The role of Pre-harvest Aminoethoxyvinylglycine (AVG) Treatments on Total Phenolics,Antioxidant Capacity and Fruit Quality Attributes of Sweet Cherry Cultivars

The present study was conducted to investigate the effects of pre-harvest aminoethoxyvinylglycine (AVG) treatments on fruit quality parameters and bioactive compounds of sweet cherry fruits (Prunus avium L. cvs. ’0900 Ziraat’, ‘Regina’ and ’Sweetheart’). Whole trees were sprayed once with an aqueous solution containing AVG (0, 100 and 200?mg L^?1) three weeks before the anticipated commercial harvest. Measurements were performed a week before anticipated harvest date, at anticipated harvest date and a week after anticipated harvest date. AVG treatments significantly maintained flesh firmness of all three sweet cherry cultivars. Harvest was delayed at least for a week through the keeping of flesh firmness with AVG treatments. The treatments slowed down the red skin color development in all three cultivars. The measurements performed over fruits collected at different ripening stages revealed that AVG resulted in decreased total phenolics and total anthocyanin and ultimately decreased antioxidant capacity in sweet cherry fruits. AVG treatments also decreased soluble solids content and increased titratable acidity of the fruits. This study revealed that pre-harvest AVG treatments were more effective in delaying sweet cherry fruit softening. The main advantage is to maintain the firmness of late-harvested fruit by retaining fruit quality attributes of sweet cherry fruit.     

Ästhetische Premiumfrüchte trotz nasser Klimate – Obstbau in Südkorea

Horticulture Korea today earns 10 billion euros, to which fruit contributes 2.6 billion euros and vegetable production 6.7 billion euros. Apple, kaki, nashi, grape and Citrus contribute 100,000?ha to the overall fruit acreage of 188,000?ha. Koreas fruit industry stagnates and lacks trainees. The consolidation in the apple industry in the last ten years from 53,000?ha in 1995 to 26,000?ha today was due to over-sized aged trees on vigorous rootstocks and – by Asian standard – small-sized, sour, green and low-priced apple varieties like ‘Golden Delicious’. The new Korean cultivars ‘Hongro’ (12%) and ‘Kamhong’ (3%) supersede – apart from the major cv. ‘Fuji’ with a 65 % market share- late ripening and poorly coloured Japanese cv. ‘Tsugaru’ (8%) and ‘Kogetsu’ (5%). Apple harvest extends from August until mid November. The 200,000?t strawberries are from protected cultivation on 7,000?ha. Korea produces 2.3 million t fruit and is largely self-sufficient (84%) for fruit, except for bananas and Citrus, with 440,000?t imports and 33,000?t exports (Satsuma mandarins and Nashi to Taiwan and Japan) and 92% self-sufficiency for vegetables. Fruit consumption of 56?kg/head is half that in Germany with 120?kg/head and vegetable consumption with 170?kg/ha twice that in Germany of 90?kg/head. Apart from university research, the rural development agency (RDA) comprises a central horticultural research institute (NHRI) in Suwon with a dedicated apple (Gunwi, Daegu) and nashi (Naju) research station with extension service. Apples, peaches and nashi are bagged, particularly for export, to fulfil the fruit quality requirements. These comprise a cosmetic skin finish free of blemishes and lenticels, 250–400?g fruit mass, (dark) red colouration and sweet (13–18?° Brix) taste without acidity (0.3–0.4%), resulting in a sugar acid ratio of ca. 43?:?1 with farmgate prices of 2.4?€/kg and retail prices of 2.8–4.8?€/fruit. Historic, Japan inflicted, measures such as defoliating of fruit-bearing branches and bagging to protect the peel, which will be consequently removed with valuable nutrients, are now being questioned and re-considered. Overhead irrigation protects the orchards from frost and hence prevents alternate bearing. Korean apple orchards are devoid of apple scab (Venturia inaequalis), apple canker (Nectria galligena) and fire blight (Erwinia amylovora), despite large annual precipitation of 1,000–1,500?mm, and hence require few pesticides. With farm sizes of 0.8?ha, the 41,000 fruit farmers are not very mechanised; 3% of them subscribe to organic farming and a quarter to a voluntary IFP scheme. GAP is discussed, but QS-EUREP GAP quality schemes are not implemented given the large farm number and few fruit exports.     

