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  • Association of varieties in stone fruit plantations
    29-33.
    Views:
    190

    In the majority of Hungarian orchards of stone fruits, the planting distance is 6-7 m x 4-5 m. As many of the current varieties are self-incompatible, planting designs are applied to provide for adequate pollinisers. As long as differences in blooming time are small, i.e. 3-5 days at most, overlaps of blooming of the associated varieties are sufficient for fruit set.

    In sour cherry, one leading variety, Pándy, is self-incompatible and requires two polliniser varieties at least (Ciganyneggy or some sweet cherry varieties). Pándy is, moreover, cross-incompatible with the varieties Debreceni bőtermő, Kántorjánosi and Újfehértói fürtös being all of them self-fertile as most of new varieties recommended, by the way, for being planted to monovarietal blocks.

    Among European plums there are varieties registered as male sterile, self-incompatible, parially self-fertile and self-fertile, respectively. For the purpose of cross pollination, the choice of two varieties, at least, to be associated to any variety belonging to the first three groups, is recommended. The number of rows in blocks planted to self incompatible or male-sterile varieties should not be higher than 2-(4). Inter-incompatibility has been observed within the currently recommended assortment, between the varieties Cacanska najbolja and Stanley, only. Chinese-Japanese plums are scarcely represented in Hungarian plantations. Variation of blooming time in varieties is somewhat more pronounced, i.e. 5-8 days. There is but a weak tendency to self-fertility, thus practically, all varieties are considered as self-incompatible, thus the planting of two-row blocks for each of three varieties, at least, are recommended to be associated.

    Self-incompatibility and partially self-fertile apricot varieties are recommended to be combined with two polliniser varieties, at least, each planted to two-row blocks. The varieties Ceglédi óriás, Ligeti óriás, Nagykőrösi óriás and Szegedi Mammut are mutually inter-incompatible. Most of the peach varieties grown in Hungary are self-fertile, thus they are planted to large blocks, each. On sites threatened by late spring frost, it is recommended to plant (monovarietal) blocks of 4-6 rows at most. Cross-pollination may increase fruit set even in self-fertile varieties.

     

  • Brown rot blossom blight and fruit rot of apricot in Hungary
    139-141.
    Views:
    303

    The aim of our two-year study was to assess incidence of brown rot blossom blight and fruit rot caused by Monilinia laxa in 2003 and 2004. Assessments of incidence were made on cv. Bergeron (susceptible to brown rot) in a flatland and a hilly growing area (at Cegléd and Gönc, respectively). In both locations, plant protection was performed according to the integrated fruit production guidelines and small untreated plots were set up for each cultivar in both years. In 2003, when weather conditions were dry and hot, brown rot incidence was low (less than 10%) on both blossoms and fruits. Monilinia laxa did not cause significantly different blossom blight and fruit rot at the hilly (Gönc) area compared to the flatland, not even in untreated plots. However, in 2004, when spring and summer weather conditions were wet and cold, Incidence reached 95% for blossom blight and 33% for fruit rot in the untreated plots. Blossom blight incidence was 1.5-2 times higher in the flatland area compared to the hilly growing area. During the blooming period of apricot, two (at flower bud stage and at full bloom) and three (at flower bud stage, at full bloom and at petal fall) fungicide applications were necessary for the successful control at Gönc and Cegléd, respectively. The difference between the two orchards was due to the fact that blooming started one week later in the hilly region (at Gone) than in the flatland region (at Cegléd), therefore, the critical weather period coincided with blooming in the orchard in the hilly region only partially. Fruit rot incidence was similar in both regions as the amount and distribution of rainfall were similar during the fruit ripening period.

  • Pollen viability of ‘Besztercei plum' clones depending on the effect of the year
    115-121.
    Views:
    162

    The percentage of dark staining pollen grains was higher in spring of 1996 than in the previous year. Data in 1998 resemble those of 1995, concerning the large amount of medium staining pollen grains in the majority of clones. Some clones produced excellent quality pollen also in the third year. whereas there were significant differences in other clones in various years.

