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The effect of the limitation of insect pollination period on the fruit set and yield of temperate-zone fruit tree species
90-95.Views:141The 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.
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Field evaluations of 14 sweet cherry cultivars as pollinators for cv. Regina (Prunus avium, L.)
75-77.Views:218In this study, the pollen of 14 sweet cherry cultivars (‘Anella’, ‘Duroni 3', 'Badacsony', 'Cristalina', 'Ferbolus', 'Ferrovia',
'Georgia', 'Hudson', 'Kordia', 'Sam', 'Schneiders’, ‘Spate’, ‘Knorpelkirsche', 'Skeena', 'Summit', 'Sylvia') was used to fertilize the emasculated flowers of sweet cherry cv. 'Regina'. Fruit set was assessed three times during fruit development: 14 May, 30 May and 27 May 2007. We observed full incompatibility among the 14 cultivars for cv. 'Cristalina', which is in the same S-allele group as cv. 'Regina'. After analysis of our data, we have results about fertilization efficiency of the cultivars. Most of the evaluated cultivars are inadequate to fertilize cv. 'Regina' to a sufficient degree. There were two exceptions, cv. 'Sam' and cv. 'Skeena', where percentage of ripened fruits was above 20%. These two cultivars can guarantee such a pollination, which ensures ample quantity of ripened fruits. Results of this study have proved three other cultivars to be quite good pollinators for cv. 'Regina'. In conclusion, ideal pollinators for cv. 'Regina' could be — apart from above-mentioned two cultivars, 'Sam' and 'Skeena' — cvs. 'Sylvia' and 'Bianca', which was suggested by more literature sources.
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A simple model for fruit tree shaking harvest
33-36.Views:199A tree structure model was composed of trunk and main roots. It included a mass, spring and damping element, all of them reduced to the external end of the main roots. The model parameters, such as virtual turning centre, reduced mass, spring constant and clamping coefficient were measured on a real cherry tree. The model was than virtually shaken at 80 cm trunk height and acceleration and displacement amplitudes versus shaking frequency were calculated. The real cherry tree was shaken also at 80 cm trunk height by an inertia type shaker machine and the same data were recorded. The acceleration amplitude vs. frequency and displacement amplitude vs. frequency functions were similar for the virtual and real tree which proves the ability of the model. Power demand and specific power demand was then calculated in function of shaking frequency. The diagrams show that the shaking frequency of 12-14 Hz, of the practice is not the most efficient concerning amplitude, but is probably necessary from the point of view of acceleration needed to detachment of fruits.
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Experimental approach in apple tree nutrition
9-13.Views:123Authors present synthesis of experimental work, performed in the last decades, for better understanding nutritional behaviour of apple trees and related problems in fruit quality. There were evidences supporting possible deteriorating role of potassium in feeble physiological status of apples, if applied in excess. More intensive studies proved that higher potassium uptake into leaves and fruits might be also the result of increased sink power of individual fruits. Nevertheless early senescence of apples during storage and also sensibility to bitter pit were successfully related to the increased sink power of fruits, casual relations in excessive NPK fertilization, although increase in sink power need further investigations. Impaired weather conditions during early development of fruits, hostile orchard practices in pruning, thinning, irrigation and also unskilled application of growth regulators may also contribute in the enhancement of sink power and in weakened physiological status of apple fruits.
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Cracking susceptibility of sour cherry (Prunus cerasus L.) in Hungary and relation to calcium application
109-118.Views:282The rain induced fruit cracking is a big, serious problem especially for sour cherry growers but in some year sour cherry growers had also problem with fruit cracking caused by too much rainfall in the harvesting season. The cracked sour cherry fruits can be easily infected by different diseases like Monillinia sp. Cracked and infected fruits can not be transported for long distance and using for preservation because they lost their market value by the pour fruit quality. There are two possibilities to protect fruits against the rain induced fruit cracking. The most effective protection technique is the plastic rain cover over the tree rows. The installation of these equipments is too expensive for the growers. That is the reason why researchers tried to find other less expensive and sufficiently effective ways like sprayings different mineral salts, hormone and other type chemicals against the rain induced fruit cracking. Several calcium formulas calcium chloride (CaC12), calcium hydroxide (Ca (OH),) and calcium nitrate (Ca(NO3)2) can be sprayed in appropriate solution concentration.