Apfel oder Acai: Brasiliens Obstbau im ökonomischen und klimatischen Wandel

In times of recession with a 7–10% inflation rate, drop in consumption and loss in value of the Real currency, Brazil as the third largest fruit producer with 46 mil t fruit on 2.2 mil ha (2013), exports ca. 3% of its production worth ca. 765 mil (2013) – 807 (2014) US $, of which 80% is destined for Europe – the fruit export target for the future is 1 bil US $. Apple (cv. ‘Gala’ and ‘Fuji’) production under Southern hemisphere conditions (26–31°S) in Brazil rose from 0.6 mil t in 2002, peaked at 1.4 million t on 39,600?ha in 2011/12, declining in 2012/13 to 1.05 mil t due to orchard reductions in Fraiburgo as a result of lack of chilling, 1.16 mil t in both 20131/4 and 2014/15 and then 0.8 mil t in 2015/16 on 36,090?ha, resembling average apple yields in Germany on 31,400?ha.Apple orchards are essentially free of fire blight and codling moth, but with 1700?mm annual precipitation, they are affected by the scab and Glomorella fungi. Climate change affects apple production: Lack of chilling, caused by cold winters, induces vertical vegetative branches, flat speckled fruit with long pedicels (fruit stalks; cv. ‘Gala’), sunburn (cv. ‘Fuji’). Warm autumns result in a lack of fruit colouration in both varieties and prevent the cultivation of high chill apples, pears and plums.Three major fruit, orange (7.5?kg), banana (6.8?kg) and apple (cvs ‘Gala’ and ‘Fuji’; 4.2?kg apples/head/year; 2014) dominate the overall fruit consumption of 31.4?kg fruit/head/year compared with 36?kg beef, 34?kg pork and ca. 10?kg poultry resulting in ca. 80?kg meat/head/year in Brazil.In the last three years, a new range of storable apple varieties like ‘Venice’ and ’Daiane’ as well as ‘M 58/07’ and ‘M 10/09 – these latter two, still without a variety name – have been, like ’Eva’ added to the existing new breeds from EMBRAPA as very early variety (harvest in January; low chill; 150 CH) and to the summer varieties ‘Condessa’, ’Monalisa’ and ’Princesa’ (all 300–450 CH) without storability; red mutants of ‘Gala‘ (‘Gala, Maxi’ from RASIP) and of cv. ‘Fuji’ (‘Fuji Suprema’) both with 500–600 CH have been bred for growing in Brazil’s higher altitudes. The new cultivars provide medium-sized fruit, bright red peel colour and sweet taste with little acid and a sugar: acid ratio of 25–55:1, as required by Brazil’s domestic market, but so far lack market acceptance and a marketing concept.     

Wood age and leaf area influence fruit size and mineral composition of apple fruit

Summary

The influence of wood age, fruiting position and leaf area within the tree canopy on fruit mineral content and quality for several apple (Malus domestica Borkh.) cultivars was investigated. Size and Ca, Mg and K content of individual fruit on one-year (lateral and terminal positions), two-year and older than three-year wood were compared for cvs Royal Gala, Braeburn, Granny Smith and Fuji. Fruit on two-year spurs and one-year terminals was generally larger at commercial harvest than that on one-year laterals and spurs older than three years. Flower receptacles at full bloom were larger and fruit growth rates were greater from 60 to 100 d after full bloom on two-year spurs than on one-year laterals. Fruit Ca and Mg concentrations and contents at commercial harvest were highest for terminal fruit, but there was no consistent difference between fruit from other positions. One-year terminals had the greatest primary and bourse leaf areas, two-year spurs were intermediate and one-year laterals had the lowest areas of both leaf types. Removal of 50% of primary leaves and/or removal of bourse shoots from clusters at bloom reduced fruit Ca content at commercial harvest for two-year spurs, one-year laterals and one-year terminals. Bourse shoot removal also reduced Mg content for all positions. However there was no effect of leaf removal on fruit size or K content. Ca content of individual fruit increased curvilinearly with increasing total spur leaf area for fruit on two-year spurs and one-year terminals but not for fruit on one-year lateral clusters. Terminal fruit with total spur leaf areas and fruit size similar to those on two-year spur fruit had higher Ca content.     