    The warmer February-March period in 1995 induced an early blooming, and frost affected the orchard not only in winter months, but also immediately before and during blooming. Thus, frost was the possible cause of weaker quality pollen this year. In 1996 warming began a bit late, but it was not broken by drastic falls in temperature, except for the middle of April, when a smaller frost affected the orchard. It is likely that this frost did not influence pollen quality of `Besztercei' and 'Early Besztercei' plum clones significantly. In 1998 warming was continuous and steady, the orchard was not affected by frost immediately before blooming. In March, however, there was frost almost every day, according to daily minimum temperatures.

  • Effect of the placement of self-incompatible apricot varieties on their yield in commercial plantations
    82-86.
    Views:
    254

    Earlier studies concerning self-, free- and cross- fertilization of apricot varieties grown in Hungary, proved the existence of self-sterile as well as self-fertile varieties within the recommended assortment. The self-sterile and partially self-fertile varieties should be planted in association with polliniser varieties, only. The present paper reports about the yields of trees of the widely grown, self-sterile local variety, Ceglédi óriás (Giant of Cegléd), depending on the distance of adequate polliniser trees. In the univarietal, 27 row-wide block of the relevant variety, an efficient polliniser, Magyar kajszi was planted to the 10th and 19th row. In the close vicinity, another block of polliniser, Rózsakajszi C. 320 was located. The number of fruits set per tree has been counted or estimated in two consecutive years. In both seasons, the yield of the Ceglédi óriás trees diminished with the growing distance from the nearest polliniser trees. Those trees in the center of the block, between the two (10th and 19th) rows of Magyar kajszi bore acceptable yield (40 kg/tree in 1987), however, considerable reduction of the number of the fruits set was stated already in the 4-5th row from the polliniser away. Similar gradient of fruit set was apparent in relation to the neighbouring block of Rózsakajszi C 320. The beneficial effect of the vicinity of polliniser varieties was obvious as far as the distance of the 10th row. Taking into consideration the self-sterility, the early blooming time and the poor fertilization of the variety Ceglédi óriás, a planting design of associating it with at least two polliniser varieties (e.g. Gönci magyar kajszi and Ceglédi bíbor) is highly recommended. On the basis also of earlier results, a proposal has been developed for the association of apricot varieties as recommendations for optimising yields. Blooming time, fertilizing potential, schedule of the picking season and market possibilities have to be considered simultaneously.

  • Flowering performance of some Modern Rose Varieties in Hungary
    69-75.
    Views:
    144

    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.

  • Floral biology, pollination and fertilisation of temperate zone fruit trees
    7-12.
    Views:
    406

    The knowledge of blooming, pollination and fertilisation and its use are indispensable in maximizing of cropping potential of fruits in economical fruit production. In attaining maximum yield a greater attention has to be focused on choosing cultivar combinations, and results of experiments on blooming, pollination and fertilisation must be applied carefully.

    To have efficient bee pollination requires attention at the time of designing an orchard. It requires further attention at the time of bloom of any of the fruit-hearing species. Markets demand new types of fruit which forces constant changes in the cultivar composition of orchard. The blooming, pollinating and fertilisation characteristics of cultivars chosen have to be known before an orchard is set up. Apart from the general knowledge of trees considered to be planted, there is a great need to know the flowering, pollinating and fertilization characteristics of each cultivar in detail.

  • General principles in variety-association for intensive plantations of pomeceous fruits
    96-101.
    Views:
    256

    Under conditions of Hungary, more than 400 varieties of apple, pear and quince varieties have been observed for time of blooming and fertility relations in order to check the possibility of their use for intense plantations in different combinations with polliniser varieties. Low (below 3%) rate of self-fertility occurred at 65% of apple varieties. That partial self-fertility, however, is far from being sufficient to produce acceptable yield, thus allogamous pollination is absolutely necessary. The same is true for the rear and quince varieties grown in Hun­gary, too. The normal development requires the presence of viable seeds in the fruit set, most in quince, therefore, association of the right varie­ties is most important in that species. Apple and pear varieties are assigned according to their blooming time to 4, quince varieties to 3 groups. The yield of all three pomaceous species declines with the growing distance from the potential pollen source. In the intense plantations, the critical (maximum) distance to be observed is 20 m for apple and 15 m for pear and quince. In combining the placement of varieties, also the principles of a variety-specific cultivation are to be considered carefully. The double objectives are satisfied most by the system of Malus­pollinisers developed for intense plantations.