The aim of our trial is to determinate the fruit cracking susceptibility of wide grown Hungarian sour cherry varieties and find the most effective calcium formula and its concentration for spraying in orchards to prevent the fruit cracking. In the first trial year (2006) cracking index of tested sour cherry varieties were determined under field and laboratory conditions. Under field conditions were not found differences between cracking tendency of tested cultivars. After results of immersing fruits in distillated water for 24 hours tested sour cherry varieties were divided to three groups by the susceptibility to rain induced fruit cracking: very susceptible (`Maliga emléke', 'Piramis', 'Érdi jubileum', 'Erdi nagygyümölcsű’ and 'Meteor korai'); susceptible ‘Érdi bőtermő, Tandy 279' and Cigány 59.; moderately susceptible/tolerant ("T" and "R" clones). In the second trial year (2007) calcium chloride (CaCl2) and calcium nitrate (Ca(NO3)2) were sprayed in 0,35m/m%; 0,5m/m% and 1,0m/m% solution concentration. One more commercial product "Damisol-Kalcium" was also applied in the advised 1,0m/m% concentration. Like in the trial year before (2006) under field conditions we did not kept differences between the cracking susceptibility of varieties and calcium treatments. As the result of laboratory testing (immersing calcium treated fruits in distillated water) we kept that calcium chloride (CaCl2) seems the most effective against the fruit cracking in 0,5m/in% solution concentration. The other calcium formulas also decreased the cracking ratio but in less scale.
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Fruit drop: The role of inner agents and environmental factors in the drop of flowers and fruits
13-23.Views:400The basic conditions of fruit set (synchronic bloom, transfer of pollen, etc.) still do decide definitely the fate of the flower (Cano-Medrano & Darnell, 1998) in spite of the best weather conditions (Stösser, 2002). Beyond a set quantity of fruits, the tree is unable to bring up larger load. A system of autoregulation works in the background and causes the drop of a fraction of fruits in spite of the accomplished fertilisation and the equality of physiological precedents (Soltész, 1997). There are also basically genetic agents in action. The further development of fruits maintained on the tree depends mainly on the growing conditions (e.g. water, supply of nutrients, weather adversities, pruning, fruit thinning, biotic damages, etc.), which may cause on their own turn fruit drop especially at the time of approaching maturity.
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Severely pollen-limited fruit set in a pear (Pyrus communis) orchard revealed by yield assessments and DNA-based paternity assignment of seedlings
67-74.Views:163In commercial fruit tree orchards, consistently high yields are necessary for a durable economy. The Swedish pear cultivar 'Carola' has been noted for low setting in some orchards, possibly due to insufficient pollination. In this study, fruit set was evaluated in a research orchard where `Carola' had been planted together with four potential pollinators. Total yield and number of fruits was noted during three and four years, respectively. In 2003, seeds were germinated from the harvested `Carola' fruits, and the paternity of three seedlings from 50 trees was determined with RAPD analysis. 'Clapp's Favourite' had sired 39.6% of the seedlings, closely followed by `Seigneur d'Esperen' (30.7%) and 'Clara Frijs' (26.7%) whereas 'Skanskt sockerparon' only sired 1.1% of the seedlings. The remaining 2.3% appeared to have been derived by selfing. Pollen-limited seed set was indicated at surprisingly short distances; accumulated number of fruits on the `Carola' trees was significantly higher when separated by only 2 m from one of the two most efficient pollinators, 'Clapp's Favourite' or 'Seigneur d'Esperen‘, compared to trees 4—l0 in away in the same row. Number of viable seeds per fruit was also higher in fruits from trees immediately adjacent to the pollinators, suggesting an effect of improved pollination success. The importance of very short inter-cultivar distances for efficient pollen transfer became even more clear when comparisons involved the true pollination distances as determined by RAPD; the accumulated yields decreased linearly from 55 kg at a 2 in distance to only 17 kg at 13 m.
