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Pri poskusu ugajanja potrošnikom, v njihovi želji po visokokakovostni hrani brez ostankov FFS, ob pridelavi na trajnostni/sonaravni način in upoštevanju vseh strogih okoljskih zahtev, je sadjar velikokrat postavljen v izjemno težek položaj. Različni zorni koti pri determiniranju kakovosti z vidika sadjarja, potrošnika, hladilničarja in trgovca, ne poenostavijo situacije. Zaradi pridelovalnih sistemov, kjer veljajo zelo stroge omejitve uporabe FFS (oz. sintetičnih FFS), se velikokrat rizik, ki se pojavi predvsem zaradi mikrobne nestabilnosti plodov, prenese iz nasada v hladilnico. Izrazite spremembe okoljskih dejavnikov, med katerimi delno obvladujemo le vodo, postavljajo sadjarja v položaj, ko mora bolj, kot kadarkoli prej, s fiziološkega stališča razumeti vplive okoljskih stresnih dejavnikov. Slednji so ekstremne nizke temperature, sušni stresi, stresi zaradi visokih temperatur, močno sončno sevanje, močni vetrovi, spremenjen režim padavin itd. Obvladovanje pridelave z upoštevanjem vsega, kar doprinese okolje, terja od sadjarja močno prilagajanje in prav tako veliko znanja. Tako, kot sadjar, pa se mora prilagajati hladilničar. Poznavanje zrelostnega stanja plodov ob vskladiščenju je bistveno preskromen podatek, na osnovi katerega se pridelek umešča v različne programe skladiščenja. Za uspeh v poobiralnih tehnologijah mora hladilničar poznati zgodovino nasada, vodni in prehranski program ter program uravnavanja oveska.

Strokovna monografija je nastala ob izvedbi projekta Evropskega inovativnega partnerstva (EIP) 16.5 z naslovom Okoljski vidiki preusmeritve v ekološko pridelavo sadja. Vsebina je okoljevarstveno in trajnostno naravnana, a še vedno namenjena uspešni in zadostni pridelavi visokovredne hrane. V zadnjih letih smo priča dejstvu, da velik del potrošnikov izrazito favorizira ekološko pridelano hrano, a istočasno ne želi ali ne more plačati njene nekoliko višje cene. Večina pridelovalcev bi rada ustregla potrošnikom, a se zaveda večjih tveganj, ki izvirajo iz manjšega nabora in slabše učinkovitosti pripravkov za varstvo rastlin, ki so dovoljeni v ekološki pridelavi. Dejstvo je, da zadovoljivo obvladovanje razvoja populacij škodljivih organizmov v ekološkem sadjarstvu zagotovo ni mogoče le z zamenjavo pripravkov za varstvo rastlin, zato je vsebina te monografije namenjena predstavitvi funkcije in monitoringa koristnih organizmov v nasadih jablan kot ključnih akterjev za uspešno ekološko pridelavo sadja.

Na Fakulteti za kmetijstvo in biosistemske vede Univerze v Mariboru smo ugotavljali, kako različni dodatki v slivovi marmeladi vplivajo na senzorično oceno marmelad. Kot osnovno surovino smo uporabili slive sorte 'Čačanska lepotica', kot dodatke pa mlete klinčke, mleti ingver in mleto pomarančno lupino v podmerku 6 g/L. Namerno smo izbrali dodatke, ki so aromatični in imajo hkrati dokazane antioksidativne lastnosti. V začetku junija 2017 smo izvedli senzorično ocenjevanje z uporabo hedonskega testa, kjer so preskuševalci ocenjevali všečnost vonja, barve, okusa, konsistence, razmerja med sladkor/kislina ter skupni vtis posameznih vzorcev. Hkrati so se preizkusili tudi v prepoznavanju dodatkov. Rezultati senzoričnega ocenjevanja kažejo, da dodatki statistično značilno vplivajo na oceno všečnosti barve, okusa, razmerja sladkor/kislina ter skupni vtis posameznega vzorca. Najboljšo skupno oceno je prejel vzorec marmelade z dodatkom pomarančne lupine, najslabšo pa vzorec z dodatkom klinčkov. Hipotezo, da bodo preskuševalci najboljšo oceno dodelili poznanemu okusu, smo ovrgli.

