Berries of sea buckthorn (Hippophae rhamnoides L.) are characterized by increasing popularity due to their presumable healtheffects. The aim of this study was to compare the antioxidant capacity and total polyphenolic content in the berries of six Hungarian grown sea buckthorn genotypes and characterize the genetic variability in this trait. Th...e harvest time of sea buckthorn berries affects the antioxidant capacity and total phenolic contents in berries of three popular cultivars of German origin. Berries harvested in October had higher antioxidant capacity compared with those harvested one month later. The extent of the difference was genotype-specific. Our analysis revealed a nearly 3-fold difference between the lowest and highest antioxidant capacities of the 6 tested genotypes with ‘Leikora’ showing the highest ferric reducing antioxidant power and total phenolic content. The TEAC values ranged between 1.76 and 3.13 mmol Trolox/100g fresh weight with Pető 1 and ‘Frugana’ having the highest values. The results presented in this study demonstrated that Hippophae rhamnoides berries possess in vitro antioxidant activity strongly determined by genotype but also influenced by harvest time.
The objective of the present study is to explore the effect of cooling irrigation (aspersion) on the beginning of bloom and on the micro-climate of the plantation. The results show that the water sprayed in the orchard by micro-jet influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of tempe...rature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect, The frequent repetition (20 minute intervals) may keep the temperature low also in the buds. The beginning of bloom may delayed for more than ten days. The dynamics of blooming was characterised by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control in spite of equal temperatures measured in the plots. Under our (Hungarian) climatic conditions, the method is successfully used to delay blooming dates. The main result is the diminution of the frost damage in the spring and the security of yield. The costs and water requirement should be calculated later.
Authors investigated the expression of the primigenic dominance in the flowering and fruit from open and self pollination of four apple cultivars ('Gala Royal', 'Golden Smoothee', Pink Lady' and 'Vista Bella') during two consecutive years in Western Hungary on three different growth inducing rootstocks (M. 9, MM. 106 and seedling). There were n...ot significant differences in the effect of the rootstocks on the flowering order in a flower cluster. Significant difference in the fruit set in open pollination was found among individual flowers in a cluster, mostly between the king bloom and the second flower. The rate of the fruit set from self-pollination was very low without any significant difference among individual flowers in the cluster.
Mosses are traditionally used as ornamental plants, especially in Japan, USA, England (moss gardens) and Germany, French (green roofs). In shadow areas (where the members of Poaceae usually cannot grow well), mosses are potentially use as “grass”. The stocks of moss colonies maintain optimal microclimate and decrease desiccation of soils (l...ike mulch). Additionally, mosses are evergreen, attractive all year, during winter. In our study, 18 moss species were propagated by fragments (as mixture, with the use of 16 species) and transplantation of carpets (with Brachythecium rivulare and Calliergonella cuspidata) in Szentendre. The aim was to find the most durable species and the best way of propagation. In an outdoor, irrigated garden, propagation by fragments was effective (with 63% coveration) and higher values (93% and 76%) were obtained in the cases of non-irrigated stocks of Amblystegium serpens (in trays) and moss carpets. In vertical structures (moss picture-frames with the use of mixtures), protonema of 2 species (Hypnum cupressiforme and Eurhynchium hyans) covered 24 and 33% of the 0.5 x 0.5 m sized area.
The cooperation of Hungarian professionals with Chinese, Thai, South-Korean, Taiwanese and Brazilian colleagues should deserve much more attention than actually done. We refer to the transfer and adaptation of production technologies as well as biotechnological developments in vegetables, fruits, ornamentals and medicinal plants from the Temper...ate Zone to the tropical and subtropical regions. According to our information Hungarian colleagues involved in extension work are highly esteemed on the same level as Japanese, Chilean, Italian and French colleagues. We could state that immigration of investors, local enterpreneurs as well as those coming from expansive regions of Europe, North America and oversses, representaives of supermakets keeps to be accelerated by the increasing confidence triggered also by the successful management of profitable plantations, vineyards and fruits initiated first about 15 years ago.