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Fruit drop: I. Specific characteristics and varietal properties of fruit drop
59-67.Views:370The basic conditions of fruit set (synchronic bloom, transfer of pollen, etc.) still do decide definitely the fate of the flower in spite of the best weather conditions. Beyond a set quantity of fruits, the tree is unable to bring up larger load. A system of autoregulation works in the background and causes the drop of a fraction of fruits in spite of the accomplished fertilisation and the equality of physiological precedents. This study discuss this physiological process based on the international specific literature. The further development of fruits maintained on the tree depends mainly on the growing conditions (e.g. water, supply of nutrients, weather adversities, pruning, fruit thinning, biotic damages, etc.), which may cause on their own turn fruit drop especially at the time of approaching maturity.
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Specialities of the vegetation start and level of primary fruit set affect fruit quality
17-22.Views:165Thinning is a h ighly crucial point of the apple production technology. According to results of numerous studies the earliest thinning is deemed to have the best amending effects. There can be considerable difference between trees of the same cul tivar and age in a plantation in respect to their flowering, in the numbers of fruits set and also in their canopy volume. Thus it can be crucial -just l ike in the case of pruning- to establish a fruit thinni ng su i ted for specif ic characteristics of actual trees. This experiment was established to examine how does primary fruit set (fruit load before thinning) and further on specific (fruit/TCS cm2) and absolute (fruit/tree) fruit-load of the trees affect quality attri butes at harvest. Our experiment was establ ished in a plantation on medium-tight loamy soil in north-east of Hungary. Harvest date was determined w ith the joint observation of the calendar date, starch-index, flesh firmness, background colour and fruit weight. Three fruit-load levels were established based on local experience and on data of several years, I Ot/ha lower and higher besides the advised optimum yield in the same orchard with slender-spindle shaped 'Gala must' cultivar standing on M9 rootstock in 1m x 3,8 m spacing. In the establishment of the 15, 25 and 35t/ha fruit-load levels on 20-20 apple trees total number of fruits set was counted at each tree. After this number of apples due to be removed was defined using an objective index on the basis of trunk cross sections (fruit/TCScm2) (Lafer, 1999). The following attributes were measured: weight (g), flesh firmness (lb/cm2) total soluble solid content (Brix %) and total titrate-able acid content (g/J).From the data on sugar and acid content quality index (Pomona value) was determined (Thialult, 1970). We could ascertain, that in an orchard, of the same aged but in concern to trunk cross sections somewhat different trees besides the specific index (apple/TCS cm2 the absolute fruit load (fruit/tree) can also be an important data, that has considerable effect on the internal quality. Secondly we could observe, that higher level of fruit load before thinning (primary fruit set) negatively affects quality index of the apples irrespective of the specific fruit load level (fruit/cm2 TCS) set later. Results underlines necessity of the earliest chemical thinn ing.
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Interaction of nutrient supply and crop load of apple trees (Malus domestica Borkh.)
33-35.Views:148Long term fertilisation trials were combined with storage experiments with 'Jonathan' apple trees and fruits to study influence of tree nutrition on quantity and quality of crop. The site of experiments is a typical Carpathian-basin environment with loamy silt soil, high lime content and arid summers. Conclusions has been drown from six years' set of data. Augmented levels of soil fertilisation increased cropping capacity of apple trees, however, the fruit load has not met with cropping capacity in every year. More the def cit came into view in crop load, less the fruit quality resulted in. The deficit in cropping capacity, however, could not have been determined with simple rates as fruit weight per trunk circumference or similar. Better determination was obtained where foliar nutrient contents were correlated to crop per tree figures. In general terms, the N and Ca content in leaves increased with yields when K and P content formulated reciprocally. When storage quality of 'Jonathan' apple fruits were related to crop load (kg/tree), influence of crop deficit became visible. As the crop load and foliar nutrient levels interacted, the fruit quality (number of disordered apples after 6 month of storage) subjected of both physiological phenomena. Higher determination degree were obtained when crop load was assessed together with single or multiple foliar analysis data.
