The aim of the present study was to determine the effect of nitrogen supply on yield and fruit quality of apple cultivars and to explore the relationships between canopy density and the different fruit quality parameters.

The experiments were carried out at Kálmánháza, in Eastern Hungary in a private orchard in 2003-2004. The response of four apple cultivars ('Elstar', 'Gala Prince', 'Granny Smith', 'Idared') to different nitrogen dosages was studied. The assessed and calculated indices were: yield, fruit diameter, fruit height, shape index, fruit mass, firmness, dry matter content and colouration. The results indicated that nitrogen fertilization has a significant effect on the yield and fruit quality of apple cultivars. The calculated specific yield values were reduced by the application of nitrogen via the increase in the volume of the canopy. An opposit trend was observed for fruit diameter, fruit height and fruit weight, which increased with increasing nitrogen supply. The reduced shape index caused flattening of fruits.

However, the improvement of fruit quality via increasing nitrogen dosage is only virtual, since these dosages increase the fruit size, but firmness, dry matter content and colouration are diminished, which decreases the value of the fruits on the market.

The authors also studied the relationships between canopy density responsible for assimilation and light supply of the fruits and the different fruit quality parameters. The closest linear inversely proportional relationship was found in the case of colouration. There was a negative linear relationship between canopy density and firmness or dry matter content. The relationship between canopy density and fruit mass could be described by a quadratic polinomial function.

Planting of new high density apple orchards showed an increasing tendency over the last ten years. Growers use in those orchards mainly dwarfing or semi dwarfing rootstocks. The spacing for those orchards is recommended based on Dutch and German experiences; however, the optimization of orchard planting density as a key factor for successful orchard management should consider the local climate conditions. An experimental orchard was planted in 2000 to investigate the effect of spacing on three dwarfing rootstocks with two apple cultivars `Jonica' and 'Gala Must'. We compared 8 planting densities (1270-3704 tree/ha) and two tree shapes (slender spindle and vertical axis). In this paper the data of the first five years' growth and bearing are presented. After 4 years, the decreasing tree densities caused reduced trunk cross sectional area. Tree density had a significant positive effect on cumulative yield per hectare. From the examined rootstocks, M.9 Burgmer 984 gave the smallest canopy for both cultivars. The trees on M.9 T.337 and on Jork 9 rootstocks have stronger growth. The light interception was measured under the canopy by AccuPAR (Decagon Devices Inc.'s).

Summary The aim of study was to investigate growth (crown growth and trunk diameter) and fruit characteristics [dry matter content (%), pectin (%), total acid (%) contents] of 10 pear cultivars ('Móri császár', 'Nyári Kálmán', 'Mogyoródi óriás', 'Fehérvári körte', 'Szegfa körte', 'Piroska', 'Mézes körte'). The crown development of the cv. 'Fehérvári körte' can be regarded as outstanding among the examined cultivars. The growth of the cv. 'Mogyoródi óriás' was low, this cultivar showed the poorest growth vigour. The width of the crown in several cultivars developed at a similar rate as the height of the crown. Outstanding values were shown by cvs. 'Fehervári körte' and 'Móri császár'. The development of trunk diameter was the highest for cvs. 'Piroska' and 'Hóka', and large growth of trunk diameter can be seen on cv. 'Fehervári körte'. Cvs. 'Mogyoródi óriás' and 'Mezes körte'showed weak growth. Outstanding dry matter content of fruits was measured on cvs. 'Fehervári körte' and 'Mézes körte'. The total acid content of fruits of cvs. 'Mézes körte' and 'Fehérvári körte'' was significantly different from the total acid content of cv. 'Mogyoródi óriás'. Pectin content was low in fruits of cvs. 'Mogyoródi óriás' and 'Fehérvári körte', while cv. 'Mézes körte' contained significantly more pectin. Vitamin C content we found was rather high in cvs. 'Mézes körte' and 'Fehérvári körte'.

In our research, fruit colour and the shoot's red pigmentation were evaluated in the hybrids of Rubus idaeus and Rubus parvifolius crossings. Y and Ys genes beside the T genes determine the fruit colour of interspecific hybrids, which is characteristic for raspberry. For the explanation of the significantly higher results of segregation then expected at the yellow fruit colour hybrids, we have supposed the presence of a second yellow gene (Y₂). In the yellow colour, a lot of different shade colours can be identified from light yellow to the apricot colour. In the regulation of the production of yellow and red colour, several other genes can participate also. Identification of these genes would require more additional research. The C gene determines the shoot colour of raspberry and in the case of wild raspberries we have revealed the role of a dominant Pr gene. The Y and Pr genes are descended linked. The value of crossing over is approximately 15%. The anthocyanin production inhibitory effect of the Y gene extends only for fruit. At the shoots of yellow fruit plants, strong anthocyanin production was observed.

