We examined Blumeriella jaapii (Rehm) v. (Arx) infection on 21 sweet cherry cultivars in the cultivar-collection of the Experimental Station Pallag of the University of Debrecen, in 2004 and 2005. Considerable differences were detected in the infection degree of the different cultivars. In 2005, due to the more humid weather, the average infection highly exceeded data of the previous year. No symptomless cultivars were detected in either year. The least sensitive ones were Linda and the cultivar 11/106. The most sensitive cultivars were Early Müncheberg, Biggareau burlat and Round Solymári. Infection degrees of Alex, Rita and Vega were different from those of other cultivars on the basis of the two experimental years. It is important to consider both the specific weather conditions of the year and cultivar resistance at planning the plant protection system. It is recommended for each cultivar to perform a fungicide-spaying after the harvest.

Although a high portion of domestic orchards is cultivated extensively, quality Hungarian sour cherry is a highly demanded product throughout Europe. Trees are slightly pruned, or not pruned at all. Thanks to the unique character of the species, older wood parts are pilling up. Thus, the interior of the canopy is inactive, fruits and shoots confine the exterior layer of the canopy.We established pruning treatments in the sour cherry plantation in the Horticultural Exhibition Garden of the University of Debrecen, involving two age groups in two spacings. The trees are standing on seedling rootstock. The involved varieties were: Érdi bőtermő, Debreceni bőtermő and Kántorjánosi. We examined how to encourage shoot formation and the regeneration of older, pilling wood of the interior canopy parts.Applying strong rejuvenating cuts, the most shoots were generated on the 3rd and 4th year laterals. Wood parts older than the 3rd year shall be removed by leaving short (2-3cm) stubs. This way, older, passive woodparts can also be made to burst out. From the examined varieties the Kántorjánosi showed the most favourable regenerative ability. Due to summer pruning, more shoots regenerated on the axis of the trees, than on those rejuvenated in the dormant season.

Increasing the intensity of production in the case of pear can be the solution to satisfy the market demand forr high-quality fruit. The aims in this technology are the canopy treatments and the maintainance of consistently high quality yields in the long run. The experiments were performed with cv. William’s pear, a cultivar grown on large areas in Hungary. To create the optimal canopy shape for earlier fruiting, we performed shoot selection and the cutting back of shoot tips. Our results show, that both pruning methods – applied at 3 different dates – decreased the number of short fruiting parts (spurs), and increased the number of vegetative shoots. The sole exception was from this the effect of shoot tip removal when done at the earliest date.

In this study, the pollen of 14 sweet cherry cultivars (‘Anella’, ‘Duroni 3', 'Badacsony', 'Cristalina', 'Ferbolus', 'Ferrovia', 'Georgia', 'Hudson', 'Kordia', 'Sam', 'Schneiders’, ‘Spate’, ‘Knorpelkirsche', 'Skeena', 'Summit', 'Sylvia') was used to fertilize the emasculated flowers of sweet cherry cv. 'Regina'. Fruit set was assessed three times during fruit development: 14 May, 30 May and 27 May 2007. We observed full incompatibility among the 14 cultivars for cv. 'Cristalina', which is in the same S-allele group as cv. 'Regina'. After analysis of our data, we have results about fertilization efficiency of the cultivars. Most of the evaluated cultivars are inadequate to fertilize cv. 'Regina' to a sufficient degree. There were two exceptions, cv. 'Sam' and cv. 'Skeena', where percentage of ripened fruits was above 20%. These two cultivars can guarantee such a pollination, which ensures ample quantity of ripened fruits. Results of this study have proved three other cultivars to be quite good pollinators for cv. 'Regina'. In conclusion, ideal pollinators for cv. 'Regina' could be — apart from above-mentioned two cultivars, 'Sam' and 'Skeena' — cvs. 'Sylvia' and 'Bianca', which was suggested by more literature sources.