  • Comparative study of plum cultivars belonging to different taxons during 1980-1996
    13-19.
    Views:
    149

    The program of the Research Institute of Cegléd, comprises the acclimation and selection of 7 Prunus-species and 39 cultivars grafted on Myrobalan C. 679 (P. cerasifera) seedling stocks. In addition two varieties have been investigated on three different rootstocks each: Myrobalan C. 174 (P. cerasifera), Bitter almond C. 449 (P. arnygdalus var. amara) and Sweet almond C. 471 (P. amygdalus var. dulcis). Fruits of commercial quality are produced maroly on some cultivars of P. salicina-, P. italica- and P. cerasifera character. Authors explain the three possible causes of low yields experienced in non-European plums:

    1/ unfavorable environmental conditions

    2/ lack of irrigation and

    3/ superficial information concerning the variety, rootstock and adequate traditions as well as growing practices.

    A rather tight correlation has been stated between blooming dates and the main ripening period. However, the early blooming time alone cannot be considered as the cause of low productivity. The decay of plum trees is attributed to special ecological requirements and phytosanitary problems of the foreign plum cultivars. The analysis of regression revealed stochastic relations involving several other characters too, which facilitate the planning of cross-combinations in the breeding program.

  • Climatic indicator analysis of blooming time for sour cherries
    11-16.
    Views:
    196

    County Szabolcs-Szatmár-Bereg produces more than the half of the total sour cherry grown in Hungary. Successful production, i.e. yield, depends largely on weather conditions. Most attention should be paid to the weather during the blooming period, being most decisive from the points of view of quality as well as quantity. In order to predict yields expected, the characterisation of the most important weather parameters is necessary. For that purpose, the database of the Institute of Research and Extension Service for Fruit Growing at Újfehértó Ltd. has been utilised. Records of weather conditions were collected throughout the period 1984-2005, i.e. daily minimum, maximum and mean temperatures (°C), precipitation (mm), and phonological diary of sour cherry varieties ’Újfehértói fürtös’, ’Kántorjánosi’ and ’Debreceni bôtermô’. Data of 7 indicators have been traced: number of frosty days, the absolute minimum temperatures, means of minimum temperatures, number of days when daily means were above 10°C, means of maximum temperatures, number of days without precipitation, and number of days when precipitation was more than 5 mm. On the one hand, we surveyed the changes; on the other hand, estimates have been attempted for the future changes expected during the following decades. The indicators being associated with certain risky events may serve for the prediction of the future recommendations to prevent damages.

  • Toxicity of fungicides to honey bees (Hymenoptera: Apidae) and their effects on bee foraging behavior, pollen viability and fruit set on blooming apples and pears
    96-98.
    Views:
    179

    Fungicides fosetyl-AL, triadimefon, dodine, mycobutanil and fenarimol were tested for honey bee (Apis mellifera L.) mortality and effect on bee foraging, pollen viability and fruit set in blooming apple and pear. None of the materials were toxic to honey bees or reduced pollen gemination or fruit set.

     

  • Comparison of flower bud development in almond, apricot and peach genotypes
    93-98.
    Views:
    215

    The phenological processes of flower bud development of stone fruits during dormancy are not thoroughly known. The yield of these species, especially of almond, apricot and peach is determined basically by dormancy of flower buds, the survival rate of buds during winter frosts and by their ability to develop normal floral organs in the next spring. After the initiation of floral primordia, flower bud development is taking place in continuous space until blooming, though at different speed characteristic to the species. To study flower bud development during dormancy we applied two alternative methods in different genotypes of almond, apricot and peach: (1) examination of pollen development (microsporogenesis), and (2) the measurement of pistil length. The samples were collected from the central part of Hungary during the dormancy period of 2004/2005. The three fruit species differed significantly in the speed of flower bud development, it was the quickest in almond, followed by apricot and peach. In addition to the species, there were significant differences in the process of microsporogenesis and pistil development between genotypes within species and also between the different types of shoots on which the buds were located. On short shoots buds developed at a higher speed, than on long shoots. Based on our observations, on the short shoots the period of endodormancy was shorter with 5-30 days, according to genotypes, compared to the long shoots. This difference, however, decreased to 2-3 days by the time of blooming.