V letu 2009 smo na Fakulteti za kmetijstvo in biosistemske vede UM ugotavljali vpliv kombinacije temperature in odmerka pektinaz na hitrost bistrenja jabolčnega soka sorte 'Topaz'. Obravnavanja v poskusu predstavljajo kombinacije različnih odmerkov pektinaz tipa Pektinez XXL (0,1 ml/l in 0,05 ml/l) ter temperature v času bistrenja (7 °C, 12 °C in 20 °C). Meritve motnosti soka so bile izvajane v 30 min intervalih s pričetkom neposredno po stiskanju in zaključkom 1020 min po stiskanju jabolk. Teko celotnega izvajanja poskusa so rezultati pokazali zanemarljiv vpliv temperature na hitrost bistrenja soka. Kot odločilni dejavnik za hitrost bistrenja se je potrdil dodatek pektinaz, ki je signifikantno pospešil bistrenje soka, ne glede na velikost odmerka pektinaz.

V Sadjarskem centru Maribor – Gačnik smo v letu 2010 proučevali razvoj nekaterih parametrov zrelosti in kakovosti sliv (Prunus domestica L.). V poskusu so bile vključene slive sort ´Hanita´ in´Valor´. Namen poskusa je bil ugotoviti povezavo med razvojem barve povrhnjice plodov ter razvojem okusa, ki ga determinira razmerje med topno suho snovjo in titracijskimi kislinami. Rezultati poskusa so pokazali, da barva povrhnjice plodov kot parameter kakovosti in hkrati zrelosti pri različnih sortah sliv ni dober pokazatelj razvoja okusa (in posredno kakovosti plodov) in zato ni dober napovednik optimalnega časa obiranja, saj se je v letu 2010 pri sorti ´Valor´ razvila 17 dni pred užitno zrelostjo in pri sorti ´Hanita´ cca 14 dni pred užitno zrelostjo plodov.

The study carried out at the Faculty of Agriculture and Life Sciences of the University of Maribor aimed to evaluate the attractiveness of dried persimmon fruit depending on the method of preparing the fruit for drying. The methods varied in terms of the ripeness of the fruit, the thickness and shape of the slices, the presence of seeds (in fertilised fruits) and the presence of peel. Sensory evaluation was performed by students and staff, using a hedonic scale, where evaluators evaluated the appearance (shape and colour) and taste (sugar-acid ratio, texture, tartness, presence of fruit peel, and general impression) of the fruit. Dried unfertilized persimmons, with the presence of peel, cut into 3 mm thick slices, were given the highest score for overall attractiveness. In terms of taste, unfertilised, peeled persimmon slices scored the highest. Considering all parameters, the results showed that unfertilised persimmons were more suitable for drying and that the presence of the peel was not a disturbing factor for consumers.

Geomorphologic characteristics like altitude and terrain slope have an important but often neglected impact on light conditions in orchards. The study concentrated on the impact of altitude and terrain slope in combination with various colours of anti-hail nets (red, grey, blue, green and black) on the light and microclimate conditions in apple orchards. The results exhibit a large reduction of the photosynthetically active radiation (PAR) under the nets, most prominently under blue and red nets (reduction between 38.7 and 45.6%), while the impact of coloured nets on other microclimatic parameters (average air temperature, relative air humidity, temperature of dew point, wet-bulb temperature, heat index, minimum air temperature, maximum air temperature) remain irrelevant. The only consistent difference is an average of 2% increase of maximum air temperature under the blue net in comparison to other treatments. The use of the net also significantly reduce the wind speed (on average by 56.3%) and air flow (on average by 63.4%), and changes the distribution of precipitation in the orchard, most prominently in cases of heavy rain and drizzle. Regarding the orchard’s geomorphologic characteristics, a positive relationship exists between altitude and PAR., Geomorfološke lastnosti, kot so nadmorska višina in naklon terena, imajo pomemben in pogosto spregledan vpliv na svetlobne razmere v nasadih. V raziskavi je bil preučevan vpliv nadmorske višine in naklona terena v kombinaciji z različnimi barvami protitočnih mrež (rdeča, siva, modra, zelena in črna) na svetlobne in mikroklimatske razmere v nasadu jablan. Rezultati kažejo veliko zmanjšanje fotosintetskega aktivnega sevanja (PAR) pod mrežami. Najbolj izrazito zmanjšanje PAR je pod modro in rdečo mrežo (med 38,7 in 45,6%). Vpliv barvnih mrež na druge mikroklimatske parametre (povprečna temperatura zraka, relativna zračna vlažnost, temperatura rosišča, temperaturna točka vodne kapljice, indeks toplote, minimalna temperatura zraka, maksimalna temperatura zraka) je neizrazit. Glede na ostala obravnavanja je ugotovljena le konsistentna in v povprečju za 2% višja maksimalna temperatura zraka pod modro mrežo. Uporaba mrež tudi bistveno zmanjša hitrost vetra (v povprečju za 56,3%) in pretok zraka (v povprečju za 63,4%) ter spremeni porazdelitev padavin v sadovnjaku, najizraziteje v primeru močnega dežja in rosenja. Glede na geomorfološke značilnosti sadovnjaka je gotovljena pozitivna povezanost med nadmorsko višino in PAR.