For Hungary, the presence and achievements of Hungarian horticultural expertise in tropical and subtropical zones yielded unequivocal advantages. Therefore, the next actual step of development would mean the organisation of a network of the "Units of Horticultural Mission" in the tropic and subtropic countries. We are convinced that those Units will stimulate the traffic of technologies as centers of transfer within and between the regions and contribute to the increasing influence of professionals on the production and trade of horticultural commodities. The introduction and testing of new varieties of vegetables, fruits, medicinal plants (as well as ornamentals), the development of the growing technologies, adaptation and acclimation of Temperate Zone germ plasm representing the general trends of advanced production will be the most important tasks of the Mission with a sufficient oversight upon the whole world. It is taken as a fact that Hungarian horticulture and breeding is competitive on the world market. We are ready to contribute to the development of horticulture on a worldwide scale. The Hungarian R & D will be attentive in the future to manage the accumulated capacities by information and mediating needs and offers to the volonteers of the profession. The reality of the above propositions are amply proved by successes of the Agroinvest Co and of other professionals registered in abroad.
To keep on the top of the world list of the profession we have to follow up the international trends by our permanent presence on the most important centers of administration and production of the world in order to hold on the hot line of the Hungarian administration competent in financing the R & D activities. We need specialists which are open minded, speak languages, familiar with the tricks of informatics, economics and politics, competent in deals, able to make decisions, etc. The education and training should be strenghtened to he conform with those trends. That proposal involves also the need to follow up the activities of the transnational companies, the regular, active participation on international conferences, the permanent attention paid to electronic informations available in the worldwide networks as well as the printed periodicals of horticulture. It is also related to the attraction of investors to the developments aimed within the country as well as abroad. At last but not at least we have to keep in mind that the work performed abroad by the Hungarian professional is a kind of "para-diplomatic mission" which cannot be substituted by any other, sometimes very expensive activity charged on the officia erliplomatic missions. The benefit of it is, however, valid to the whole country because false stereotypes developed during the last 50 years cannot be abolished otherwise.
The specific conditions of the formation of three different types of sunburn (sunburn browning, sunburn necrosis, and photooxidative sunburn) have been recently characterized on apple fruit. However, no information is still available on leaf damage. Therefore, the aims of this study were i) to extend the knowledge on fruit damage, ii) character...ize leaf damage and iii) find relationship between fruit and leaf damage. The observations were made on 586 apple accessions in a gene bank orchard located in Hungary. The incidence of the three different types of fruit symptoms were recorded and based on the visual symptoms, two different types of leaf sunburn (sunburn yellowing and sunburn necrosis) were characterized. The most frequent type of fruit sunburn observed was sunburn browning. Photooxidative sunburn was found for less number of accessions, and only some accessions were affected by sunburn necrosis. Fruit were far more susceptible than leaves; (>60%) of the examined accessions were affected by fruit damage and (<3%) by leaf damage. Although a large number of accessions were affected, the percentage of fruit damaged within accessions was not that excessive; ~6% of the fruit assessed showed the symptoms of sunburn browning. Significantly fewer fruit were damaged by sunburn necrosis (~1%) or photooxidative sunburn (~1.4%) than sunburn browning. The percentage of leaves damaged within accessions were simlarly very low (~1%). Close relationship between fruit and leaf damage was found. Accesions with relatively heavily sunburned leaves usually had severe fruit damage as well. Leaves showing sunburn symptoms were usually closely located around those fruit which were sunburned severely. Leaf damage of sunburn was found on spur leaves in a great majority of the accessions damaged, shoot leaves did not seem to be susceptible to sunburn.