  • Erratic fruit set in almond under warm climates
    59-64.
    Views:
    286

    The cause for the erratic yields of the two main almond cultivars grown in Morocco has been searched in order to recommend possible solutions for a high and stable production. The lack of sufficient bloom overlap between ‘Marcona’ and ‘Fournat de Brézenaud’ in many years may be one of the reasons of this erratic behavior, but not the only one, as the same behaviour may be observed in two simultaneously blooming cultivars, ‘Ferragnès’ and ‘Ferraduel’. The relatively high temperatures observed during the blooming period
    significantly reduced the stigma receptivity of these cultivars and, as a consequence, their effective pollination period, showing that stigmatic receptivity is a limiting factor for fruit set in ‘Marcona’ and ‘Ferragnès’ and their subsequent yield reduction under warm conditions. Thus, in the present context of global warming, the search for cultivars tolerant to heat stress during flowering will acquire a special interest, as well as the combination of cultivars with the same chilling and heat requirements to ensure a simultaneous bloom.

  • Comparison of honeybee behaviour in blooming fruit plantations
    147-151.
    Views:
    275

    Field observations were made on the fl ower visiting behaviour of honeybee foragers in commercial fruit plantations of apricot, Japanese plums, sour cherry, apple and pear. The number of inspected cultivars was 18. The intensity of fl ower visiting by honey bees was markedly different when data of different fruit species are compared. Most intense bee activity was registered on the Japanese plums, somewhat less on apricots, the intensity diminished signifi cantly with apples and pears. Our data presented on the honeybee visitation of Japanese plums can be regarded as new fi nding because no information has been available so far on the relative attractiveness of this fruit species compared to European fruit tree species. Japanese plums were somewhat more attractive to honeybees than apricot and much more attractive than sour cherry, apple and pear. The behaviour of honeybees as visiting the blooming trees displayed specifi c differences according to the fruit species (apricot, sour cherry, pear), which coincide largely with earlier results. It is notable that the fl ower visiting behaviour of honeybees on Japanese plums has been found to be fairly similar to the same on European plums.

  • Seasonality of weather and phenology of reproductive organs of flower of sour cherry cultivars in Hungarian climatic conditions
    75-80.
    Views:
    212

    Sour cherry (Prunus cerasus L.) is one of the most important fruit crop grown in Hungary, The flowering phenology and pollen shedding/stigma viability ratio, in an effort to elucidate the reproductive phenology of nine economically important sour cherry cultivars (Érdi bőtermő, Debreceni bőtermő, Csengődi, Kántorjánosi 3. Pándy 279. Úfehértói fürtös, Petri, Éva, and Oblacsinszka) all widespread in the Hungary, was studied at Újfehertó climatic condition. The main aims were to investigate how possible environmental cues influence timing and development of phenophases and whether different cultivars have different seasonal responses to these cues. Likely effects of climatic changes on phenological development patterns were also considered. Our results revealed important aspects of the reproductive biology of sour cherry flowers. The amplitude of the phenophase "beginning of blossoming" between cultivars did not exceed 6 days. There is maximum 3 days difference in blooming length of different direction in each cultivar. Pándy 279 showed high variability when the position of flowers changed on the tree shoots. Újfehértói fürtös was stable in all four directions of tree. The pollen shedding period and stigma viability ratio was well synchronous. Pollen shedding phenomenon occurred in the range limitation of secretary activity of stigmas in all five cultivars. Distribution of pollen shedding over the secretary activity of stigmas is almost good. In all five cultivars maximum pollen shedding occurred about the high temperature part of the day.

