Einfluss rezenter Klimaveränderungen auf die Phänologie bei Kernobst am Standort Klein-Altendorf – anhand 50-jähriger Aufzeichnungen

This project examines the effects of climate change on pome fruit phenology at Klein-Altendorf in the Rhineland fruit-growing region in the West of Germany, using 50 years of weather data and phenology records, including beginning of flowering (F1), full bloom (F2), harvest date and leaf drop of apple and pear, with the following results:

1. Fifty years of weather records and pome phenology data showed a distinct separation between a first phase (1958–1987), which was 0.42°C cooler, and a second phase (1988–2007), which was 0.66°C warmer than the long-term, 50 year temperature average of 9.4°C, indicating the start of the climate change in 1988.
2. Annual average temperatures rose from 8.8°C to 10.2°C, i.e. by 1.4°C over 50 years at Klein-Altendorf, which affected the apple phenology. A comparison of the second phase (average temp. 10.1°C) with the first phase (9.0°C) resulted in a temperature rise of 1.1°C; the temperature rise in the winter (1.2°C) was greater (by 0.2°C) than in the summer (1.0°C). This temperature rise in the last 20 years (second phase, 1988–2007) was more pronounced in the winter months January ( $ + $ 1.7°C) and February ( $ + $ 1.8°C) than in the spring months March and May both with $ + $ 1.4°C leading to enhanced early post-bloom fruit drop, and July ( $ + $ 1.3°C) and August ( $ + $ 1.6°C).
3. Annual precipitation remained constant at ca. 600?mm with an increase in February, March and April and an equivalent decrease in May (?10?mm) and July (?7?mm) during fruit development.
4. Soil temperatures increased by 2.6°C and hence greater than the air temperature ( $ + $ 1.45°C) over the last 50 years; this increase was most pronounced between January and March.
5. Minimum air temperatures increased also by 2.6°C from ?6.1°C in March 1958 to ?3.5°C in March 2007. The more advanced flowering, brought about by warmer January to March temperatures, now coincides with late spring frosts, thereby maintaining the risk of yield loss due to spring frost in April, a month when the minimum temperature still continues to drop.
6. On average, apple and pear flowering was 10 days earlier without extension of the flowering period after warm winters and appeared more severely affected than the harvest period (3–9 days) and leaf drop (2–3 days earlier) with distinct varietal differences. The apple flowering period was 4 days shorter in the last 10 years and reduced from 12–15 days to 8–10 days. Early maturing cultivars (cvs) ripened 3–4 days earlier, while late cvs ripened 8–12 days earlier. The period between harvest and leaf drop was extended by 2–7 (apple) to 11 days (pear), which requires regional differentiation according to the respective climatic zone and may be beneficial for nutrient translocation into the perennial woody parts of the tree.
7. Since the changes in the temperature-based vegetation period did not explain the effects of climate change on pome phenology, a `pomological vegetation interval' between the beginning of flowering and beginning of leaf drop was defined and was extended by climate change in spring by 0–10 days in apple and by 8 days in pear. Based on flowering (F1, F2) advances, the Meckenheim fruit-growing region was more strongly affected by the climate change compared with other European fruit growing regions.

     

Entwicklung eines Qualitätsindex zur Verbesserung der Verbraucherakzeptanz bei Äpfeln

During the term of two years this study attempts to consider consumers preferences within existing quality management systems in retail. The aim was to develop a quality index which involves sensory characteristics. Therefore, about 4000 fruits of the cultivars ‘Fuji, Yataka’, ‘Elstar, Elshof’, ‘Golden Delicious, Reinders’ and ‘Jonagold, Rubinstar’ were analyzed in three steps in the first experimental period (about 1000 fruits per cultivar). In the first place different fruit characteristics such as flesh firmness and chlorophyll content were measured non-destructive. Next the fruits were tested sensorial by consumers at four retail trade locations in Osnabrück. For the assessment of the taste an eight part of an apple was used. The remaining seven eight parts were required for destructive investigations. Coefficients of linear correlation between results of non-destructive respectively destructive analysis on the one side and sensorial determined results on the other side were calculated. Unexpectedly, the correlations between these different parameters were small. Therefore, more data will be collected in a second experimental period to develop the quality index.     