We analyzed the relationship to sour cherry quality parameters of average temperature, maximum temperature, minimum
temperature, night and day-time temperature, precipitation and climatic water balance variables. Three cultivars of sour cherry were included
in the selection: “Debreceni bôtermô”, “Kántorjánosi”, and “Újfehé
present only those that proved to be the best fit.We couldn’t find any significant differences in the weather tolerance of the varieties. The data
base of sour cherry quality parameters covers the 1998 to 2008 intervals. The researched parameters were the following: dry matter content
(%), sugar content (%), C-vitamin (mg), total acid content (%). Maximum temperature, the difference of night and day-time temperature and
minimum temperature all have a significant correlation with the investigated quality parameters of sour cherry. Minimum temperature shows
a quadratic relationship with sugar content, while night and day-time temperature differences show the same with dry matter content. The
other weather parameters had a linear correlation with the quality parameters of sour cherry. The research results show that an increasing
amount of precipitation causes decreasing tendency in total acid content of sour cherry, so that increasing temperature has a positive influence
on total acid content. Big differences in night and day-time temperature also has positive effects on the dry matter and sugar content of sour
cherry while the amount of precipitation has a negative effect. High minimum temperatures cause decreasing sugar content respiratory energy
losses are significant if dawn temperatures do not drop considerably.A more favourable climatic water balance has a positive effect on vitamin
C content in cases of a large negative water balance, vitamin C content is generally low.
Vitamin C (L-ascorbic acid) being essential for many living organisms, including man, became once more into the focus of interests because of its numerous physiological effects. Its anti-scurvy and anti-oxidant properties have already been recognised since long in the human body, but it turned out gradually that it has many other functions. In...plants, its primary importance is defense against the photo-oxidative stress.
The present review is intended to reveal some details of the artificial synthesis of vitamin C. Emphasis is put on the metabolism of L-ascorbic acid in higher plants. Biosynthetic processes, translocation and accumulation are discussed in detail on the basis of recent results published in the scientific literature.
Apple (Malus x domestica) is considered practically self-incompatible, polleniser is essential for its economical cultivation. When choosing a polleniser many biological and economical parameters should be taken into consideration. Scab resistant apple varieties and multi-resistant candidates — bred in Hungary — were investigated i...n our experiment in 2007-2008. Blooming time groups were created according to the overlap of the blooming of the varieties and candidates. Observations were set up in Szigetcsép — the Research Station of Faculty of Horticultural Science. The orchard was planted in 1997. Trees were trained to slender spindle on Rootstock M9. Varieties have been assigned four blooming time groups. 'Reglindis' started blooming in both years. Candidate MR-09 belonged to the early group in 2007 and to the mid-early group in 2008. Latest varieties are 'Freedom' and `Baujade'. Candidate MR-10 belonged to the mid-late group.
Our investigation was carried out in several orchards in Hungary. This study reviews applicability of the different spatial analytical techniques in orchard especially models based on surface relief, such as digital elevation model, digital terrain model, slope and aspect maps. In recent time, the generation of digital elevation model has becom...e a popular examination method. However, the elevation models generated from contour lines or elevation points could be applied to evaluate agro- ecological potential of fruit orchards to some extent. The highest deficiency of these models is the fact that these show the altitude of soil surface only and do not demonstrate landmarks on the surface. Consequently, the calculation of the radiation value results data relating to soil surface. The terrain model generated and applied by our team demonstrates fine surface texture and the landmarks in the orchard, so it is suitable for further examination.
In propagation of plum by hardwood cuttings, the success of rooting is affected by several factors. Many authors deal with the timing of cutting collections, others investigate the optimal extent of hormonal stimulation. However, there is no data, as yet, about the coherence between these two factors. The aim of this experiment was to find the...most advantageous condition s, with regards to both timing and IBA doses, for rentable propagation of the examined varieties. Five varieties were studied: 'INRA Marianna GF 8- 1', 'Myrobalan B', 'MY-KL-A', 'INRA Saint Julien GF 655/2' and 'Feher besztercei'. Cuttings were collected on seven occasions, during late autumn and winter, and were treated with IBA solutions of different concentrations. The optimal dose of IBA was found to be dependent both on the variety and the actual date of cutting collection . Results are reported, along with suggestions for optimal doses and collection periods.