  • Some important growing characteristics of apple and apricot cultivars in two fruit growing regions in Romania
    51-56.
    Views:
    147

    The aim of this study was to determine some important growing characteristics of 5 resistant apple (Rajka, Rubinola, Topaz, Otawa and Goldstar) and 7 apricot (NJA 19, Goldrich, Harcot, Venus, Comando, Olimp, Cea mai buna de Ungaria) cultivars in two fruit growing regions in Romania from 2000 to 2003. Height of the apple trees (4-year-old tree) ranged between 1.96 m (cv. Topaz) and 2.39 m (cv. Rubinola). Diameter of the crown ranged from 0.96 m (cv. Goldstar) to 1.12 cm (cv. Rajka). The trunk diameter ranged from 3.5 cm (cv. Goldstar) to 5.0 cm (cv. Rajka). The surface of the trunk section was the lowest for cv. Goldstar (9.7 cm') and the largest for cv. Rajka (19.6 cm). Height of the apricot trees (4 years old tree) ranged between 2.69 m (cv. Venus) and 3.38 m (cv. NJA - 19). Diameter of the crown ranged from 2.59 m (cv. Comandor) to 2.77 m (cv. Cea mai buna de Ungaria). The trunk diameter ranged from 9.54 cm (cv. Goldrich) to 13.30 cm (cv. NJA - 19). Length of annual branches was the lowest for cv. Goldrich (45.1 cm) and the highest for cv. NJA - 19 (83.8 cm). Bud swelling of apricot trees began on 8 March for cv. NJA - 19 and ended on 11 March for the control cultivar (Cea mai buna de Ungaria). The blooming started on 16 March for cv. NJA - 19 and 27 Mach for the control cultivar. Duration of fruit growth was 89 days for cv. NJA - 19 and 128 days for cv. Comandor. When the temperature decreased to 1.5 °C (in 2001), percentage of viable pollen grains ranged between 48.86 % (cv. Olimp) and 91.57 % (cv. Venus). The germinating grains ranged from 31 % (cv. Olimp) to 90 % (cv. Harcot). Free pollination was the lowest for cv. NJA - 19 (29 %) and the highest for cv. Harcot (41%), while self-pollination ranged between 6 (cv. Olimp) and 11 % (cvs. Comondor and Harcot). Apple yield ranged from 16.65 t/ha (cv. Otawa) to 24.35 t/ha (cv. Rajka) and the differences varied from 4.45 t/ha to - 3.25 t/ha compared to the control varieties. Apricot yield ranged from 11.47 kg/ tree or 9.53 t/ha (cv. Cea mai buna de Ungaria), to 38.83 kg/tree or 27.34 t/ha (cv. Olimp) and the differences varied from 3 t/ha to 17 t/ha compared to the control varieties. Apple fruit weight ranged from 162 g (cv. Otawa) to 222 g (cv. Goldstar) and apricot fruit weight from 42.52 g (cv. Goldrich) to 68.38 g (cv. Comandor). Color, taste and aroma were very specific to cultivars.

  • Colour stability of the flowers in some modern rose varieties in Hungary
    61-66.
    Views:
    166

    A variety trial has been carried out to study the colour changing — colour stability of the flowers of some modern roses, especially of Hungarian varieties. 100 floribundas and polyanthas were observed. Colours of the petal surface were examined at three fenological stages of the flowers: at the bud, at the young open flowers and at the aged open flower stages. The colour difference was described in HLS standard. Our work shows that valuable Hungarian varieties can be found in both studied classes, but more floribundas bred in Hungary had good colour stability than polyanthas. The best Hungarian floribundas were 'Pest' and 'Remenyik Sándor emléke', although 'Regen', `Szent Lász1ó em­léke' and 'Szabó Dezső emléke' were quite good. The best Western-European floribunda rose was 'Perneille Poulsen'. Their colour stability was reliable in different situations. Colour changing of the two best varieties was almost unperceivable from the bud to the young petals and from the young to the aged petals. In the polyantha class there was only one perfect variety: the Czech `Cs1 Cerveny Kriz'. The 'Fairy Damsel' was almost excellent as well. The best Hungarian polyanthas were `Domokos Pál Péter emléke' and 'Savaria'.

