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The effect of nitrogen supply on specific yield and fruit quality of apple (Malus domestica Borkh.)
7-21.Views:191The 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.
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Luminescence variations in cucumber (Cucumis sativus L.) leaves derived from different regeneration systems
50-52.Views:157Plants obtained from in vitro culture can show increased susceptibility to environmental stress conditions. In the process of their adaptation to natural conditions it requires monitoring of their physiological state. The methods used to check this phenomenon should estimate quickly and exactly the tolerance to suboptimal environmental factors. Such requirements are satisfied by the methods of measuring chlorophyll luminescence in vivo, e.g. fluorescence induction and delayed luminescence. The objects of our studies were cucumber plants regenerated from cultures of callus and embryogenic cell suspension, as well as the plants obtained from seeds. The plants derived from in vitro cultures displayed a poor physiological condition at the early phase of adaptation characterised by higher susceptibility both to stress caused by increased density of the light flux and low temperature (4 °C) in comparison with the plants obtained from seeds.
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Development in intensive orchard systems of cherries in Hungary
76-86.Views:317High 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.
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In vitro regeneration from cotyledons of watermelon
96-98.Views:166Cotyledonary segments of five different genotypes of watermelon were used to induce organogenesis. Five different hormone combinations were applied to enhance the induction of shoot formation on the surface of the segments. The phases of organogenesis were followed with light and scanning electron microscope. Shoots were obtained after four weeks, then the shoots were transferred to hormone free medium for root induction.
This method of regeneration can be applied in transformation experiments. GUS histochemical assay was made to check the expected success of using Agrobacterium for the transformation.
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Anatomical relations of root formation in strawberry
71-75.Views:176Anatomical relations of root formation are traced throughout the life cycle of the strawberry plant from the germinating seed up to the runners of the adult plant. Histological picture of the root changes a lot during the development of the plant. First the radicle of the germ grows to a main root, which makes branches into side roots and later adventitious roots are formed on the growing rootstock or rhizome. The anatomy of the different types of roots is also conspicuously different. First tiny branches appear relatively early after germination on the seedling's radicle, but soon the hypocotyl of the seedling thickens and develops side roots, which are already somewhat stronger. During this interval, the first true leaves are formed. The 4th or 5th of them being already tripartite, and the initiation of new roots extends into the epicotylar region of the shoot. The second years growth starts with the development of reproductive structures, inflorescences and runners starting from the axils of the new leaves. Near the tips of the runners below the small bunch of leaves, new root primordia are initiated. The tiny radicle of the germ develops a cortical region of 5-6 cell layers. Cells of the central cylinder are even smaller than the cortical parenchyma and include 3-4 xylem and 3-4 phloem elements as representatives of the conductive tissue. Roots originating from the shoot region are much more developed; their cortical zone contains 17-20 cell layers, whereas the central cylinder is about half as large. In the next year, new roots are formed at the base of the older leaves. These roots differ hardly from those of the last season in size and volume, however, they are recognised by colour and their position on the rhizome. The roots of the last year are dark, greyish-black, and grow on the lower third length of the rhizome, on the contrary, the new ones, on the upper region, are light brown. Roots starting from the shoot or rhizome are, independently from their age or sequence, mainly rather similar in size and diameter, thus being members of a homogenous root (homorhizous) system, i.e. without a main root. Plants developed and attained the reproductive phase develop in the axils of the leaves runners being plagiotropic, i.e. growing horizontally on the surface of the soil. The runners elongate intensely, become 150-200 mm, where some long internodes bear a bunch of small leaves and root primordia on short internodes and a growing tip. Runners do not stop growing, generally, further sections of 15-25 cm length are developed according to the same pattern, with small leaves on the tip. The growing tip of the runners is obliquely oriented, and small, conical root primordia are ready to start growing as soon as they touch the soil. The roots penetrate the soil, quickly, and pull, by contraction, the axis of the runner downwards, vertically, developing a new rhizome. The short internodes elongate a little and start developing adventitious roots. At the end of the growing season, the plantlets arisen on the rooted nods of runners are already similar to the original plants with homogenous root system. On the side of the adventitious roots, new branches (side-roots) are formed. The root-branches are thinner but their capillary zone is more developed being more active in uptake of water and nutrients. The usual thickening ensues later.
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Comparative anatomical study of leaf tissues of scab resistant and susceptible apple cultivars
43-45.Views:182According to previous studies some anatomical features seem to be connected with resistance or susceptibility to scab caused by Venturia ineaqulis (Cke./Wint.) in case of a given cultivar. Study of leaf anatomy of three scab resistant (‘Prima’, ‘Florina’, MR–12) and two susceptible (‘Watson Jonathan’, ‘Golden Delicious Reinders’) apple cultivars have been made. Preserved preparations made of leaves has been studied by light microscope. Studied parameters were: thickness of leaf blade, thickness of palisade and spongy parenchyma, thickness of epidermal cells, thickness of the cuticle. By measuring leaf thickness and epidermal cell thickness visible differences appeared in certain cultivars, while most conspicuous difference has been shown in thickness of the cuticle.