Up until today, apple sport mutants proved to be indistinguishable from each other and their progenitors at the molecular level using random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) marker techniques. This is not surprising, since the genomes of these somatic mutants differ... only in one or a few small regions that affect economically important characteristics, such as improved fruit colour, size, or flavour. In most cases, these genome differences are probably caused by retrotransposons which are able to convert their RNA transcripts to DNA with reverse transcriptase enzyme prior to reinsertion, but unable to leave the genome and infect other cells. Retrotransposon insertions can alter the expression of other genes and/or the structure of encoded proteins. The sequence-specific amplified polymorphism (S-SAP) technique is capable of revealing the genetic distribution of retrotransposable elements over the whole genome. The present study used this approach to try to characterize and distinguish 'Jonathan' somatic mutants via fingerprinting, which is an unsolved problem.
Based on the results of our experiments, both the relative and the effective intensity of bee visitation were rather different depending on the cultivars as well as the time of the day. While it varied between relatively extreme values (40-80%) in the morning for the varieties examined, there were much smaller differences between the intensity...of bee visitation at the afternoon, because the relative bee visitation attained 70-90% at each cultivar. These results showed that the differences arising from intensity of bee visitation of different cultivars should be taken into consideration more carefully in the morning in orchard planning and in estimating the number of honeybee colonies required.
The results showed that the greatest percentage of fruit set and the highest number of viable seeds per fruit were measured on branches of those cultivars that were most frequently visited by pure pollen gatherer bees as well as by bees collecting both nectar and pollen (mixed behaviour). The effect of pure pollen gatherers and of bees with mixed behaviour was highly significant from the statistical point of view on the fruit set and the number of viable seeds per fruit.
Those bees that were sucking nectar only from apple flowers did not proved to be effective pollinators at all. Relationship between their number and the fruit set as well as the number of viable seed per fruit were not significant because the coefficient of correlation was close to nil.
The ratio of side worker nectar gatherers was negatively correlated with the fruit set and the seed content of fruits of apple cultivars examined at both of our experimental sites, at Mosonmagyaróvár and Feketeerdő as well. The presence of side worker nectar gatherers resulted in higher decrease of fruit set and seed content of fruits at Feketeerd6 than at Mosonmagyaróvár, especially in the morning.
The effect of flower visiting intensity by other pollinating insects was found to be fairly variable according to the time of the day. In the morning they had no effect on the fruit set as well as on the seed content of fruits either at Mosonmagyaróvár or at Feketeerdo. However, at the afternoon, when their intensity was greater, the correlation was a bit stronger.
The main fields of open ground ornamental plant cultivation in Hungary are: Woody ornamental nursery products (trees, shrubs, conifers) (950 ha cultivation area and 4-6 million plants sold per years.; Rose bushes (around 140 ha and 2-4 million bushes per year); Perennial plants (20-30 ha and 3-4 million plants per year); Dried flower...s (200-250 ha of land and a production value of 5-700.000 HUF per year). The paper is discussing in detail the structure, development and tendencies of ornamental nursery production (with figures in tabulated form) and later gives shorter assessments of the present state and perspectives of the other three fields. Finally, a list is given of the Hungarian professional associations and unions, education and research centres involved in ornamental plant growing and trade.
The colour of fruits is considered to be an important quality indicator. Saleability greatly depends on how well covered the colour is of the specific type of fruits. It is a well-known phenomenon by growers that apples get nicer colours in one year while in other years the basically red and green colour cultivars can be differentiated only by...morphological characteristic features. Cover colour is one of the phenometric variables and it is a well-known fact that significant differences can be experienced year by year. The experienced oscillation can be the cause of inappropriate water- and nutriment supply, however it can be the result of some kind of plant disease, extremely high or low temperature, setting rate above the average and outstanding fruit density. In the present examination it is postulated that the degree of cover colour is mostly influenced by day and night temperature. Therefore, our study aims to find out whether it is true or not. Cover colour belongs to those phenometric characteristic features, only the final value of which is taken into consideration; due to their nature of establishment or forming time it seems useless to follow closely the change in the time of vegetation. However, determining the start of colouring and knowing the dynamics of full colouring could carry very important information for growers. If it is possible to determine the curve describing the time change of colouring, we have a possibility to estimate it by means of enviroment variables. So it is also possible to model pigmentation in the future. Knowing this, colouring irrigation could be made more efficient in the future. For this, as a first step, it is inevitable to find out what the relationship is between the main meteorogical variables, namely day and night temperature and the difference between day and night temperature, and colour cover. In this study we summarize and show these interrelations.