In this study, we focused on the possibility of forecasting the development of skin color in apples on the basis of weather forecast by using a machine learning methods. We used supervised learning and generated models via the use of six decision trees. The purpose of the research was to build models that would allow for in-practice-acceptable accuracy in the prediction of the development of fruit skin color (especial a colour parameter a*), for three apple varieties. For cv. ‘Gala, Brookfield’, the most accurate models were generated by using decision tree J48 (89.13% accuracy). For late ripening cv. ‘Fuji, Kiku 8’ and cv. ‘Braeburn, Maririred’, the most accurate model was obtained by using decision tree LMT (91.73 and 96.65% accuracy). The data confirm that the applicability of predictive models strongly depends on the accuracy of weather forecasts. In regard to the seven-day weather forecast, which was used for expert models, the accuracy of the models was, on average, reduced by 10.73%.

Size is an important property of all fruit as it determines, together with crop load, fruit yield. The aim of this study is to model the increase in fruit size during cell expansion based on diameter or length and to predict fruit size and volume, including the variation in size and volume, at harvest. The size of individual fruit during growth of fruit (four apple, two tomato and six pepper cultivars) was measured from early fruit set until harvest at several seasons. Size data were evaluated as diameter and length using the von Bertalanffy growth model, adapted to include the variation in size between individuals and the effect of growing temperature. The adapted von Bertalanffy model describes the increase in diameter and length and their variation. For any fruit type, size increased along the same generic growth model. A single stochastic variable, the biological shift factor, was sufficient to describe the variation in development time, initial size and maximum size. For all batches the percentage variation explained for were well over 93% with growth rate constants similar per species and only a minor effect of growing temperature. Prediction of the maximum size distribution based on measurements half way the cell expansion period is explored and discussed. Size and its distribution can be predicted based on a single measuring point in time but with two or three points in time the prediction system becomes more robust.

Size increase (expressed as diameter) of four apple cultivars in five seasons during about 130 days before harvest, was analysed with a simple first order production mechanism. All variation in diameter among individual fruit could be attributed to the same origin (development stage or biological age), with explained parts (R2 adj) of more than 98%. The same general behaviour of diameter development was observed in two tomato cultivars whose fruits where grown at two different temperatures. These data were also analysed using the same model with explained parts (R2 adj) of about 90%. Converting diameter into volume (assuming a perfect sphere), the usually observed asymmetrical sigmoidal behaviour was obtained, frequently described in growth modelling with the Richard's curve. A similar sigmoidal behaviour was also observed in the accumulation of dry matter (DM), as measured with NIR technology in growing mangoes. The cubic root of these data on DM could be analysed using the same model formulation, including the variation between individual fruit, with R2 adj well over 90%. Accumulation of DM ends at harvest, so the mechanism of DM production can very well define the final level of DM obtained in harvested fruit. Since sugars and DM are strongly related (e.g., conversion of starch into sugars, Brix values), a very similar mechanism could govern the accumulation of sugars. Destructively measured data on sugars were collected in nectarines, showing indeed a very similar overall behaviour and variation. This indicates that growth (diameter, mass) and quality increase (DM, sugars) could be described by a very similar mechanism, providing the first tools in the quest to harvest quality.

Selection of a proper cultivar is one of the most important management decisions when investing into apple orchard. This paper presents a methodology for evaluation of suitability for cultivation of some apple cultivars by using a multi-criteria model based on analytical hierarchy process. The software tool Expert Choice was used to support growers in making decisions about which new apple cultivar to grow. The model was applied to 13 cultivars with data derived from questionnaires completed by group of experts of different fields (orchardists, experts for fruit production economics and fruit marketing, cultivar breeders, experts of state service and commission for introduction of new cultivars, experts for fruit storage and fruit quality assessment, plant protection and fruit growing advisers). The results are shown as priority for individual cultivar. The potential of the model for assessing apple cultivar is demonstrated with the aim of providing a comprehensive explanation and justification of the assessment technique. It also indicates strong and weak points (in market potential, fruit estimation, production demands and tree estimation) of each assessed cultivar.