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Recent findings of the tree fruit self-incompatibility studies
7-15.Views:184This 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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Sampling experience in a cherry plantation
21-28.Views:196Experiments in a cherry plantation were performed to find out that samples taken from various parts of the foliage of the tree what extent represent the whole tree. One tree from three different cherry varieties was selected. In the selection, we tried to form a good representation of the foliage of the orchard. 8 sampling locations were designated on each tree, in two different heights and four different directions according to the points of the compass.We measured the main sizes of the fruits in three orthogonal dimensions with a digital slide gauge with an accuracy of 0.01 mm; the mass of each cherry by an analytical balance, with an accuracy of 0.001 g; the mass of the stones with the same analytical balance, and then calculated the stone-pulp ratio. The measured and calculated data are used to characterize the sample in question.
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Effects of crop load on tree water use in apple (Malus x domestica Borkh.)
29-31.Views:118Sap flow rate measurements were carried out during two consecutive ('on' and 'off') years in an apple orchard cv. 'Florina' M.26 to analyse the effects of various crop load on tree water use. Sap flow rate was measured by thermal dissipation method in trunks of nine trees from June to the harvest. Crop load was between 0.2-9.0 fruits • cm -2 of trunk cross section area (equal to 0.5-35.0 fruits•m-2 of leaf area), trunk diameter varied between 4.7-8.7 cm.
Total leaf area was estimated by leaf counting or using shoot girth and leaf area relationship. In both years, fruit growth rate was determined by measuring diameter of 280 marked fruits with 7 days frequency. Fruit volume calculated as a function of fruit diameter based on a previously determined relationship.
Total leaf area of trees ranged from 4.4 to 19.5 m2 and it was closely related to trunk cross section area. At high crop load the fruit growth rate peaked in August with 0.51.tree-l.day-1 and the leaf area specific total fruit volume reached 61 m2 before the harvest.
There was a linear relationship between total leaf area and daily water use, while the leaf area specific water use was influenced by crop load rate. The relationship was described by piecewise linear regression with the breakpoint at crop load rate of 12 fruits•m2 of leaf area. At low crop load the slope of the fitted regression line was less than at high crop load rate.
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Effect of the placement of self-incompatible apricot varieties on their yield in commercial plantations
82-86.Views:144Earlier 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.
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Floral biology of tree fruit rootstocks
153-161.Views:152The modern nursery industry requires seed sources of a high quality and regular quantity year by year. Besides the seed sources of processed cultivars (Bartlett pear, Shipley, Elberta peach) special seed orchards are planted with selected seed trees producing high quality and genetically determined seed (hybrid seed or inbred lines). Seedlings are still the most common commercial source of rootstocks for stone fruits (almond, apricot, peach, plum, prune and walnut). Although clonal rootstocks are spreading, usage of seedlings is still predominant at stone fruits and nuts. For successful seed production and planning of seed orchard the knowledge on floral biology, flower fertility, pollination, blossom time of trees (selected clone or cultivars) used for seed production is essential. In this field very little systematic research was carried out most of the papers were published in the second half of the 20th century. Our mini review gives an overview on the importance of flower fertility in the mating systems applied in seed orchards, and the research results on floral biology of fruit tree rootstocks propagated by seed (Prunus avium, Prunus mahaleb, Prunus armeniaca, Prunus cerasifera, Prunus insititia, Prunus amygdalus, P persica, P amygdalopersica, Pyrus pyraster, Pyrus communis and Pyrus betulifolia) over the last decades.