In this three-year study, incidence of brown rot (Monilinia spp.) on fruit of plum and apricot cultivars were evaluated in Kecskemét, Hungary. Results showed that most plum and apricot cultivars expressed symptoms caused by Monilinia spp, graded between 2 and 4 (10–75%) by the end of the summer in 2008–2010. Assessments on plum showed that... only cultivars ‘Besztercei’, ‘Silvia’ and ‘Tuleu gras’ were partly tolerant to Monilinia spp., while the most susceptible cultivars were ‘Bluefre’ and ‘Stanley’. The most tolerant apricot cultivars were ‘Borsi-féle kései rózsa’, ‘Piroska’, ‘Pannónia’ and ‘Magyar kajszi’ while the most susceptible ones were cvs. ‘Budapest’ and ‘Mandulakajszi’. Susceptibility classes showed that only one plum (’Silvia’) and one apricot cultivar (‘Borsi-féle kései rózsa’) were available with low susceptibility.
High density central leader systems, the so called "spindle trees" are spreading in intensive stone fruit orchards established for hand picking in Hungary. Results of Brunner (1972, 1990) and Zahn (1967, 1996) inspired the researchers to implement their theories into practice under our climate and special soil conditions. For...sweet cherry it is essential to apply an orchard system appropriate for hand picking because of the European market requirements. In intensive sweet cherry orchards two new training and orchard systems are developed and adapted to environmental conditions in Hungary based on previous inventions. The first step of the development is represented by modified Brunner-spindle, which applies the delayed heading of the central leader and the sectorial-double-pruning system from Brunner (1972), resulting intensive orchard of 600-800 trees/ha density, planted on standard vigour rootstocks. Modified Brunner-spindle trees are developed with a central leader and wide-angled branches on it. Light bearing wood is positioned on the central leader and wide-angled branches. During training, shoots for branches are bent or a sectorial double pruning is used. The growth of central leader is reduced by delayed heading, and the strong upright shoots are pinched in summer. Based upon tree size spacing of 5 m between row and 2.5-3 m between trees is recommended, tree height is around 3.5-4 m. This training system is useful for hand-picking; 60-70% of the crop can be harvested from ground. Modified Brunner-spindle is suitable for either standard or moderate vigorous rootstocks. The cherry spindle is an intensive orchard planted with 1250-2300 trees per hectare and it is recommended for sweet and sour cherries on semi dwarf to vigorous rootstocks, depending on soil fertility and quality. Trees are 2.5-3.5 m high, 75-80% of the crop can be harvested from the ground. Permanent basal scaffolds are developed on the basis of the canopy to counteract the stronger terminal growth. The tree is headed only once, after planting, from the following year the central leader grows from the terminal bud. The central leader developed from the terminal bud results moderated growth in the upper parts of the tree head. The strong upright shoots that may develop below the terminal bud are pinched to 3-4 leaves in the summer or removed entirely. The weaker, almost horizontal shoots growing from the central leader form fruiting twigs in the following year if their terminal bud is not removed. Brunner's double pruning is used only once or twice on the permanent basal branches because of its good branching effect. Trials on various rootstocks are running to find optimum spacing and fruiting wood management. The training and pruning guidelines are discussed in the paper. The average crop of bearing years is around 20-30 t/ha depending on site and cultivars. This new system is spreading in Hungary, around 70 ha sweet and sour cherry orchards are trained according to our guidelines.