The interest in wild growing fruits was increased considerably by the pharmaceutical industry, the cosmetics as well as by the food industry. (Stefanovits-Bányai et al., 2004). Elderberry (Sambucus nigra L), sand thorn (Hippophae rhamnoides L.), cornet (Cornus mas L.), dog rose (Rosa canina L. bearing hips) and the Sorbus species (Sorhus ssp.) have been well known medicinal and/or ornamental plants since long. Recently, precious substances have been detected in their fruits, which are indispensable in healthy foods. Several species and micro-species of the genus Sorbus are components of the native flora of Hungary, and the fruit of some of them have been consumed traditionally, however, they are preferably considered as ornamentals. The nursery of Alsótekeres (Balatonvilágos) maintained some 16 clones of Sorbus species, which are mainly apomictic "micro species" of. the collection. In 2003, a comprehensive analysis of sorb fruits born on apomictic micro species was initiated in order to find those, which will be suitable to establish plantations. It turned out that considerable differences exist between the fruits of individual taxa, however, it is largely influenced by seasonal effects. According to physical measurements, a scale of mean fruit masses could be established. As for chemical ingredients of the fruits, those are of special interest, which are involved mainly in anti-oxidant activities of the organisms (calcium, potash, phosphorus, copper, magnesium).

The major part of the pepper growing farms in Hungary operate as family enterprises with areas varying between 1,000 and 3,000 m². As a result of the small size, their profitability is greatly dependant on the technological level and market circumstances. Most of these farms are characteristically affected by the lack of capital, therefore, they are unable to implement any further developments with their own forces. Greenhouse pepper production on rockwool had already been subjected to analysis earlier in our research, however, those calculations were directed solely at the profitability and efficiency of production. Based on the data from 2004 in 2005 yet another and more profound analysis was set as the objective. Besides the methods already applied before, several dynamic indicators have been introduced which could also be useful for practical applications. The graphs can permit growers to monitor the temporal distribution of the costs incurred and revenues earned during production. Thereby it is easier to plan the costs and more simple to distribute them more rationally over the production period. Our experiences suggest that this sort of analytical method is applicable only in cases where a very careful and precise collection of data is ensured and the results obtained can not be generalised as being valid only for the single farm analysed. Experiences and results, however, make us consider the dynamic economic analysis as being very useful both for beginners and practicing horticulturists.

During our experiments, the storability of paprika (Capsicum annuum) samples was measured by a non-destructive acoustic method. The aims of our work were the determination of the applicability and reproducibility of the acoustic stiffness method for paprika, the investigation of the optimum measuring conditions. In order to compare the main paprika varieties regarding shelf-life, our further aim was to follow the softening phenomenon or textural changes (i.e. changes in stiffness) of different paprika varieties measured by the non­destructive acoustic stiffness method. Five different varieties of paprika grown in hydroponics growing system were used for the measurements. All paprika varieties were stored at 20 °C for two weeks. Samples were tested on every 2nd or 3^rd day. The acoustic method was found to be suitable to follow the softening of paprika samples. The characteristic frequency of the acoustic signal could be well detected and clearly separated from the other vibration peaks. Tapping the top of the paprika was observed to give a clearer and less noisy signal compared to the signal obtained by tapping the sample's shoulder. The acoustic results showed the same tendencies with regard to softening during storage as the impact method showed in our previous experiments.

Ganoderma lucidum (Reishi mushroom), the object of our experiments, is also known to contain medicinal compounds. This fungus has been used for many centuries as medicine in China. The fruiting body of the fungus contains carbohydrates, amino acids, little protein, fat, alkaloids, vitamins and minerals. Two groups of its substances are reported to be effective particularly. One of them is constituted by the polysaccharides, whose antitumor and immunostimulating effects are well demonstrated, and the other is constituted by the triterpenes. The latter include ganoderic acids, ganolucidic acids and lucideric acids. These acids have been reported to suppress liver hyperactivity (Lelley 1999). The experiment was carried out with 8 Reishi mushroom strains in 3 repetitions. Experiments were performed on 3 different substrates The spawn run period took approximately 2 weeks, the first fruiting bodies appeared on the 33rd day from inoculation, but the formation of the fruiting bodies took almost 70 days on the different substrates. Spawn run presented a diversified picture as influenced by the specific substrates. No spawn run was seen with any of the strains on the substrate composed of 100% wheat straw. Among the strains the fastest spawn run was produced by GA02 and GA06. The earliest start of spawn run was registered for substrate 1 after 1 week.