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S-locus genotyping on stone fruits in Hungary: a review of the most recent achievements
39-43.Views:200Central Europe can be taken as a geographical and historical connection zone between the western growing countries and Asian gene centres of Prunus tree fruits. The determination of the S-genotype of stone fruit (mainly almond, plum, cherries and apricot) cultivars and landraces has both practical and theoretical significance. Our group has allocated complete S-genotypes for more than 200 cultivars and selections of almond, Japanese plum, sweet cherry and apricot. Among Eastern European almond cultivars, two novel cross-incompatibility groups (CIGs) were identified. S-alleles of a related species were also shown in P. dulcis accessions; a fact seems to be indicative of introgressive hybridization. Our results with Japanese plum clarified and harmonized two different allele nomenclatures and formed a basis for intensive international studies. In apricot, a total of 13 new S-alleles were identified from Eastern European and Asian accessions. Many Turkish and North African cultivars were classified into new CIGs, III–XVII. Results suggest that the mutation rendering apricot self-compatible might have occurred somewhere in south-east of Turkey and we were successful to confirm the presumed Irano-Caucasian origin of North African apricots based on the geographical distribution of S-alleles. In sweet cherry, new alleles have been identified and characterized from Turkish cultivars and selections. In addition, wild sweet cherry and sour cherry S-alleles were also shown indicating a a broader gene pool in Turkey as compared with international cultivars. We also used S-genotype information of Ukrainian sweet cherry cultivars to design crosses in a functional breeding program. Our results exhibit an increased number of S-alleles in tree fruit accessions native to the regions from Eastern Europe to Central Asia, which can be used to develop S-genotyping methods, to assist cultivation and draw inferences for crop evolution.
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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.
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Analyses of temporal dynamics of brown rot development on fruit in organic apple production
97-100.Views:170In a two-year study, yield loss and temporal dynamics of brown rot development caused by Monilinia fructigena (Aderh. & Ruhl.) Honey were quantified and analysed in two organic apple orchards (Debrecen—Pallag and Debrecen—Józsa). The first infected fruits were observed at the beginning of August in both years and both locations, except for one occasion when the first infected fruit was found at the end of July. Temporal disease development was continuous up to harvest time in both years and locations. In the two years, pre-harvest yield loss on the trees amounted between 8.9% and 9.3% at Debrecen-Pallag and between 9.7% and 10.8% at Debrecen—Jozsa by fruit harvest. Incidence of infected fruits on the orchard floor ranged from 32.4% to 43.2% and from 53.3% to 61.9%, at Debrecen—Pallag and Debrecen—Józsa, respectively, by fruit harvest. Analyses of temporal disease progress showed that the best-fitted mathematical function was the power function in both orchards and years. Both parameters of the power function clearly demonstrated that incidence of brown rot on fruit increased faster on the orchard floor than on the tree. Moreover, the disease increase was faster at Debrecen—Józsa in most cases than at Debrecen—Pallag. Our results indicated that the strategy of disease management, the ripeness of the fruit and the presence of a wounding agent played an important role in the yield loss and in the temporal development of fruit disease incidence caused by M. fructigena in organic apple orchards. Biological and practical implications of the results are discussed.
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The impact of location, row direction, plant density and rootstock on the sunburn damage of apple cultivars
19-30.Views:220The effect of row direction (N-S, E-W), plant density (conventional and intensive) and rootstock (M9, MM106 and crab apple) on the sensitivity of 41 apple cultivars to sunburn injury was studied at 6 locations (Derecske, Kálmánáaza, Nagykutas, Nagylapos, Siófok, Tornyospálca).
During the observations the cultivars had rootstock-specific properties in respect of sunburn-susceptibility. Accordingly, the injury was decreased in the order: M9, MM106 and seedling rootstocks. The differences in sensitivity depend on the canopy of trees, caused finally by the growing vigour of rootstocks. Accordingly, the highest value of sunburn injury was observed on M9 rootstock, because this rootstock has a dwarfing effect upon the scion cultivars. Thus, vegetative area of these trees grow very slowly and the foliage is not enough compact to protect the fruit from solar radiation. The size and density of the foliage increased in the order: M9, MM 106 and crab apple seedling as rootstock. Moreover, relationships were demonstrated between the diameter of upper part of the crown, the leaf area, the number of fruits per tree and the injury of sunburn.
Authors categorized the cultivars in respect of values of sunburn incidence: 1. „Not sensitive", II. „Moderately sensitive" and HI. „Strongly sensitive" categories were constituted. Generally, Topaz and Gala cultivars showed low damage (or were free from symptoms), in contrast to this, Golden mutants suffered relatively much. The most sensitive cultivar was Jonica on all the three rootstocks. We searched for relationship between the fruit quality parameters and the frequency of sunburn. Significant correlation was found in the cases of fruit size and the extent of cover-colour. The latter is interpreted with the fact that the best coloured fruits are found on the periphery of crown as a consequence of more intense irradiation.
