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Irrigation of pear (A review)
65-73.Views:178The 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.
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Actual state of research concerning vitamin C as reflected in the literature (Review article)
7-15.Views:173Vitamin C (L-ascorbic acid) being essential for many living organisms, including man, became once more into the focus of interests because of its numerous physiological effects. Its anti-scurvy and anti-oxidant properties have already been recognised since long in the human body, but it turned out gradually that it has many other functions. In plants, its primary importance is defense against the photo-oxidative stress.
The present review is intended to reveal some details of the artificial synthesis of vitamin C. Emphasis is put on the metabolism of L-ascorbic acid in higher plants. Biosynthetic processes, translocation and accumulation are discussed in detail on the basis of recent results published in the scientific literature.
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Studies on the drought responses of apple trees (Malus domestica Borkh.) grafted on different rootstocks
29-36.Views:371The morphological and chemical changes in the leaves of eight apple varieties grafted on M4, M26 and MM 106 rootstocks were examined during fruit development in non-irrigated plantation. The aim of the experiment was to examine the defensive mechanisms in apple trees under the mild and serious dryness occurring during fruit development. The content of a relative chlorophyll (SPA D value) of the apple leaves on eastern side of the trees was lower than western and southern sides under drought occurring du ring fruit devclop111ent Under sustained drought from first of July to August the SPAD value, the weight of leaves were larger and the stomata density was significantly larger than in the previous periods. There was a close positive significant correlations bet ween SPAD and stoma density both in the group with less sensitive to drought (r=0,8429) and in the large water demanded group (r=0,9209) equally. The rate of increase in SPAD values and the stoma density was slower in the group with drought tolerant, than in the group required good water supply. The varieties being sensitive to water deficite such as Akane. Pink Lady and Red Rome van Well have a l ready responded intensively to short time of drought by the increasing of carbohydrate and antioxidants product ions. At 42 days of sustained drought as soon as the level of carbohydrate in the leaves decreased, the antioxidant s contents of the leaves rised suddenly in the apple varieties with moderate water requirement s as Greensleeves and ldared. Gala apple variety seemed to be able to defend the drought for longer time because there was no change in relatively high level of carbohydrates and antioxidants of their leaves under severe drought during fruit development.
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Fruit drop: II. Biological background of flower and fruit drop
103-108.Views:294The 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.
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Erratic fruit set in almond under warm climates
59-64.Views:256The 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. -
Identification of ripening-related genes in strawberry fruit by cDNA-AFLP
33-41.Views:150An RNA fingerprinting study of strawberry receptacle and achene tissue was performed to identify candidate genes involved in fruit ripening. Quantitative cDNA-AFLP was used to detect differential gene expression in green, white, pink and red stages of fruit ripening. Based on hierarchical average linkage clustering the differentially expressed genes formed three major groups, genes expressed only in green receptacle, genes expressed mainly in white, pink and red receptacle, and in achene. 130 transcript-derived fragments (TDFs) were isolated and sequenced. Most TDFs did not show any homology to sequences with known functions, others were homologous to genes involved in oxidative stress response, signal transduction, regulation of development and cell-wall metabolism. Novel genes, so far not associated with strawberry ripening and ripening in general, were identified, such as genes encoding a bHLH protein, putative nitrilase-related protein, putative HD-zip protein. The differential pattern of gene expression draws the attention to the significance of ripening induced-or repressed promoters in strawberry fruit, whose isolation and characterization can be useful tool for functional genomics. For this purpose nine cDNA-AFLP fragments related either to ontogeny or senescing were completed with 5'UTR aiming at more precise annotation and future promoter isolation. Although tens of potentially important transcriptome changes were identified, the function of many ripening induced genes remain unknown.
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Mathematical and Statistical Modelling of Impact Symptoms and Application to Tomato
75-80.Views:104Drop tests were performed with different tomato cultivars. „Rupture" and „no rupture" conditions were determined as results. The proportion of „rupture" was shown versus the drop height and the relationships were described by a logistic function. The different cultivars are compared on this basis. The tests and results are suitable for the evaluation of stress sensitivity of tomatoes.
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Importance of orchard floor management in organic fruit growing (nutritional aspects)
61-67.Views:273Worldwide research goals and concerns are to soil conservation and improve. This conception is mostly actual in horticulture where the numbers of high-density plantings are continuously increasing. High-density orchards cause more intensive nutrient and water uptake. So that the preservation of soil moisture and nutrient level are key factors in qualified fruit growing. On the other hand due to the climatic changes the water supply of trees will be satisfied among worse conditions than some decades ago. Appearance of water supply problems and water stress is increased in organic growing, where the number of corrections is limited anyway. Furthermore, floor management is a successful tool in weed management which causes many problems for organic growers due to the prohibition of synthetic herbicides. This paper will mainly focus on the nutritional aspects of methods of orchard floor management for growers adopting organic fruit management to make their production profitable.
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Comparative study of three rosemary (Rosmarinus officinalis L.) clones during the growing season
67-72.Views:153The 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.
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Microclimatic studies on different aged apple plantations
7-11.Views:189The purpose of measuring parallel canopy and out of canopy microclimates was to find out in what extent climatic parameters measured in different aged canopis differ from each other and from the values characteristic to out-of-canopi areas. The importance of phytoclimatic researches seems to lie in the fact that if the reactions of fruit trees towards meteorological elements are continuously followed, we have the possibility to provide growers with information. These pieces of information are like defining the optimum time of phitotechnical interventions (summer pruning, sorting sprouts, thinning fruits, etc.), the necessity of applying mulching, defining the method and time of irrigation and applying plant protection activities. By means of phytoclimatic researches, it is possible to react to unfavourable meteorological impacts within a certain extent. It is also possible to successfully reduce the risks of late spring and early autumn frost damage, as well as the risks, content and measure of experienced heat and water stress conditions by finding out about the physical characteristics of the canopis' internal area.
