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Malus taxa and the progenies of Malus floribunda selected in Hungary, as gene sources of resistance breeding
25-28.Views:254One of our objectives in the apple breeding program of the Department of Fruit Science, beside creating new varieties, is to search for new gene sources. After evaluating the disease resistance of Malus taxa available in Hungary, we put the promising selected individuals through further examinations. Their habit and growth vigor was observed, as well as productivity and fruit characteristics were evaluated. Malus fusca seems to be a new, promising gene source in Hungary among the examined taxa. Beside its optimal canopy, growth vigor and fruit characteristics, it has the advantage to be in distant relationship to Malus x domestica, therefore its resistance is based on a different genetic basis. SBG 1 selection of Malus spectabilis can be recommended as a new gene source for resistance breeding. The range of gene sources can further be widened by selected clones of Malus floriblunda (BA I), Malus x zumi (BA) and Malus baccata (SBG 6). An additional value of Malus taxa chosen by us is that they show resistance not only to apple scab, but to powdery mildew as well, and according to our results, they have optimal habit, acceptable productivity and good fruit quality. Nine hybrids were selected from first Malus progenies which proved to be resistant to apple scab and powdery mildew. These are valuable not only as gene sources of breeding, but as pollenizers or ornamental trees, while their decorative fruits can be used in inside decorations and flower arrangements.
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The estimation of pollen viability of snowdrop (Galanthus nivalis L.)
141-144.Views:236In the present experiment pollen viability of snowdrop were tested using four vital dyes (TTC, Baker' procedure, MTT and FDA) to determine their potential to differentiate fresh living pollen from pollen heated for 12 hours at 80 °C (killed pollen). We found that two of the four dyes previously employed to determine viability also stained killed pollen in the case of snowdrop, while the FDA and MIT did not. We suggest that the two latter are probably the best method to test snowdrop pollen viability, since they do not normally stain either killed or aborted pollen.
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Increasing the vitamin D level of oyster mushrooms by UV light
119-123.Views:653Vitamin D is essential for the human body and mushrooms are one of the natural sources of it. Many research works are aimed at enhancing the vitamin D2 content of mushrooms with UV irradiation in order to increase their vitamin D2 level, by transforming their natural ergosterol content into vitamin D2. The subjects of most of these studies are different kind of post-harvest cultivated mushrooms. In our experiment biologically active, pre-harvest oyster mushrooms were treated in the growing room with UVB and UVC light. UVB and UVC lamps (operating on 312 and 254 nm) and 6 time periods of irradiation (15, 30, 45, 60, 75 and 90 min) were used. After three consecutive days of treatments the yield were measured and samples were taken for vitamin D2 and ergosterol analysis. Data showed considerable increase (from 0,67 μg/g to 3,68 μg/g, f.w.) in vitamin D2 levels at every time period in case of both wavelengths.
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Scab resistance in Malus sp. progenies - inheritance and resistance stability
9-15.Views:259Susceptibility of progenies of some Ma/us species to apple scab was evaluated. Susceptibility of hybrid families was observed first in greenhouse after artificial inoculations by the suspension of the pathogen, Venturia inaequalis (Cooke) Wint., then in open field. The Hungarian type of Malus floribunda, which proved to be scab resistant in our examinations, has a positive effect on the segregation of progenies to resistant and susceptible individuals as a male parent, not depending on the rate of susceptibility of the other parent. However, the German type of Malus floribunda and Malus prunifolia act as dominant, highly susceptible parents.
Malus x purpurea and Malus baccata, which proved to be highly susceptible to apple scab in open field and in artificial inoculations, transmits its susceptibility only slightly to its progenies as a male parent.
According to our experiments, the inheritance of scab resistance of Malus floribunda cannot be considered as monogenic, as published by other authors.
Scab susceptibility of parents influences the segregation of progenies to resistant or susceptible individuals. The moderately scab susceptible `Idared' as female parent has a statistically proved positive effect on the segregation of its progenies.
More factors indicate the appearance of a new race of Venturia inaequalis (Cke.) Wint.: change of the symptoms in the greenhouse; considerable increase of susceptible individuals after greenhouse inoculation in 1997; more and more progenies of the male parent Malus floribunda became susceptible to scab in open field.