According to our experiments the tested group of non-destructive methods offers a useful tool not only to follow the texture changes of vegetables during storage but to characterize the firmness and vision parameters during the growing period as well. Advantages of these methods are: they are mobile, easy to set up, easy to use and quick. The suitable maturity state — and so the optimum harvest date also - can be determined by these methods. In addition, these methods can be built into sorting lines making possible to sort and classify great amounts of produces. These methods help the producer to offer homogenous products of controlled quality. They can be used for measuring different effects on vegetable's quality parameters (fertilization by different microelements, different irrigation effects on the product) as well.

Research project to establish a Hungarian valerian cultivar with acceptable production, biological and chemical properties of five promising Valeriana officinalis L. lines were studied. The populations were not homogeneous especially with regard to leaf shape and colour. Line 'IV/1' showed the strongest vigour, was characterised by the highest root-yield (381.79 g/plant), volatile-oil (0.60 m1/100 g) and valtrat content (1.15%). However, the highest valeric-acid content (0.20%) was measured in another line, 'I/5'. According to our results, the above-mentioned lines (1/5', 'IV/1') could be the basic material of breeding work in the future.

The growth rate of three rosemary clones, `Harmat', 'Salem' and `Horvát', their essential oil content and its components as well as the total phenol content and total antioxidant capacity in their aqueous and ethanolic extracts were compaired. Total phenol content (determined by Folin-Ciocalteau reagent) and antioxidant power (FRAP-value) of aqueous and ethanolic rosemary extracts were measured by spectrophotometric method. The essential oil content was determined from drug by water-steam distillation. `Harmat' showed the most intensive growth through the vegetation period. The total antioxidant power of the ethanolic extracts from all the three clones was similar: a decrease was observed at the end of the season. In most cases more antioxidant compounds were dissolved in the aqueous extracts. The total quantity of phenolic compounds shows a good correlation with the potential extent of stress effects. The difference among the phenol contents of the various clones can be derived from the difference in their tolerance, because phenols have antioxidant effects contributing to protection against harmful impacts. Difference between the two extraction methods (aqueous and ethanolic) is due to the distinct solubility of compounds. Some other components, like essential oil compounds also possess antioxidant effect and in this way they may influence the antioxidant power of extracts.

Three varieties of different species of annual bedding and balcony plants were examined in balcony boxes in three different places (Budapest, Solymár-Kerekhegy, Tázlár) in order to determine their tolerance to different climate conditions. The experiment proved that Celosia argentea L. var. plumosa 'Savaria' and Dichondra repens J. R. Forst. et G. Forst 'Silver Falls' tolerate well the Hungarian extremely dry, hot and changing climate. Nemesia Vent. 'Blue Bird' developed and flowered well only in cooler and protected conditions; therefore, this species can be offered to a more balanced climate as the western areas of Hungary and the mountains.

Growing of native perennial species became more and more popular in the last ten years. In order to obtain more information on their histological structure, investigations were done on Aster linosyris, Inula ensifolia and Prunella grandiflora. The histological features are usually relating to the plants' ecological demands which is an important aspect in their growing. Differences were found in the structure of the stem of Asteraceae and Lamiaceae members. While separated vessels were formed in the stem of Aster linosyris and Inula ensifolia, continuous vessel-system forms in the stem of Prunella. Alternating segments of collenchyma and chlorenchyma are found in the stem of Aster linosyris, while palisade parenchyma is situated both on the abaxial and adaxial surface of the leaves. Vessel-system of the root is tetrarch. Histological structure of the stem of Inula ensifolia differs from Aster linosyris in the broader cortical parenchyma which is composed of approx. 8-12 cell layers. It contains neither collenchyma nor chlorenchyma. In the stem of Prunella grandiflora a nearly continuous vessel-ring is formed from the four primary vessels. Long, multi-celled hairs were observed in the district of angles of the stem.

Investigations were done in order to obtain more information on the histological structure of bulbs of Allium moly, Allium sphaerocephalon, Muscari armeniacum and corms of Crocus sativus. While starch grain were found in the bulb of Muscari armeniacum, fluid nutrient content were shown in Allium species. Narrow and fleshy scales were found in the bulbs of Muscari. Histological characteristics of Allium moly and Allium sphaerocephalon showed a closer relationship with corms than with the bulbs. To clarify this question, further investigations are needed (Bailey, 1942; Larson, 1980).

