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Sunburn assessment: A critical appraisal of methods and techniques for characterizing the damage to apple fruit
7-14.Views:307Many methods and techniques have been introduced for measuring alterations in the fruit and in its surrounding environment related to sunburn incidence. The research objectives, fruit materials and the environment to be evaluated dictate the methods to follow. These procedures are either non-destructive and involve techniques that allow us to track the course of sunburn development and related environmental parameters, or destructive and involve the removal of fruit from the tree for field/laboratory measurements. Techniques employed can be used for pre-symptomatic monitoring (before symptoms become visible) or characterizing the symptoms already present. The principles behind the measurements and their usefulness for sunburn assessments are discussed and critically evaluated in this review paper. Descriptions and evaluations of the methods and techniques were made in the following groups: 1. Thermal measurements; 2. Visual assessments; 3. Fruit quality measurements; 4. Measurements of physiological and biochemical alterations; and 5. Practical evaluation of sunburn damage. Thermal measurements involve methods tracking the ambient temperature and fruit surface temperature, and their relation to sunburn formation. Visual assessments cover all measuring techniques (skin color, chlorophyll fluorescence, radiation reflection, electron microscopy) that are able to detect changes on/in the fruit skin related to sunburn formation. Fruit quality measurements are used to point out differences in qualities (soluble solids, firmness, titratable acidity, and water content) between unaffected and sunburned areas of the fruit. The measurements of physiological and biochemical alterations (gas exchange, pigment analysis, enzyme activity, gene expression) give us a better insight to the mechanism of sunburn formation. Practical evaluations involve many procedures that are used by scientists to characterize the susceptibility of cultivars, evaluate protection technology, etc. For this purpose, the following methods are in use: expressing the percentage of the total fruit surface area affected by sunburn or the percentage of the total number of fruits damaged on the tree, or even a scale based on the severity of the symptoms occurred. All assessing methods and techniques described here have their pros and cons as well as their specific applicability, therefore any of these cannot be favored to use exclusively for assessing sunburn incidence. The combination of these techniques will be the best choice to meet a given research objective perfectly.
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Fruit Quality of Sweet Cherry Cultivars Grafted on Four Different Rootstocks
59-62.Views:175A rootstock trial planted at the Szigetcsep experimental station in 1989 involved the study of two cultivars- `Germersdorfi FL 45' and 'Van' -grafted on four different rootstocks — 'Colt', `MxM 14 — Brokforest', `MxM 97 — Brokgrow' and 'Saint Lucie 64' as a control. The trees were trained to the "Modified Brunner-spindle" system and came into bearing in 1993. The yield per tree, fruit weight and fruit diameter have been measured each year since then. The refractivity, the acid content of the fruit juice, fruit cracking after four hours' dipping in water and stone weight ratio have also been measured since 1995. In 1997 and 1998 these parameters as well as fruit cracking after 24 hours' dipping were measured. Fruit firmness and fruit colour were also estimated. In almost every observed parameter significant differences were found between the scion cultivars. Yield efficiency was significantly higher on 'NUM 14' and 'Saint Lucie 64' than on the other two rootstocks. As regards fruit weight, in both cultivars and over an average of six years, it was found that trees on low yielding tree on 'Colt' rootstock had the highest fruit weight values and on heavy producing `MxM 14' the smallest. Soluble solids content was higher on 'Colt' and `MxM 97'. No significant differences between the rootstocks were found in acid content of the fruit juice. There were significant differences between the rootstocks in fruit cracking after 4 and 24 hours' dipping in water. Seemingly with respect to cultivars and rootstocks the year has a considerable effect on fruit cracking.
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Extending the vase life of Solidago canadensis cut flowers by using different chemical treatments
83-86.Views:182In order to increase the vase life as well as quality of leaves of goldenrod (Solidago canadesis), the effect of 8-hydroxyquinoline sulphate (8-HQS), silver thiosulphate (STS) and l-methylcyclopropene (l-MCP) were investigated. 8-HQS was used as a continuous treatment at 400 ppm with or without sucrose at 50 g/l. The treatment of STS was used by putting the flower bases at 0.4 mM for 6h with or without sucrose at 50 g/l. l -MCP was used at 0.5 g/m3 for 6h dry or in water. Except the treatment of l -MCP in water, the chemical treatments, which were used, led to the increase vase of life of leaves as well as to the inflorescence of cut solidago spikes compared to the control. The best treatment in this concern was 8-HQS at 400 ppm without sucrose, which resulted in longest vase life of leaves as well as inflorescences and lowest percent loss of fresh weight of initial.
