Blažková J., Drahošová I., 2012. Impact of pruning time on tree vigour and productivity of three sweet cherry cultivars grown on two semi-dwarf rootstocks. Hort. Sci. (Prague), Tree pruning in two different terms (March and August) was applied in a sweet cherry orchard of Kordia, Těchlovan and Vanda cv. planted on Colt and P-HL-A rootstocks established in 1996 in the spacing 6 × 1.5 m. Tree vigour, yields and mean fruit weight were evaluated in this study in relation to the term of the pruning. The subject of this paper is the experimental orchard in the stage of full productivity and the study is a continuation of a previous publication focussed on its performance till 2005. The vigour of Kordia cv. trees on both rootstocks pruned in August was distinctly weaker. Trees of Těchlovan cv. on P-HL-A grew significantly stronger after pruning in August, whereas in the case of Vanda cv. this effect was found on the Colt rootstock. In comparison to the results from the first period of the study when specific productivity was mostly higher after tree pruning done in August, it is in the subsequent stage generally better to prune in the spring time. This change of tree response is evidently connected to a rate of tree ageing and the spring term of pruning probably compensates this development.