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.     

Mechanische Fruchtbehangsregulierung bei Apfel verbessert Fruchtgröße,Fruchtfestigkeit, Fruchtausfärbung und die Source: Sink – Verhältnisse mit mehr Einzelfruchtständen (Singlets) bei ‘Gala’

The objective of the MSc project was to improve fruit quality, i.e. fruit firmness, colour and size, by mechanical blossom thinning. Ten-year-old slender spindle apple cv. ‘Gala, Mondial’ trees at Campus Klein-Altendorf near Bonn, Germany with an intense flowering of 7–8 on the 0–9 scale were blossom-thinned on 21 April 2009; unthinned trees served as control. Rotor speeds were 360 rpm or 420 rpm at 5 or 7.5 km/h tractor speed using 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 was mounted on the front three point hitch of the tractor with the following results:

1. Mechanical thinning reduced the number of apple fruit from 18 per branch section in the un-thinned control, 12–13 in the medium to 8 fruit in the strongest thinning (420 rpm, 5 km/h).
2. Similarly, the number of singlets (one fruitlet/flower cluster) nearly doubled from ca. 2 per branch in the control to 3–4 after mechanical thinning, as intended.
3. The natural June drop after mechanical thinning resembled that in the un-thinned control.
4. Mechanical thinning increased fruit mass by 20 g—48 g relative to the un-thinned control.
5. Mechanical thinning with 420 rpm increased the portion of premium fruit >?70 mm (class I) by 43?% (7.5 km/h) and 63?% (5 km/h); combined mechanical and hand-thinning yielded the largest portion of fruit >?70 mm (70?%), but with a dramatic loss in yield (55?%).
6. Mechanical and manual thinning improved the portion of well coloured fruit (75–100?% coloured) (78–98?%) when compared to the un-thinned control fruits with 55?%, probably due to selective removal of shaded fruits from the inner tree canopy.
7. Overall, mechanical thinning alone gave better results than hand thinning alone or its combination with hand-thinning in cv. ‘Gala’; mechanical thinning waived the need for hand thinning in this experiment.
8. Mechanical thinning improved fruit firmness from 9.4 kg/cm² in the un-thinned control to 10.4 kg/cm².
9. Neither vegetative growth nor subsequent fruit drop were stimulated by this type of mechanical thinning.
10. The risk of both alternate bearing and over-sized fruit was waived due to the variety employed.
11. An economic evaluation showed a net profit of € 220/ha in the weak (420 rpm—7.5 km/h) aνô € 1,844/ha in the intermediate (360 rpm—5 km/h), but a net loss of € 1,120/ha (420 rpm—5 km/h) for the strongest thinning treatment, assuming a cost of € 120/ha for the mechanical treatment and a saving of € 200 for reduced hand thinning.

Overall, the positive results of a better fruit quality (size, colour and firmness) offer the potential of mechanical blossom thinning in cv. ‘Gala’, which is difficult to blossom-thin chemically.     

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.     

Determination of Energy Use Efficiency of some Apple (<Emphasis Type="Italic">Malus x domestica</Emphasis>) Production in Turkey: a Case Study of Eğirdir Region

This research aims to make an analysis of energy use efficiency of apple (‘Starkrimson Delicious’ and ‘Golden Delicious’) production in E?irdir region of Turkey, during the production season of 2012. Production data this research was collected in 2013. In order to determine the energy use efficiency of apple, various surveys have been conducted in 71 apple farms, selected through Simple Random Sampling method, located in E?irdir region of Turkey. The data have been collected through face to face questionnaires and first hand observations. The energy input and output values in apple production have been calculated as 34,703.63 MJ ha^?1 and 95,034 MJ ha^?1, respectively. Energy inputs consist of diesel fuel energy by 29.04?%, chemical fertilizers energy by 24.28?%, machinery energy by 15.70?%, chemical energy by 9.84?%, human labor energy by 8.54?%, electricity energy by 5.63?%, irrigation energy by 3.97?%, farmyard manure energy by 2.88?% and lime energy by 0.12?%. Energy use efficiency, energy productivity, specific energy and net energy in apple production have been calculated as 2.74, 1.16 kg MJ^?1, 0.86 MJ kg^?1 and 60,330.36 MJ ha^?1, respectively. The total energy input consumed has been classified as direct, by 47.17?%, indirect, by 52.83?%, renewable, by 15.38?% and non-renewable, by 74.62?%.     

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.

