Studies were made on the bee visitation of 6 quince cultivars and on the foraging behaviour of honeybees at quince flowers for 3 consecutive years. The bee visitation was highly intense because both the plantation and its surrounding was overpopulated by honeybee colonies. Some 5.5 bee visits were counted in average at 50 opening quince flowers in 10 minutes and some 9.7 flowers were visited of the 50 ones observed meanwhile. This equals some 7 bee visits per flower per day per in good weather. Bee visitation, however, was variable and it was greatly different in the three consecutive years with fairly favourable weather. Some cultivars tended to be more and others less visited by honeybees than the others but these differences were not consequent at each occasion. No consequent relationship between the weather and the bee visitation of quince trees could be recognised. It was concluded that .other factors were responsible for the variable nature of the bee activity at quince. Most honeybees tended to collect pollen (51.6% in average for the 3 years) and usually much less gathered for nectar only (19.9%), and the rest of them were mixed behaviour foragers gathering for both (28.5%). There were some slight differences in the foraging behaviour of honeybees at some cultivars but these differences were not always consequent in consecutive years. Also the nectar production of flowers failed to affect the bee visitation and the foraging behaviour of honeybees definitely. For the variable nature of bee visitation and bee behaviour at quince flowers, supplementary pollination is needed to achieve as high set of fruits as high is required to a good crop at quince (at least 20-25% because the flower density is low of this fruit tree species). Since the intensity of bee visitation at the flowers is the only reliable estimate of the necessity of supplementary bee pollination further research is needed to explore the relationship between the number of honeybee visits and the consequent fruit set at quince.
Quince (Cydonia oblongaMill.) is a minor fruit crop, which is primarily used for marmalade, jam and sauce.Very few quince cultivars are known all over the world and in many cases similar names are used for presumably different cultivars. The aim of the present study was to evaluate and characterize the genetic diversity of 36 quince cultivars and selections with SSR markers. Seven out of 8 SSR markers designed from apple sequences could successfully yield amplification also in quince cultivars. Number of alleles per locus ranged from 2 to 3 alleles. These allele numbers are quite low when compared to apple. It is supposed to be the consequence of a genetic bottleneck. In spite of the low allele number per locus, the 36 quince cultivars formed 30 different genotypes. The ratio of homozygosity was low, which might be coupled with the self-(in)compatibility phenotype of quinces. SSR markers proved unable to differentiate putatively closely related cultivars (e.g. ‘Bereczki’ and ‘Bereczki bôtermő’). In general, the level of polymorphism among the tested quince genotypes was much restricted due to the low allele number detected. However, it must be considered that the number of analysed SSR loci is not enough high to estimate the overall heterozygosity of the quince genome. Further experiments are needed and the SSR markers proved to be a reliable and useful tool for such analyses.
Nectar production of six quince cultivars were measured during three consecutive years. The nectar production of quince can be regarded to be small compared to other temperate zone fruit tree species since quince flowers contained 1.07 ± 0.06 mg of nectar in average. The extreme values, however, ranged between 0.1 and 7.3 mg/flower and this indicated that the nectar production was highly variable. The distribution of the nectar production was definitely skew because low values were definitely much more frequent than the highest ones. Our findings do not corroborate the earlier statements on the high sugar concentration of quince nectar. We found some 21-27% sugar in average, only. The normal distribution of the sugar concentration also indicates that the typical sugar concentration may be between 20-30%. Accordingly, the sugar concentration of quince nectar is rather low compared to other temperate zone fruit tree species (except pear). There was a significant negative correlation between the amount of nectar and its sugar concentration in quince flowers in all of the three years of the study (r= -0.51, n=37, p<0.02 in 1996, r= -0.57, n=28, p<0.1 in 1997, r= -0.35, n=9 I, p<0.001 in 1998). No definite difference was established between the nectar production of quince cultivars. Nevertheless, one cultivar tended to produce less and two other ones produced somewhat more nectar in average than the rest of the 6 cvs investigated but the extreme values of nectar production of cultivars overlapped in most cages.