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Effect of certain bentonite products on the temporal variation of elemental content in white wine
15-21.Views:146The 'terroir' character of wines can be shaped with certain technological elements such as bentonite fining. Bentonite is an agent used for the removal of thermolabile proteins in wines. However, during fining, the quantity of certain wine components can change, including the elemental composition of the wine. According to the recommendations of bentonite suppliers, wines should be racked off the bentonite fining sediment within 2-3 weeks. However, in winemaking practice, wines can remain on bentonite fining sediment for up to 1-4 months. One reason for this is that racking wines off the sediment has a negative impact on wine quality. Thus, it is a question of how much the later or earlier racking time can alter the elemental content of the wine. Our study aimed to examine the elemental content of wines treated with three different bentonite products sampled from over the bentonite fining sediment at various time points. Our investigation was conducted with the 2019 vintage white wine of the University of Debrecen. Fining was performed with three bentonite products: Nucleobent, BW200, and Granubent Poretec. The sampling schedule following fining was: 0 days - unfined control, 7th, 14th, 27th, 56th, and 85th days. The macro-, meso-, and microelement contents (P, K, Ca, Mg, S, Al, Na, B, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd, Ba, and Pb) of the wines were determined using ICP OES and ICP MS devices. Our results showed significant changes in the Al, Na, Cr, Fe, Co, Ni, Sr, Ba, Cu, and Pb contents of the wines depending on the sampling time. It is noteworthy that all three bentonite products increased the Al and Pb contents of the wines. For Fe, dynamic increases were observed over time with the BW200 product, reaching the threshold value of susceptibility to brakeage. However, from a winemaking technology perspective, it was favorable for the Cu content of the wines to decrease with both earlier and later racking times, for all bentonite products examined. Based on the elemental analyzes of the white wines studied, it can be concluded that racking of wines should be timed according to the recommendations of suppliers.
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The necessity and possibilities of irrigation in fruit growing under conditions of Hungary
93-94.Views:768Climatic and soil conditions are highly suitable for most temperate fruit species and promise profitable yields with good quality. An accurate choice of the growing site is, however, decisive because of the wide range agro-climatic variation an soils within the country. One of the most important factors is the annual precipitation which does not exceed, in general, 700 mm. The aims of irrigation practices are, succinctly speaking, the improvement of quantity and security of yields and the guarantee of quality. The relative importance of those criteria changes according to the fruit species. In up to date apple, pear and cherry production, micro-irrigation systems are mainly considered. According to recent experiences, the micro-jet type of water distribution should be preferred to the dripping system. In cherries, the choice of the method is motivated by the need to prevent fruit cracking. Most of the peach and apricot plantations are located on the dry and moderately dry regions of the country. Because of the late freezes, the improvement of security is crucial. There the investment of irrigation systems should concentrate to the possibility of anti-freeze sprays. High water requirements of plums are met in Hungary by irrigation where the method should be decided at the plantation and adapted to the harvesting procedure which could be mechanised or (in high density plantations) picked by hand. Sour cherries are perhaps the less dependent on watering under Hungarian conditions. Yields in small fruits: currents, gooseberries, raspberries and strawberries could be increased by irrigation to 40-50 % and may improve quality too. In those cultures the system of moving flexible wing tubes are considered to be the best irrigation technique.
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Evaluation of fruit quality parameters of Rosa taxa from the Carpathian basin
81-87.Views:278From the wide range of genetic sources available in Hungary, we have chosen as objective the evaluation of those rose taxa, which — on the base of their quality and morphologic features — are suitable for selecting fruit production varieties or parent varieties for further breeding. We examined physical and inner parameters of fruits of Rosa taxa, and evaluated the correlations by mathematical statistic methods. Namely, if a correlation can be found between physical and inner parameters, fruit production value can be determined by less examinations in the future. According to our results, there is a large variability in some physical parameters (weight, diameter of fruits; weight, number of achenes) as well as in inner content values (vitamin C, glucose, fructose, K, Ca, Fe, Zn and Cu content) of rosehip, regarding production year, habitat and even the individual of examination. Twice as much ascorbic acid can be found in achene-free fruits, and nearly five times as much in their dry product as in fresh whole fruits. It was established repeatedly, that vitamin C concentrates in fruit flesh, and ascorbic acid content can be preserved better in achene-free flesh. There is no essential difference in citric acid and carbo-hydrate content of whole and achene-free rosehips. However, macro- and microelement content of whole fruits is 30-40% higher than that of achene-free fruit flesh. The connection between fresh weight and diameter, as well as achene number and seed weight of fruits can be described by the function y=axb. A significant relationship can be found in case of K-Fe, Ca-Mg, Ca-B, Ca-Mn and Zn-Cu, between fresh weight and B content of fruits. According to our examinations, fresh weight of rose species with a higher citric acid content is usually higher, while their Fe content is smaller. Glucose content of fruits of rose species is directly proportional to their Ca and Zn contents. Zn content of rose species with higher fructose content is usually smaller.