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Review on rain induced fruit cracking of sweet cherries (Prunus avium L.), its causes and the possibilities of prevention
27-35.Views:751The rain induced fruit cracking is a big, serious and costly problem for cherry growers. Cracked fruits lose their value and they are not marketable because of the poor fruit quality. Cracked fruits have different storage diseases and shorter storage and shelf life.
There are many influencing factors of the cherry fruit cracking such as: water uptake; fruit characteristics (fruit size, fruit firmness; anatomy and strength of the fruit skin, stomata in fruit skin, cuticular properties, osmotic concentration, water capacity of the fruit pulp, growth stage of the fruit,); orchard temperature and other environmental conditions;
The most effective protection technique is the plastic rain cover over the tree rows. The installation of these equipments is too expensive for the cherry growers. That is the reason why researchers tried to find other less expensive and sufficiently effective ways against the Lim induced fruit cracking.
Several calcium formulas: calcium chloride (CaC1,), calcium hydroxide (Ca (OH)2) and calcium nitrate (Ca(NO3)2 ) can be sprayed in appropriate concentration. Spraying with other mineral salts (aluminium and copper salts, borax) and PBRs (Plant Bioregulators) may be also effective to reduce fruit cracking.
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Mechanical behavior of catching surfaces used for fruit harvesting
59-64.Views:104Various fruit gathering devices are important part of tree shakers used in fruit harvesting. The catching surface is generally used in the form of a stretched thin sheet interacting with the falling fruit. This interaction depends on many factors such as the shape and mass of the fruit, the falling height and the mechanical properties of the catching material.
In recent investigation different canvas, composite and silk materials were selected and their mechanical behavior was experimentally determined. Using the energy conservation principle, the main impact characteristics of the falling fruit was derived and used. Static and dynamic loading tests were carried out using spherical intenders and artificial fruits. Investigations have shown that, using the appropriate material characteristics, the catching surface can serve as a cushioning material and it can considerably reduce the impact stresses in the falling fruits.
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Sunburn assessment: A critical appraisal of methods and techniques for characterizing the damage to apple fruit
7-14.Views:309Many methods and techniques have been introduced for measuring alterations in the fruit and in its surrounding environment related to sunburn incidence. The research objectives, fruit materials and the environment to be evaluated dictate the methods to follow. These procedures are either non-destructive and involve techniques that allow us to track the course of sunburn development and related environmental parameters, or destructive and involve the removal of fruit from the tree for field/laboratory measurements. Techniques employed can be used for pre-symptomatic monitoring (before symptoms become visible) or characterizing the symptoms already present. The principles behind the measurements and their usefulness for sunburn assessments are discussed and critically evaluated in this review paper. Descriptions and evaluations of the methods and techniques were made in the following groups: 1. Thermal measurements; 2. Visual assessments; 3. Fruit quality measurements; 4. Measurements of physiological and biochemical alterations; and 5. Practical evaluation of sunburn damage. Thermal measurements involve methods tracking the ambient temperature and fruit surface temperature, and their relation to sunburn formation. Visual assessments cover all measuring techniques (skin color, chlorophyll fluorescence, radiation reflection, electron microscopy) that are able to detect changes on/in the fruit skin related to sunburn formation. Fruit quality measurements are used to point out differences in qualities (soluble solids, firmness, titratable acidity, and water content) between unaffected and sunburned areas of the fruit. The measurements of physiological and biochemical alterations (gas exchange, pigment analysis, enzyme activity, gene expression) give us a better insight to the mechanism of sunburn formation. Practical evaluations involve many procedures that are used by scientists to characterize the susceptibility of cultivars, evaluate protection technology, etc. For this purpose, the following methods are in use: expressing the percentage of the total fruit surface area affected by sunburn or the percentage of the total number of fruits damaged on the tree, or even a scale based on the severity of the symptoms occurred. All assessing methods and techniques described here have their pros and cons as well as their specific applicability, therefore any of these cannot be favored to use exclusively for assessing sunburn incidence. The combination of these techniques will be the best choice to meet a given research objective perfectly.