Summary The orientation of this research was to evaluate the classic parameters regarding the external and internal quality of tomato fruits cv. 'Brilliant' at different stages of maturity and to define the dynamics of their changes during the ripening in storage at 18 C. Principal component analysis (PCA) and multivariate canonical discriminant analysis (DA) were used to classify tomato samples according to quality (internal and external) and nutritional value based on fruit mass, fruit skin colour, contents of soluble solids (SS), total titratable acids (TTA), ascorbic acid (AA), and total antioxidant potential (TAP). Several methods are usedfor determining AA content and TAP in plant samples. A simple routine method, direct redox titration with iodate solution and spectrophotometric determination of TAPSP, as described by Singleton and Rossi, also called total phenols, were used respectively. The results show that the stage of maturity (based on fruit skin colour) strongly determines the quality and nutritional value of the tomato fruit. Tomatoes harvested at table maturity (red colour, index a*/b* ≥ 0.85) have a significantly higher nutritional value (in terms of antioxidants - TAPSP and AA content) and overall quality than those harvested at an earlier maturity stage and then ripened in storage. This brings out the importance of short food supply chains and, from the viewpoint of overall fruit quality, it raises doubt about harvesting before reaching table maturity. On the other hand, it is necessary to be extremely attentive when determining optimal maturity, because when the plant becomes over-ripe or when stored, the nutritional value and overall quality decrease drastically. Besides the colour parameters, AA content is the most important chemical marker for a simple quality control. By using a simple and reliable analytical method for determining AA content, such as direct redox titratiation, the monitoring of tomato fruit quality could also be easily performed in situ.

Traditionally, crop load and fruit yield from previous seasons are used as indicators for prediction of fruit size. Disregarding the inevitable biological variation between fruit, von Bertalanffy (1938) described the growth, expressed as length, of virtually any living organism. The model is here extended to include the variation between individuals in a batch. Using this extended model, fruit size and its variation can be predicted, using measurements of a large number of fruit at a single point during early development. The diameter of 200 tomatoes was measured 15 days after full bloom (DAFB). Using the density function derived from the extended von Bertalanffy model, and applying prior knowledge of some of the model parameters, the variation in size at harvest could be predicted. Validation of the results was obtained by comparing the predicted sizes with the diameters of the same tomatoes at harvest.

During the 2008–2010 growing seasons, an alternative ‘zero residue apple production system’ was compared with integrated apple production with cvs ‘Idared’, ‘Golden Delicious’, ‘Jonagold’ and ‘Gala’ in commercial orchards at several locations throughout Slovenia, using data envelopment analysis (DEA), and multi criteria assessment by an analytical hierarchical process (AHP). The principle of the ‘zero residue apple production’ is a combination of integrated (IP) and organic apple production. During the first 3 months of the growing season (1 April–30 June), pesticides used in IP with rapid degradation (8–10 applications) were used to control pests and diseases. During the second part of the season from 1 July to harvest, organic products (6–12 applications) were employed compared with 19–25 applications overall in IP. The goal of the alternative system was to reduce the amount of applied conventional pesticides by 40 % and to minimize pesticide residues in fruits to below the limit of 0.5 % of the legal maximum residue level (MRL) or below the residue concentrations of 0.005–0.01 mg/kg and to retain the high long-term level of yield, fruit quality, and net income per hectare. The number of pesticide residues was reduced from 4.2–5.5 in IP to 1.8–3.4 in zero residue cultivation, while 3 year average yields (class 1 fruit) were 4–9 % lower than in IP. The break even prices ranged from € 0.31 for Idared in IP, € 0.34 for ‘Elstar’ of both production systems to € 0.35/kg for zero residue cultivated ‘Golden Delicious’. Overall, a price increase of just € 0.02/kg for residue free apples would make this new ‘zero residue apple production’ profitable then representing a realistic alternative to the standard integrated apple production system.

Consumer expectations of apple fruit quality have been steadily increasing over the last couple of decades. One of the main quality attributes affecting product price is colour, determined primarily by the relative amounts of pigments chlorophylls, carotenoids, and anthocyanins, which can be measured non-destructively by visible spectrophotometry. This paper provides a brief overview of studies dealing with the optical pigment-determination of intact apple fruits in visible part of electromagnetic spectrum. Firstly ripening-associated pigment changes in apples as well as the basics of light interaction and measurements in turbid materials are explained. Subsequently the two most appropriate methods for pigment determination of intact apple fruit are presented along with examples. This is followed by a discussion of the various reflectance and remittance indices for the qualification, as well as quantification, of the main apple pigments. Results are reported regarding studies on the relationships between spectral data and derived indices with various destructive quality and ripening parameters. In the conclusion some of the main findings reviewed in this paper are outlined and discussed briefly .