Einfluss von Biostimulanzien und Lichtreflexionsfolie auf die Fruchtqualität und Farbentwicklung bei Apfel

The aim of this research was to improve inner and external fruit quality and fruit colouration using four-year-old apple ‘Braeburn, Hillwell’ trees on M9 (3?m × 1?m spacing) by employing reflective ground covers and biostimulants at Klein-Altendorf, nr. Bonn, Germany (50°N). Two reflective ground covers were spread on both sides of tree rows seven weeks before anticipated harvest and two biostimulants were applied two times – four and two weeks before harvest. Adjacent trees of the same row without reflective ground cover or without biostimulants served as control.Reflective ground covers significantly improved red colouration from 71°hue in the control to 49°hue with the ground cover Lumilys® and to 40°hue with Extenday®. The red colouration of the lower surface of fruits improved from 85°hue in the control to 52°hue with Lumilys® and 40°hue by Extenday®. Apple trees with Extenday® and Lumilys® produced 69% and 44% well-coloured fruit (with 75–100% fruit colouration) compared with 16–26% in the control.By contrast, an acceleration of ripening processes was not observed in plots with reflective ground covers compared with the control. There were no differences in sugar contents (°Brix) and fruit firmness (kg/cm²), but starch breakdown in fruit with reflective mulch was significantly delayed compared with the control resulting in retarded maturation.An economic analysis based on material costs and lifespan – excluding the labour costs for spreading and removing the ground covers – showed an economic advantage, if these mulches are used more than once a year.Both biostimulants showed neither effects on inner and external fruit quality nor on fruit colouration. Fruits with Wuxal®ATRiun or Sunred® did not improve the percentage of well-coloured fruits (75%–100% fruit surface with red colouration) compared with the untreated control. Similarly, inner and external fruit quality showed no significant differences in fruit firmness, sugar content and starch degradation. An economic analysis based on chemicals’ costs – excluding the labour costs for applying the biostimulants – resulted in no economic advantage. The chlorophyll – based ‘Index of Absorption Difference’ (IAD; measured non-destructively by the DA-meter) in some cases correlated positively with the Streif (maturation) index based on destructive assessment fruit firmness, sugar content and starch breakdown in an ‘ART system’.     

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.     

Vergleich von Anbausystemen bei der Birne in Abhängigkeit von Sorte und Unterlage: Schlanke Spindel und Güttinger-V-System

To the tenth leaf the influence of two planting systems on yield and fruit size of pear cultivars ‘Conference, 202’ and ‘Alexander Lucas’ grafted on the rootstocks Quince A (MA) and Quince C (MC) was investigated. The planting systems “Slender Spindle” (3.25?×?1.25 m) and “Güttinger-V-System” (3.50?×?0.60 m) were compared. The “Güttinger-V-System” led to higher yields than the planting system “Slender Spindle”. In average of both cultivars and rootstocks the difference between the planting systems amounted to 75.9 t/ha from the third to the tenth leaf. To the additional yield of the “Güttinger-V-System” face additional costs for the installation of the orchard and for the formation of crown. Thus the decision for this planting system will be influenced in a high measure from the producer price.     

Mechanische Fruchtbehangsregulierung verringerte den Junifruchtfall und verbesserte die Fruchtqualität und Fruchtgröße bei ‚Conference‘- und ‚Alexander Lucas‘-Birnen