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Recent findings of the tree fruit self-incompatibility studies
7-15.Views:205This review endeavours to collect all recent and substantial contributions to the quickly deepening fields of tree fruit self-incompatibility studies and hence updating previously published reviews. Studies carried out to discover the molecular basis of gametophytic self-incompatibility are summarized and a newly described model for the solanaceous plants is also outlined. We describe recent findings in all economically important fruit tree crops involving apple, European pear, sweet and sour cherries, almond, Japanese plum, sloe, Japanese apricot, European apricot and peach. Additional DNA sequences are now available for both the pistil and pollen component genes in several species and their molecular, evolutionary or economic implications are discussed in the light of the fruit setting behaviour.
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Morphological characterization of shallot (Allium cepa L. var. aggregatum) segregating populations obtained from natural-outcrossing in Ethiopial-outcrossing in Ethiopia
74-83.Views:2Shallot is a vegetable and condiment crop widely used in Ethiopia and globally. However, absence of improved and adaptable varieties has been the major cause of low productivity. Narrow genetic base of local shallot germplasm owing to vegetative reproduction of the crop, among others, has been the root cause of low productivity. Nevertheless, some plants within the germplasm were observed bolting and producing viable seeds, presenting an opportunity for genetic diversification. Consequently, a germplasm enhancement program was initiated using these naturally outcrossing genotypes where about eighty-one genotypes were generated. The present study was thus undertaken with the objective of characterizing, classifying, and selecting the eighty-one genotypes for future breeding activities. The genotypes were planted in 9x9 simple lattice design with two replications at Debre Zeit Agricultural Research Center (Ethiopia) during the dry (irrigated) season of 2021. The genotypes were evaluated for fifteen growth, yield, and quality traits. Significant variations were observed among the genotypes in terms of bulb yield, bulb height and diameter, total soluble solids, bolting percentage, and bulb skin color. Bulb yield of the genotypes ranged from 31.33 t/ha in DZSHT-79-1A to 9.63 t//ha in DZSHT-45-1A-1. DZSHT-51-2 (207.93 g) was the highest yielder per plant whereas DZSHT-065-6/90 (74.51 g) was the lowest yielder. DZSHT-14-2-1/90 had the thickest bulb (44.69 mm) significantly thicker than twenty two genotypes which had bulb diameter ranging from 28.92 mm to 20.29 mm. DZSHT-81-1/90 was a genotype with the longest bulb height (52.33 mm) while DZSHT-147-1C was a genotype with the shortest bulb (33.12 mm). DZSHT-307-1/90 had the highest TSS (16.78°Brix) significantly differing from DZSHT-002/07 which had the lowest TSS (11.17 °Brix). Dry matter of the genotypes ranged from 12.00% to 22.79%. DZSHT-004/07, DZSHT-111-2-1, DZSHT-41-2B and DZSHT-72-2 had DM% greater than 20% which coupled with greater than 14 °Brix could make them suitable for dehydrated shallots. Among the 81 genotypes characterized 4 (4.9%), 7 (8.6%), 13 (16.1%), 28 (34.6%) and 29 (35.8%) were yellow, golden, light red, red and dark red in colour, respectively. Fifteen of the genotypes had at least 50% bolting plants whereas twenty nine of the genotypes had less than 25% bolting. The results revealed that seven principal components explained approximately 76% of the observed variation. Cluster analysis grouped the genotypes into seven clusters, with the majority falling into three clusters. The study successfully identified genotypes with diverse and important traits and availed both the genotypes and the information for future breeding programs. These genotypes could be used for the development of improved hybrid and open pollinated shallot varieties with higher yield, quality and pest resistance/tolerance attributes.
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Experiments on the Resistance or Pepper Cultivars to Macrophomina phaseolina
74-75.Views:124The ashy stern blight of pepper (Capsicum annuum) is often caused by Macrophomina phaseolina. Serious wilt disease occurred between 1994 and 1996 of pepper plants in Hungary. In 1996-98 screening experiments were made on many pepper cultivars. Culture (Knopp) solution experiments, pot experiments, greenhouse and field trials were carried out. We determined the incidence of disease by visual examinations, testing on PDA culture, and light microscope. There were significant differences in susceptibility of cultivars and breeding materials.
