Control of Fungal Storage Rots of Apples by Hot-Water Treatments: A Northern European Perspective

In the Lower Elbe region of Northern Germany and in other Northern European fruit production areas, about 80?% of all storage rots of apples are caused by Neofabraea alba and N. perennans. Other pathogens include Colletotrichum acutatum, Monilinia fructigena, Phaci­diopycnis washingtonensis, Neonectria galligena, Botrytis cinerea, Penicillium expansum and Fusarium avenaceum. Hot-water treatments of freshly harvested fruits for 3 min at 50–52?°C gave high efficacies against most of these storage rots except F. avenaceum. Substantial evidence supported a heat shock-induced antimicrobial response rather than a direct killing of fungal inoculum as the principal mode of action of hot-water treatments in apples. Shorter exposures for?<?30 s at 55–60?°C also provided good control of fungal storage rots and thereby offer new possibilities for this technology in Northern European fruit production. These possibilities include the integration of a hot-water unit into existing grading lines and the option to treat fruits at different time points, e.g. at harvest, after short-term storage and/or after long-term storage.     

<Emphasis Type="Italic">Dactylonectria torresensis</Emphasis> as the Main Component of the Black Root Rot Complex of Strawberries and Raspberries in Northern Germany

In a long-term survey of black root rot of strawberries and raspberries in Northern Germany in 2007–2014, fungi with and without Cylindrocarpon-like anamorphs were isolated as potential pathogens. Dactylonectria torresensis was the most common species, being isolated from 18% of strawberry roots obtained from nursery plants and 37% of roots from production fields, as well as 21% and 29% (respectively) of raspberry roots. Less frequently isolated fungi with Cylindrocarpon-like anamorphs included Ilyonectria crassa, Ilyonectria sp. 2, I. pseudodestructans, I. robusta, C. obtusisporium and Ilyonectria sp. 1. Severe disease symptoms were reproduced by artificial inoculation of strawberries with D. torresensis, I. crassa and Ilyonectria sp. 2, milder symptoms with C. obtusisporium. A wide range of other root-pathogenic fungi such as Fusarium oxysporum, Verticillium dahliae, Ceratobasidium fragariae, Gnomoniopsis fructicola, Hainesia lythri, and species of Cadophora, Leptodontidium, Pythium, Phytophthora, Plectosporella, Pestalotiopsis and Truncatella were either isolated only sporadically or were not associated with black root rot symptoms, suggesting that they did not play any major role in this disease in Northern Germany. Visible disease symptoms and high frequencies of D. torresensis isolations in many batches of nursery plants indicated that these may comprise a major source of contamination of production fields. The previously unrecognised prominence of D. torresensis resolves a long-standing puzzle concerning the cause of the ongoing black root rot epidemic in Northern German strawberry and raspberry production.     

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.     

Betrachtung möglicher Auswirkungen des Klimawandels auf Schadpilze im Obstbau am Beispiel von Fruchtfäuleerregern an Äpfeln

Whereas the rise in temperature during the past 30–40 years has already had clear impacts on the phenology of fruit trees and pathogenic insects, there is a lack of such correlations for fungal pathogens. An examination of fruit rots indicates that pathogenic fungi react differentially to climate change due to their complex infection biology. The appearance of the black rot fungus Diplodia seriata in Northwestern Europe is best explained by rising temperatures during the vegetation period. An increase in fruit rot caused by Nectria galligena is anticipated when milder and more humid winter months favour canker formation on twigs and branches, thereby increasing inoculum for fruit infections. An increasing importance of Neofabraea alba and Glomerella cingulata and/or G.??acutata as storage rots of apples in Northern Germany cannot be safely correlated with the climate change at present. Research on fungi is currently being expanded at the OVB Jork in order to ensure a faster identification of new pathogens and a more thorough investigation of relevant features of their infection biology.     