In the absence of any chemicals approved for thinning pears but market demand for large particularly cv. ‘Conference’ fruit, the objective of the present study as part of a MSC thesis was to improve fruit quality i.e. achieve these fruit sizes by mechanical blossom thinning. Therefore, 18-year-old cv. ‘Conference’ pear trees, trained as super spindles, on quince A rootstock with a spacing of 4?×?0.4 m were used in Klein-Altendorf near Bonn, Germany; cv. ‘A. Lucas’ and un-thinned trees served as control. These pear trees with intense flowering were blossom-thinned on 15 April 2009 with rotor speeds of either 300 rpm or 400 rpm both at 5 km/h tractor speed with the new mechanical thinning device developed at the University of Bonn in 2004–2006. Therein, a vertical mast supports three horizontal rotors, whose vertically rotating tines remove excessive flowers; the device is mounted on the front three point hitch of the tractor. In 2009, a year with severe June drop, mechanical thinning reduced the intensity of the natural June drop with increasing rotor speed and was stronger reduced in cv. ‘A. Lucas’ (by ?38%) than in cv. ‘Conference’ (by ?27% relative to the control). In cv. ‘A. Lucas’, the natural June drop was as strong as mechanical thinning and resulted in large-sized 80 mm pear fruit in the control; mechanical thinning with 400 rpm further increased fruit mass by 16 g relative to the un-thinned control or 6 g larger than in the thinning with 300 rpm. In cv. ‘Conference’, fruit fell within the next larger fruit size class after the stronger mechanical thinning with 400 rpm at 5 km/h: the portion of pear fruit in the 75/80 mm size class was 2 fold and in the 80/85 mm size class was 6 fold that in the control. The portion of <?60, 60/65 mm and 65/70 mm fruit was halved relative to the control; the average fruit mass was increased by 40 g. Vegetative growth appeared unaffected by mechanical thinning. The risk of both over-sized fruit and over-thinning appears small, since mechanical thinning reduced the natural June drop and did not induce subsequent fruit drop. Mechanical thinning was more efficient in cv. ‘Conference’, as intended, despite more intense flowering in cv. ‘A Lucas’. An economic evaluation proved difficult, since the natural June drop particularly in cv. ‘A. Lucas’ led to large-sized fruit (80 mm) in the control, and any (mechanical) thinning is associated with lower yields (?26% in cv. ‘Conference’ and ?12% in cv. ‘A. Lucas’). Overall, the results indicate the potential of mechanical thinning as a substitute (or combination partner for chemical thinning if approved) in pear.     

Nährstoffaufnahme von Obstbäumen im 1. und 2. Standjahr

The nutrient uptake of fruit trees in the first and second year of cultivation was analyzed. The following fruit species and fruit varieties were examined: sour cherry (‘Schattenmorelle, Rheinland’, Hüttners Hochzucht 170?×?53, one year old tree), pear (‘Conference’, Quince A, two year old tree), apple on M 9 inoculated with the varieties ‘Pinova’ (two year old tree with one year old crown, two year old tree), ‘Elstar’ (one year old tree, two year old tree with one year old crown, two year old tree), ‘Jonagold’ (one year old tree, two year old tree with one year old crown, two year old tree) und Süßkirsche (‘Regina’, Gisela 5, two year old tree).

1. There was low nutrient uptake in the first and second year of cultivation.
2. In the second year of cultivation the nutrient uptake of all fruit species was clearly higher than in the first year of cultivation.
3. In average of the proved fruit varieties the nutrient uptake in the first year of cultivation was: 8?kg N/ha, 2?kg P/ha, 6?kg K/ha, 1?kg Mg/ha and 9?kg Ca/ha.
4. In average of the proved fruit varieties the nutrient uptake in the second year of cultivation was: 3?kg P/ha, 9?kg K/ha, 3?kg Mg/ha and 26?kg Ca/ha.
5. Especially in the first year of cultivation the trees of the stone fruits showed a higher nutrient uptake per tree than the trees of the pome fruits. But related to the nutrient uptake per hectar this difference reversed or became infinitely small.
6. The nutrient uptake of both the three apple varieties and the different plant materials showed only low differences.

     

GiSelAs, PIKUs und neue Giessener Klone: Ergebnisse aus europäischen und nordamerikanischen Kirschenunterlagenversuchen

Published results on vigour and productivity from European and American trials are compared for 8 size-controlling rootstocks for sweet cherries. Taking the different conditions into account, the clones can be ordered according to their size-control: most dwarfing is GiSelA 3, followed by GiSelA 5. GiSelA 12 grows a bit stronger. Next are GiSelA 6 and 148/13. PIKU 1 and 318/17 show stronger, and PIKU 3 the most vigorous growth. On GiSelA 3, GiSelA 5, GiSelA 6 and 318/17 high yields can be achieved. PIKU 1 stands out by high yields under weak conditions. Yielding potential of PIKU 3 proves to be low. Productivity on GiSelA 12 and 148/13 cannot be assessed due to the small number of data. The problems of this evaluation and the results for each of the 8 clones are discussed.     