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Pollen viability of ‘Besztercei plum' clones depending on the effect of the year
115-121.Views:537The percentage of dark staining pollen grains was higher in spring of 1996 than in the previous year. Data in 1998 resemble those of 1995, concerning the large amount of medium staining pollen grains in the majority of clones. Some clones produced excellent quality pollen also in the third year. whereas there were significant differences in other clones in various years.
The warmer February-March period in 1995 induced an early blooming, and frost affected the orchard not only in winter months, but also immediately before and during blooming. Thus, frost was the possible cause of weaker quality pollen this year. In 1996 warming began a bit late, but it was not broken by drastic falls in temperature, except for the middle of April, when a smaller frost affected the orchard. It is likely that this frost did not influence pollen quality of `Besztercei' and 'Early Besztercei' plum clones significantly. In 1998 warming was continuous and steady, the orchard was not affected by frost immediately before blooming. In March, however, there was frost almost every day, according to daily minimum temperatures.
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Ripening related processes in strawberry, a nonclimacteric fruit: a short overview
105-109.Views:408Fruits are essential part of the human diet: they provide vitamins, minerals, antioxidants to the mankind. Physiologically they can be divided into two groups-climacteric and nonclimacteric - depending if they display any respiratory peak and dramatic increase in ethylene biosynthesis or do not. Ethylene is a gaseous hormone playing a very important role in several physiological processes in plants. While climacteric fruits, like apples, bananas, tomatoes, peaches, apricots show increased ethylene biosynthesis and dramatic respiratory peak during their ripening, nonclimacteric fruits, like strawberries, grapes, citrus do not.
The most widely used fruits for studying nonclimacteric ripening are strawberries: several papers are focusing on the identification and characterization of ripening related genes from this plant. Therefore here we attempt to summarize the most important advances in strawberry fruit development, and ripening.
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Mathematical and Statistical Modelling of Impact Symptoms and Application to Tomato
75-80.Views:252Drop 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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Effect of postharvest on the economic viability of walnut production
28-38.Views:677In this study we were studying the question whether walnut production under domestic natural and economic circumstances shall be considered a profitable activity or not. Our partial objective is to determine, what level of natural inputs and production costs are required for walnut production, what yield level, selling price and production value can be attained, what level of profitability, rentability and efficiency may production have, is the establishment of a walnut orchard profitable on the entire lifespan of the plantation, and the production of which is more efficient: the dry shelled walnut production requiring postharvest activity or the raw, shelled walnut without postharvest activities. In this study, comparison of two systems is conducted. First version: producer establishes a walnut plantation and sells walnut raw and shelled. Second version: producer also invests into a drying facility, and in this case the end product is the dry, shelled walnut. If the producer sells walnut right after harvest in a raw bulk, total production costs in productive years reaches 974,011 HUF/ha. Attainable yield is 2.63 t/ha with 396.3 HUF/kg selling price, therefore the profit is 138,258 HUF/ha with 14.19% cost-related profitability. In the case when the producer sells dried, shelled walnut, production costs are 25% higher compared to that of raw walnut due to the cost of drying. By calculating with the postharvest loss, average yield is 1.84 t/ha, however, its selling price is way higher (882.84 HUF/kg), therefore the profit per hectare reaches 475,496 HUF with 39.01% cost-related profitability. Thus it can be stated that walnut production in an average year may be profitable even without postharvest, but efficiency is improved significantly when the producer sells the products dried. Investment profitability analysis revealed that production of raw, shelled walnut is not economically viable, since the plantation does not pay off on its entire lifespan (30 years), while walnut production with postharvest is efficient and rentable, since both net present value (NPV) and internal rate of return (IRR) showed more favourable values than in the previous case, and the orchard pays off in the 21th year after establishment.