The Genus <Emphasis Type="Italic">Fragaria </Emphasis>in Croatia

Only three native species of genus Fragaria (F. moschata, F. vesca and F. viridis) are recorded in three regions of Croatia. These species as well as many of their hybrids, are, or once were, cultivated for their edible fruits. The majority of cultivated strawberries in Europe belong to garden strawberries F. x ananassa (hybrids of F. chiloensis and F. virginiana). The most expanded wild strawberry species in Croatia is a woodland strawberry (F. vesca) whose berries are gathered seasonally as wild edible fruits. They often contain higher amount of nutrients and bioactive compounds in comparison to cultivated varieties. The research on the genus Fragaria species distribution in Croatia has not been carried out, and so is the case with many others wild growing fruit species in Croatia. By summing up a number of individual citations and observations, it is possible to get a perspective regarding the current state of their distribution.     

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.     

Tragbares Ethylenmessgerät mit hoher Auflösung durch neue Sensortechnologie

A new electro-catalytic sensor for the measurement of the gaseous ethylene (C₂H₄) concentration in air is described here. The measuring principle is based on ethylene oxidation to CO₂ and H₂O on a gold-plated anode with weak sulphuric acid as a catalyst, the small ethylene molecules are trapped in the pores of the gold-plated anode; the measurement consumes ethylene. During the warming-up phase, the unit automatically calibrates its zero by employing dried, ethylene-free gas from the built-in drying and potassium permanganate columns. Thereafter, the unit requires calibration with humidified gas from gas supplied externally e.g. from a cylinder at a concentration of between 4–10 ppm C₂H₄; this end-point calibration is kept until switching off. The accuracy was 96–98% with a SD of 0.05–0.15?ppm C₂H₄ and a variation coefficient of 0.5–2%, when the calibration gas of 8?ppm C₂H₄was measured after the calibration. The measuring range is 0–50?ppm C₂H₄ with an accuracy of ±?5% and displayed resolution of 1?ppb. For a typical 30?sec measurement, the instrument draws a ca. 150?ml gas sample and appears suitable for measurement of individual fruit in an open or closed gas system, single gas samples or traditional injection of a ca. 5?ml gas sample. Temperature and humidity (and as additional options CO₂ concentration, another gas or ethylene analogues like MCP) are displayed concomitantly. The reproducibility of the values was 93% with 3 subsequent measurements of a variety of fruits. The unit can be operated on mains or built-in battery providing up to 8?hours operation and weighs about 4.5?kg including battery, which makes it portable for in-situ ethylene measurement after calibration with an external gas supply. The instrument appears to be an elegant alternative to the traditional determination of ethylene concentration based on a 10?ml sample from the head space of jar after several hours of accumulation, by a gas chromatograph with N₂ as tracer gas, Poropak?Q column and flame ionisation detector (FID).     

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.     

Mechanische Fruchtbehangsregulierung

The objective of the present study was to thin apple flowers without use of chemicals, in order to improve fruit quality, reduce labour for hand thinning and overcome alternate bearing. The newly developed device comprises three rotors with adjustable angles and vertically rotating ropes, which remove excess apple flowers. Eleven year-old cv. ‘Braeburn’ apple trees were thinned at flower opening (BBCH growth stage 61) with the new device in Klein-Altendorf near Bonn, Germany. Adjacent untreated, hand-thinned or chemically (benzyladenine-)thinned apple trees of the same rows served as controls. Tree branches remained un-damaged by the vertically rotating ropes. Slight leaf damages of less than 8% were observed at the fastest rotor speed of 320?rpm, which also gave the best thinning results. The portion of class one fruits >?70?mm was increased by 10% without yield loss and by up to 20% with yield losses of ca. 5–10%, depending on the settings, relative to the untreated control. This was equivalent to fruit mass gains of 10?g without yield loss and of 20?g with 10%–20% yield loss with economic gain in both cases. The single or double-sided mechanical thinning required 1.2?h ha^?1 or 2.4?h ha^?1 at a tractor speed of 2.5?km h^?1 and reduced the subsequent hand thinning by respectively 20% or 45% (by 7?h or by 15?h/ha or its cost by 50–135 €/ha). The new device gently removed up to one third of both peripheral and central flowers at a cost of less than 100 €/ha and with a negligible risk of over-thinning and without effect on return bloom.     

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.     

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.