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Effects of Foliar Nutrition on Onion Seed Storage under Modified Atmosphere Packages
93-100Views:198Modified atmosphere packaging (MAP) and controlled atmosphere storage techniques to reduce the oxygen around the food are largely used for the preservation of fresh produce. There have been great technological advances in this area of preservation, particularly as it refers to improving the quality and shelf-stability of highly perishable food products, such as produce. Two successive winter seasons of 2008/2009 and 2009/2010 were conducted under sandy soil conditions to study the effect of spraying with 12 commercial compounds on onion seeds storage under modified atmosphere packages. Germination percent of seeds decreased in 5°C than storage in room temperature. Germination percent of seeds was gradually decreased with increasing the storage period. Packaging treatments had a significant effect on germination percent of seeds. All the packaging treatments had the higher germination percent than the paper package (control). The highest germination percent after 12 months of storage was recorded for the treatment with non perforated polypropylene in room temperature and polyethylene and non perforated polypropylene in 5°C. Catalase activity decreased with the prolongation of storage period. The non perforated polypropylene package had the highest catalase activity. The treatment with non perforated polypropylene had the highest catalase activity after 12 months of storage in both room and 5°C temperatures. Peroxidase activity of seeds was gradually decreased with increasing the storage period. The highest peroxidase activity after 12 months of storage was recorded in non perforated polypropylene in both storage temperatures.
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Cracking susceptibility of sour cherry (Prunus cerasus L.) in Hungary and relation to calcium application
109-118.Views:279The rain induced fruit cracking is a big, serious problem especially for sour cherry growers but in some year sour cherry growers had also problem with fruit cracking caused by too much rainfall in the harvesting season. The cracked sour cherry fruits can be easily infected by different diseases like Monillinia sp. Cracked and infected fruits can not be transported for long distance and using for preservation because they lost their market value by the pour fruit quality. There are two possibilities to protect fruits against the rain induced fruit cracking. The most effective protection technique is the plastic rain cover over the tree rows. The installation of these equipments is too expensive for the growers. That is the reason why researchers tried to find other less expensive and sufficiently effective ways like sprayings different mineral salts, hormone and other type chemicals against the rain induced fruit cracking. Several calcium formulas calcium chloride (CaC12), calcium hydroxide (Ca (OH),) and calcium nitrate (Ca(NO3)2) can be sprayed in appropriate solution concentration.
The aim of our trial is to determinate the fruit cracking susceptibility of wide grown Hungarian sour cherry varieties and find the most effective calcium formula and its concentration for spraying in orchards to prevent the fruit cracking. In the first trial year (2006) cracking index of tested sour cherry varieties were determined under field and laboratory conditions. Under field conditions were not found differences between cracking tendency of tested cultivars. After results of immersing fruits in distillated water for 24 hours tested sour cherry varieties were divided to three groups by the susceptibility to rain induced fruit cracking: very susceptible (`Maliga emléke', 'Piramis', 'Érdi jubileum', 'Erdi nagygyümölcsű’ and 'Meteor korai'); susceptible ‘Érdi bőtermő, Tandy 279' and Cigány 59.; moderately susceptible/tolerant ("T" and "R" clones). In the second trial year (2007) calcium chloride (CaCl2) and calcium nitrate (Ca(NO3)2) were sprayed in 0,35m/m%; 0,5m/m% and 1,0m/m% solution concentration. One more commercial product "Damisol-Kalcium" was also applied in the advised 1,0m/m% concentration. Like in the trial year before (2006) under field conditions we did not kept differences between the cracking susceptibility of varieties and calcium treatments. As the result of laboratory testing (immersing calcium treated fruits in distillated water) we kept that calcium chloride (CaCl2) seems the most effective against the fruit cracking in 0,5m/in% solution concentration. The other calcium formulas also decreased the cracking ratio but in less scale.
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Study of genetic resources for Powdery mildew resistance by biochemical and physiological parameters on peaches and nectarines in Romania
57-61.Views:122During 1997-2002, studies on the physiological and biochemical changes due to powdery mildew attack in peach and nectarine cultivars and hybrids belonging to different classes of resistance had been performed at the Research Station for Fruit Tree Growing (RSFTG) Baneasa Bucharest, located in the southern part of Romania. The study was based on disease assessments in the field and on other diagnosis criteria.