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Visualization of the Gas Chromatography/Mass Spectrometry Data of Muscat Ottonel Must and Wine Measurements
16-21.Views:386The lack of interpretation methods useful in evaluating the aroma-profiles of wines makes it necessary to thoroughly investigate alternative evaluation procedures. By adding three appropriate normal hydrocarbon standards to all sample extracts, measuring the Programmed Temperature Retention Indexes of the components and by normalizing the peak areas to that of the 1-alpha-Terpineol (in musts) or Benzeneethanol (in wines), the aroma features could be visualized. The relationship or identity of the aroma patterns could be deduced from the presence or absence of similar polygons in the -constellation-map" of the components.
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First selections of the Hungarian apple breeding program for multiple resistance
9-13.Views:387The aim of the first Hungarian apple breeding program for multiple resistance started in the beginning of the nineties is to widen Hungarian apple assortment by good quality, resistant apple cultivars with excellent productivity and ecological capability to the most important fruit growing areas in Hungary. In the first years of seedling production we made early selection for susceptibility to apple scab in greenhouse. Alter this, field observation of susceptibility to powdery mildew, scab and canker and a yearly negative selection was carried on. From 1997, fruit quality was evaluated as well, and from 2001 the resistance of shoots to Erwinia ainylovora (Burrill/Winslow et al.) was examined using inoculations in greenhouse conditions. From the progenies of crosses in 1992 and 1993, six candidates were announced to national recognition out of hybrids examined for more than a decade. Descriptions of these selections from 'Prima' progenies and the most important data of their resistance, growing habit, morphological characteristics and fruit quality are shown in this article.
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Sugar composition of floral nectar in sour cherry cultivars
109-113.Views:437The composition of floral nectar in sour cherry cultivars studied in 1997 at Újfehértó was in agreement with our previous data, the three most frequent sugar components being glucose, fructose and sucrose. Nectar secreted at night is generally more diluted than nectar produced during the day. None of the nectar samples produced at night reached the threshold value (100 mg/ml) of bee visitation. In the majority of cultivars the difference in concentration between night and day nectar is not too high, but in two cultivars, 'Korai pipacs' and ‘Újfehértói fürtös’ the difference is quite significant. Most sucrose was found in the nectar of cvs. 'Érdi jubileum' and ‘Újfehértói fürtös’, but a high amount of sucrose was measured also in the flowers of 'Korai pipacs' and 'Meteor USA'. Nectar concentration varies from opening of the flower to petal fall to a smaller or greater degree, depending on the given cultivar. From the 9 sour cherry cultivars studied ‘Újfehértói fürtös’ and Tandy 48' had the most attractive nectar for bees. There was no correlation between nectar composition and free fertilisation. On the basis of nectar composition the majority of the sour cherry cultivars studied can be classified into the sucrose-rich category; only one cultivar, 'Érdi jubileum' had a sucrose-dominant secretory product. The composition of nectar in the studied sour cherry cultivars is preferred by bees.
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Studies on the drought responses of apple trees (Malus domestica Borkh.) grafted on different rootstocks
29-36.Views:1388The 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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Evaluation of precision farming with regard to horticulture
105-110.Views:231The global positioning system was made available for public use, which made it possible' to apply a new management tool in agriculture. Precision farming gives much more information on plant-growing than former methods, which makes it possible to use technologies more suitable for micro-sites. It is supposed that more profitable production can be realised with its aid and the strain on the environment can be reduced, not to mention other economic advantages.
The study makes economic conclusions about the method more and more widely used in plant production taking the yield mapping of Józsefmajor Experimental Farm as a basis and starts ideas about its possible application in arable land olericulture, viticulture and fruit production.
These issues are important because precision farming has existed in glass-culture for a long time from another perspective, which should be spread to open ground horticultural enterprises that are labour and asset intensive, qualitative farming forms with great plantation value.
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Grape variety comparison of different stress tolerance based on the quantitative measurement of carbohydrates
37-40.Views:350The analyses of various host-pathogen relationships have established the response reaction roles of carbohydrates — especially monosaccharides — measurable in the vegetal parts of the host. Published results also provide information concerning the way various pathogens utilize carbohydrates and concerning the carbohydrates pathogens prefer out of the "selection" provided by the host plant. The role of carbohydrates in the response reactions to abiotic stress has been studied on several plant species as well — currently, too, it is an often discussed area of research. The above-mentioned results form the basis of our intention to study the connection between susceptibility to grey mould and the quantity of measurable carbohydrates in the leaves of grape varieties of various stress tolerance levels.
