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  • Flower characters and self-fertilization capacity in relation to the bee pollination at sour cherry cultivars
    121-132.
    Views:
    210

    Detailed studies and comparisons were carried out on those flower characters of sour cherry cultivars that may affect bee pollination of flowers. Flower characters of sour cherry are fairly similar to other temperate zone fruit tree species. Their relatively small flowers distinguish the Cigánymeggy-types of cultivars from the flowers of tart cherries cultivars that are conspicuously larger, almost as large as the sweet cherry flowers. The relative position of flower organs was much more variable according to the season than according to the cultivars. So the differences were rather the consequences of seasonal effects than of variety features of sour cherry cultivars. As far as individual cultivars are concerned differences in the nectar production and the sugar concentration are revealed rather between groups of cultivars than between individual cultivars. The pollen production of flowers was extremely changeable in consecutive years. Most honeybees collected nectar at sour cherry flowers; pure pollen gatherers and mixed behaviour bees were half as frequent but differences among the behaviour of honeybees according to cultivars cannot be stated. The fidelity of honeybees to sour cherry is less expressed than to some other fruit tree species. Accordingly, it is very strongly suggested to take the competitive effect other plant species (weeds) flowering in and around the orchard carefully into account when organizing additional bee pollination in sour cherry plantations. Several sour cherry cultivars possess more or less self-fertilization capacity but this is greatly changeable according to the season. It has been proved that self-sterile sour cherry cultivars are sensitive even on the partial restriction of the effective time of bee pollination and it is to be stressed too that even in the case of partly self-fruitful cultivars bee pollination is also vital in yield formation because medium or strong restriction of the effective bee pollination period is of a definite negative effect on their fruit set and yield. In years with unfavourable weather the yield can dramatically be reduced sometimes down to nil. However, very high fruit set is also unfavourable because a negative correlation was detected between the final set and the mean mass of fruits.

  • Cracking susceptibility of sour cherry (Prunus cerasus L.) in Hungary and relation to calcium application
    109-118.
    Views:
    321

    The rain induced fruit cracking is a big, serious problem especially for sour cherry growers but in some year sour cherry growers had also problem with fruit cracking caused by too much rainfall in the harvesting season. The cracked sour cherry fruits can be easily infected by different diseases like Monillinia sp. Cracked and infected fruits can not be transported for long distance and using for preservation because they lost their market value by the pour fruit quality. There are two possibilities to protect fruits against the rain induced fruit cracking. The most effective protection technique is the plastic rain cover over the tree rows. The installation of these equipments is too expensive for the growers. That is the reason why researchers tried to find other less expensive and sufficiently effective ways like sprayings different mineral salts, hormone and other type chemicals against the rain induced fruit cracking. Several calcium formulas calcium chloride (CaC12), calcium hydroxide (Ca (OH),) and calcium nitrate (Ca(NO3)2) can be sprayed in appropriate solution concentration.

    The aim of our trial is to determinate the fruit cracking susceptibility of wide grown Hungarian sour cherry varieties and find the most effective calcium formula and its concentration for spraying in orchards to prevent the fruit cracking. In the first trial year (2006) cracking index of tested sour cherry varieties were determined under field and laboratory conditions. Under field conditions were not found differences between cracking tendency of tested cultivars. After results of immersing fruits in distillated water for 24 hours tested sour cherry varieties were divided to three groups by the susceptibility to rain induced fruit cracking: very susceptible (`Maliga emléke', 'Piramis', 'Érdi jubileum', 'Erdi nagygyümölcsű’ and 'Meteor korai'); susceptible ‘Érdi bőtermő, Tandy 279' and Cigány 59.; moderately susceptible/tolerant ("T" and "R" clones). In the second trial year (2007) calcium chloride (CaCl2) and calcium nitrate (Ca(NO3)2) were sprayed in 0,35m/m%; 0,5m/m% and 1,0m/m% solution concentration. One more commercial product "Damisol-Kalcium" was also applied in the advised 1,0m/m% concentration. Like in the trial year before (2006) under field conditions we did not kept differences between the cracking susceptibility of varieties and calcium treatments. As the result of laboratory testing (immersing calcium treated fruits in distillated water) we kept that calcium chloride (CaCl2) seems the most effective against the fruit cracking in 0,5m/in% solution concentration. The other calcium formulas also decreased the cracking ratio but in less scale.

  • Effect of boron nutrition on nutrient uptake and fruit quality of tart cherry in Eastern Hungary
    45-48.
    Views:
    286

    Effect of the foliar boron (B) application on nutrient uptake and fruit quality of tart cherry (Prunus cerasus L.) was investigated from 2008 to 2009 on mature four favourite Hungarian tart cherry cultivars like ‘Oblacsinszka’, ‘Érdi bôtermő’, ‘Újfehértói fürtös’ and ‘Petri’. Tart cherry trees grown in Eastern Hungary (Újfehértó) on an acidic sandy soil with low B content. Trees were treated with B by foliar application (0.5% B) at full bloom and untreated with B served as a control. B sprays strongly affected on B content of inflorescences. However, B sprays had no consistent effect on summer leaf B status. In our experiment stronger year effect was observed at leaf B status than flower B status. The effectiveness of early spring boron applications are limited and mostly affected the flower B status only. Moreover, treatments had inconsistent effect on studied fruit inner parameters. Monosaccharides, vitamin C and organic acid contents of sour cherry were stronger affected by cultivars than applied treatments.