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Irrigation modeling in a pear orchard
75-79.Views:214The pear has large water requirement, therefore the planting of high density and grass covered pear orchards are needed irrigation
conditions in Hungary. Drip irrigation spread in the orchards is due to the 90–95% of water use efficiency. One of the key role of irrigation is the
proper determination of evapotranspiration and crop coefficients. As there is a considerable lack of information for different crops or fruits the
Penman-Monteith method is used for the estimation of evapotranspiration, using CROPWAT 8.0. The research field was the genetic collection of
pear at Újfehértó, in Hungary, which is situated in Nyírség meso-region. Our aim was to establish drip irrigation at this site. Based on the results
of CROPWAT irrigation model the mean amount of the total gross irrigation is between 230–270 mm, within 3 irrigation interval regarding
climatic and rainfall data of the last 10 years. In 2009, due to heavy drought, the total gross irrigation was 355,4mm/year on sandy soil calculating
with 45% total available water depletion in 5 irrigation interval. The sizing of the irrigation system was set to the maximum 0.55 l/s/ha, which is
6.3 l/tree/h. 6.3 l/tree/h can be carried out with a drip emitter having 16 mm wing lines diameter, 4 l/h water flow at 3 atm pressure. -
Evaluation of generative accomplishment of new apple cultivars in Hungary
11-15Views:254In a two year study, 14 new apple cultivars (cvs ’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’ and club cultivar) were studied in Eastern Hungary at Nyírbátor. The following parameters were measured: trunk cross sectional area (cm2), harvest time with yield (date, kg/tree, number/tree), fruit size (mm), fruit surface color (%), and color intensity of the fruit surface (1-5). According to our two year assessments regarding, the best generative accomplishment was achieved for the cvs ‘Gala’ sorts trained to slender spindle and the cv ‘Red Jonaprince’ trained to super spindle. According to the trunk cross sectional area the ‘Gala’ sport trained to slender spindle showed the strongest growth among the 4 years old trees, while the cv ‘Fuji SW’ and the cv ‘Jeromine’ presented lower vegetative accomplishment. The ripening time of the cultivars started at the end of August and finished at the beginning of October. ‘Gala’ mutants trained to slender spindle provided the highest yields. Fruit size of all cultivars reached the market required standard, however, cvs ‘Red Jonaprince’ and ‘Red Idared’ produced large fruits over 90 mm. The fruit size of the ‘Gala’ sort was 72–75 mm. Most of the cultivars showed high fruit surface color and color intensity.
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Treatments for improving tree growth, yield and fruit quality and for reducing double fruit and deep suture incidence in “Desert red” peach trees
7-19.Views:270Five years old “Desert red” peach trees budded on Nemaguard rootstock and grown in sandy soil at commercial orchard Al-Nubaria city, El-Behira Governorate-Egypt were treated with some agricultural treatments involving thinning out pruning, fruit thinning and foliar application of potassium silicate (25% S +10% K2O) at 0.1% and super grow (20% N, 20% P2O5 and 20% K2O) at 0.3% in 2014 and 2015 seasons, to study their effects on yield and fruit quality and the relationship between nutrient balance and yield of “Desert red” peach trees. Beside, testing the influence of used treatments on two physiological disorder, double fruit and deep suture %. Also, economic evaluation of different treatments was done. All obtained data were statistically analyzed using a randomized complete block design. Depending on the obtained results in this study, it could be concluded that application of thinning out pruning 35%, fruit thinning by leaving 15 cm between fruits on one-year old shoot at 20 days after full bloom and foliar application of potassium silicate which sprayed five times during each growing season at fruit set, the second fruit development stage, the beginning of the fruit color change and twice after month from harvest, most profitable treatment for peach trees grown under conditions of this investigation. This treatment gave the best vegetative growth, yield, fruit quality, higher crop value with high net income /fed. from “Desert red” peach trees, in addition, reduced the percentage of double fruit and deep suture by more than 50% in both seasons, therefore, the study recommends this treatment for “Desert red” peach growers.