Fruit pigmentation in ripening cv. ‘Gala, Schniga’ apples was monitored under the influence of fertigation weekly during 21 July–31 August 2009, i.e. 34 days before and 7 days after the optimal harvest date in Slovenia. The soil was a heavy loam clay with high humus content (2.8 %) and high acidity (low pH 4.9). The spectral indices NDVI (Normalized Difference Vegetation Index) and NAI (Normalized Anthocyanin Index) were obtained by a PA 1101 on attached fruit on the transition between the ground and blush colour of the fruit surface. NAI increased slowly from 0.25 to 0.6 two weeks prior to optimum maturity. NDVI values fell from 0.9 to 0.2 before and during ripening, with significant changes starting ca. 3 weeks before and during the week after the optimum harvest date. Fertigation delayed fruit ripening viz harvest date by ca. 4 days. Fertigation delayed changes in the intensity of the fruit’s epidermal pigments, expressed as NDVI for 1 week and NAI for 4 weeks, respectively, but had no significant effect on fruit colour or NDVI and NAI values at the optimal harvest date. At this time, those fruits from the fertigated trees were firmer with a lower starch index compared with the un-fertigated control. Statistically, highly significant correlations were found (p ≤ 0.01) (r = 0.35 to r = 0.91, R2 = 0.11–0.83) between all the studied spectral and standard parameters i.e. fruit fresh firmness, soluble solids content and starch index.

Colour and taste are important attributes of apple fruit quality and have therefore been widely studied. Nevertheless, because of the destructive sampling methods commonly used to obtain the data, and of the subsequent traditional analyses, ignoring the effects of biological variation, the knowledge on the kinetic mechanisms of synthesis and degradation of individual quality components during fruit development and growth is still lacking. Spatio-temporal changes of taste components (sugars: fructose, sucrose, glucose, organic acids: malic, citric, shikimic and fumaric acid) and colour aspects (a) in individual apple fruits were monitored to assess the dynamics and mechanisms of change during development and ripening with respect to location within fruit as a factor and the variation between individual apples. Data were analysed with non-linear indexed regression based on either a logistic or an exponential process oriented model assessing the technical variation simultaneously. The rate constants for colour or taste component were roughly similar between cultivars, suggesting a similar mechanism of development and confirming the generic nature of the model. There was a very large biological variation in individual quality components observed in the raw data (the biological variation), which can be almost exclusively explained by the difference in the maturity stage between individual fruit. The explained parts (R2 adj) were, with one exception, higher than 0.90. The major contribution of this study is the fact that all the herein monitored taste defining components can be analysed and described with the same process-oriented model.

Field trials were carried out from 2008 to 2011 at Maribor, Slovenia to determine the effect of new copper fungicide formulations on the copper content in apple fruits, separated in peel and flesh, of seven cultivars at harvest. Apple trees were treated 12–18 times per season with formulations based on copper oxychloride or sulphate (trial standards), copper hydroxide and their complexes or chelates with amino acids, peptides, EDTA, urea, and octanoic or gluconic acids at the same rate of 200 g of pure copper ions (Cu2+) per hectare irrespetive of the product. Copper formulations were applied with Teejet 800067 flat fan nozzles mounted on a vertical boom of the sprayer, which gave a droplet volume median diameter (VMD) of 120 microns and 130–180 droplet impacts per square centimeter, as determined on water sensitive papers. The new formulations of copper in the form of salts of fatty acids or organic complexes or chelates had a higher penetration rate into apple fruit tissue than the traditional formulations based on Cu-hydroxide, Cu-oxychloride and Cu-sulphate. The copper content in the fruit depended on the ratio between copper solubility in the formulation, rate of penetration into the fruit and stability of the copper fungicide deposit on the fruit surface. Despite being applied at lower hectare rates, frequent applications led to the exceeding of the permitted EC maximum residue level of 5 mg/kg fresh mass (FM). MRL was most often exceeded with the application of formulations based on Cu-octanoate and Cu-gluconate and less often in case of the application of complexes of copper with amino acids, peptides or urea. A comparison of the copper content between different cultivars showed that cv. ‘Jonagold’, ‘Golden Delicious’ and ‘Elstar’ accumulated more cooper than other cultivars. Copper concentrations in the peel exceeded that of the flesh at least twice. The potential effects of accumulation of copper in woody tissue of bearing shoots after long-term application of highly systemic copper formulations on growth and blooming of apples are discussed too. Some apple growers may not be aware of much higher penetration rate of these new copper products (fungicides, fertilisers or plant strengtheners) and should be warned about the necessity to adapt their spraying schedules despite applications of a low hectare rates of copper, i.e. the number of treatments and proper seasonal timing, to avoid exceeding of EU MRL of copper in fruit.