     

A Pragmatic Approach for Obtaining Lines Possessing Desirable Traits in Silk Banana

Silk Banana is amongst the most popular groups of bananas grown in different parts of the world. However, the commercial scale cultivation requires identification of superior genotypes with desirable attributes including growth, yield, quality and resistance to Panama wilt disease which is a major concern. Panama disease caused by the fungus Fusarium oxysporum f. sp. cubense has been wreaking havoc in banana plantations throughout the world. A large number of varieties fall prey to the pathogen and hence world’s banana production has been threatened to a considerable extent, Silk Banana being the most vulnerable. Long term use of chemicals has not only failed to provide protection against the disease but has also raised concern about the environmental health. Resistance breeding is thus only viable alternative; however, breeding in banana is hindered by a number of inherent problems. In this communication, a systematic approach was proposed taking a typical case of Silk Banana var. Nanjanagud Rasabale to preselect lines possessing Panama wilt resistance and other desired traits. The proposed methodology comprised of identification of spontaneous variants in growing regions of the variety and their subsequent screening using a multi-pronged strategy. A number of lines exhibiting superiority in terms of tolerance to panama wilt, precocity, plant stature, physicochemical and shelf life related attributes have been reported. Considering overall performance, six promising lines were identified. This methodology has wider applicability as it could be effectively exploited with suitable modifications for identifying lines with desired traits in other varieties of banana.     

Comparison of Climate Change Effects on Pome And Stone Fruit Phenology Between Balkan Countries and Bonn/Germany

The objective of the joint project between the two universities of Bonn and Sarajevo was to study the effects of climate change associated with warmer winter and spring temperatures on fruit tree phenology. Changes in flowering date of apple and cherry were correlated with local weather data obtained concomitantly on-site at four locations in the Balkan countries Slovenia, Serbia, B & H and at Bonn, Germany.Phenological data of flower opening (F1; BBCH 61) of apple cv. ‘Golden Delicious’ originated from 55 years at Cacak (44?°N, Serbia) and at Klein-Altendorf, University of Bonn (50?°N), cv. ‘Bobovec’ from the University of Ljubljana (46?°N, Slovenia) and cherry cv. ‘Burlat’ (35 years at Klein-Altendorf, 50?°N) and 20–30 years at Tuzla (44?°N, B & H) and Mostar (43?°N, Bosnia & Herzegovina; B & H).The annual precipitation showed a negligible change in the last 55 years of ±5% in the Balkan countries (e.?g. Cacak, 699?mm), but only ±1.8% at Klein-Altendorf (605?mm) with a slight shift to more winter rainfall.Regression analysis showed an increase in mean temperature of 1.7?°C (annual) and 1.45?°C for the vegetation period at Klein-Altendorf (last 55 years), Germany. In the evaluated Balkan stations, the greatest increase in annual air temperature between two climate phases (until 1987 versus from 1988 until now) was at Ljubljana (1.4?°C) and Cacak (1.2?°C) in contrast to the least increase (0.3?°C) at Tuzla (annual average 10?°C) and an intermediate value (0.9?°C) in the warmer Mostar (annual average 14.5?°C).This recent temperature increase advanced flower opening by 10–14 days for apple such as cv. ‘Golden Delicious’ at Cacak and 7–10 days (last 55 years) at Bonn and 4–5 days (last 35 years) for the early cherry cv. ‘Burlat’ at Klein-Altendorf/Bonn; at Mostar and Tuzla, the effect of climate change was greater with the early cherry cv. ‘Burlat’ (26 days) compared with the difference of the late cherry cultivar (16 days). Before recent climate change (1973–1987), cherry flower was advanced by 10 days in the warmer med climate at Mostar but delayed by 16 days in the cooler Tuzla. The results, i.?e. the flower advancement in the Continental climate but flower delay in the med climate, are discussed with respect to the risk of late frost and countermeasures to combat climate change effects.     

Ursache des Triebsterbens an Heidelbeeren in Norddeutschland: Schadpilze oder Winterfrost?