Non-Destructive Evaluation of Edible Coatings Effects on Keeping Quality of European Plums (<Emphasis Type="Italic">Prunus domestica</Emphasis> L.) by Laser Light Backscattering Imaging

Fruits of European plum (Prunus domestica L.) show high rates of transpiration. Consequently, they are highly perishable fruit. In the present study, the potential of an edible coating (Versasheen®-based with sorbitol as plasticizer) to improve storage life and keeping quality was evaluated on fruit of the plum cultivars ‘Jojo’ and ‘Tophit plus’. Plums were picked at commercial harvest date and stored at 2?±?0.5?°C (90?±?2% rh) for up to 28?d plus 2?d at 20?°C to simulate shelf life. Every seventh day, plums were analysed for transpiration, colour changes and laser light backscattering imaging (LLBI) at a wavelength of 785?nm to non-destructively investigate variations in quality properties of plums. Finally, fruit flesh firmness, soluble solids content, and titratable acidity were determined destructively. Results indicated that coating of fruit of both cultivars increased their surface resistance against water vapour transfer resulting in lower transpiration rates and thus lower mass losses compared to controls. Consequently, coating of fruit considerably delayed the decrease in flesh firmness. Moreover, edible coating retarded the increase of FWHM785 in coated plums. In this context, FWHM785 proved as a rapid and non-destructive tool to monitor changes in mechanical properties in heavily coloured plums. Results highlight that edible coatings successfully extend post-harvest life of plums.     

The Growth of Apple Central Fruits as Affected by Thinning with NAA,BA and Naphthenic Acids

Plant growth regulators such as α?naphthylacetic acid (NAA) or 6?benzyladenine (BA) are commonly used for thinning apple fruits. NAs exhibits an auxin- and gibberellin-type biological activity, stimulate the uptake and translocation of auxins in plant tissue, as well as IAA synthesis and act as surfactants. It was assumed that NAs applied at the stadium of early fruit growth might cause fruit abscission in apple, similarly to NAA. The goal of the research was to test the presumed thinning effect of naphthenic acids on apple cultivars ‘Golden Delicious’ and ‘Red Delicious’. Three treatments were applied on both apple cultivars including 16.5?μL L^?1 NAA, 200?μL L^?1?BA and 2.63?mg L^?1?potassium salts of NAs. Cortical cell size and the number of cell layers were measured in order to determine the contribution of cell size and cell division in early fruit growth, as affected by chemical thinning treatments. The effects of plant growth regulators NAA, BA and NAs on fruit set, fruit size and the anatomy of the fruit cortex highly depend on varietal differences. In ‘Golden Delicious’ fruit set reduction by chemical thinning increases both the number of cell layers and cell size of apple fruit, while in ‘Red Delicious’ NAA inhibits fruit growth, while BA is ineffective. Cell growth promoting activity of NAA and NAs, accompanied by the decrease in fruit set and reduced competition among fruits within the canopy, results in a significant fruit weight increase at harvest. The research confirms the auxinic properties of NAs, and their assumed thinning activity.     

Differential effect of cultivar and harvest date on nectarine colour,quality and consumer acceptance

The influence of nectarine cultivar and the harvest date on fruit colour, fruit size, fruit quality parameters, and consumer acceptance were assessed. The analyses were carried on cultivars with different fruit taste (acidity and sweetness), from 5-years-old trees at the IRTA-Experimental Station of Lleida (Spain). The six cultivars were grouped in three pairs in which each had a similar commercial harvest date. Each pair comprised by a non-acid cultivar and an acid cultivar, except the pair of ‘Big Top^®’ and ‘Mesembrine^®’, which included two non-acid cultivars. The nectarines were harvested at 8 days intervals on five harvest dates, three of which were before the commercial harvest date, one at commercial harvest and another 1 week after commercial harvest.     

