To be able to grow stone fruit species, the peach and the nectarine varieties, yield stability is very relevant. However, the climate is suitable in Hungary for growing stone fruits. We have to calculate with damage. Important winter damage and spring frost damage occur in every second year on the Great Pplains. To reveal the frost tolerance of... cultivars and to clarify the differences among growing areas is the most important point of peach and nectarine production.
We, made our experiments in the winter of 2005 (January-February), at Pallag, Zsombó, Siófok, Sóskút and Szatymaz. These former places are determinant in peach and nectarine growing in Hungarian respects.
In our experiments we analyzed 10-10 fruit shoot from 82 varieties, and we measured the frost damage and the flower bud density.
The minimum and the maximum frost damage values (%) at the different growing places were 7.6-38.7 at Siófok, 6.5-31.3 at Sóskút, 34.3-100 at Szatymaz, 83.7-99.6 at Pallag and 51.9-99.6 at Zsombó. There were expressive differences between the same cultivars depending on the growing area.
The frost damage of „Suncrest” variety was 7.6% at Siófok, 8.2% at Sóskút but it was 69.8% at Szatymaz. The „Maystar” variety had 17.6% at Siófok, 12.4% at Sóskút and 87.2% frost damage at Szatymaz. In case of „Redhaven” variety the frost damage values were 16.8% at Sóskút, 54.6% at Szatymaz. We collected fruit shoots from three different heights in case of „Cresthaven” variety. In case of 1 meter height the frost damage was 74.6%, at 2 meter height 44.7%, and 25.2% at 3 meter.
We experienced also big differences in flower bud density (flower bud/10 cm) of varieties. The following cultivars had the highest flower bud density (6-7 bud/10 cm): „Suncrest”, „Meystar, „Maria Luisa” and the „Maria Bianca”, „Redhaven”, „Michellini” had the lowest flower bud density (2-3 bud/10 cm).
After our experiments we established that there were very expressive differences among the frost damage of peach and nectarine varieties from different climatic conditions and there are also big variance between the frost damage values of those fruit shoots, what were collected from different heights, but from the same variety. It conspicuous very good among our items, that difference of the flower bud density is very big among the varieties.To be able to grow peach and nectarine successfully, the suitable variety (low frost damage value, high flower bud density) and the suitable growing are is determinant.
The majority of stone fruit species are self-incompatible, a feature that is determined by a specific recognition mechanism between the S-ribonuclease enzymes residing in the pistils and the F-box proteins expressed in the pollen tubes. Failure in the function of any component of this bipartite system resulted in self-compatibility (SC) in many... cultivars of Prunus species. Peach (Prunus persica (L.) Batsch.) is the only species in the Prunoideae subfamily that is traditionally known to be self-compatible, but its molecular background is completely unknown. Isoelectric focusing and S-gene specific PCR revealed that SC is not due to functional inability of pistil ribonucleases. We hypothesize that SC may be a consequence of a kind of pollen-part mutation or the action of one or more currently unknown modifier gene(s). Only two S-alleles were identified in a set of peach genotypes of various origin and phenotypes in contrast to the 17–30 alleles described in self-incompatible fruit trees. Most important commercial cultivars carry the same S-allele and are in a homozygote state. This indicates the common origin of these cultivars and also the consequence of self-fertilization. According to the available information, this is the first report to elucidate the role of S-locus in the fertilization process of peach.
Although there are many critical points in peach production, in Hungary, winter frost damage is one of the most significant. Serious winter frost damage on the Hungarian Great Plain was the focus of our experiments. The adequate growth and the most adaptable varieties are determining factors in peach production. In our experiments, we compared...three growing areas (Siófok, Sóskút, Szatymaz) and four different varieties (Suncrest, Redhaven, Meystar, Michellini). Throughout these growing areas and with varieties, we wanted to demonstrate the differences in the frost damage values of the flower buds in 2005 and 2006.
In the course of the statistical trials, we found that the difference between the varieties is significant (table 2). The most tolerant variety as for frost tolerance is the ‘Michellini’ variety, and the worst is the ‘Suncrest’ variety. We also found that these data are significant. When we examined the varieties according to their growth, we got the same results (table 3). We determined that the differences between growth are significant and related to these four varieties and the two years (2005-2006), that frost damage was the highest at Szatymaz, and that it was the lowest in Sóskút.