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A study of processes active in regeneration of different sweet cherry varieties
55-57.Views:217Cherries belong to the group of fruit trees, which require little attention in pruning. The process of getting bald branches is less accentuated, which is associated with the light requirement of organs changing along with the aging process. The growing habits of the varieties (length and number of growing shoots, etc.) is closely related with the productivity of fruiting parts. The ability of regeneration and the functional effectiveness of fruiting structures are expressed by the distribution according to their age. The differences registered justify the necessity to develop pruning policies for each particular type of variety. For that purpose, we have to examine the age dependency of the processes related to regeneration, which may serve as starting point of a pruning strategy. Growth of some parts should be stimulated in order to develop or regenerate fruiting parts. Some branches need to be rejuvenated, partially, as an antidote to progressive senescence. Every intervention is aimed to strengthen the development of the most productive constructions. Reactions induced by rejuvenation should be expressed in fruiting intensity. A pruning program adapted to the particular variety as well as to the actual phase of a rotating pruning system should anticipate results.
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The effects of growth regulators in proliferation of Sorbus redliana 'Burokvölgy'
77-83.Views:203The Hungarian cultivar Sorbus redliana 'Burokvölgy' was proliferated on Murashige and Skoog (MS, 1962) medium with half-strength macroelements and 100 mg/1 meso-inositol, 20 g/1 sucrose, 11 g/1 agar-agar. Different combinations of kinetin (KIN), metatopolin (mT), benzyladenine (BA), benzyladenine-ribosid (BAR) and indolebutiric acid (IBA) were tested, and pH was adjusted to 5.6 every case using KOH. The cultures were incubated at 20-24 °C in 8/16 hours dark/light photoperiod for 50-52 days. The main aim of our research was to find the optimal growth regulator and its optimum concentration. Purthermore, to determine the chlorophyll contents of the in vitro propagated plants' leaves. During the proliferation, the highest number of shoots were observed in the case of using BA + IBA, and on the medium containing 0.75 mg/I BA + 0.05 mg/1 IBA 8.93 shoots were found. The addition of KIN + IBA decreased the number of shoots and increased the sizes of leaves — the widest (11.2 mm) and longest (17.8 mm) leaves were obtained on the medium containing 1.00 mg/I KIN + 0.05 mg/1 IBA. The longest shoots (36.46 mm) were found in the case of applying 0.75 mg/1 BAR + 0.05 mg/I IBA. The BA + KIN + IBA combination resulted the shortest shoots. Sometimes not only shoot regeneration but spontaneous rooting was observed during the multiplication. The highest chlorophyll content (1.569 mg/g total chlorophyll, 1.132 mg/g chlorophyll-a, 0.437 mg/g chlorophyll-b) was obtained in the presence of 1.0 mg/I KIN + 0.05 mg/1 IBA.
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Differences of pollen and pollenkitt attractiveness of some cultivated and ornamental apples for honeybees
145-150.Views:133Differences in the attractiveness of pollen according to plant families and species for the honeybees had been examined by researchers, but pollen samples of cultivars were not tested yet. This examination attempts to evalu2te the differences in attractiveness of pollen of some cultivated and ornamental apples to honeybees. We applied biotest with equal amounts of hand collected pollen samples and by a nucleus of bees with brood. The evaluation was based on the number of visitation by foraging honeybees on the samples during the time of the experiment which was determined. Pollenkitt samples were also tested in a separate experiment.
The data were analysed by variance analysis and significant differences were found according to the number of bee visitation in the attractiveness of the pollen and pollenkitt samples of apple cultivars.
The visualisation of pollenkitt was done by light microscope and SEM.
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New evaluation method to detect physiological stress in fruit trees by airborne hyperspectral image spectroscopy
37-40.Views:171Nowadays airborne remote sensing data are increasingly used in precision agriculture. The fast space-time dependent localization of stresses in orchards, which allows for a more efficient application of horticultural technologies, could lead to improved sustainable precise management. The disadvantage of the near field multi and hyper spectroscopy is the spot sample taking, which can apply independently only for experimental survey in plantations. The traditional satellite images is optionally suitable for precision investigation because of the low spectral and ground resolution on field condition. The presented airborne hyperspectral image spectroscopy reduces above mentioned disadvantages and at the same time provides newer analyzing possibility to the user. In this paper we demonstrate the conditions of data base collection and some informative examination possibility. The estimating of the board band vegetation indices calculated from reflectance is well known in practice of the biomass stress examinations. In this method the N-dimension spectral data cube enables to calculate numerous special narrow band indexes and to evaluate maps. This paper aims at investigating the applied hyperspectral analysis for fruit tree stress detection. In our study, hyperspectral data were collected by an AISADUAL hyperspectral image spectroscopy system, with high (0,5-1,5 m) ground resolution. The research focused on determining of leaves condition in different fruit plantations in the peach orchard near Siófok. Moreover the spectral reflectance analyses could provide more information about plant condition due to changes in the absorption of incident light in the visible and near infrared range of the spectrum.