Effects of position on canopy and harvest time on fruit physico-chemical and antioxidant properties in different apple cultivars

Fruit from Granny Smith, Fyriki, Fuji Kiku 8, and Imperial Double Red Delicious apple (Malus domestica Borkh.) trees planted in single or double rows, were harvested from different positions in the canopy, during the last month before commercial harvest. Fruit physico-chemical and antioxidant capacity, using the radical DPPH, were measured, in skin and flesh tissue. Greater total phenol content and total antioxidant capacity per fresh weight and serving portion of skin and flesh tissue, were found in Imperial Double Red Delicious and Fyriki apples, compared to Granny Smith and Fuji Kiku 8. The variation among cultivars in antioxidant contents was greater in peeled, compared with unpeeled fruit, highlighting the importance of eating unpeeled fruit. During the last two weeks before commercial harvest the total phenol content and total antioxidant capacity per fresh weight increased in skin of Granny Smith (by 24% and 42%, respectively) and Fuji Kiku 8 (by 19% and 27%, respectively). Fruit from the more sun—exposed parts of canopy had usually better red coloration and the effect was more pronounced in Fuji Kiku 8 and Fyriki, followed by Imperial Double Red Delicious and a lower effect was found in Granny Smith. Greater total soluble solid content, but not flesh firmness, were also found in fruit from the more sun—exposed parts of canopy, in all cultivars. The skin of fruit from the upper positions in the canopy had greater total phenol content and total antioxidant capacity, in all cultivars, apart from Fyriki. Antioxidant contents in flesh tissue were also greater in the upper positions of canopy in Fuji Kiku 8 and Imperial Double Red Delicious, and to our knowledge this is the first report on plant canopy effects on apple flesh antioxidant compounds.     

Ausdünnungsstrategien für die Apfelsorte ‘Elstar’ – Erfahrungen mit Ammoniumthiosulfat, Calciumhydroxid und Benzyladenin

‘Elstar’, the most widely grown apple variety in the Netherlands, requires adequate fruit thinning to obtain regular bearing and the commercially desired fruit size and fruit quality. During several years studies have been carried out to look for alternative thinning methods to replace carbaryl, an insectide which also induced thinning when applied to young fruitlets, but that is no longer registered in the Netherlands. During recent years research on apple thinning has focused on the use of ammonium thiosulphate (ATS) as a flower thinner combined with 6-benzyladenine (BA) as a fruitlet thinner. This paper reports on a trial in which the fruit thinning efficacy of this combined treatment with ATS and that of BA on its own were evaluated. In addition, the use of slaked lime (Ca(OH)₂) to cover the leaves and reduce leaf photosynthesis at three different times during fruitlet development was tested, alone or in combination with an application of BA. The best chemical thinning treatment of this trial was the combination of 3 applications of ATS during flowering followed by BA at a fruit size of 13.8?mm. This treatment gave 82% of the thinning necessary to obtain the target fruit load. This treatment also effectively improved fruit size distributions, fruit colour and internal fruit quality. Slaked lime did not thin ‘Elstar’ effectively, most probably because it did not cause sufficient reduction of light interception by the canopy.     

苹果采前落果与内源激素的关系

为了探讨苹果采前落果与内源激素之间的关系,在采前8周间定期测定了不同苹果品种的果柄、果台和离层形成部位组织中IAA、ABA含量;在采收前20d内定期测定了离层部位组织中细胞壁分解酶(Cellulase)的活性;在收获期测定了果实乙烯的发生量。结果表明:不同品种果柄、果台和离层部位组织中IAA和ABA含量变化有差异,但它们变化的总趋势相似,都是随着果实成熟IAA含量下降,而ABA含量上升;不同品种的成熟果实中乙烯发生量有很大差异,以落果多的品种显著大于落果少的品种;采前落果重的品种离层部位组织中细胞壁分解酶的活性在果实成熟期急剧增加。由于果实进入成熟阶段后,IAA含量下降,ABA含量升高,ABA/IAA之间的相对平衡被打破,高ABA/IAA以及高乙烯会刺激离层组织中细胞壁分解酶的活性增高,进而促进离层形成,这可能是导致落果发生的原因。     

Einfluss selektiver mechanischer Fruchtbehangsregulierung auf Ethylensynthese als Stressindikator sowie Ertrag und Fruchtqualität bei Kernobst