The southern part of Romania has favourable ecological conditions for growing peach and nectarine but trees have been attacked by various pathogens such as Sphaerotheca pannosa (Wallr.: Fr.) Lev. var. persicae Woronichin fungus for a long time. The presence of the pathogen causes important changes in the quantity and quality of fruits and affects the metabolism of trees.
This study was focused on several physiological and biochemical parameters such as photosynthesis and respiration intensity along with catalase activity; and changes in some biochemical compounds such as free, total and linked water content, dry matter, nitrogen and protein content, tannin levels. The aim was to find possible correlation among the above parameters and the biotic stress induced by the powdery mildew fungus calculated as attack degree (AD%).
Results showed that photosynthesis diminished significantly in the case of the attacked phenotypes, the respiration was more intense in the infected cultivars and catalase proved to be less intense in the affected plants. The total water content significantly increased in contrast to the dry matter and tannin contents, which greatly reduced in the case of resistant cultivars such as 'Victoria', Vectared 7', 'KB 11-40'. The total nitrogen and protein levels showed less influence on resistance to powdery mildew on all cultivars. All genetic material found resistant to powdery mildew is currently used in peach and nectarine breeding programs in Romania.
Further studies focused on isolation and characterization of resistance genes for powdery mildew resistance will be done in the future based on data collected during several years.
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Evaluation of morphological parameters and bioactive compounds in different varieties of beetroot (Beta vulgaris L. ssp. esculenta GURKE var. rubra L.)
31-35.Views:389Beetroot consumption based on pickled beets generally in Hungary which is due to the higher yield from second crop harvested in autumn and processed by manufacturing industry. Researches of the past years confirmed its favourable nutritional-physiological effects on human body so demands, as for fresh salad, also increased. The trial aimed at testing the interaction of varieties on quality parameters and in the same time suggestions are made how to use different varieties of beetroot according to its quality. Morphological and sensory evaluations were examined on 10 varieties of beetroot harvested in autumn. The regular spherical shape can reduce the refining loss during the processing of beetroot which is beneficial for the manufacturing industry. In our trial the root shape of Libero, Mona Lisa and Rubin varieties approached most the regular spherical shape (diameter/length – 1.0) which is favoured by not only processing industry but also fresh market. The highest red pigment content (betanin) was observed in Mona Lisa, Akela and Cylindra (34.58–47.66 mg/100 g). A similar trend could be observed in yellow pigments (vulgaxanthins) which proves the close correlation between the quantities of the two pigments (r=0.898). Highest total polyphenol (77.13–83.37 mg GAE/100g) and flavonoid (21.73–22.73 mg CE/100g) contents were detected in Akela, Mona Lisa and Bonel. These varieties are favourable for fresh salad and they can satisfy processing requirements also. Highest water soluble solids content was found in Akela (7.15%). In our conditions nitrate (NO3-N) values below 900 mg/kg were examined in all of the varieties which is favourable in the case of beetroot.
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Concentration of ‘Oblachinska’ sour cherry juice using osmotic distillation
31-34.Views:230Sour cherry is one of the most famous and characteristic Hungarian fruit what is also commonly used in food production as a colour additive. The sour cherry cultivar, ‘Oblachinska’ was shown to be a rich source of antioxidant compounds, including mainly anthocyanins. Valuable compounds in fruit juice – vitamins, polyphyenols etc. –are heat-sensitive molecules, which should be taken into account during the process of concentration to prevent degradation. Osmotic distillation seems a suitable option to product high quality sour cherry juice because this process does not require high temperature or pressure. Raw juice with approximately 15°Brix was used for the experiment and tried to concentrate up to 60° Brix where the water activity low enough to inhibit the microbiological deterioration. Before and after the process, TPC (total phenolic compounds) and FRAP (ferric reducing antioxidant power) was measured using spectrophotometric methods to determine the effect of the osmotic distillation. Our results point out that osmotic distillation is a promising method to concentrate sour cherry juice and prevent the loss of valuable compounds.