Holzhäcksel- und Miscanthusmulch erhalten die Bodenfeuchte und fördern die biologische Bodenaktivität sowie vegetatives und generatives Wachstum junger Apfelbäume

Tree rows of a two-year-old apple (cv. ‘Topaz’) orchard in Klein-Altendorf near Bonn, Germany, were mulched with either a) shredded broadleaf tree trunks (5?cm; 29?t dm/ha) in January 2005, b) high (6?cm; 17?t?dm/ha), or c) low (3?cm, 7?t dm/ha) shredded stems of Miscanthus in July 2004 to conserve resources and achieve closed systems; uncovered soil served as control. The following results were obtained in this MSc thesis during the 2005 growing season:

1. Soil covered with any of the three mulches mineralised 7–14?kg less nitrogen per hectare throughout the growing season resulting in a more balanced nitrogen mineralisation. The reduction in nitrogen supply prevented late vegetative growth and contributed to good fruit colouration.
2. The largest soil respiration was recorded with wooden chips as mulch with a peak of 1.6?CO₂?m^–2?h^{– 1} in June/July, followed by Miscanthus mulch and the uncovered control, which indicates enhanced microbial activity in the summer as a result of medium C/N ratio, warming and better aeration of the wood chips.
3. The organic mulches preserved soil moisture with values of less than 53 centibars and with less fluctuation than in the control.
4. The organic mulches reflected ca. 10% of incident PAR 1?m above ground, i.e. more light than uncovered soil, all without affecting fruit colouration.
5. The two thicker (5?cm and 6?cm) organic mulches suppressed weed population by 63–67% relative to the control.
6. The two thicker (5–6?cm) organic mulches improved potassium uptake by the apple leaves with 1.5 % K relative to 1.3 % K in the control on a leaf dry matter basis, but reduced their calcium and magnesium content.
7. Wood chips as mulch improved vegetative growth of the apple trees during the growing season, measured as trunk diameter, of 4?mm, followed by 3.6?mm of the high Miscanthus and 2.8?mm in both the low Miscanthus mulch and the control.
8. The organic mulches enlarged apple fruit diameter from 78?mm in the control to 80?mm with a concomitant increase in fruit weight from 180?g in the control to 185–188?g.

     

Dynamische Absenkung des Sauerstoffgehaltes bei der Lagerung von Äpfeln

The influence of dynamic controlled atmosphere (DCA) with stepwise oxygen reduction in comparison to conventional ultra-low oxygen (ULO) storage (1.4% O₂) was examined with apples belonging to the cultivars ‘Elstar’, ‘Holsteiner Cox’ and ‘Boskoop’. In order to avoid fruit-damaging fermentation processes, regular analyses of fruit samples for fermentation products were carried out by headspace gas chromatography. The effect of storage methods on fruit quality was quantified after fruits had been removed from DCA or ULO conditions, and again after incubation in different post-storage conditions. The results showed significant improvements in fruit flesh firmness in ‘Holsteiner Cox’ and ‘Boskoop’ after removal from DCA storage and also after post-storage for three weeks under cold storage condition, as compared to ULO storage. The occurrence of skin spots on ‘Elstar’ apples was also significantly reduced by DCA storage.     

Bioindikatoren für den Dormanzstatus bei Obstgehölzen

This contribution is part of a bachelor thesis, which reviews the literature about suitable bio-indicators for the current dormancy status of a (fruit) tree in the winter. This is part of an on-going chilling research project and evaluation of the three chilling models as to their suitability for fruit growing in temperate zone regions with cool winters. The aim is to provide information on the dormancy status of a tree for the application of cultivation techniques to overcome dormancy.     

Erstnachweis der räuberischen Gallmücke Lestodiplosis diaspidis (Kieffer, 1910) (Nematocera: Cecidomyiidae) als Prädator der Maulbeerschildlaus Pseudaulacaspis pentagona (Targioni-Tozzetti, 1886) (Homoptera: Diaspididae) in Deutschland

In 2015 within an initial test for the biological regulation of the White Scale (Diaspididae: Pseudaulacaspis pentagona) in a fruit orchard near house gardens in Pfinztal-Soellingen near Karlsruhe on heavily infested mulberry (Morus nigrum) a predatory gall midge Lestodiplosis diaspidis (Kieffer, 1910) (Nematocera: Cecidomyiidae) has been detected. This is the first record of this beneficial species for Germany. The importance of this gall midge as an antagonist of White Scale should be investigated in further studies.     