The effect of the partial and/or complete limitation of the insect (bee) pollination period was studied in three consecutive years at 6 quince cultivars. Quince is greatly sensitive to the limitation. Complete limitation of insect pollination resulted in no yield and also a partial limitation of the insect pollination period (exclusion of the bees at the first or at the second half of the blooming) depressed the final set and the yield by 60-70% at least or more, sometimes down to no yield. No real correlation was found between the mean mass of fruits and the fruit set. The mass of fruit seems to be rather a character of the cultivars. A loose but significant correlation was established between the intensity of honeybee visitation and the consequent yield of quince. As much as some 4-5 and 8-10 honeybee visits are needed a day on one flower to achieve the required optimal fruit set that has been declared to be 20-25% for quince in the literature. These are extremely high bee visitation figures, accordingly, no doubt the commercial quince plantations require much higher number of honeybee colonies than other temperate zone fruit tree species to supplementary pollination
Quince (Cydonia oblonga Mill.) has been long regarded to be a health-promoting fruit. Although it is mainly consumed in processed form, its relatively heat-stable polyphenolics were confirmed to be responsible for most of the beneficial effects. This review aims to show basic nutritional information on quince fruit such as carbohydrate, fibre, pectin and mineral element contents. In addition, vitamin and polyphenolic contents and composition as well as the physiological effects of quince consumption were also surveyed. Information on presumable protective effects against several diseases including infl ammation, atopic dermatitis, ulcers and cancer is summarized. Potential antibacterial effects of quince polyphenolics were also considered. Polyphenolics are supposed to be responsible for the major part of benefi cial health-effects, and phenolic compounds predominantly accumulate in peel. There exists a considerable extent of genetic variation in phytochemical composition among cultivars, which might be exploited in designing future breeding programs for quince improvement and opening new ways for health-related uses.
Fruits of twelve quince (Cydonia oblonga Mill.) commercial cultivars and selections were compared in the ferric reducing antioxidant power (FRAP) and total phenolic content (TPC) of intact and peeled fruits. The antioxidant capacity and total phenolic content ranged between 5.99 and 63.10 mmol AA/100 g FW, and 3.92 and 12.83 g GA/100 g FW, respectively. These ranges cover an almost 8-times variation among the tested genotypes in case of antioxidant capacity and also declares two-times variation for total polyphenolic content. Cultivars ‘Aromate’ and ‘Bereczki’ possessed the lowest antioxidant capacity and ‘Román portugál’ and ‘Bereczki’ had the lowest polyphenolic contents. In contrast, cultivars ‘Champion’ and ‘Konstantinápolyi’ possessed the highest antioxidant capacity and ‘Mezôtúri’ and ‘De Husi’ had the highest polyphenolic contents. The Pearson’s coeffi cient was relatively moderate but signifi cant (r=0.51) indicating a weak interdependence between FRAP and TPC values of quince fruits. Our results led us to the conclusion that quince might be considered as a valuable source of antioxidants and polyphenolics.
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.
Literature dealing with flowering and fertilisation of quince is scarce. Most controversial and scanty are informations on observations of self- and cross-pollination. According to our observations, differences in blooming time are few (2-3) days only, thus flowering of most varieties is synchronous. The varieties observed are grouped as early, intermediate and late flowering ones. Self fertility of the individual varieties, however, was not assessed unequivocally, therefore it is recommended, by safety reasons, to consider quince actually as a whole to be auto-incompatible. Artificial self-pollination (or rather geitonogamy) as well as cross pollination with other varieties increased substantially fruit set if compared with the results of natural self-pollination (autogamy). According to the fruit set of their open pollinated flowers, varieties have been classified according to fertility as low (below 10 %), medium (between 10 and 20 %) and high (more than 20 %). Cross fertility of varieties is highly variable depending on combination and on season. Contradictory data are probably due to the sensitivity of quince to conditions of search. Better fruit set was coincident with higher number of stout seeds per fruit. Well developed seeds are definitely a prerequisite of larger fruit size.
In the small demonstration orchard of the College Faculty of Horticulture at Kecskemét the blooming time, the flower density and the honeybee activity was observed at a number of cultivars of 20 flower species during four consecutive years.