     

1-Naphthaleneacetic acid and 6-benzyladenine thinning of a common slender spindle ‘Jonagold’/M.9 apple orchard. II: Partial tree spraying

Summary

Mature slender spindle ‘Jonagold’/M.9 apple (Malus × domestica Borkh.) trees were thinned using 10 mg l^–1 1-naphthaleneacetic acid (NAA) or 100 mg l^?1 6-benzyladenine (BA) and an axial fan sprayer at a spray volume of 1,500 l ha^?1 applied to the whole canopy, or with smaller volumes, where only the upper half of each canopy was sprayed. Partial spray applications of NAA or BA (at 1,000 l ha^?1, 750 l ha^?1, or 500 l ha^?1) to the upper half of the trees did not cause any reduction in final fruit numbers on the upper half, or on the lower half of each tree. When the whole tree was sprayed to run-off with the same thinning agent, or at 1,500 l ha^?1, successful thinning on both the upper and lower parts of the canopy occurred. Good spray coverage (from 51% to 77%) was also observed on leaves at all canopy positions measured, when whole trees were sprayed at 1,500 l ha^?1.The development of an innovative crop load regulation strategy was an objective of the ISAFRUIT Smartfruit Project.     

Einfluss verschiedener Ausdünnverfahren auf die Source: Sink-Verh?ltnisse und Fruchtqualit?t von Zwetschen

Chemical thinning agents for stone fruits are scarce. Hence, the objective of the present work was to improve fruit quality,viz size in plum, using mechanical and chemical thinning or combinations thereof; untreated, i.e., un-thinned plum trees of the same rows served as control. Plum trees of the medium-sized cv. ‘Ortenauer’ on dwarfing St. Julien GF 655/2 rootstock, with maximum flower intensity in 2009, were grown near Bonn, Germany. Trees were mechanically thinned in April 2009 with the blossom thinner developed by the University of Bonn with 300, 400 or 500?rpm at a tractor speed of 5?km/h. Half of the trees were additionally chemically thinned with both ammonium thiosulphate (ATS) (15?l/ha) at full bloom and an ethylene releasing compound (0.375?l/ha) 35 days after full bloom. The objective of 1/3 flower i.e. fruitlet removal was successfully achieved even with the slowest rotor speed of 300?rpm. The number of fruit per metre fruiting spur was reduced from 46 to 18–27, equivalent to a (source: sink) leaf: fruit ratio of 5:1. Mechanical thinning significantly enlarged fruit mass from 28?g in the un-thinned control to 30–32?g with rotor speeds of 400 or 500?rpm. Additional chemical thinning with ATS and an ethylene-releasing compound resulted in no further increase in fruit mass. Inner fruit quality (sugar) of the plums appeared unaffected by either mechanical or chemical thinning, except for fruit firmness. Plums thinned with an ethylene releasing compound were softer and ripened earlier than respective control fruit, possibly due to the ethylene release. The lesser fruit density per tree after thinning reduced the potential for fungal infections such asMonilia due to faster drying of the fruits after precipitation. Mechanical thinning reduced thinning by manual labour from 31?min. per tree in the un-thinned control to 24?min. by ca 25%, i.e., by 7?min. per tree; this is equivalent to a net financial gain of 400–500?€/ha, after expenditure (120?€/ha; 1.5?h/ha), for thinning. Overall, both efficacy of blossom removal and fruit mass enlargement scored best after mechanical thinning around 400?rpm, indicating that mechanical blossom thinning provides a suitable alternative for chemical and/or manual thinning or can be combined with either of those options. An additional advantage of mechanical blossom thinning is to overcome or avoid alternate/biennial bearing due to its early application at bloom time; a similar effect was observed with the ethylene-releasing compound applied 35 days after full bloom.     

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.     

Cherry 2016 – Abschlusskonferenz des EU Projektes COST Cherry FA 1104 im Anbaugebiet der Tragana Rodochori-Kirsche in Nordgriechenland

The final COST Cherry FA 1104 conference was organized in Greece, Europe’s 4^th largest cherry producer after Poland, Italy and Spain. Altitudes of ca. 600 m asl provide sufficient chilling (1200 Chilling Units) for early flowering at 40°N at the beginning of April in Greece’s predominant cherry growing region Macedonia; honey bees provide pollination. Cherries are cultivated on fertile soil without frost protection or polytunnels and harvested from 25 May to 15 June. Old varieties and trees are eventually replaced by new varieties in intense plantings on micro-propagated GiSelA 6 or Piku rootstocks from local tissue culture labs; nurseries provide the grafted trees for the cherry industry. The pomology institute in Naoussa was founded at a site of a grapevine nursery 50 years ago in 1961 for research and to support the industry and extended to cherry from 1970 onwards. A small portion (13–17?%) of the 60,000 t harvest is exported mainly to Europe (8–10,000 t), while Russia imported 6000 t of Greek cherries until 2014, before the Russian embargo started. Export quality is achieved by hand thinning of the small fruitlets with scissors after flowering. These large-fruited cherries of EU protected origin ‘Tragana Rodochori’ obtain farm gate prices of 2–3 €/kg making the Greek cherry industry worth € 120 million a year.     