  • Self pollination in peach
    76-78.
    Views:
    242

    The peach is though considered to be a self fertile fruit species, also some self sterile and male sterile varieties have been registered. The latter type seems to be frequently met in Asian varieties, whereas in the USA and Europe, J. H. Hale and Flaminia are grown. The purpose of the present study was the assessment of fertility relations of peaches and nectarines grown in Hungary. The authors studied, since 1974, more than 100 different peach and nectarine varieties as for fertility relations, especially their autogamous or geitonogamous fruit set on isolated, i.e. bagged flowers at bud stage, then set free after blooming finished. Isolated flowers of some varieties were also self pollinated, artificially. According to the results the varieties have been assigned to four alternative groups. Self sterile varieties in the proper sense have not been found, but partial self sterility (less than 10% fruit set), self fertility (10 to 20% fruit set) and high self fertility (more than 20% fruit set on selfed flovters) was generally met. The majority of the varieties belonged to the last two groups, nevertheless. the rate of fruit set displayed seasonal variation, the maximum was in one case 89.9%. The purposeful self (hand)pollination of the isolated flowers increased fruit set, substantially. Varieties rated as partially self-sterile are J. H. Hale and Fuzador (the former being partially male sterile too). Although in some years and some varieties, fruit set legged below 10% but according to the means the majority of nectarines are assigned to the self fertile category whereas most peach varieties, either for fresh consumption or industrial types, were highly self fertile.

     

  • Technologies developed to avoid frost damages caused by late frost during bloom in the fruit growing regions of Siófok and Debrecen
    99-105.
    Views:
    382

    The aim of the study was to fi nd out which of the methods used to avoid damages of late frosts would be the most effective for the fruit growing practice. Three technologies have been tested in the regions of Siófok and Debrecen-Pallag. The antifrost irrigation proved to be the most advantageous. For that purpose microjet sprayers are used, which are thrifty and do not need for that purpose large containers. With the aim to secure an even distribution of water, the sprayers are distributed on three levels: above and inside of the crown as well as on the level of trunks. On a large scale, a single microjet above the crown level would be suffi cient. By means of a detailed analysis served to set the optimum intervals between spraying phases: with each 15, 10, 5 and 3 minutes during half a minute. The synchronous presence of water and ice below the freezing point, the released freezing heat plus the water used much above the freezing point (9–10 °C) altogether maintains the temperature above around 0°C near the fl owers or growing fruitlets, meanwhile, the surrounding air cools down to –8 °C. The effectiveness of the generally used anti-frost would be increased substantially by the former application of cooling irrigation, which delays the blooming date. The Frostbuster represents a new technology developed for the same purpose of frost defence. It uses butane burning and produces high (80-90°C) temperature with a strong blast of air. On the protected area sensors have been distributed for measuring temperature and relative humidity. The means of the measurements proved a rise of temperature, which was suffi cient to save the fruit trees until the difference is less than –3–3.5 °C. Our analyses stated that paraffi n candles avert the frost until –4 °C. Its success depends largely on the intensity of air movements. A small wind would be enough to frustrate the effect. The results show clearly the utility of Frostbuster and paraffi n candle combined is approved.

  • Floral biology of hazelnut (Review article)
    7-19.
    Views:
    282

    Floral biology of hazelnut (Review article)

  • Antioxidant capacity and total polyphenol content of Lavandula cultivars at different growing areas in Hungary
    65-69.
    Views:
    334