A variety trial has been accomplished to study the flowering performance of some modern roses. Blooming time and blooming intensity were studied in Hungarian and Western European varieties. 120 Floribundas, polyanthas and climbings were observed. Our work shows that valuable Hungarian varieties can be found in all the three studied classes. The... best Hungarian climbing roses at blooming intensity were `Futótűz', `Rozalia', ‘Sarolt and 'Szent Erzsébet emléke'; best floribundas were ‘Báthory István emléke', 'Munkács', 'Szent Margit emléke; and the best Hungarian polyanthas were `Csinszka', `Domokos PáI Péter emléke'. Some really good flowering Western-European rose varieties have also been found, the best ones were 'Clg. Gertrude Westphal' climbing, 'La Sevillana' floribunda and 'Beauty of New South Wells', 'Happy' polyanthus. 'La Sevillana' and 'Picasso' were in strong bloom for the longest time.
In Hungary, the floribunda and polyantha classes had good flowering intensity to the almost the same extent, floribundas had stronger, and polyanthas had longer flowering waves, but the ever-blooming ability of the climbing roses was moderate in the dry midsummer.
The present paper evaluates the result of irrigation experiments carried out on snap beans sown in spring and summer and grown with and without irrigation. The experiments were run over the course of 12 years. In the average of 12 years, the yield was 2.8t ha-I for spring sown and 1.9 t ha-I in summer-sown plants without i...rrigation. The lowest level of profitable production, the 5.5t ha-I was reached twice in the case of spring sowing and only once in the case of summer sowing. Profitable yield production can be ensured only with regular irrigation and thus the yield may be increased by 4-5 times. In four of the twelve years we determined the canopy surface temperature of snap bean stands with and without irrigation. A Raynger II infrared remote thermometer determined the canopy surface temperature every day at 13.00 hours. The canopy temperature can well characterize the water supply of plant stands. This parameter may be used for describing the degree of drought and the water turnover of plant stands with different water supply. The positive values of foliage-air temperature differences (SDD) numerically express the degree of drought and the water supply of the crops. The results indicated that a 1 °C higher SDD value may cause 90-130 kg/ha yield loss.
Numerous apple varieties have been tested parallel with traditional Jonathan varieties during four years, 1990-1994 on three different geographical areas of Hungary. The picking time took place at three different times in a year: ten days before the probably optimal picking time, at close-to-optimal picking time, and ten days after the optimal...picking time. The effect of storage on quality of fruits have been tested in February, March, and April under circumstances of a semi-industrial storage experiment.
The results of experience can contribute to answer numerous current, from point of view of practice important topics:
- The stochastic relations between various fruit quality parameters at different varieties
- The change of fruit — quality during storage
- The effect of different picking date on storage losses
- The possibilities of storage — loss predicting by the utilization of multiple regression analysis.
The most important results of experiences are as follows :
- The starch — degradation test and Streiff — index are well applicable for practical purposes to determine the optimal harvest-date.
- On base of analysis of various losses and physiological diseases the high importance of mass loss is obvious. In the variety Jonnee the earlier picking date considerably increased the mass loss. The effect of variety on mass loss is rather limited. In the Jonathan varieties the Jonathan spot was a rather important physiological disease. The late picking time increased the frequency of Jonathan - spot. At optimal date of harvest at Jonnee the frequency of Jonathan -spot was lower, than at Jonathan M 41. In the Jonathan M41 and Jonnee the importance of scald was rather limited, but in the Wellspur Delicious and Smoothee this disease occurred relatively frequently. In the Smoothee the earlier picking time considerably increased the probability of scald.
- The multiple regression analysis yielded reliable results, fit for prediction of storage losses and diseases on the base of chemical and physical properties, determined at the time of picking.
The minirhizotron system gives opportunity to study the root development without disturbing the soil and root. We have found certified differences in root development during the year 2013 among the rootstocks grafted on ‘Cabernet sauvignon’. The number of roots varied according to the rootstocks in different depth of soil layers and also va...ried the development of ripeness of the root system. We conclude that root system development is affected by soil physical and chemical properties, but differences according to the rootstock genotype on the similar type of soil exist.