Profilierungstechniken in der Ernährungs- und Lebensmittelforschung

High throughput profiling techniques are applied increasingly in nutritional sciences as tools for the identification of metabolic phenotypes in response to food as well as for identification of the modes of action of individual constituents of the diet.     

Erfolgreiche Bekämpfung des Apfelschorfs mit Kalziumhydroxid

Zusammenfassung In einer 12-jährigen Apfelanlage mit den Sorten Elstar, Fiesta, Golden Delicious, Jonagold und Kent wurde im Jahre 2004 die Schorfbekämpfung durch Überkronenberegnung mit Suspensionen von Kalziumhydroxid (5 g/l) durchgeführt. Im Zeitraum 7. April bis 30. September 2004 wurde insgesamt 62-mal für 15 min beregnet. Drei verschiedene Zeitpunkte der Behandlungen wurden getestet. Bei Behandlung A wurde mit der Beregnung begonnen, wenn nach Mills 100% Infektion erreicht waren. Bei den Behandlungen B und C wurde die Beregnung 6 bzw. 20 h später gestartet. Bei den nicht behandelten Kontrollen waren zum Zeitpunkt der Ernte bei Golden Delicious 30% und bei Jonagold 23% der Früchte mit Schorf befallen. Die Kontrollbäume der anderen Sorten hatten keinen Fruchtschorf. Die Früchte der drei Behandlungen waren bei der Ernte und nach einer 7,5-monatigen Lagerung im Kühllager oder im ULO-Lager frei von Schorf. Die Bonitur auf Schorfbefall der Blätter erfolgte zum Zeitpunkt der Ernte an 3 Langtrieben pro Baum mit je etwa 20–25 Blättern. Bei der Ernte im September/Oktober wurden bei allen Kontrollen Schorfflecken gefunden. Die Extreme reichten von 20 bis fast 60% befallene Blätter. Die Blätter der Langtriebe aller Behandlungen waren schorffrei. Bei den Behandlungen hatten die Blattunterseiten im Mittel bis zu 15% Schorfläsionen. Das liegt vermutlich daran, dass bei der Überkronenberegnung die Blattunterseiten nicht vollständig benetzt wurden. Die Ergebnisse zeigen, dass Schorfbekämpfung mit Überkronenberegnung von Kalziumhydroxid möglich ist.     

Farbige Hagelnetze: Ihre Netzstruktur sowie Licht- und UV-Durchlässigkeit bestimmen die Ausfärbung der Apfelfrüchte

Structure and light transmission of new translucent (white), black, red and green hailnets mostly of Italian origin were examined with the following results:

1. Coloured hail nets comprised double twisted longitudinal (parallel to the tree rows) and single transverse high density polyethylene (HDP) fibres of 288?μm to 356?μm diameter.
2. Black and green-black hail nets contained double black longitudinal fibres. White-translucent, grey or red hail nets contained double longitudinal translucent or red fibres.
3. Transverse single fibres were black in black, grey and red-black hail nets, soot-impregnated for UV protection, providing strength and durability, but translucent-white, red or green in the other nets and may tear upon overloading, leaving hail net strips parallel to the ridge.
4. Light was reduced by ca. 7% (PAR) – 20% (UV) by white-translucent, 11% (PAR) – 28% (UV) by red-white, 12% (PAR) – 23% (UV) by green-white, 13% (PAR) by light grey, 15% (PAR) – 26% (UV) by green-black or 16% (PAR) – 23% (UV) by red-black and 18% (PAR) – 29% (UV) by black hail nets measured 50?cm underneath; hail nets transmitted more NIR than PAR/visible light followed by UV with a peak at 375?nm. Light transmission increased by 3% above 500?nm (green) in green and by 2–5% above 570?nm (orange-red) in red hail nets, affecting neither the red?:?far red (666?:?730?nm/R?:?FR) ratio nor the phytochrome system.
5. The mesh size, i.?e. the distance in between the fibres, varied from translucent (white) hail nets with the largest mesh size of 3?×?9?mm, followed by 3.9?×?6.9 with green-white, 3.3?×?7.7?mm with red-white, 3.5?×?6.5 with green-black nets, 2.8?×?6.9?mm with grey as well as red-black and black hail nets both with the smallest mesh of 2.5–3?×?6.5?mm; these large variations in mesh size between hail nets predominantly influenced their light transmission, which was also affected by the proportion of translucent or black fibres in a hail net. A simple test is proposed to estimate the geometric light transmission without a magnifying glass based on measuring mesh size with a ruler and correcting for fibre strength and proportion of translucent or black fibres.
6. Fruit colouration of the poorly coloured apple cv. ‘Pinova’ followed this geometric light transmission, while that of the late-ripening, well-coloured cv. ‘Fuji, Kiku 8’ was sufficient and unaffected by hail net colour; fruit yields of the young apple tress were unaffected by net colour.
7. Black hail nets appear suitable for single-coloured green, or bi-coloured apple varieties with good colouration, or those otherwise susceptible to sunburn in Southern Europe. Crystal hail nets (with their translucent fibres, widest mesh size and largest light transmission), or grey hail nets (with twin translucent longitudinal, single black 0.32?mm strong transverse fibres and 2.5–3.5?mm?×?6–8?mm mesh) appear suitable for apple crops in Northwest-Europe with sunlight deficiency and without risk of sunburn. Red-white nets appear unsuitable due to the greater shading than the translucent fibres and for landscape reasons; their alleged photo-selective effects as reported from Southern Italy, Israel and Chile are interpreted to be due to reversal of photo-inhibition under high light intensities and heat in these regions.
8. Labelling of hail nets with tear and Langley values for UV durability is suggested.

     

Erh?hung der Temperatur bei der Apfellagerung durch Einsatz von 1-MCP

The investigations should purify whether the temperature during apple storage can be increased by application of 1-MCP to decrease energy consumption and costs. The investigations were carried out over 2 years with the following treatments: Year 1: The apple cultivars ‘Elstar, Elshof’ and ‘Gala, Must’ were investigated. For both cultivars 3 different storage temperatures (1, 2 and 4°C) with and without application of 1-MCP were examined. Each temperature and 1-MCP treatment was investigated both under CA-/ULO-conditions with 1.5% O₂ and 2% CO₂ and in cold storage with normal atmosphere. Year 2: The apple cultivars ‘Jonagold, Jonica’ und ‘Golden Delicious, Weinsberg’ were investigated. For both cultivars 3 different storage temperatures (1, 2 and 4°C) with and without application of 1-MCP were examined. Each temperature and 1-MCP treatment was investigated both under CA-/ULO-conditions with 1.5% O₂ and 3% CO₂ and in cold storage with normal atmosphere. The influence of temperature, storage atmosphere and 1-MCP application on fruit firmness, soluble dry matter (sugar) and fruit acid was investigated on 6 dates (September to October in the first year) respectively on 5 dates (October to March) during the storage period. Following results were obtained:

1. In the first year storage temperature did not influence the content of soluble dry matter of both cultivars. Application of 1-MCP led to a less decomposition of soluble dry matter. In the second year the content of soluble dry matter decreased slightly with increasing temperatures. A clear positive effect of 1-MCP-application was not noticeable. Altogether an increase of storage temperature has no or only a small influence of the content of soluble dry matter. 1-MCP can slow down the decomposition of soluble dry matter.
2. An increase of storage temperature had no or only a small influence of fruit firmness. With increasing storage temperature fruit firmness decreased slightly.1-MCP application led to a higher fruit firmness, especially during cold storage in normal atmosphere. In both years all cultivars showed a same or higher fruit firmness at 4°C with 1-MCP application under CA-/ULO-conditions as at 1°C without 1-MCP application under CA-/ULO-conditions.
3. An increase of storage temperature had no or only a small influence of the content of fruit acid.1-MCP application under CA-/ULO-conditions reduced the decomposition of fruit acid. In both years usually all cultivars showed a same or higher content of fruit acid at 4°C with 1-MCP application under CA-/ULO-conditions as at 1°C without 1-MCP application under CA-/ULO-conditions.