Fruit crop species were in flower during 3-4 months altogether. The blooming period of them was classified into five groups as early (almond, apricot, gooseberry), middle early (sweet cherry, red currant, currant-gooseberry, black currant, white currant, peach, plum, sour cherry), middle late (pear, strawberry, apple), late (black elder, quince, medlar, raspberry, blackberry-raspberry) and very late blooming period (blackberry). The blooming period of the members of the groups of early and medium early blooming often coincided partly and the same happened between the medium and the medium late as well as between fruits of late and very late flowering.
The flower density of some fruit species is extremely variable (currant-gooseberry, medlar), while at others it is fairly stable and evenly dense in consecutive years (sour cherry, sweet cherry, strawberry). At other fruit species it is moderately changeable. Some fruit species tended to attract more honeybees than others (plum, apple, quince, medlar) and some of them tended to attract much less (black elder, pear) but most species can be regarded as of medium attractivity.
On the flowers of some fruit species (pear, strawberry, quince) honeybees gathered pollen predominantly. At most fruit species however pollen and nectar gathering behaviour seemed to be gradually changing during the season. Namely most honeybees tended to gather pollen at the flowers of the early blooming fruit species, but on the other hand typical foraging behaviour gradually shifted to nectar gathering at the flowers of fruit species of moderate and late blooming periods.
The plantation of intensive growing orchards and steady increase in yield is essential to return the growing cost by sale. Seasonal crop fluctuation of pear is increased by the frequently occurrence of drought and climatic changes. This study reviews genetic and growing factors determined the alternancy of pear and present the new knowledge concerning on water saving irrigation techniques. Use of dwarfing rootstocks, root pruning, branches pruning and new water saving irrigation make the changes in vegetative and generative growth that successfully improve the alternancy of pear growing. According to publications BA 29 of clonal quince rootstocks exhibited the best protection mechanism against to drought. Regulated deficit irrigation (RDI) applied during rapid shoot growth and slowly fruit growth result a decrease in shoot growth and 60% of water saving in pear orchard while there was no influence on harvested yield. Partial rootzone drying (PRD) microjet irrigation applied in pear orchard result 23-52% of decrease in water use, however concerning explorations are contradictory. Further investigations need to improve the efficiency of new irrigation technology adapted pear varieties based on monitoring of soil water status and measurement of stem water potential as stress indicators of plants.
In the Carpathian basin there are still maintained the main historical fruit varieties and traces of traditional farming. The Department of Fruit Science considered the utilisation of obsolete varieties in breeding as source of resistance to local adversities, moreover, the practice of traditional .farming using those varieties should be also explored. In the present study, the farming methods and variety structure of two substantially different growing sites are described. One is an alluvial plain along a river were an ancient form of farming based on the control of sluices. The second is practised by clearing the forest on the slopes of the central range and of the Carpathian chain. During the course of our research we succeeded to find 8 pear, 29 apple and a few quince as well as medlar varieties. Further endeavour would be the conservation of those varieties, preferably on the spot together with their growing techniques as relicts, also as aesthetic components of that particular landscape. Our committed partners in this work are the National Parks.
Size and surface morphology of pollen has been studied in 87 twit varieties of 10 fruit species during the period of 1990-1995. No preceding work of that type came to our knowledge, yet.
The samples comprised a wide variety of cultivars included male sterile, self-incompatible, partially self-fertile stone fruits, diploid and hexaploid plums, diploid and triploid apples.
The large number of species and varieties facilitated the comparison of items within and between the respective species.
It was stated that the size, shape and surface morphology of pollen is genetically determined and those data, combined with other variety characters, are suitable for the classification and distinction of varieties.
In assessment of pollen size and shape, their moisture content is crucial. The major diameter of the swollen pollen as well as the length and width of the dry grains are characteristic to species and/or to variety.
The width and shape changes largely with moisture content. Large grains are proper to quince, apricot, peach and almond, medium sizes are found in apple, sweet cherry, sour cherry, European plum, whereas small size is typical to Japanese plums.
The low number of varieties studied does not allow conclusions concerning differences within pears, quinces and almonds as species. In the rest of species, valid differences have been registered as between varieties.