Einfluss schwach wachsender Apfelunterlagen auf Wachstum,Ertrag und Fruchtgröße verschiedener Sorten – Teil IV: Abschließende Bewertung

From 2001 to 2005 the influence of the dwarfed apple rootstocks M?9 (clone: Burgmer 984), Fleuren 56, Supporter 1, P?16, P?22, J-TE-F, J-TE-E and M?27 on growth, yield and fruit size of the apple varieties ‘Elstar, Elshof’, ‘Boskoop, Herr’ and ‘Jonagored’ was investigated on the locations Auweiler, Dresden-Pillnitz, Osnabrück and Wurzen in Germany.All rootstocks induced a less vegetative growth as the rootstock M?9. In comparison with M?9 the crown volume of the trees ranged from 92% (Supporter 1) to 52% (M?27). The highest yield potential showed the rootstock P?16. Her specific yield (kg/m³) was 17% higher than the specific yield of M?9. All rootstocks produced a lower individual fruit size as M?9. J-TE-E and J-TE-F produced the lowest specific yield.     

Determining the Energy Usage Efficiency of Walnut (<Emphasis Type="Italic">Juglans Regia</Emphasis> L.) Cultivation in Turkey

The aim of this study is to reveal the energy balance of walnut in Central Anatolian Region in Turkey. This study has been conducted at the walnut cultivating facilities during the 2014–2015 production season in K?r?ehir, Konya, Nev?ehir and Ni?de provinces of Central Anatolian Region in Turkey, where walnut cultivation is intense. In the study, a total of 28 walnut cultivation facilities, yielding walnut, have been selected through Neyman method and surveys and observations have been performed in these facilities. The agricultural input energies and output energies used in walnut cultivation have been calculated to define the energy use efficiency. According to the study findings, the energy inputs in walnut cultivation are calculated respectively 17,851.33?MJ ha^?1 (74.40%) chemical fertilizer energy, 2229.87?MJ ha^?1 (9.29%) fuel energy, 1640.64?MJ ha^?1 (6.83%) irrigation water energy, 1539?MJ ha^?1 (6.41%) machine energy, 508.02?MJ ha^?1 (%2.11) chemical energy, 180.35?MJ ha^?1 (0.75%) human labour energy and 43.33?MJ ha^?1 (0.18%) farm manure energy. Production outputs have been calculated as 14,679.52?MJ ha^?1. Following the energy calculations, the output/input ratio, specific energy, energy efficiency and net energy calculations have been calculated respectively as 0.61, 30.20?MJ kg^?1, 0.03?kg MJ^?1 and ?9313.02?MJ ha^?1. Benefit-cost ratio was calculated as 1.88, by dividing the gross value of production by the total cost of production per hectare in walnut production.     

Yield and Quality Response of Young ‘Gala,Galaxy’ Trees under Different Irrigation Regimes

This study was conducted in 2007–2008 to determine the effects of different irrigation regimes on yield, quality and water-yield relationships of young dwarf ‘Gala, Galaxy’ apple trees in Isparta-Turkey. Irrigation water was applied based on a ratio of class A pan evaporation (rates of 0.0 (k_cp0), 0.25 (k_cp1), 0.50 (k_cp2), 0.75 c (k_cp3), 1.00 (k_cp4) and 1.25 (k_cp5)) with 5-day intervals. The effects of irrigation regimes on yield and fruit weight were statistically significant. Seasonal evapotranspiration was measured as 246.5–608.2 mm and 289.3–631.9 mm in 2007 and 2008, respectively. Water use efficiency lead to a yield ranging from 0.0023 to 0.0055 t ha^?1mm^?1 and from 0.0033 to 0.0111 t ha^?1mm^?1 and irrigation water use efficiency varies from 0.0009 to 0.0073 t ha^?1mm^?1 and from 0.0045 to 0.0186 t ha^?1mm^?1 in 2007 and 2008, respectively. The annual average yield response factor, ky, was 1.22. As a result of the research, it was concluded that the irrigation schedule for the 0.75 k_cp3 treatment, applying 0.75 of evaporation from class A pan, could be used in the irrigation of young dwarf apple trees without evident reduction in yield and that high water use efficiencies could be obtained.     