The overall objective of this work was to improve fruit quality, break alternate bearing and reduce hand thinning using fewer chemicals in fruit crops. A device was constructed for mechanical thinning, which consisted of three independent horizontal rotors with ropes and freely adjustable angles on a frame, mounted on a front three point hitch and powered by the tractor hydraulics. This can be adapted to any fruit tree trained as spindle, Solaxe, (tall) vertical axis or fruit wall (le mur fruitier) irrespective of rootstock employed. Rotor speed varied from 300 to 460?rpm at either 5 or 7.5?km/h tractor speed. Eight-year-old or twelve-old apple trees cvs. ‘Gala’ and ‘Golden Delicious’ were mechanically thinned in 2007 between pink bud and full bloom (flower bud stages 6–8 or F1–F2) near Bonn, Germany; non-thinned and hand-thinned apple trees of the same block and variety served as control. Mechanically thinned flowering branches showed a similar amount of ethylene efflux (0.4–0.6?ppm C₂H₄/branch) as non-thinned flower branches, preventing potentially unexpected subsequent fruit drop, except for those removed by the rotors. The impact of the horizontal rotors on the branches was from the upper side and removed excessive flowers right to the tree trunk viz. the centre of the tree canopy, where fruits of lesser quality are expected leaving 2–3 flowers per cluster. Leaf damage was less than??10%, even at the fast rotor speed of 420?rpm, which was associated with negligible wood injury. Mechanical thinning induced firmer and sweeter fruit, i.e. tastier apples with longer shelf life, relative to control fruit from non-thinned apple trees. The greatest efficacy in terms of final fruit quality in the grading/sorting was achieved by a rotor speed of 360?rpm at a tractor speed of 5?km/h: Fruit mass increased by up to 20?g and the proportion of fruit larger than 70–75?mm by 10–30% compared with the fruit from non-thinned trees. Mechanical thinning with this newly constructed device led to a 10–20% reduction in yield, but increased returns due to better fruit size and colouration in apple with the potential to overcome alternate bearing.     

Nachernte-Behandlung von Äpfeln mit Calciumchlorid

From 2003 to 2006 the efficacy of post-harvest dips in calcium chloride solution was investigated for apples. Aim of these investigations was to find out the influence of different factors on the Ca-uptake of apples after harvest. The Ca-uptake of the fruit was influenced by following factors:

• the calcium chloride concentration of the dip solution,
• the duration of the dip,
• the duration of fruits' wetting,
• the apple cultivar,
• the addition of a wetting agent and
• the maturity of the fruit.

To get an appreciable Ca-uptake, the addition of a wetting agent is necessary. For a dip time of two minutes calcium chloride concentrations of 7 or 7.5% are needed. Apparently injuries of the apple skin don't appear. An elongation of the dip time or the duration of wetting increased the Ca-uptake. Cultivar and maturity of the fruit affect the Ca-uptake. The increase of the Ca-content can proved only close to the apple skin (skin to 2?cm depth).     

Estimation of the Colour Properties of Apples Varieties Using Neural Network

The consumer acceptance and the quality standard of agricultural products such as apple are determined mostly by their colour. Colour is measured with a colorimeter and quantified using the C.I.E. L^*, a^*, b^* colour space system. It is used commonly by researchers for the classification and identification of apple fruit. To the best of our knowledge, the present study is the first study investigating the prediction of some colour properties of six apple varieties through artificial neural networks (ANN). The apple varieties are ‘Amasya’, ‘Starking’, ‘Granny Smith’, ‘Pink Lady’, ‘Golden Delicious’, ‘Arapk?z?’ and the colour properties are L^* (lightness), a^* (redness), b^* (yellowness), C^* (chroma), h^* (hue angle), CI (chroma index). General Regression Neural Networks (GRNN) and Adaptive Neuro Fuzzy Interface System (ANFIS) structures were employed to predict the colour properties. According to the experimental and simulation results, the proposed ANFIS predictor had a superior performance in prediction of these colour parameters.     