Streuobst stands, i.e., tall fruit trees on vigorous rootstock on traditional grassland, represent an important source of raw material for the processing industry and for traditional fruit processing on family-run farms. Apart from production aspects, the high-stem orchards also play a role in the conservation of the traditional landscape, and indirectly in maintenance of the viability of rural areas. In this paper, a qualitative multi-attribute model for the assessment of Streuobst stands with respect to their multifunctional characteristics is presented. The assessment is based on four groups of attributes: (1) production criteria (percentage of missing trees), (2) biodiversity (fruit species and varieties, artificial human intervention), (3) landscape diversity (visual appearance, eco-diversity and erosion protection), and (4) function of the stand (row or individual trees, countryside appearance). The assessment is based on the aggregation of input attribute values to an overall assessment through user-defined decision rules. The model was applied to 85 sample stands in NE Slovenia. The assessment shows that most of the stands (48) were rated as “very poor” or “poor”, mainly as a result of poor cultivation and lack of maintenance.

The purpose of this study was to evaluate the contribution of extractable antioxidants and non-extractable phenolics to the total antioxidant activity (TAA) of plums. Therefore, the antioxidant activity was determined (ABTS assay) in aqueous–organic extracts, as well as in the extraction residues which were a subject of two different acidic treatments to release hydrolysable tannins and non-extractable proanthocyanidins (NEPA). In addition, the changes in TAA during the last week of ripening were investigated. Extractable antioxidants contributed less than 18% to the TAA, considerably higher values of antioxidant activity were associated with hydrolysable tannins and NEPA, suggesting that the antioxidant activity of plums may be underestimated in the literature. The ripening resulted in an increase of TAA up to 38% in excess of the value determined on the first sampling date. TAA showed a similar pattern over the ripening period for all cultivars studied.

BACKGROUND: In managing apple orchards, crop load and rate of nitrogen (N) fertilisation are two factors with a significant influence on fruit quantity and quality, because they affect all physiological processes in the tree. Both factors are strongly related to external and internal fruit quality, especially to skin colour, sugar and acid contents and mineral composition, and consequently to the keeping quality of fruits. The aim of this study was to assess the effects of both factors (three crop load levels and two N fertilisation levels) on the colour development of Golden Delicious apples during the last month on the tree in two consecutive seasons. Data on skin colour (L*, a*, b* values) were analysed using nonlinear mixed effects modelling to extract information on the variation in biological shift factor for colour and to link this variation to the different strategies used concerning N fertilisation and crop load. RESULTS: The major source of information is contained in the a* value. The behaviour of the a* value could be described by a logistic or an exponential model depending on the season and the experimental set-up. Nonlinear mixed effects analysis estimating the biological shift factor (maturity) for each individual fruit (random effect) while estimating the rate constant of the decolouration process in common (fixed effect) resulted in explained parts well over 95%. CONCLUSION: The variation in maturity stage between individual fruits is large. Season has the most profound effect on the estimated values, far more important than that of crop load or fertilisation level. The magnitude of variation in colour due to crop load and N fertilisation is not too large. Its effect on the maturity stage of fruits is more profound: the higher the crop load, the higher the variation. The effect of fertilisation seems to be opposite: the higher the fertilisation level, the lower the variation.

The trial was conducted in a ‘Gala’/M9 orchard and the experiment was designed as a randomized block comprising four treatments (application of Prohexadione-Ca: 125 mg-l, 250 mg-l, 2 x 125 mg-l, and control - without growth regulator). Experiments have been carried out for 2 years (2003, 2004). Application of Regalis reduced trunk cross-sectional area increment, and cumulative extension shoot growth. The effect increasing with concentration, and a greater inhibition was obtained when the trees were sprayed two times. Compared to control, return bloom of Regalis-treated trees was not affected. No negative effects of treatment with Regalis on yield per tree were observed, but some reduction of average fruit weight was found.

Biological variation is omnipresent in nature. It contains useful information that is neglected by the usually applied statistical procedures. To extract this information special procedures have to be applied. Biological variation is seen in properties (e.g. size, colour, firmness), but the underlying issue is almost always to the variation in development or maturity in a batch of individuals generated by small scale environmental differences. The principles of assessing biological variation in batches of individuals are explained without putting emphasis on mathematical details. Obtained explained parts increase from about 60 to 80 % for the usual approach to 95 when the biological variation is taken into account. When technical variation or measuring error is small even 99 % can be achieved. The benefit of the presented technology is highlighted based on a number of already published studies covering the colour of apples during growth and storage and the firmness of cut tomatoes during storage

The trial was conducted in 'Fuji'/M9 orchard in Slovenia with 5100 trees ha-1. The experimental design was as split-block comprising three rates of nitrogen (N) as broadcast fertilizer application with 60, 90 or 120 kg N ha-1, and three crop load (5.0, 3.5 or 1.5 fruits cm-2 trunk cross sectional area (TCSA)). Treatments with different N rates lasted two years beginning in the fourth year after planting. In the 4th growing season, crop load was adjusted by hand thinning whereas in the next year fruits were not thinned (control year). The major effect of excessive crop load on 'Fuji' apple was reduced return bloom. A positive relationship was found between N rates and TCSA in year of applied treatments and return bloom in control year. Results showed no significant effect of N treatment on size and internal fruit quality.

