The aim of the present study was to study the effect of biennial bearing (irregular yields) on the generative production of apple cultivars 'Golden Reinders' and 'Summerred' on M.9 rootstock. The observations were made at Nagykutas in West-Hungary for four years. The authors have studied the flowering time, flower density, fruit density, fruit...drop, seed content, yielding and fruit quality in the on-year and off-year. Based on the results, it can be stated that the alternation does not cause a significant change in the flowering time of cvs. 'Golden Reinders' and `Summerred': the difference between the flowering time of trees in the on-year and off-year period was 0-1 day. However, there were significant differences in the flower density. 'Golden Reinders' proved to have a weaker tendency to alternation similarly to the statements of the literature. Alternation (off-year) was observed only in three years from the studied four years. While in the case of `Summerred', strong alternation was observed in all four years. In fruit density, there were differences among the cultivars and among the different cycles of biennial bearing. Fruit density (and its opposite, fruit drop) changed inconsistently in the period between flowering and harvest. In the case of 'Golden Reinders' and 'Summerred' 2 and 4 fruit drop periods were detected, respectively. In the off-year, the different periods were less distinct, in most cases they were overlapping each other. The dynamics of fruit drop was related to seed content per fruit. The lower the seed number was, the higher the degree of fruit drop was. In both the high- and off-year cycles, the number of seeds in fruits on the tree and on the ground increased with time. In the yield parameters (fruit number, fruit load, yield efficiency), the differences were greater among the yields of trees in the high- and off-year cycles for 'Summerred'. The fruit quality parameters were greatly influenced by the fruit load of the trees in the different alternation cycles. In general, it can be stated that fruit mass, diameter and height were lower on trees in the on-year. A similar trend could be observed in flesh firmness, cover colour and dry matter content, but the differences were smaller. 'Summerred' was more sensitive to the differences in fruit load.
The aim of this study is to investigate the effect of different growth inducing rootstocks on fruit drop of apple. This research was conducted for 3 years at Nagykutas, Western Hungary on apple cv. 'Arlet'. For the experiments, 3 different growth inducing rootstocks were choosen: M.9 (weak), MM.106 (moderate) and crabapple seedling (strong). Th...ere were 3 fruit shedding periods on the trees grafted M.9 and MM.106 rootstocks, but in the case of crabapple seedling, only 2 were found. The measure of fruit drop was closely related to seed count of fruits; seed number was the lowest, fruit drop was the highest. The lowest seed number was counted in fruits from trees on crabapple seedling. Seasonal changes of leaf:fruit ratio mainly depended on shoot growth and fruit drop. The rise of the curve of leaf:fruit ratio was very important during the first phase of fruit development, in especially at the end of June and in the beginning of July. The cause of this is that first and second periods of fruit drop appeared during this term. The rise of the curve was important in the beginning of June and the end of July on crabapple seedling. Decreasing tendency of quality parameters was found of fruits from trees on M.9, MM.106 and seedling rootstocks, except flesh firmness which was the highest in fruits from trees on crabapple seedling.
Fruit set and fruit drop rates of 9 sour cherry cultivars (‘Érdi bôtermő’, ‘Debreceni bőtermő’, ‘Kántorjánosi’, ‘Újfehértói fürtös’, ‘Éva’, ‘Petri’ ‘Oblocsinszka’, ‘Pandy 279’ and ‘Csengôdi’) of eight years-old trees grown in Újfehértó, located in the Eastern north part of Hungary which graft...ed on Prunns mahaleb have been studied. Significant differences have been found in fruit set among cultivars. The average percentage of fruit set was 18.3%, which the ‘Oblacsinszka’ by 32.6% the highest fruit set, while ‘Debreceni bőtermő’ is very similar to ‘Pandy279’ showed lowest (12%) fruit set. Seasonal changes of fruit set and drop shows that there are four abscission peaks. The first fruit abortion wave appears during second week after pollination Thereafter, the second and third dropping period was found during the third and forth weeks after pollination. The forth abscission happened on the forth week after pollination. The highest fruit drop happened on ‘Pandy279’ (92.4%) very similar to ‘Éva’ (90%) while the lowest fruit drop observed in ‘Oblocsinszka’ (71.5%)
The 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 s...pite 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.
The 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.
The 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 wo...rks 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.