    Lavandula species are worldwide grown essential oil producing medicinal plants with considerable economic value. Beside volatile oil, lavender also contains different phenolic compounds which have been less widely studied till now. Cultivation of lavender has become widespread in Hungary in the recent years, however, growers have limited knowledge on the productivity of cultivars available. In our research we were aimed to studying the antioxidant capacity and total polyphenol content of samples collected in two growing areas (Dörgicse and Szomód) from flowers of two L. angustifolia (‘Hidcote’, ‘Munstead’) and two L. × intermedia (‘Grosso’, Grappenhall’) varieties, during the full blooming period of 2017. Antioxidant capacity of the samples was determined by FRAP assay (Benzie and Strain, 1996), while total polyphenol content (TPC) was measured by a modified method of Singleton and Rossi (1965). According to our results, varieties of L. × intermedia showed higher values of antioxidant capacity and of total polyphenol content, than those of L. angustifolia cultivars. Among them, both the antioxidant capacity (179.6 mg AAE/g DW) and total polyphenol content values (152.4 mg GAE/g DW) of ’Grosso’ from Dörgicse were the highest. Concerning FRAP values of all the cultivars investigated, larger variability were found in Dörgicse, than in Szomód. Regarding the effect of growing area, each cultivar represented similar FRAP values in Dörgicse and in Szomód, except for ’Grosso’. However, in the case of TPC values, higher variability was observed between the growing areas, especially in the case of ’Grosso’. In the future our studies on lavender polyphenols will be completed with qualitative evaluation of the values obtained by HPLC analysis.

  • Nectar production of pear (Pyrus communis L.) cultivars
    67-75.
    Views:
    278

    Detailed studies were made on the nectar production of 44, 16 and 18 pear cultivars, respectively, in a cultivar collection of pear during three consecutive years with highly different weather in the blooming. Results clearly show that pear does not necessarily produce small amount of nectar as stated in the world literature. In fact, pear can produce extremely high amount of nectar sometimes much higher than other temperate zone fruit trees species but its nectar production is highly subjected to weather, first of all to air temperature. Low nectar production seems to be more frequent than high one and cold weather can prevent its nectar production at all. On the other hand, results corroborate to the earlier statements on the low sugar concentration of pear nectar. There is a highly significant negative correlation between the amount of nectar produced by pear flowers and its sugar concentration (r = -0.52, n = 291, p< 0.001 for 1996, r = -0.34, n = 197, p< 0.001 for 1998). Sugar concentration in individual flowers may be up, to 40% in exceptional cases but generally it is well below 20%. Very high figures for sugar concentration in pear nectar at the literature seem to be incomprehensible. In contrast of some earlier statement in the literature no real difference could be established in the nectar production of pear cultivars, based on much more measurements than in earlier studies. Very low sugar concentration in pear nectar can explain the fact that the overwhelming majority of honeybees are pollen gatherers at pear trees even in the case of exceptionally high nectar production.

     

  • Fruit drop: II. Biological background of flower and fruit drop
    103-108.
    Views:
    329

    The most important components of fruit drop are: the rootstock, the combination of polliniser varieties, the conditions depending of nutrition, the extent and timing of the administration of fertilisers, the moments of water stress and the timing of agrotechnical interventions. Further adversities may appear as flushes of heat and drought, the rainy spring weather during the blooming period as well as the excessive hot, cool or windy weather impairing pollination, moreover, the appearance of diseases and pests all influence the fate of flowers of growing and become ripe fruits. As generally maintained, dry springs are causing severe fruit drop.

    In analysing the endogenous and environmental causes of drop of the generative organs (flowers and fruits), the model of leaf abscission has been used, as a study of the excised, well defined abscission zone (AZ) seemed to be an adequate approach to the question. Comparing the effects active in the abscission of fruit with those of the excised leaf stem differences are observed as well as analogies between the anatomy and the accumulation of ethylene in the respective abscission tissues.

  • Temporal changes of the frequency of spring frost damages in the main fruit growing regions in Western Hungary and in East Hungary
    81-87.
    Views:
    316

