ABstrAct:Sixteen new plum cultivars mostly bred in Germany were tested together with several standards in a high density experimental orchard established at Holovousy in the spring of 2004 with spacing 5 × 1.5 m. Trees were trained as spindles on St. Julian A rootstock. In the orchard the following characteristics were evaluated: tree vigour based upon measuring of trunk-cross section area and canopy volume, yields, time of flowering, time of fruit ripening and basic parameters of fruit quality. The highest yields and precocity of fruiting were recorded on cultivars Tophit, Jojo, Elena, and President, whereas the least productive were Ruth Gerstetter, Anna Späth, and Topgigant Plus. Cultivars Katinka, Jojo, Topper, and Empress had the highest values of yield efficiency whilst the lowest ones were recorded on Topgigant Plus and Anna Späth. All evaluated cultivars were characterized by mean start of fruit ripening and length of harvest period. Topgigant Plus had the largest fruits (mean 75.9 g) followed by Bluefre, Empress and Tophit, whereas the smallest ones were recorded in Katinka, Gabrovská and Valjevka. The highest scores for fruit quality were given to Hanita, Tophit and Presenta. New cultivar Tophit was the most remarkable regarding all evaluated characteristics including its time of ripening that would prolong the season of commercially grown fresh fruit cultivars for use in the Czech Republic.

Thirteen plum cultivars on two rootstocks (Myrobalan and Wangenheim Prune seedlings) were studied in a trial established in the spring of 1998 at spacings 5 × 1.5 m. Trees were trained as spindles. Čačanska najbolja was the most vigorous in this trial, followed by Čačanska rana, Herman and Domestic Prune. The weakest tree vigour was observed on Wegierka Dabrowicka, followed by Čačanska rodna and Empress. Čačanska najbolja, Wegierka Dabrowicka and Valor had the highest yield per tree, whereas Čačanska rana had the lowest yields. Bluefre was the most precocious cultivar. Wegierka Dabrowicka had the highest yield efficiency followed by Empress and Valor. On the contrary, Čačanska rana, Early Blue and Domestic Prune belonged to the least productive cultivars. Trees on Wangenheim Prune seedlings grew about one third weaker than those on Myrobalan seedlings but their yield efficiency was about 31% higher although their yields per tree were about 12% lower. The largest fruits were recorded with Bluefre. Čačanska rana, Empress, Valor and Oneida were also ranked among large fruit varieties with minimum differences between them. The mean harvest season of evaluated cultivars started by Herman on the 12 th July and ended by Oneida on the 9 th September. Valor and Empress had the best performance of tree growth, bearing habit and fruit size, which indicates their good suitability for the modern types of plum orchard. Bluefre may also be of some interest for growers because of the best precocity and large fruit size, and Oneida for prolonging the whole harvest season.

Blažek J., Pištěková I., 2012. Final evaluation of nine plum cultivars grafted onto two rootstocks in a trial established in 1998 at Holovousy. Hort. Sci. (Prague), 39: 108-115.Nine plum cultivars newly introduced into production were evaluated in a replicated trial established in 1998 on two rootstocks planted in a spacing of 5 × 1.5 m. Trees were trained as spindles and evaluated regarding vigour, canopy performance, level and stability of yields, yield efficiency, fruit size, time of flowering and harvest season until 2010. Significant differences among cultivars were found but the most interesting were related to tree vigour, yield efficiency and fruit size. Dwarfing influence of Wangenheim seedling was negligible in Empress and Čačanska lepotica but mostly visible in Sanctus Hubertus. Wegierka Dabrowicka on both the rootstocks had the highest yield efficiency, exceeding 3 kg/m 3 of trunk cross-section area. Yield efficiency of trees grafted on Wangenheim was generally higher than those grafted on Myrobalan but the greatest difference was evidenced on Domestic Prune (more than 25%). Suggestions in terms of trees-spacing are definitively proposed upon results of this study.

The growth of fruits was evaluated during three growing seasons on four apple cultivars 'Angold', 'Jonagold', 'Rubinola' and 'Topaz'. The follow-up period was defined by the start of flowering, the date of attaining of T-stage by fruitlets and the start of optimal harvest ripening, which for each cultivar was determined on the basis of starch index, flesh firmness and soluble solids. The close relationships were detected between time of attaining the T-stage and term of harvest maturity for three of four studied cultivars.

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