1-Naphthaleneacetic acid and 6-benzyladenine thinning of a common slender spindle ‘Jonagold’/M.9 apple orchard. I: Dose effects and spray distribution in the crowns

Summary

To find the most appropriate rates of application of plant growth regulator (PGR) thinning-agents for a common slender spindle apple (Malus × domestica Borkh.) orchard, different volumes of dilute 1-naphthaleneacetic acid (NAA) and 6-benzyladenine (BA) were sprayed ha^?1. Mature ‘Jonagold’/M.9 trees, 3.0 – 3.5 m high and 1.2 – 1.5 m wide, planted in a single row system with 3,030 trees ha^?1, were used. Significant thinning was observed in the case of dilute sprays of NAA at 10 mg l^?1, or BA at 100 mg l^?1, to run-off, using 2,000 l ha^?1 or 1,500 l ha^?1; while 1,000 l ha^?1 did not result in sufficient thinning. Thinning using smaller volumes (250, 500, or 750 l ha^?1) was also significant if the concentration of PGR thinner was proportionally higher (i.e., based on the 1,500 l ha^?1 application rate of more dilute sprays of NAA at 10 mg l^?1 or BA at 100 mg l^?1). Spray distribution measurements in the crowns showed better spray deposits when higher water volumes (i.e., more dilute PGR solutions) were sprayed at all positions (bottom, middle, or top) of the canopy. At 2,000 l ha^?1, 54 – 72% coverage of the leaf area was observed; but, at 250 l ha^?1, coverage was only 10 – 21%. The lower 30% of the canopy was covered poorly when smaller volumes of water (250, 500, or 1,000 l ha^?1) were applied. When 1,500 l ha^?1 was sprayed, good coverage of the lower and upper surfaces of the leaves occurred, and no differences in canopy positions were measured. It was concluded that 1,500 l ha^?1 (i.e., dilute PGR) spraying was the most appropriate volume to use when calculating the dose of NAA or BA to be applied ha^?1 to common (3.0 – 3.5 m-high) mature slender spindle apple orchards on M.9 rootstock. This study was part of the ISAFRUIT Smartfruit Project, aimed at improving existing methods for apple crop regulation with more precise use of PGR thinning agents and with minimum impact on the environment.     

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.     

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.     

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.     

Effects of Irrigation Frequency on Yield and Quality Parameters in Apple c.v. ‘Gala,Galaxy’

This study was conducted in 2007 and 2008 in order to determine the effects of irrigation frequency on the yield and quality parameters of dwarf trees of the apple cultivar ‘Gala, Galaxy’ in the first and second year of cultivation. Irrigation water was applied at 3?, 5?, 7?, and 10-day intervals as much as the amount of water consumed from the field capacity. Statistical analysis revealed that the effects of irrigation frequency on yield were significant. Since the trees used in the experiment showed mainly vegetative growth, the effects of irrigation frequency on the fruit quality characteristics varied. Irrigation water amount was applied as 355.7–446.5 mm and 359.2–538.9 mm to the experimental treatments in 2007 and 2008, respectively. The evapotranspiration measured was in the range 400.7–491.5 mm in 2007 but in the range 440.2–600.5 mm in 2008, while the yields in the same years ranged from 1.54 to 2.84 t ha^?1 and from 2.61 to 6.06 t ha^?1. Water use efficiency varied between 2.40 and 4.80 t ha^?1mm^?1 in the first year of the experiment but between 3.45 and 7.08 t ha^?1mm^?1 in the second year. The I₂ treatment, in which the highest yield and water use efficiency were recorded in both years of the experiment under the experimental conditions, was determined as the irrigation scheduling.     

Einfluss organischer N-Dünger auf die Ertrags- und Wuchsleistung der Apfelsorte ‘Jonagold’

In the organic production of fruits there are 30% lower yields than in the conventional or integrated production. Changes concerning plant protection, weed control and N-fertilization are discussed to be possible causes. In the presented trials the influence of organic N-fertilizers on growth and yield of the apple-variety ‘Jonagold’ is investigated. The organic fertilizers “Vinasse” (product resulting from the converting of sugar-beet molasses), “Haarmehlpellets” (pellets of grounded pig bristles), “Rizinusschrot” (grist of the seed of Ricinius communis), “Rapsschrot” (coarse colza meal), “Phytopearls” (residue of maize converting), “Maltaflor” (malt germs and “Vinasse”) and manure were proved. Also the mineral N-fertilizers calcium-ammonium-nitrate and compost were used. The tests were made both in an orchard with integrated production (location Osnabrück) and in an orchard with organic production (location Jork). All tested fertilizers had no influence on the growth and yield of the apple variety ‘Jonagold’. The annual N-uptake of apple-trees in their years of highest yield adds up to 90 and 100?kg?N/ha. This consumption was met by the N-supply of the soil (N_min in Feb./March + N-mineralisation) on both locations. To prevent a possible temporary N-deficit in the first half of the vegetation period a fertilization (30?kg?N/ha) is suggested with organic fertilizers, which release a high N-amount at the latest from the second year of utilization.     

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.