In the summer of 2010 and during the following two seasons, a twig dieback of blueberries (Vaccinium corymbosum) was observed in southern Lower Saxony especially in younger plantations of the variety ‘Duke’. The sudden onset of a chlorosis and necrosis of individual twigs was associated with a destruction of the vascular cambium and with longitudinal streaks of brown discolourations in the xylem tissue deposited during the previous year. New shoots were often formed from the intact roots and from regions of older twigs located immediately above the soil surface. Potentially pathogenic fungi, including Godronia cassandrae, Phomopsis spp., Diplodia seriata, Pestalotiopsis sp., Paraconiothyrium sporulosum, Colletotrichum acutatum, Fusarium avenaceum and F. lateritium, were found sporadically on dead twigs, each fungus being present in 6 or fewer of the 12 plantations surveyed. Winter frost damage of xylem tissues was determined to be the main cause of the disease, facilitated by a delayed termination of vegetative growth which led to a lack of winter hardiness at the time-point of the first serious frost events.     

The Response of Soilless Grown ‘Michele Palieri’ (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.) Grapevine Cultivar to Deficit Irrigation Under the Effects of Different Rootstocks

Global warming, altering the physiology and irrigation demand of grapevines, has already been perceived in certain premium viticulture regions across the world. Selection of proper rootstocks for especially new cultivars has vital role for a sustainable viticulture under water-deficit conditions. The grapevine cultivar ‘Michele Palieri’ has been finding a good reception on the global markets. The objective of this study was to determine the response of ‘Michele Palieri’ cultivar to deficit irrigation using different rootstocks with distinct genetic origins. Two irrigation regimes (Full Irrigation [FI] and Deficit Irrigation [DI]) were applied to the vines of different grafting combinations of ‘Michele Palieri’ with Kober 5 BB, Richter 99, Richter 110, 140 Ruggeri, 44–53 Malégue or grown on own roots. Two years old vines were cultivated in 60?L pots containing sterile peat under controlled glasshouse conditions. Irrigations were regulated according to soil water matric potential (Ψm) levels using tensiometers. The volume of the irrigation water that has to be applied to attain 100% field capacity was performed as FI, while 50% of FI was considered as DI. The water was transported directly into the pots by micro-irrigation systems consisting of individual spaghetti tubes. The vines of DI treatment showed visible symptoms of mild water stress (e.?g., loss of turgor in shoot tips), but no defoliation or leaf necrosis occurred. DI treatment reduced the gs of ‘Michele Palieri’ scion cultivar in varying levels depending on the rootstock. DI treatment also affected vegetative growth of the scion cultivar in different levels. For example, the greatest decrease (26.7%) in shoot length resulting from DI was determined in ‘Michele Palieri’/5 BB grapevines, followed by own rooted vines (13.1%), while the lowest change (2.4%) was found in vines grafted on 110?R. Overall findings of this study imply that the rootstocks originating from V. berlandiery?×?V. rupestris hybrids (110?R, 99?R, 140?Ru and 44–53?M) better performed in a similar genetic aptitude under deficit irrigation regime while the rootstock 5 BB (V. berlandiery?×?V. rupestris) showed more susceptible responses. On the other hand, the general response of own rooted vines were better than those grafted on 5 BB. Therefore, the use of one of V. berlandiery?×?V. rupestris hybrids may be a better choice for viticulture under semiarid regions.     

Einfluss schwach wachsender Apfelunterlagen auf Wachstum, Ertrag und Fruchtgröße verschiedener Sorten – Teil I: ‘Elstar’

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 variety ‘Elstar, Elshof’ 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 89 (Supporter 1) to 51% (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. A higher specific yield and a higher individual fruit size as M 9 only produced the M 9 clonal selection Fleuren 56. J-TE-E produced the lowest specific yield.     