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Toxicity of fungicides to honey bees (Hymenoptera: Apidae) and their effects on bee foraging behavior, pollen viability and fruit set on blooming apples and pears
96-98.Views:311Fungicides fosetyl-AL, triadimefon, dodine, mycobutanil and fenarimol were tested for honey bee (Apis mellifera L.) mortality and effect on bee foraging, pollen viability and fruit set in blooming apple and pear. None of the materials were toxic to honey bees or reduced pollen gemination or fruit set.
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Carbohydrate utilization of Erwinia amylovora in vitro
31-34.Views:378Nectar is a multi-component aqueous solution that promotes bacterial multiplication. The concentration of nectar in plant flowers is not stable since it is under the influence of environmental conditions, especially free moisture and relative humidity. Experiments were conducted with "artificial nectar" and directed along two lines: (1) determination of the optimal concentrations of carbohydrates for the growth of E. amylovora development (2) consumption of different carbohydrates besides basic sugars.
Solutions of "artificial nectar" were prepared in different compositions by changing the dominance of basic sugars (fructose — glucose —sucrose) in proportions of 2:1:1, 1:2:1, 1:1:2 and between concentrations of 10-0.6% (diluted with Basal minimum broth) in order to determine optimal conditions for the development of E. amylovora.
At a basic sugar concentration of 10% bacterial multiplication started and continued until I log degree (from 106 to 107 cfu/ml). At concentrations of 5% and 2,5 % cells developed with nearly the same kinetics (from 106 to 8x107 cfu/ml and from 106 to 9x107 cfu/ml, respectively). Multiplication was more pronounced and nearly the same at concentrations of 1.2 % and 0.6 % (from106 to 2x108 cfu/ml). At a basic sugar concentration 30% total sugars bacterial multiplication did not occur, while at 20 % it was negligible, not measurable photometrically.
At minimal concentrations of F, G, S (between 1-0.1 %) bacterial cells were still able to multiply, producing organic acids from sugars.
Our study showed that E. amylovora requires only a small amount of sugars (0.1%) for multiplication (acid production) while high concentrations inhibit multiplication. There was a negative correlation between sugar content and cell density. The optimal range of sugar concentration was at about 1%.
Effect of "less frequent carbohydrates" to E. amylovora multiplication was also determined using the API 50 CH strip. We could provide information on utilization of 39 carbohydrates by the bacterium at different categories as follows: Not utilized-, Slowly and weakly utilized-, Slowly and completely utilized-, Quickly and completely utilized carbohydrates. We suppose that carbohydrates that belong to the latter two groups could play an important role as nectar components in promoting E. amylovora multiplication in the blossoms of pome fruit trees.
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Continuous and discontinuous nectar secretion in some pear cultivars
77-79.Views:212Hourly nectar secretion was studied in five pear cultivars between 1997-1999. Some cultivars (e.g. ‘Csákvári téli') secreted nectar continuously during the whole day, offering both nectar and pollen for pollinating insects. Discontinuous secretion (e.g. cvs. ‘Viki', `Nyárig tartó 6/19') is less advantageous from the viewpoint of insect attraction. In some cases, however, discontinuity or continuity of nectar secretion varied even within a cultivar (e.g. 'Solymári cukor', ’Jó szürke’) in different years.
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The effect of pre-fruiting temperatures on the yield of Pleurotus strains
49-51.Views:277Authors studied the effect of different temperatures prior to fruit body appearance on the yield of 3 Pleurotus strains P70, HK35 and 357. After 17 days of incubation at 25 °C and 28 °C the substrate blocks were kept for 7 days at 13, 16, 19, 22 and 25 °C. Then temperature was reduces to 16 °C during harvest time. Tests showed difference of some degrees in the optimal prefruiting temperature requirements of the strains which could result in even in 10-15% surplus yield. It is advisable to use technologies specially adapted to strains.
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The effect of rootstock on the nectar production of apple cultivar `Idared'
15-25.Views:236Approaches based on the daily rhythm of apple flowers provide a new stage in nectar research, where the synchronous functioning of sexual organs is studied. In the flower biological studies the insect attraction of flowers was also studied. The two most important factors of insect attraction are the pollen- and nectar production of the flowers. From 1993 to 1998 we studied the food, that flower had to offer for the pollinating insects at different times of the day.
Studies were carried out on 'Idared', one of the hybrids of 'Jonathan' apple cultivar. The fruit of 'Idared' is bigger than the fruit of `Jonathan'. It is bright red, transportable, has a bigger productivity and is not subject to Jonathan-spots. Concerning its inner characteristics, it is juicy, the flesh consistency is better than that of 'Jonathan', but its acid/sugar ratio is worse (Sansavini et al. 1981).