The purpose of phenometry is to examine the measurable parameters of the plants in order to follow up the consequences of weather processes. We should fi nd the reasons, why the diameter of fruits grows larger in one season and smaller in the next. Variation may occur as a response to insuffi cient provision of water or nutrients, but also beca...use of pathological effects and of extremely high or low temperatures, moreover, of extraordinary heavy fruit load. There are phenometrical characteristics, which consider the fi nal consequences (density of fl owers, fruits set, drop of fruits), whereas other parameters could be followed up (size, length and width of fruits) as the dynamic components of growth. The quantitative parameters of growth are functionally related to each other, where the weather conditions, soil humidity and nutrients are on the input side, thus it is possible to model the growth of fruits as a function of the environment. Initially, the relations between the main weather variables and the phenometrical data have to be cleared. In the present study, the interactions between the mentioned phenomena are presented and numerically defi ned.
For 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 m...onthly 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.
Frostbuster is a new system, engine and technology, developed to protect fruit plantations from the frost damage. In order to raise domestic experiences and measurements, experimental approach has been initiated to prove the utility of the system under excessively low temperature in the plantation of the Siófoki Gyümölcstermesztési Zrt (Fru...it Growing Co. Siófok). The first opportunity ensued in the night of February 23-24, 2011, when the temperature sank to 12°C below zero. The question was to see whether we could prevent the drop of temperature by the frostbuster technique. The margin of an anticyclone staying on East Europe secured a stable condition to make tests. The only difference from the imaginable conditions of dangerous frosts was the heat keeping capacity of trees was weak, much inferior than compared with trees in full boom. As a consequence, the tree rows represented much lower heat-capacity and cooled down much quicker than blooming trees in springtime, i.e. their temperature was more variable. The other difference was, compared with an episode in spring that the hard frost lasted much longer than usually in spring. For testing the system, those conditions had even more advantage. Six meteorological stations helped us in measurement. Data-collectors were timed to 1 minute distances and the bulk of data proved to be beneficial for testing the Frostbuster. The results prove that the system is adequate to keep the temperature continuously higher than the surrounding field under excessively low temperatures. Further measurements are still needed to find the optimal solutions fitting to the growing site and its microclimate. Results presented offer a basis of further proofs.
The objective of the present study is to explore the effect of cooling irrigation (aspersion) on the beginning of bloom and on the micro-climate of the plantation. The results show that the water sprayed in the orchard by micro-jet influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of tempe...rature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect, The frequent repetition (20 minute intervals) may keep the temperature low also in the buds. The beginning of bloom may delayed for more than ten days. The dynamics of blooming was characterised by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control in spite of equal temperatures measured in the plots. Under our (Hungarian) climatic conditions, the method is successfully used to delay blooming dates. The main result is the diminution of the frost damage in the spring and the security of yield. The costs and water requirement should be calculated later.
We analyzed the relationship to sour cherry quality parameters of average temperature, maximum temperature, minimum
temperature, night and day-time temperature, precipitation and climatic water balance variables. Three cultivars of sour cherry were included
in the selection: “Debreceni bôtermô”, “Kántorjánosi”, and “Újfehé
present only those that proved to be the best fit.We couldn’t find any significant differences in the weather tolerance of the varieties. The data
base of sour cherry quality parameters covers the 1998 to 2008 intervals. The researched parameters were the following: dry matter content
(%), sugar content (%), C-vitamin (mg), total acid content (%). Maximum temperature, the difference of night and day-time temperature and
minimum temperature all have a significant correlation with the investigated quality parameters of sour cherry. Minimum temperature shows
a quadratic relationship with sugar content, while night and day-time temperature differences show the same with dry matter content. The
other weather parameters had a linear correlation with the quality parameters of sour cherry. The research results show that an increasing
amount of precipitation causes decreasing tendency in total acid content of sour cherry, so that increasing temperature has a positive influence
on total acid content. Big differences in night and day-time temperature also has positive effects on the dry matter and sugar content of sour
cherry while the amount of precipitation has a negative effect. High minimum temperatures cause decreasing sugar content respiratory energy
losses are significant if dawn temperatures do not drop considerably.A more favourable climatic water balance has a positive effect on vitamin
C content in cases of a large negative water balance, vitamin C content is generally low.