Eustoma grandiflorum (Raf.) Shinn. 'Echo' Fl cultivars ('Echo White', 'Echo Rose', 'Echo Blue', 'Echo Blue Picotee') were used and multiplication of shoots was evaluated on Murashige and Skoog (1962) basal medium with 11 g/1 agar-agar and 20 g/1 sucrose. To test the effect of BA different concentrations were added: 0.10, 0.25 mg/1 and a culture medium without BA. Differentiation of roots was examined on Jámbor-Benczúr and Marta (1990) basal medium with the same concentration of agar-agar and sucrose. To examine the effect on rooting, various concentrations of NAA were used: 0.5, 1.0, 2.0, 3.0 mg/l. The pH was adjusted to 5.6 in every case using KOH. We studied the after-effect of different concentrations of BA during the acclimatisation. During the multiplication, the cultivar 'Echo White' formed the most shoots and the smallest leaves on the medium with 0.10 mg/1 BA. Fortunately, in the case of this cultivar, the number of shoots was reduced and the length of leaves was increased succesfully on the medium without BA. The other three cultivars developed the longest leaves on the medium containing 0.10 mg/1 BA. Sometimes not only shoot regeneration but spontaneous rooting was observed during the multiplication. Examining the rooting, the highest percent of roots was found on the medium with 1.0 mg/1 NAA, and the cultivar 'Echo Rose' formed the most roots on this medium. Higher concentration (2.0 and 3.0 mg/1) of NAA already reduced the number of roots in all of the cultivars. During the acclimatisation, the percentage of survival was 76.3% and the tallest plants with the longest leaves were found on the multiplication medium with 0.25 mg/1 BA. 'Echo Blue Picotee' gave the best results with the tallest pieces and longest leaves on this medium.

Phyllotreta species (Coleoptera, Chrysomelidae, Halticinae) rank among the most important horticultural pests in the Northern Hemisphere. Leaf damage caused by flea beetles upsets the water balance, blocks plant growth and sometimes causes a high level of mortality of seedlings. Several species are known to act as vectors of numerous pathogens as well. Chemical communication plays an important role in the host finding, feeding and oviposition behaviour of flea beetles. In the first phase volatile mustard oils (isothiocyanates and thiocyanates) are released from the host plants through the decomposition of non-volatile glucosinolates (chemicals specific to Cruciferae) by myrosinase, and beetles are attracted to the source of release from a distance. Among the isothiocyanates, allyl isothiocyanate is the longest known and widespread compound utilized in the host-plant location of Phyllotreta species, but some species may have a stronger preference to other isothiocyanates or thiocyanates. The attractive effect of the plant volatiles is enhanced by the emission of a male-produced aggregation pheromone. The presence of such a pheromone was first demonstrated in Phyllotreta cruciferae Goeze. In this species R5R,5aS)-1,1,5,8-tetramethy1-1,2,3,4,5,6,5a-heptahydrobenzo[1,2-a][7]annulene] was found to be the main pheromone component. Significant attraction by the pheromone was recorded only in the presence of ALLYL ITCN. The biological activity of the pheromone compound was connected to the plus (+) chirality. The same component seems to be occurring also in the pheromones of several other Phyllotreta spp. as well, suggesting a wider occurence in the genus. Once attracted by the joint effect of plant volatiles and aggregation pheromone, the presence of the non-volatile glucosinolates in the plant tissues is necessary for continuous feeding. Aggregations of flea beetles on suitable host plants, which result from the joint effects of plant-derived and pheromonal chemical cues detailed above may also be good rendez-vous occasions, increasing the probability of encounters with the opposite sex and mating in the vicinity of the optimal oviposition site. Due to the horticultural importance of Phyllotreta spp., deciphering details of their chemical communication has considerable significance in the development of new methods of integrated control.

