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Spatial and temporal variation of extremely abundant maxima of precipitation in Hungary during the period between 1951 and 2010
107-114.Views:252The study deals with the accumulated database of 16 meteorological stations in Hungary during a period of 60 years. The purpose was to reveal the spatial and temporal structure of the appearance of extreme values in the daily distribution of data concerning precipitation. We strived to answer the question whether the frequency of incidences of daily maxima did they change or not during the 60 year-long period in the main growing regions of the country. It is demonstrated on geographical maps how the size and frequency of precipitation episodes ensued, and what are the typical traits of changes in intensity as well as in frequency of happenings projected according to their spatial and temporal distribution. From the point of view of fruit and vegetable growing, it is of prime interest what kind of frequency and intensity of changes occurred in precipitation. The temporal distribution of extremities though did not seem to change signifi cantly in some areas, but the recognition of changes may help conspicuously the planning and the choice between alternatives of species and varieties as well as technologies of horticultural managements for the long run. Extremely intense rains during a short time may cause erosion and stagnant water, thus we have to know what are the odds of risk. The temporary distribution of changes helps us to judge upon the reality of anxieties, which are expected according to the existence of trends. Seasonal or monthly distribution is visualised by maps, what is expected and what is accidental as for a decision in planning. The spatial distribution of coeffi cients of variation help us to decide what is the local chance of extreme happenings at different parts of the country and what is its coeffi cient of uncertainty. The risk of any undertaking dependent on conditions of weather could be expressed numerically by a coeffi cient of risk.
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Spatial and temporal variation of extremely low minimum temperatures in Hungary during the period between 1951 and 2010
75-80.Views:180For this study, data of 16 meteorological stations have been processed over a period of 60 years with the purpose to reveal the spatial and temporal structure of the frequencies of absolute extreme minima in Hungary with special reference to the surmised global rise of temperatures on a worldwide scale. In the main areas of fruit growing, the monthly or seasonal absolute temperature maxima and minima are presented during the 60 year-long period and projected on the geographical map. For the main fruit- and vegetable growing regions the probability of winter- and late frosts is of prime interest. The time series of extreme temperatures though did not prove signifi cant changes over the period observed, but the information upon changes and their tendencies is a precious tool being utilised in planning, choice of adequate varieties for a longer period of time in the future. The deleterious winter frosts experienced in fruit production is not a consequence of a sole drop to a minimum temperature, but of an earlier period of mild temperatures during the winter, which sensibilised the trees. Frequent and extreme variations of temperatures may cause troubles at any time during the year and reduce the yields conspicuously. We ought to get familiar with the hazards of our climate and fi nd optimal solutions to mitigate the damages expected. The seasonal and monthly distribution projected on the geographical map we can follow up also the spatial relations and the signifi cance of their occurrence. Coeffi cients of variation between meteorological happenings at different localities facilitate the calculation of the probability of risks on the surrounding areas.
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Apple powdery mildew caused by Podosphaera leucotricha: some important features of biology and epidemiology
45-51.Views:340In this review, some important features of biology and epidemiology are summarised for apple powdery mildew (Podosphaera leucotricha). In the first part of the review, the geographical distribution or the pathogen are discussed, then the morphology and taxonomy of the causal organism are described. Disease symptoms or apple powdery mildew are also shown and then host susceptibility/resistance is discussed in relation to durability of resistance. In the second part of this review, the general disease cycle of powdery mildew on apple are demonstrated and some basic features of powdery mildew epidemiology (such response of the pathogen to temperature, relative humidity, and rain as well as spore production, spore dispersal, diurnal patterns and temporal dynamics of the pathogen/disease) are also given on apple host.
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Dynamic economic analysis of greenhouse pepper production on rockwool on a family farm
43-47.Views:122The major part of the pepper growing farms in Hungary operate as family enterprises with areas varying between 1,000 and 3,000 m2. As a result of the small size, their profitability is greatly dependant on the technological level and market circumstances. Most of these farms are characteristically affected by the lack of capital, therefore, they are unable to implement any further developments with their own forces. Greenhouse pepper production on rockwool had already been subjected to analysis earlier in our research, however, those calculations were directed solely at the profitability and efficiency of production. Based on the data from 2004 in 2005 yet another and more profound analysis was set as the objective. Besides the methods already applied before, several dynamic indicators have been introduced which could also be useful for practical applications. The graphs can permit growers to monitor the temporal distribution of the costs incurred and revenues earned during production. Thereby it is easier to plan the costs and more simple to distribute them more rationally over the production period. Our experiences suggest that this sort of analytical method is applicable only in cases where a very careful and precise collection of data is ensured and the results obtained can not be generalised as being valid only for the single farm analysed. Experiences and results, however, make us consider the dynamic economic analysis as being very useful both for beginners and practicing horticulturists.
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Temporal changes of the frequency of spring frost damages in the main fruit growing regions in Western Hungary and in East Hungary
81-87.Views:220Most of the risk in Hungarian fruit growing is the damage caused by late spring frosts. The frequency of late frosts seems to increase nowadays. The aim of the study was to check this contention: what is the real probability of the damages. Based on earlier experiences, the physiological LT50 function has been elaborated for new fruit varieties, which are eligible to moderate the danger when being threatened by frost. By means of this technique, the probability of freezing is distinguished between frost susceptible, frost resistant and medium frost resistant fruit species and varieties around their blooming time. The degree of frost damage depends on the duration and severity of the low temperature and not at least on the frost tolerance of the plant. For that purpose, the frequencies of frost damages were studied at two Transdanubian and two Trans-Tisza fruit growing sites by means of a meteorological database for the 60-year-long period 1951–2010. Being aware of the LT50 values changing during the phonological phases of the fruit trees from budding, bloom, fruit set and fruit growth, the number and date of critical (frosty) days could be settled. An important role is attributed to the orographic relief and the height above the sea level of the site, as 20–30 m differences and expositions may become decisive within the same plantation. The spatial distribution of damages is also dependent on the air circulations within the Carpathian basin. At the southern and northern borders of the country, especially valley bottoms represent additional risks of frost. Most spring frost damages are experienced in April 20–22, and cause heavy damages by temperature minima between – 3°C and – 6°C. The severity of damage depends largely on the temperature of the preceding few days. The earlier bloom the heavier damage is expected. The study is emphasising the importance of the varieties. Frost tolerance of some varieties may lower the risk of spring frosts by 40–50%, as experienced on the plantations. The quantifi cation of the risks based on data raised during the last years will be suitable to defi ne the security of yields of each growing site successfully.