A comparison of different thinning products applied to the apple variety ‘Elstar Elshof’ in the Lower Elbe region

6-Benzyladenine (BA) showed only a slight thinning effect which was probably correlated with low temperatures during application. It is concluded that under the current climate of the Lower Elbe region temperature is a more important factor than fruit size for determining the time-point of BA application. Ethephon at 300?ppm produced a stronger effect, even if this was still insufficient in the present case. Higher concentrations (450–600?ppm) are required for strongly flowering ‘Elstar’ plantations older than 4?years, but this invokes the risk of excessive thinning. Therefore, the application of Ethephon requires a high degree of experience on part of the fruit farmer. Metamitron, applied once at 350?ppm, showed similar effects to Ethephon. An enhanced effect might have been obtainable if a second treatment had been applied some 10?days later. No phytotoxic damage was observed. Metamitron would be an interesting fruit thinning agent and should be considered for registration in Germany. Naphthalene acetic acid (NAA) and NAA + BA gave the best results in the experiment for 2006?described here. It is not yet clear whether the degree of flowering for 2007 will be influenced in a similarly positive manner as for Ethephon. Since NAA and Metamitron have not been registered for Germany, their practical use cannot be recommended.     

Einsatz von Kennzahlen und Beratungsbriefen als Controlling-Instrument für Beratung und Gartenbaupraxis an der Niederelbe

The first business management analyses of fruit farms from the Altes Land (Lower Elbe Valley, Northern Germany) date back to the financial year 1956/57 and were published in 1958 by Prof. A. Löhden in the journal Mitteilungen des Obstbauversuchsringes des Alten Landes e.V. The data compiled by Löhden from the Agrarian Report were used by the Chamber of Agriculture of Hannover to evaluate the book-keeping of those fruit farms which it supported with business development grants. In the early 1980s the fruit advisory services had to implement a comparison of the book-keeping data of fruit farms. This business management advice has been expanded subsequently. At present, some 120 fruit farmers participate at the annual comparison of the Fruit Advisory Service and the Centre of Business Management in Horticulture. The use of this controlling instrument for evaluating key business data will be demonstrated in the current article on the basis of two examples.     

Ultrasound-Assisted Extraction of Phenolic Compounds from Unripe Grape (Qora)

Optimization of the extraction and analysis of phytochemicals can improve the production and quality of foods. The aim of this study is to evaluate ultrasound-assisted extraction of phenolic compounds from unripe grape (Vitis vinifera). At first stage, conventional thermal extraction was carried out in order to optimize the temperature (50, 70, 90 °C) and duration (20, 40, and 60?min) of the process (control). Investigations showed that the optimum condition of temperature and duration is 70 °C and 30?min, respectively. Then, grape pulp was treated for 30?min by ultrasound at a fixed frequency of 20?kHz. Results showed that ultrasound application increased the total phenolic content of the samples considerably. In addition, individual phenolic composition of the samples, namely rutin, gallic acid, hydroxybenzoic acid, syringic acid, p-coumaric acid, quercetin, and resveratrol were measured by HPLC. A good relation was observed between chromatographic and total phenol results. This study showed that ultrasound-assisted extraction is a sufficient method to produce verjuice as a rich and inexpensive source of antioxidants.     

Auswirkungen des Klimawandels auf die Verfügbarkeit von Kältewirkung (Chilling) für Obstgehölze in Deutschland

To quantify the effects of climate change on fruit production in Germany, this study aimed at determining long-term trends in winter chill, as calculated with the Chilling Hours and Dynamic Models (Chill Portions). An idealized daily temperature curve was used to convert daily temperature records from 43 weather stations, taken throughout the twentieth and late nineteenth centuries, into an hourly dataset, which was then converted to units of winter chill. Besides exposing temporal trends in winter chill, the data could be spatially interpolated, yielding contiguous maps of typical winter chill in Germany around 2010, as well as chilling losses since 1950. Throughout Germany, winter chill varied between 1700 and 3000 Chilling Hours or 125 and 150 Chill Portions. The areas of highest winter chill were located in the northern parts of the country. For the whole of Germany, there were no significant temporal trends. The extent of interregional variation in winter chill depended on the chilling model used. While the Chilling Hours Model showed strong declines in winter chill for the areas around Dresden and Leipzig, as well as for the Lake Constance region, the Dynamic Model did not detect such dramatic changes. More than a decline in winter chill, increased heat during the winter months might become a challenge to German fruit growers. As already experienced during the extraordinarily warm winter of 2006/07, warm temperatures during the winter can cause fruit trees that fulfill their chilling requirements relatively early to bloom prematurely. This can then lead to elevated risk of frost damage and hamper the homogeneity of flowering.