BACKGROUND: Homogeneity in appearance is one of the quality aspects asked for in the supply chain. Decreasing the biological variation in batches of harvested apples (cultivars Braeburn, Fuji and Gala) becomes increasingly important. Skin colour is one of the aspects that determine both optimal harvest and stage of development. Skin colour is affected by location in the canopy. The rules of development of biological variation are now established and will be used on skin colour data. RESULTS: The Minolta colour aspects a*, b* and L* measured before commercial harvest change in a sigmoidal fashion and can be analysed including the biological variation, with a logistic model in indexed nonlinear regression, obtaining explained parts of above 90%. The mechanism of colour change is not affected by state of development or location in the canopy. The location in the canopy affects the intensity of both red and green colouring compounds. The variation in colouration is not affected by the location in the canopy. CONCLUSION: The red-coloured apple cultivar (Gala) depends more on the location in the canopy than the less-coloured cultivars (Fuji and Braeburn). The colour development in Fuji apples is considerably slower, with a much larger variation in stage of development. The location in the canopy affects all aspects of biological variation (biological shift factor and asymptotic starting level of colouration) for all three colour aspects L*, a* and b*, but only the mean value, not the standard deviation. The biological shift factors per colour aspects are linearly related. Once induced, variation remains constant during development.

The influence of different storage conditions on the storability of packaged shredded cabbage has been studied. The cabbage cultivar Fieldrocket was cut and packaged in glass jars and in polyethylene (PE) or polypropylene (PP) film. Several initial atmospheres were established within the packaged cut cabbage: 100 % N2, 5 % O2/95 % N2, 10 % O2/90 % N2, normal atmosphere (NA), 70 % O2/30 % N2 and 100 % O2. Samples were stored at two different temperatures of 0 and 10 °C for 7 days. Variation in CO2 and O2 concentrations was higher at 10 °C compared to 0 °C and the highest at the atmosphere consisting of 70 % O2/30 % N2. A decrease of O2 below 3–5 % and an increase of CO2 above 2–5 % in the packed product resulted in the appearance of anaerobic metabolism. An initial atmosphere consisting of 100 % O2, and a storage temperature of 0 °C resulted in delayed anaerobic metabolism compared to other atmospheric conditions and storage temperature of 10 °C. Rinsing of fresh cut cabbage also resulted in lower accumulation of acetaldehyde and ethanol. A higher variation in CO2 and O2 concentrations, and consequent accumulation of anaerobic metabolites had a negative influence on the sensorial properties of the cut cabbage. The higher permeability of PE film compared to PP and glass enabled faster exchange of CO2 and O2, which resulted in lower accumulation of anaerobic metabolites. However, a higher O2 concentration had a negative influence on the colour of fresh-cut cabbage. The best results were achieved by packing the fresh-cut cabbage in PE film with an initial atmosphere of 100 % O2 and stored at 0 °C., U radu je istražen utjecaj različitih uvjeta skladištenja na kakvoću pakiranoga rezanog kupusa. Upotrijebljen je kultivar Fieldrocket koji je, nakon rezanja i pranja, pakiran u staklenke, polietilensku (PE) ili polipropilensku (PP) foliju. Kupus je pakiran pri različitoj početnoj atmosferi: 100 % N2, 5 % O2/95 % N2, 10 % O2/90 % N2, normalnoj atmosferi (NA), 70 % O2/30 % N2 i 100 % O2. Svi su uzorci skladišteni na 0 i 10 °C tijekom 7 dana. Intenzitet respiracije bio je veći u uzorcima skladištenim pri 10 °C, pakiranim u atmosferi sastava: 70 % O2 i 30 % N2. Snizivanje udjela O2 ispod 3–5 % i povećanje udjela CO2 iznad 2-5 % dovelo je do pojave anaerobnog metabolizma. Početna atmosfera od 100 % O2 i temperatura od 0 °C odgodila je pojavu anaerobnog metabolizma u usporedbi s ostalim sastavima atmosfere pri temperaturi od 10 °C. Ispiranje narezanog kupusa vodom smanjilo je nakupljanje acetaldehida i etanola. Veći intenzitet respiracije uzrokovao je jače nakupljanje anaerobnih metabolita, te je negativno utjecao na senzorska svojstva narezanog kupusa. Veća propustnost PE folije u usporedbi s PP folijom omogućila je bržu izmjenu CO2 i O2, a time i manje nakupljanje anaerobnih metabolita. Međutim, povećanje udjela O2 u atmosferi pakiranja negativno je utjecalo na boju svježe narezanog kupusa. Najbolji su rezultati postignuti pakiranjem svježe narezanog kupusa u PE foliju s početnom atmosferom od 100 % O2, pri temperaturi od 0 °C.