Plant diseases caused by phytoplasmas have increasing importance in all over the world for fruit growers. Lately, phytoplasma diseases occur on many fruit varieties and responsible for serious losses both in quality and quantity of fruit production. In the long-run these diseases cause destruction of fruit trees. The apricot phytoplasma disease... (Ca. Phytoplasma prunorum) was first reported in Europe in 1924 from France. In 1992 the disease has also been identified in Hungary. On the base of growers' signals serious damages of "Candidatus Phytoplasma prunorum" Seemüller and Schneider, 2004 (formerly: European stone fruit yellows phytoplasma) could be observed in different stone fruit plantations in the famous apricot-growing area nearby Gönc town, Northern-Hungary. Field examinations have been begun in 2009 in several stone fruit plantations in Borsod-Abaúj-Zemplén County mainly in Gönc region which is one of the most important apricot growing regions in Hungary, named “Gönc Apricot Growing Area”. Our goals were to diagnose the occurrence of Ca. Phytoplasma prunorum on stone fruits (especially on apricot) in the North-Hungarian growing areas by visual diagnostics and confirm data by laboratory PCR-based examinations. All the 28 collected samples were tested in laboratory trials and at 13 samples from apricot, peach, sour cherry and wild plum were confirmed the presence of phytoplasma (ESFY). On the base of observations it seems evident that the notable losses caused by "Ca. Phytoplasma prunorum" is a new plant health problem to manage for fruit growers, especially apricot producers in Hungary.
In 2011 a very rare occurence of leaf curl (leaf blaster) disease symptoms of apricot (pathogen: Taphrina deformans) was observed in different apricot plantations in Eastern-Hungary (Debrecen-Józsa, Hajdú-Bihar county) and Northern-Hungary (Bekecs district, Borsod-Abaúj-Zemplén county). The pathogen is common on peach and nectarine resultin...g serious symptomps and considerable damages in almost every year, although in this year infections of peaches were very low close to the locations. Although there are some references that apricot and even almond are hosts of the fungus but in Hungarian circumstances the infestation on apricot counts unique and rare. Observations were made on symptoms, microscopic photos and measures were taken on exoasci, ascospores and blastospores, respectively. As far as we know this is the first description of Taphrina deformans fungus on apricot in Hungary.
...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">In the last twenty years, three phytoplasma diseases were identified in Hungary, viz. European Stone Fruit Yellows (ESFY) (caused by Candidatus Phytoplasma prunorum), pear decline (caused by Candidatus Phytoplasma pyri), and apple proliferation (caused by Candidatus Phytoplasma mali). Candidatus Phytoplasma prunorum was isolated from apricot, peach, plum and japanese plum. Cacopsylla pruni the vector of ESFY was also isolated and identified. Infection of Candidatus Phytoplasma pyri was diagnosed from pear and Candidatus Phytoplasma mali was found on apple and pear. The three phytoplasmas cause different damages on their host plants. The most economically important phytoplasma disease is the ESFY. It seriously impairs apricot and japanase plum trees. After infection of apricots and japanese plums show yellowing and defoliation, and within a few years die in apoplexy-like symptoms. The disease on japanese plum is so severe that this fruit practically can not be cultivated in Hungary. Pear decline is the most serious problem especially in intensive pear plantations. The vector Cacopsylla pyri, C. pyrisuga and C. pyricola can be found in almost all pear orchards. Because of the regular presence of psyllids in intensive pear orchards the insecticide control is necessary. Apple proliferation is not an important disease in Hungary. All of our isolations of ’Candidatus Phytoplasma mali’ occured in organic orchards and record was not available in Hungary lately.
The European stone fruit yellows (ESFY) phytoplasma disease caused by pathogen ’Ca. Phytoplasma prunorum’ induces serious damages in cherry, sour cherry, peach, and apricot orchards mostly in Europe. Its known vector is the plum psyllid (Cacopsylla pruni). Many articles report on the biology (morphology, taxonomy, life cycle etc.) and the m...ethod of transmission of the pathogen by the vector, and the possibilities of their control. This paper reviews our knowledge about the vector, and summarises the results of an inland research carried out in a northeastern Hungarian apricot orchards. Our goal was to show some important data for the farmers or anyone who is interested in this disease and its vector. And give some known method that we can protect our orchards against them to prevent the appearance of the disease. As the psyllid that became infected with the pathogen can hold its infectionous capacity during their lifetime, it is very important to have enough knowledge about their lifecycle, that we can determine the right time and method to control them. We also have to know how to identify them; therefore, this paper lists several important data which can be helpful. The most important keys of identification are their wing color, which dark borwn in the apex and brown is in the remaining part of the forewing. The length of the antennae is also an important factor, since other genuse’s species have longer antennae than twice the width of the head. C. pruni has as long antennae as twice the width of the head. They return to Prunus species in early spring and we have to protect our orhards in this period against them. We have to use preparations with a knock down effect on them to prevent the inoculation of the pathogen into the trees in our orchards.