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Pedological and agrochemical investigations on media using in vegetable forcing
119-122.Views:111In spite of the several good properties of peat, recently, some experiments were carried out with the aim of finding natural materials which can substitute for peat. According to the results, several inorganic and organic materials were proved to be suitable for this purpose. This study examines the effect of different organic materials (example: pine bark, composts, peats) on the growth and yield of green pepper (Capsicum annuum L., variety Danubia). We found that the most developed plants were grown in peat-mixtures and pine bark. The average fruit weight was the highest at those plants which were planted also in these media. The plants which were grown in composts fell short of our expectations in development and in yield, too.
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Mulching in grape plantations
25-31.Views:140In continuous studies regarding the conservation of the advantageous condition of the soil structure, the highland plantations that are surrounded by living waters have major importance where the erosion of the soil, nutrients and chemicals endangers the quality of the water and the living world of the waters. At the same time the extreme weather and dry summers of the past years have made it important to look for soil cultivation solutions and technologies that are capable of decreasing the evaporation of the soil, for enhanced conservation of soil moisture and to improve the soil structure that is required for the growth of healthy roots. In our experiment we have studied soil mulching with organic plant residue, by sods and the effect of the mechanical cultivation on the soil and on the grape through two growing seasons. From the studied treatments, the mulching with organic plant wastage showed the most efficient results from the point of view of the nutrient distribution in the grape and yield. It also had a positive effect on the soil structure and humidity.
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Agroclimatological properties of growing sites assigned to apple and pear production in Hungary
95-97.Views:171Apple and pear growing sites in Hungary are classified into four regions according to the Hydro-thermic Coefficient: dry, moderately dry. moderately humid and humid. Most of the plantations of apple and pear are located in regions considered as moderately dry and moderately humid. Within that category, the two respective species have different preferences, i.e. the ecological features of Hungary give different opportunities for apple and pear growing. Apple is grown almost everywhere in the country, successfully. The selection of cultivar-regions is needed mainly for increasing competitiveness on the market. Main apple growing regions are listed in 3 large groups. For the definition of cultivar-regions, mainly the configurations of soil and precipitation, i.e. conditions of the soil and opportunities of gaining water were decisive. Market factors are also considered. The area assigned to pear is much less than that of apple, in Hungary. Some well known and popular varieties would require high air humidity which cannot be presented in most of Hungary. Therefore, the possibility to establish regions for pear varieties is restricted, we have to create a particular micro-environment. Two groups are potential. The first one comprises sites where the annual precipitation is 700 mm, at least. There, apple and pear production would compete each other. In more dry habitats (less than 700 mm annual precipitation), micro-environments should be found and only drought-resistant, mainly summer-ripe cultivars should be chosen with, preferably, low tendency of sclereid formation. In that case, neither irrigation could help to produce adequate quality in varieties sensitive to low air humidity.
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Effects of nitrogen fertilizer application rate and time to first harvest on leaf area index; leaf nitrate content and yield of irrigated leaf rape (Brassica napus L. var. Giant)
64-75.Views:224In Zimbabwe, smallholder cultivation of leaf rape is of considerable importance due to the increasing demand for the leaf vegetable from the rapidly increasing urban populations. A two-season field trial was conducted in the Agricultural Practice Experimental Plots of the Midlands State University in central Zimbabwe. The objective of the study was to establish selected biometric responses of leaf rape to N fertilizer rates and time to first harvesting. Increasing the rate of N fertilizer application considerably improves the yield of fresh rape leaf; LAI and concentration of leaf nitrate. Delaying rape leaf harvest after N fertilizer side dressing can be used as a strategy to boost rape leaf yield for vegetable markets with high single delivery demand. When harvesting is deliberately delayed after N fertilizer application rape LAI are significantly increased. Delaying the first leaf harvests by 7; 14 and 21 days after N fertilizer side dressing amendments increases the content of nitrate in fresh rape leaves. Fresh rape yield can be more accurately predicted by values of rape LAI. Nitrate concentrations in fresh rape leaf is a poor predictor of rape yield under field conditions.
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Work quality assessment of a cherry sorting machine
57-62.Views:232The conditions of the cultivation of marketable cherries are diverse. Choosing the production site on the basis of the climatic conditions, selecting the most appropriate variety taking into account the region and the purpose of the production, utilization of the optimal production method, to ensure the required water and nutrients supply, frost and hail protection techniques, modern technology in crop protection, and professional performance of harvesting and handling, to name just a few of the most important issues. The objective of present study is to determine the qualitative characteristics of the UNITEC cherry sorting machine.