One of the most demanded research projects is the intensification of fruit production. The use of dwarfing stocks is a moderate solution as their effect is scarcely satisfactory. Climatic conditions of Hungary are continental in Eastern Europe, where Atlantic and Mediterranean effects are interacting with the continentals in a kind of basin wit...h characters of its own. Capricious meteorological episodes are often disturbing the security of development and fruiting of trees:
• winter frosts are damaging the cambium and fruiting structures of trees
• late spring frosts destroy cambium and flowers
• early autumn frosts hurt the leaves
• excessive precipitation impairs the growing fruits
• drought periods during the summer caused water stress disturbing water husbandry.
Vigorous stocks still prevail in the practice, and they ought to withstand challenges of weather hazards. The strong vigour of plants delaysthe process of senescence and the tendency of getting bald, and regeneration of plants is a sign of vitality. In present research, the trees have been trained on vigorous Prunus mahaleb stocks. Summer pruning was one of the important tools of intensive growing techniques. They were compared with traditional techniques and with plastic foil protected trees observing the vegetative as well as generative growth of them.
Two apple cultivars that display enhanced resistance to fire blight (causal agent: Erwinia amylovora) were selected. The aim of the present study was to characterize the peroxidase (POD) enzyme activity of `Szemes alma' (a historical cultivar) and MR-03, (a Hungarian multiresistant hybrid of 'Prima') and compare them to susceptible 'Jo...nathan M 40' and resistant 'Remo' controls. Peroxides enzyme activity during E. amylovora infections was investigated in artificially infected apple shoots. Increases in enzyme activities were observed in a `Jonathan M40' and in 'Remo', MR-03, `Szemes alma' cultivars. There was a consistent relationship between total enzyme activity and fire blight disease severity. High activity of the peroxidase was positively correlated with the degree of resistance to fire blight. A general hypothesis that POD activity is related to fire blight susceptibility/resistance is supported by our results.
Mass propagation of 5 newly introduced Hosta varieties was carried out by the method of micropropagation. Our aim was to determine exact variety specificity after the micropropagation period in the pattern of peroxidase isoenzymes by isoelectric focusing in pH 3-9 range and to determine that phenological phase of mother plant in which...the isoenzyme pattern of mother plant can safely be comparable to the isoenzyme pattern of micropropagated descendants. The isoenzyme patterns of descendants were similar to the mother plants of the same hybrid lines. The older leaves seemed to be not so suitable for examination than newly developed ones despite of the higher activity of peroxidase enzymes. There were big differences in isoenzyme patterns of leaves in different phenological phases. With this quick and easy method Hosta varieties could be selected already in the very early stage of micropropagation.
The aim of this three-year study was to evaluate the effect of three treatments (thiophanate methyl, charcoal dust, and control) on leaf number and plant height on three Canna x generalis cultivars (City of Portland, Richard Wallace and Robert Kemp). Results showed that the 3-year means of leaf number ranged from 13.9 to 23.1 for the three cult...ivars. The largest leaf numbers were for cultivar Robert Camp (23.1 in 2010) and the lowest for cultivar City of Portland (13.9 in 2011). Thiophanate methyl treatment produced the highest number of leaves and the values were significantly different at P< 0.05 from the control for all years and for all cultivars. Numbers of leaves in charcoal dust treatments were larger than the control treatments but it was not significantly different. Results on plant height ranged from 69.2 to 160.5 cm for the three cultivars. The largest plant height was for cultivar Robert Kemp (160.5 cm in 2011) and the lowest for cultivar City of Portland (69.2 cm in 2011). Thiophanate methyl treatment produced the highest plant height and the values were significantly different at P< 0.05 from the control for all years and for all cultivars. Plant heights in charcoal dust treatments were larger than the control treatments but it was not significantly different.