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Dynamic analysis of a simple fruit tree structure model
53-55.Views:120The effect of shaker harvest on root damage was studied on a simple tree structure model. Equations were set up to be able to calculate the relation between shaking height and stress in the roots. To get the strain at break data field experiments were carried out. The acceleration versus time curves were recorded on different heights of the stem. Evaluating measured and calculated data it can be concluded, that the risk of root damage increases when
- the height of shaking is decreased,
- the stern diameter is smaller, and if
- the unbalanced mass of the shaker is increased.
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Precision geoinformatical system of the pear gene-collection orchard
43-50.Views:202The principle task of the sustainable development is the preservation of the genetic variety, which is similar challenge in the horticulture regarding the sublimation of fruit species. The breeders of the traditional fruit strains give stock to the sustenance diversity of the agro-environment on the species and landscape level. In 2009, hyperspectral images have been taken by AISA Dual sensors from the pear gene pool in Újfehértó, Hungary. The hyperspectral data cube (in the wavelength range of 400-2500 nm, with 1.5 m ground resolution) ensured possibility to make the spectral library of pear species. In the course of the simultaneously field work the spatial position and individual extent of all pear trees was defined to set up a detailed GIS data base. The water stress sensitivity of single species and the descriptive spectral curves were determined with common evaluation of the spectral and spatial data. Based on the unique methodology processing and the hyperspectral data base suitable strains can be chosen for agro-environment and let take adaptive stocks regarding climate change into the genetic grafting work. Furthermore we could determine and map the sparsely species in the region with the help of the hyperspectral data.
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Evaluation of the vegetative and generative performance of new apple cultivars in the Nyírség region
39-44.Views:221In this paper we examine apple varieties, which are planted expansively in the development apple orchards of the Western- European countries, but about its production characteristics we don’t have or just few practical experiences in Hungary. These varieties can be described with regular and high yields, aesthetic and alluring appearance in their origin places, what ensure profitable producing for the growers. Under the Hungarian climate which tends to be often extreme (hard cold winters, late spring frosts, summer drought, heat stress) these varieties may behave differently, so before the substantial planting it is expedient to carry out variety evaluations to avoid the later failures. The place of our experiments is located in the Nyírség representing adequately the ecological conditions of the surrounding areas, so the gained results can be adapted easily in the biggest apple production site of Hungary. Regarding the vegetative and the generative parameters of the 14 examined varieties (’Gala Venus Fengal’, ’Gala Decarli-Fendeca’, ’Galaval’, ’Jugala’, ’Gala Schnitzer (S) Schniga’, ’Red Cap Valtod (S)’, ’Early Red One’, ’Jeromine’, ’Crimson Crisp (Co-op 39)’, ’Red Topaz’, ’Wilton’s Red Jonaprince’, ’Red Idared’, ’Fuji September Wonder’, club cultivar) we found significant differences. The ratio of the thickness of trunk and the main branches showed that the trees have an optimal canopy structure in accordance with the Zahn principles, so they are in harmonious growing balance. The ‘Gala’ sport trained to slender spindle produced the highest yields, while the ‘Fuji’ and the ‘Red Delicious’ sport trained to super spindle can be described with the lowest values. All the cultivars reached the eating quality (65-70 mm), from which the ’Red Idared’, the ’Red Jonaprince’ and the ’Red Cap’ produced outstanding fruit size (81-85 mm).
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Study of genetic resources for Powdery mildew resistance by biochemical and physiological parameters on peaches and nectarines in Romania
57-61.Views:122During 1997-2002, studies on the physiological and biochemical changes due to powdery mildew attack in peach and nectarine cultivars and hybrids belonging to different classes of resistance had been performed at the Research Station for Fruit Tree Growing (RSFTG) Baneasa Bucharest, located in the southern part of Romania. The study was based on disease assessments in the field and on other diagnosis criteria.
The southern part of Romania has favourable ecological conditions for growing peach and nectarine but trees have been attacked by various pathogens such as Sphaerotheca pannosa (Wallr.: Fr.) Lev. var. persicae Woronichin fungus for a long time. The presence of the pathogen causes important changes in the quantity and quality of fruits and affects the metabolism of trees.
This study was focused on several physiological and biochemical parameters such as photosynthesis and respiration intensity along with catalase activity; and changes in some biochemical compounds such as free, total and linked water content, dry matter, nitrogen and protein content, tannin levels. The aim was to find possible correlation among the above parameters and the biotic stress induced by the powdery mildew fungus calculated as attack degree (AD%).
Results showed that photosynthesis diminished significantly in the case of the attacked phenotypes, the respiration was more intense in the infected cultivars and catalase proved to be less intense in the affected plants. The total water content significantly increased in contrast to the dry matter and tannin contents, which greatly reduced in the case of resistant cultivars such as 'Victoria', Vectared 7', 'KB 11-40'. The total nitrogen and protein levels showed less influence on resistance to powdery mildew on all cultivars. All genetic material found resistant to powdery mildew is currently used in peach and nectarine breeding programs in Romania.
Further studies focused on isolation and characterization of resistance genes for powdery mildew resistance will be done in the future based on data collected during several years.