Parallel phyto- and mycocoenological investigations have been made since 2001 in all characteristic forest types in Borzsony Mts., North Hungary. The main aim of this work was the examination of similarities between plant and fungal communities, as well as the plant—fungi connections within certain habitats. Among the total 381 macrofungi species documented, 330 occurred in the investigated 7 forest stands. Wood-inhabiting fungal communities of coniferous stands can be separated unambiguously from those of deciduous stands. Communities of deciduous stands can be divided into two subgroups: those fructifying in wet and in semidry stands. The main factors which influence the composition of wood inhabiting fungal communities seem to be, in decreasing order: (1) crown layer composition; and (2) soil properties (probably only humidity). Wood-inhabiting fungal communities do not show any relation with the underwood layer of particular plant associations. Amongst soil inhabiting fungal communities, three groups can be separated: (1) those of coniferous stands and alderwood; (2) those of the two climax stands; and (3) those of the two edaphic deciduous stands. Classification of these communities is similar to classification of plants of underwood layers. Probably both are dependent upon soil properties (humidity and pH) of particular habitats, but the range of mycorrhizal partners is also decisive for macrofungi communities. All investigated stands are under forestry management, with low quantity of dead and infected wood, so forestry management type may have a great influence in composition of both wood and soil saprotrophic fungal communities.

We conducted experiments for developing an in vitro micropropagation protocol starting from meristems of Rudbeckia hirta L seedlings. We pre-soaked the seeds in sterile ion-exchanged water for 17 hours, and then achieved surface disinfection in two separate steps. First, we used concentrated household sodium-hypochloride solution for 20 minutes and, also for 20 minutes, we applied hydrogen peroxide of 10%, which was followed by washing with sterile ion-exchanged water three times. For the propagation of seedling meristems, the combination of half-strenght solid Murashige and Skoog (1962) culture medium containing 10 mg/1 of kinetin or 2 mg/I of kinetin + 0.1 mg/1 of 2iP proved to be the most suitable. The average number of shoot-buds developed from the seedling axillary meristem in the best culture media varied between 5 and 17. Without separating them, we inoculated the shoot-bud clusters on MS culture medium containing 2 mg/1 of IAA. After four weeks of incubation we obtained elongated shoots which we separated and inoculated into a new culture medium and we obtained elongated roots. The rooted plants were gradually acclimatised in the cultivation room, potted and carried to a greenhouse, and then planted in open field for subsequent observation. By adopting this method, our laboratory started the micropropagation of the superior and/or elite genotypes of the Rudbeckia hirta L. being of special value in respect of breeding.

Evidence suggests that a diet high in fruits and vegetables may decrease the risk of chronic diseases, such as cardiovascular disease and cancer, and phytochemicals including phenolics, flavonoids and carotenoids from fruits and vegetables may play a key role in reducing chronic disease risk. Recent research has proven that sour cherry (Prunus cerasus L.) is a valuable natural source of some bioactive compounds important in human health preservation. In our work, we identified the total antioxidant activity, anthocyanine content and "antioxidant density" of sour cherry varieties named "Újfehértói fürtös", "Debreceni bőtermő", "Kántorjánosi" and "Érdi bőtermő" and those of the "Bosnyák" sour cherry clones. "Antioxidant density" is a biological value indicator obtained in a synthetic way, which indicates the antioxidant capacity of the particular food, e. g. fruit and vegetable, related to 1 Calorie.

Selenium (Se) is an essential trace element for animals, microorganisms and some other Eukaryotes. It has become increasingly evident that Se plays a significant role in reducing the incidence of lung, colorectal and prostate cancer in humans. Although it is well known that some species among higher plants are able to accumulate selenium in their tissues, but others are not able to do so, and there is evidence that selenium is needed for the growth of algae, meanwhile the question of essentiality of Se in vascular plants is unresolved. We aimed to study the in vitro growing and to characterise some physiological properties in radish (Raphanus sativus L.) seedlings treated with 0 to 200 mg/1 sodium-selenate. The results showed that lower (2 mg/1) concentration sodium-selenate increased the biomass as well as the total antioxidant capacity of seedlings. The seedling's selenium content showed linear correlation with the sodium-selenate content of the medium.

Cucumber production by soil less culture on rockwool substrate in Hungary is an open system regarding its water and nutrient supply. Environmental and economical reasons require the recycling of nutrients of the system. Experiments have been planned in order to estimate the utilisation of individual nutrient elements applied. All around the vegetation period, chemical analyses monitored the depletion of the elements initially administered by sampling the solutions at successive phases from the injection to the overflow. The results have been compared with earlier experiences refering to general rules. It has been stated that the intensity of photosynthesis is decisive in determining the composition of the overflow. The less changes are observed during the period of frequent watering.

The absorption of the nutrient elements varied between 25-51% deperiding on the individual elements. The differences are significant. Further examinations are needed in order to clear:

• which are the main elements of technology, which are decisive in utilisation of nutrients
• what are the possibilities of the secondary utilisation of nutrients.