Within species, as apple and plum, the effect of ploidy (i.e. number of chromosomes) was expressed in the size of their pollen. In stone fruit species, the correlation between size. of anthers and size of pollen grains was positive.
Genetic relations between the self-fertile sour cherry varieties of the Pándy type (Debreceni bőtermő, Kántorjánosi, Újfehértói fürtös) as well as the self-incompatible apricots of "giant" fruit size are supposed to be analysed by pollen studies but there did not turn out any decisive conclusion, yet. Other characters also should be considered.
The assembly of pollen characters is decisive in the determination of the variety. The ratio of empty pollen grains, the grain size and the density as well as the size of the pits on the surface are best suited to distinguish pollen lots.
Larger cuts made during the winter pruning of pome fruit orchards a number of serious problems: the wounds serve as entrances for several branch-infecting pathogens, the numerous water shoots formed around the cut edges consume assimilates, shade the developing fruits, make the canopy dense, reduce the effectiveness of the pest management and cause extra work during next seasons pruning work. These problems can be eliminated by using proper wound protectants, like Relaco, a new Romanian wound protectant to cover larger pruning cuts of apple, pear and quince trees.
The treaments by Relaco resulted in a significant decrease in both the number and total length of water shoots formed around the cut egdes.
The duration of effective bee pollination period was limited by caging flowering branches for shorter or longer time in blooming fruit trees in a number of experiments during the past decades. In the case of self-sterile fruit species and cultivars (apples, pears, quinces, some plums, some sour cherries) even partial limitation of the effective duration of bee pollination period significantly reduced the fruit set and the yield. In the case of self-fertile apricots the effect of the total and also the influence of partial limitation of bee pollination period was the same as in the case of the mentioned self-sterile fruits. On the other hand, in the case of another self-fertile fruits (some plums, some sour cherries), the effect of partial limitation of bee pollination period was usually small, but complete (or incomplete but strong) limitation of be pollination usually resulted in a strong reduction of yield. This means that not only self-sterile but also self-fertile fruits clearly depend on insect (bee) pollination. This is because pollen dehiscence of anthers and the receptive period of stigmas do not overlap in time within the individual flowers. Stigmas in self-fertile trees, therefore, need pollen carried by bees from another flowers of the same tree (or compatible pollen from another trees). Accordingly, additional bee pollination (moving bee colonies to the orchards in flower) is needed to all kinds of temperate-zone fruit tree species when bee visitation of plantations is not abundant enough for some reasons.
In the past decades fruit production has become more and more intensive and so the interest towards the bee pollination of fruit trees has increased in Hungary. Thus insect pollination research has become more intensive in the eighties and in the nineties. Recently, high density fruit orchards are planted of dwarf trees at more and more farms in Hungary and these need highly controlled growing practices involving insect pollination, too. This is a new challenge of insect pollination research in Hungary. So it seems to be worth to compile a list on research publications having been appeared so far to create a basis to the ongoing new research. Besides papers strictly on the insect pollination of fruit trees publications on some closely related topics, first of all on the nectar production and on other flower characteristics of fruit tree cultivars that directly influence bee activity have also been included on the list.
Results of our experiments prove that pear is more or less sensitive to the reduced bee pollination period. However, the reaction (or the sensitivity) of cultivars may be different to the reduced bee pollination. Most cultivars produce much less yield under reduced bee pollination or no yield with the exclusion of bees but in the case of some cultivars total exclusion of bees does not prevent the yield formation and what is more sometimes reduced bee pollination can be resulted in somewhat higher yield than open pollination. Typical reaction, however, is a significant yield reduction with reduced bee pollination. Pear seems to be somewhat less sensitive to the partial reduction of bee pollination period than apple or quince. The first half of the flowering period seems to be more important in yield formation because usually higher yield was resulted when pear cultivars received open pollination in the first than in the second half of the blooming period. Based on our experimental results no definite relationship between parthenocarpic capacity of cultivars and the yield under reduced bee pollination can be established. So reduced bee pollination does not seem to contribute the parthenocarpic fruit formation in pear.