Gróf Degenfeld and Tokaj-Hétszőlő), especially apparent in young plantations. For Hungarian conditions it is therefore recommended to implement this technology in every second inter-row where erosion control is not required.