The Pillnitz Re-Series of Apple Cultivars – Do They Hold Promise? – 80 Years of Professional German Fruit Breeding 2008

The aim of the Pillnitz apple breeding is to combine improvements in fruit quality + yield + resistance to different pathogens in new cultivars. Early-, mid- and late-season apple cultivars were selected in two series, Pi- and Re-cultivars?. The Re-cultivars? guarantee a high degree of resistance. Triple and multiple resistant cultivars were selected with resistance to scab, mildew and fire blight: ‘Remo^®’, ‘Regia^®’, ‘Rewena^®’ and ‘Rebella^®’. ‘Rebella^®’ was found to have resistance also to bacterial canker, red spider mite and abiotic damages. The cultivars are the base for a new growing management in integrated and organic cultivation. Doubtless, the Pillnitz resistance breeding conception is a success, even if some problems remain to solved in the future. Various degrees of scab infection on Vf-resistant cultivars had been observed since 1984 in Central Europe. No infections were found in cultivars with other genes like V _f such as ‘Reglindis^®’ (V _A), ‘Reka’ (V _r), or ‘Regia^®’ (V _r). New sources are necessary for resistance breeding, especially for pyramiding of resistance genes. However, if the V _f-gene is overcome, new resistance sources and cultivars with two or more different sources of resistance to stabilize healthiness in the field will be required in the future. More explanation and advertisement about the value of resistant cultivars to promote the cultivation in commercial orchards is needed.     

Delayed harvest improves red blush development and quality of ‘Cripps Pink’ apple

The poor red blush development on ‘Cripps Pink’ (Malus x domestica Borkh.) apple fruit at commercial maturity (CM) reduces the economic return to apple growers in warmer regions of the world. The effects of delayed harvest maturity up to 6 weeks following CM on the development of red blush and fruit quality of ‘Cripps Pink’ apple were investigated at two locations in Western Australia during 2003 and 2004. The red blush, export-grade fruit, total anthocyanin, cyanidin 3-galactoside, chlorogenic acid, catechin, and epicatechin of apple fruit skin tissues increased with advancement of harvest maturity at both locations in both years, whereas hue angle, concentration of phloridzin, fruit firmness, and titratable acidity (TA) of apple fruit tissues decreased with delayed harvest. The internal ethylene concentration was elevated with the delayed harvest. The concentrations of quercetin 3-galactoside, quercetin 3-arabinoside, quercetin 3-rutinoside, quercetin 3-rhamnoside, and quercetin 3-glucoside increased up to 2 weeks following CM, and then declined in 2003 at both locations and at Perth Hills in 2004. Delayed harvest resulted in improved development of red blush on the fruit surface, accumulation of total anthocyanin, cyanidin 3-galactoside, chlorogenic acid, catechin, epicatechin, and quercetin glycosides in fruit skin, SSC:TA ratio and reduced fruit firmness possibly due to the increased ethylene production.     

Yield and fruit quality of ‘Gala’ and ‘Fuji’ apple trees protected by white anti-hail net

Covering apple orchards with nets protects them from hailstorms but this changes the amount and quality of the light supplied to the trees. This study was carried out to assess the effects of shade provided by white protection net on yield and fruit quality of apple orchards in Southern Brazil, along three growing seasons (2002/2003, 2003/2004, and 2004/2005). ‘Gala’ and ‘Fuji’ apple trees (on MM111 rootstock, raised as slender spindles, with a spacing of 5.5 m × 3 m) were left uncovered (control trees) or covered with white net. The white net reduced the photosynthetically active radiation (λ = 400–700 nm) accumulated over the trees’ canopy along a day by 18.4%, leading to a higher leaf chlorophyll content in both cultivars, and a higher specific leaf area in ‘Gala’. The shade provided by the net did not affect yield and increased fruit average weight in both cultivars. At harvest, the number of seeds per fruit and severity of russet were not affected by netting in both cultivars, as well as the incidence of watercore in ‘Fuji’. The main beneficial effects of the white net were the reduced incidence of sunburn on ‘Gala’, reduced incidence of bitter pit during cold storage in both cultivars, and reduced incidence of apple scab at harvest and of decay after cold storage in ‘Fuji’. Fruit fly damage in ‘Gala’ (assessed in one season) was reduced by netting. However, netting affected negatively some fruit quality attributes. ‘Gala’ and ‘Fuji’ apples from trees protected by the net had a poor skin color (pale blush and a more intense green background color) at harvest. The net reduced flesh firmness and SSC, and increased the starch index of ‘Gala’ apples at harvest, and reduced flesh firmness and SSC, assessed after cold storage and shelf life, in fruits of both cultivars.     