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The increasing importance of grapevine trunk diseases
21-30.Views:514Grapevine trunk diseases (GTDs) are destroying the woody parts of the plants, resulting decline or dieback of the grapevine. More detailed research of the GTD began in 1950s, when Hewitt et al. (1957) observed that specific symptoms cannot be detected on the diseased trunks every year. Latest results have also proved that abiotic factors affect the appearance and the severity of the disease. Moreover several pathogenic fungi may play role as causative agents (Bertsch et al., 2013). Eutypa, Botryosphaeria, Phomopsis dieback, esca disease complex, and Petri disease are considered the major GTDs, where a variety of pathogens attack the woody perennial organs of the vine and ultimately lead to the death of the plant (Lehoczky, 1974; Larignon & Dubos, 1997; Rolshausen et al. 2010; Kotze et al., 2011; Bertsch et al., 2013; Fontaine et al., 2015).
The GTD incidence has been reported to be increased during the last decades (Úrbez-Torres et al., 2014). The esca incidence has reached 60% to 80% in some old vineyards in southern Italy (Pollastro et al., 2000; Surico et al., 2000; Calzarano & Di Marco, 2007). The disease incidence of the esca was reported to be increased from 1.83% to almost 13%, between 2003 and 2007 in Hungary (Dula, 2011). There was detected a five times increase in the GTD disease incidence in the Tokaj Wine Region, Hungary between 2014 and 2016 (Bihari et al,
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Floral biological studies on pear cultivars in relation to fire blight susceptibility
25-30.Views:414Floral biological characteristics that may influence cultivar susceptibility to fire blight were studied in 10 pear cultivars in two Hungarian orchards from 1999 to 2003. The receptaculo-ovarial, automorphic nectary is usually bigger in tolerant cultivars than in susceptible ones. Nectary stomata are meso- or xeromorphic. Susceptible cultivars tend to have more xeromorphic stomata, where guard cells are located 1-3 cell rows below the epidermis. The size of nectar chambers is usually smaller in susceptible cultivars. Floral nectar, consisting mainly of glucose and fructose, is more abundant and less concentrated if the cultivar is susceptible to fire blight. The amount of chlorogenic acid was higher in the flowers of tolerant cultivars than in susceptible ones.
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The effect of the method and the timing of the propagation on the growth, earliness and productivity of sweet corn
134-139.Views:377Direct sowing in 16 cm deep trench covered with perforated plastic sheet (for 3 weeks), transplant using, and uncovered direct sowing (control) was tried on 2 locations, with 2 varieties (very early Kecskeméti korai extra, and middle early Kecskeméti SC-370) in Szarvas on loamy soil, and in Kecskemét on sandy soil in 1996 — after a preliminary trial concerning perforated plastic covered trench sowing in Szarvas, in 1995.
The plant height (weekly), the average leaf number/plant, the total leaf area (once), the total yield, the quality of cobs, and the earliness was measured. The results are:
- Kecskeméti korai extra during the first 6 week period the transplanted plants were the highest, but from the 7th week the plants which were sown in trench and than were covered with perforated plastic sheet (for 3 weeks) were the highest.
- SC-370: The transplanted plants were the highest-until the end of plant height development.
The plant height development stopped at the 9th week of the measurement by early, - and stopped at the 10th week by middle early variety. The average leaf number/plant varied between 9,25-10,50 and was not influenced either by variety or by the treatment. The total leaf area was (on 5th of June) the largest by transplanted plants, which was followed by plants that were sown in trench and then were covered with perforated plastic film (for 3 weeks).
- The highest yield was observed by plants, which Were sown in trench, and then were covered with perforated plastic film (for 3 weeks). Transplanted plants followed it.
- Quite the total yield (98,3%) of transplanted Kecskeméti korai extra variety plants were harvested on 4th July. 89% of the total yield was picked up of trench sown and then with perforated plastic covered plants. The harvest of uncovered control started on 15th July. The harvest of transplanted SC-370 plants started 19th July, when more than half of the total yield (57%) was picked. The uncovered control was harvested 29th July.
- The weight and the measure of cobs generally were not influenced by the treatments, but the average weight of the cobs of the transplanted Kecskeméti korai extra plants (0,21-0,18 kg) are less than the, requirement.