The results show that an increasing of storage temperature under CA-/ULO-conditions and with 1-MCP application has no negative influence on fruit quality in comparison to fruits which were stored under CA-/ULO-conditions at low temperatures without 1-MCP application.     

邹洋,梁维依,周金盼,李浩

通过分析《辋川集》及辋川图历代摹本,辋川别业中部分植物的造景手法得出了以下结论:辋川别业有采用四时造景的艺术手法进行植物造景;造景形式多为植物围合建筑;植物选取方面,除季相因素外大多采用当时流行的意向植物,以此为获得更好的诗意栖居体验。     

Mikroklima-, Farb- und Geschmacksverbesserung durch Licht reflektierende Folie zu verschiedenen Auslegeterminen bei ��Elstar��- und ��Jonagold�� ?pfeln unter schwarzem und wei?em Hagelnetz

Fruit colouration of the bi-coloured apple cvs ??Elstar Elshof?? and ??Jonagold Wilmuta?? on M9 under hailnet is often hampered due to light deprivation in the autumn, caused by shorter photoperiod, declining solar angle and decreasing light intensity. Therefore, reflective ground cover (Extenday^®) was spread early (beginning of July) or late (beginning of August) either side of the tree rows under white (88?C92% light transmission) or black (80?C84% light transmission) hailnet at the University of Bonn, Campus Klein-Altendorf (50.4°N), Germany, to improve fruit quality, particularly fruit colouration and taste, particularly sugar content. The five-year-old apple trees on M9 rootstock, spaced at 3.5 m?×?1 m, were planted in N-S orientation to optimise light utilisation; adjacent uncovered trees without reflective ground cover without hailnet served as control. The ground covers improved light reflection perpendicular from the ground in the middle of the alleyways by 14% at 90° angle, but by 5-fold at a 45° angle into the periphery of the tree canopy, both measured 1 m above ground. The diurnal course of light reflection 1 m from the ground differed distinctly from that of incident radiation: The latter depended on the East or West side of the tree row. By contrast, light reflection values depended solely on the use of reflective ground cover irrespective of hailnet and row orientation. Relative humidity and air temperature appeared unaffected by the use of reflective mulch; sunburn did not appear in any of the treatments. 1,200 colour measurements showed that the reflective ground covers improved red colouration of the downward-facing, lower and tree-facing, inner side of apple fruit of both varieties from 91?C99°hue colour angle (green) in the uncovered control to 51?C59°hue (red) irrespective of the date of spreading the mulch i.e. early or late. By contrast, no differences were observed in the sun-exposed, outer side of the fruit. The lowest fruit firmness and lowest sugar content were observed in apple fruit under the black hail-net. The firmest fruit with the largest sugar concentration (as a measure of taste) were observed in all trials with reflective mulch, particularly in the lower third of the tree canopy, starting from the uncovered control, the white hailnet to the black hailnet; sugar concentration improved with the time of mulching. Overall, the shorter time of mulching of 4 versus 8 weeks prior to anticipated harvest from the beginning of July (for cv. ??Elstar??) and mid-August (for cv. ??Jonagold??) proved sufficient for improving fruit quality, colouration and taste under both white and black hailnet at 50°N. Based on an expected 10-year lifespan with reduced UV-exposure under hailnet in North-western Europe, this currently most expensive reflective ground cover increased gross returns by 560?C840 ?/ha/year due to more well-coloured class 1 apples and a smaller percentage of poorly coloured apples (?<?25% blush) compared with the material cost of 700 or 350 ?/ha/year, if used once or twice a year, but without any labour cost involved. Financial returns varied between 210 and 490 ?/ha/year, based on double use per season of the light reflecting material, whereas single use only reached the break-even point. Hailnets are expected to increase due to climate change associated with better light conditions for reflection in the autumn and taller tree training leading to more shade in the lower tree canopy; new alternative reflective, low cost ground covers may then contribute to better utilisation of light otherwise lost in the alleyways and better economy for use in a fruit orchard.