    Most of the risk in Hungarian fruit growing is the damage caused by late spring frosts. The frequency of late frosts seems to increase nowadays. The aim of the study was to check this contention: what is the real probability of the damages. Based on earlier experiences, the physiological LT50 function has been elaborated for new fruit varieties, which are eligible to moderate the danger when being threatened by frost. By means of this technique, the probability of freezing is distinguished between frost susceptible, frost resistant and medium frost resistant fruit species and varieties around their blooming time. The degree of frost damage depends on the duration and severity of the low temperature and not at least on the frost tolerance of the plant. For that purpose, the frequencies of frost damages were studied at two Transdanubian and two Trans-Tisza fruit growing sites by means of a meteorological database for the 60-year-long period 1951–2010. Being aware of the LT50 values changing during the phonological phases of the fruit trees from budding, bloom, fruit set and fruit growth, the number and date of critical (frosty) days could be settled. An important role is attributed to the orographic relief and the height above the sea level of the site, as 20–30 m differences and expositions may become decisive within the same plantation. The spatial distribution of damages is also dependent on the air circulations within the Carpathian basin. At the southern and northern borders of the country, especially valley bottoms represent additional risks of frost. Most spring frost damages are experienced in April 20–22, and cause heavy damages by temperature minima between – 3°C and – 6°C. The severity of damage depends largely on the temperature of the preceding few days. The earlier bloom the heavier damage is expected. The study is emphasising the importance of the varieties. Frost tolerance of some varieties may lower the risk of spring frosts by 40–50%, as experienced on the plantations. The quantifi cation of the risks based on data raised during the last years will be suitable to defi ne the security of yields of each growing site successfully.

  • Overwintering capability and spring population size of honeybee colonies (Apis mellifera L.) in Hungary
    153-156.
    Views:
    114

    Honeybee races and ecotypes of different genetic background have different population development in spring. Some of them can reach the necessary population size by the beginning of Robinia pseudoacacia (black locust) blooming period. There were significant differences in the spring population development between the colonies of different genetic background. The Italian races (A. m. ligustica) and their cross-breeds over-wintered poorly in Hungary, their spring population was low and they collected small amount of Robinia honey. The Austrian improved Carniolan (A. m. carnica) colonies over-wintered well, they had the largest spring population in both years. There was no significant difference between the size of the spring population of the same colonies of different genetic background in 1995 and 1996. The rate of the population development of the colonies was different in the two examined years. There was strong correlation (r = 0.8) between the spring population size and the Robinia honey yield, and between the mid-April population size and the Robinia honey yield of the colony groups of different genetic background. Spring population size also important in the effective pollination of fruit tree species that bloom earlier than the black locust trees.

     

  • Floral analysis can be use as an early plant analytical tool to diagnose nutritional status of fruit trees?
    23-27.
    Views:
    201

    A field experiment was conducted in an integrated apple orchard (Malus domestica Borkh.) established on a lowland chernozem soil in East-Hungary, to investigate if flower analysis could be used to diagnose the nutritional status of the trees. In April 2008, during full bloom, flowers and leaves were collected. Leaves were collected again in August, at the standard sampling time from the same trees. The content of nitrogen, phosphorous, potassium, calcium magnesium and boron were measured in flowers and in leaves. Correlation analyses were carried out to establish the relation s between nutrient contents in same and different plant part s. In flowers the following ratio was found between nutrients: N:P: K:Ca:Mg:B -10: l.35:7: 1.7: I :0,02. From result s it was evident that flower as organ contain significant and comparable amount of nutrients like as leaf. The N, K and Ca content were higher in leaves than in flowers at full bloom. The opposite was true for B. The P and Mg content of flower were quite equal with leaf P and Mg at full bloom . All examined nutrients were significantly affected by cultivars both in flowers and leaves. Significant correlation, was found between flower P and leaf P, flower B and leaf B (P=O.O 1) and flower K and leaf K at blooming time (P=0.05). Significant, but weaker correlation was also found between flower K and leaf K and between flower Mg and leaf Mg al JOO days after full bloom (P=0.05). Moreover, strong, but negative correlation was observed between flower B and leaf B at 100 clays after full bloom (P=O.O 1). Within flowers, the strongest positive correlation was found between Mg and B content (P=O.O 1). Strong positive correlations were also recognised between flower K and flower N, Ca and Mg and between N and Ca in the flowers (P=0.01). The strongest correlation was found between K and P in leaves at full bloom (P=O.O 1 ). Strong significant correlation was observed between N and B in the leaves collected at standard sampling time (100 DAFB) (P=0.01). Strong, but negative correlations were found bet ween leaf Mg and leaf P, K and between leaf N and leaf P at 100 days after full bloom (P=O.O 1).