Farb- und Fruchtqualitätsverbesserung bei Äpfeln mit Monophosphat und Extenday

Monophosphates reportedly enhance red colouration of bi-coloured apple fruit by stimulating anthocyanin synthesis and, in addition with calcium or potassium, may improve fruit firmness; colour and firmness which may be restricted by the climate in Western Europe. 12-year-old cv. ‘Elstar’ apple trees at Klein-Altendorf near Bonn, Germany, were sprayed weekly with either of two monophosphates four weeks prior to harvest to improve fruit quality, i.e. colouration, sugar and firmness. White, woven reflective cloth was spread as an alternative on the grass strips between the tree rows six weeks prior to harvest for the same purpose. Untreated apple trees served as control. Neither of the three treatments affected fruit maturation, measured as Streif index. The monophosphate formulation containing calcium (Seniphos; 24% P₂O₅; 4% CaO; 2?×?10?L/ha) increased the sugar content of the cv. ‘Elstar’ apples in the outer as well as in the inner tree canopy and the reflective cloth additionally in fruit of the lower canopy close to the cloth's position on the ground. This white reflective cloth (Extenday) also affected fruit from the outer tree canopy with the largest sugar content (12.6°Brix) and firmness (7.6?kg/cm²) at harvest. The monophosphate formulation containing potassium (Rizammina 42; 8% P₂O₅, 21% K₂O; 3?×? 2.5?kg/ha) improved the category of greater 25% fruit colouration by only 3%. Both Seniphos and the reflective cloth increased this portion by 17–19%, thereby raising the portion of class-1-fruit by 8%, equivalent to additional earnings of 1,060 €/ha. The green ground colour of apples in the shaded inner canopy was retained by either monophosphate. In the well-illuminated tree periphery, however, the ground colour of fruit treated with either monophosphate was less green (more yellow-green) and the top colour was more red. The white reflective cloth induced the same positive effects on fruit colouration to a much larger extent. Both monophosphates increased fruit firmness after 4?months cold storage around 5% at a time when fruit were too soft for marketing as fresh products.     

Nicht-destruktive Erkennung von Berostung bei Birnen

The objective of the present study was to investigate possibilities of non-destructive examination of russet on pome fruit using a luster sensor (Mukhtar et al. 2014) including varietal, colour and positional influences. Therefore, pears of three varieties from the local market in December, were investigated by three means, visual observation of the type and spread of russet, 3D colour microscope and sensor technology.Visual oberservation showed that pears of cv. ‘Conference’ from Belgium exhibited the most severe russet, particularly in the spherical part of the fruit, but also with speckled russet at the elongated stalk end of the fruit. Pears of cv. ‘Alexander Lucas’ from Germany had the least russet localized at the calyx end of the fruit and those of cv: ‘Abate Fetel’ from Italy showed an intermediate level of russet at the calyx end.Three-dimensional colour microscopy at x200 magnification.showed that russet, i.?e. suberinisation of the fruit peel, on cv. ‘Conference’ caused a 2.5-fold increase in roughness of ca. 50 µm compared with ca. 20 µm on russet-devoid peel sections of cv: ‘Alexander Lucas’.Scarcely russeted peel of cv. ‘Alexander Lucas’ showed significantly larger luster levels and those of cv. ‘Abate Fetel’ the tendency of larger luster levels with a smaller variation than russet devoid fruit peel. Russet was more difficult to detect on the elongated part of the pear fruit next to the pedicel. These first results indicate that this sensor-based russet detection is based on a combination of peel roughness and colour; but require further investigations.The results of larger luster levels on russeted pears are in line with those on plums (Mukhtar et al. 2014) where polishing during harvest and postharvest handling doubled luster levels compared with the undisturbed natural amorphous fruit surface.