A trial was conducted over two years in a 'Topaz'/M9 orchard (4000 trees/ha) using a randomized block design comprised of five fertilizer treatments: 400 kg/ha Compo Guano (11% N), 880 kg/ha Maltaflor Special (5% N), 880 kg/ha Agrovit (5% N), 550 kg/ha Biosol (8% N) and an unfertilized control, and two types of orchard floor management: tree row clean-cultivated and grass within the tree row mowed. The treatments began in the third year after orchard establishment. Trunk cross sectional area (TCSA), the number of flower clusters per tree, fruit set, yield and average fruit weight were determined. The tree growth (TCSA increment) was significantly higher following treatments with Maltaflor Special and Agrovit than with Biosol. The cumulative yield per tree was higher following application of Agrovit than Biosol or Maltaflor Special, but no treatments significantly increased cumulative yield compared with the control. No significant differences were found for growth, yield and external fruit quality parameters for the other fertilizers and vegetation management methods, compared with the control.

Utjecaj folijarne aplikacije nekih hraniva, sa ili bez fertirigacije s dušikom, u uspredbi s klasičnom gnojidbom s dušikom, na vegetativni rast, rodnost, te sadržaj mineralnih elemenata u plodovima, istraživan je sa sortom Golden Delicious, cijepljenom na podlozi M9, tijekom 2000-2002. Istraživanja su obavljena u dva subpokusa: u prvom počevši s dvogodišnjim, a u drugom s trogodišnjim voćkama. U obadva pokusa voćke su uzgajane kao super vreteno (razmak sadnje 3.2 x 0.7m). Rezultati istraživanja ukazuju na veće značenje opterećenja rodom, a relativno mali učinak folijarne gnojidbe na rast, rodnost i sadržaj mineralnih elemenata u plodovima u godinama ulaska u produktivnu dob. Kada su stabla bila prikladno opterećena rodom, sadržaj i odnosi N/Ca, K/Ca i (Mg + K)/Ca bili su u granicama koje omogućuju uspješno čuvanje u hladnjači. Nasuprot tomu, u stabala s niskim opterećenjem, niti primjena folijarne gnojidbe nije pridonijela poboljšanju sadržaja mineralnih elmenata i plodovi su bili neprikladni za duže čuvanje u hladnjači., The effect of foliar application of some nutrients and fertigation in comparison with broadcast nitrogen fertilization on growth, yield and mineral fruit composition of young apple ‘Golden Delicious’, grafted on M9 rootstock was investigated in years 2000-2002. Two orchard experiments were established, one with 2-year and the other with 3-year old trees, grown at a spacing of 3.2 x 0.7 m and trained to super spindle. The results showed low beneficial effect of applied treatments, and relatively high effect of crop load on growth, yield and fruit mineral content. Ratios of N/Ca, K/Ca and (Mg + K)/Ca in fruits indicated good storage quality as related to normal crop load. Contrary to that, when treatments were applied on trees with inadequate crop load, no beneficial effect occurred and fruits showed low storage life. This result illustrates the important balance between vegetative growth and fruit load that occurs during tree establishment.

In central Europe there are many backyard fruit growers who receive no proper education about fruit tree care. Their knowledge is mostly based on various handbooks and learning through trial and error. Such learning is slow and can even result in damage to the tree. To shorten the learning time, a new interactive teaching tool EduAPPLE has been developed based on the basic laws of apple tree (Malus ×domestica) growth and training. Pruning, weighting, tying, and spreading can be interactively practiced over and over again without any danger to the actual trees. Training responses are immediately seen and are analogous to those of real trees. They are not only predetermined by a set of rules, but also calculated based on the changes the actions cause to the light interception of the tree. EduAPPLE enables high-quality views of trees and their light interception from all angles in real time and is designed for education regarding free-standing apple tree training (spindle). It can, therefore, be used in schools, universities, and other educational organizations, as well as by tree growers, including the large number of growers having only a few fruit trees.