German Fruit Research Articles

Pomological and Molecular Characterization of Apple Cultivars in the German Fruit Genebank.

Traditional varieties are a valuable tool in modern apple breeding. However, the use of synonyms and missing source documentation hinder an effective identification and conservation of relevant cultivars. During several projects, the authenticity and diversity of the apple cultivar collection of the German Fruit Genebank (GFG) was evaluated extensively. The trueness-to-type of 7890 apple trees was assessed on a pomological and molecular level. Pomological evaluations were performed by at least two experienced experts to identify the original cultivar names. On the molecular level, a set of 17 SSR markers was used to determine a unique genetic profile for each apple cultivar. The pomological and molecular characterization was expressed in terms of a comprehensive trueness-to-type criterion and the results were previously published as a well-curated dataset. In this study, the published dataset was analyzed to evaluate the quality and diversity of the apple collection of the GFG and highlight new findings based on phylogenetic and parentage analysis. The dataset contains 1404 unique genetic profiles corresponding to unambiguous cultivar names. Of these 1404 cultivars, 74% were assessed as true-to-type. The collection of diploid apple cultivars showed a high degree of expected heterozygosity (Hexp = 0.84). Genetic diversity in terms of year and location of origin was investigated with a STRUCTURE analysis. It was hypothesized that genetic diversity might decline overtime due to restrictive breeding programs. The results showed a shift dynamic between older and newer cultivars in one specific cluster, but no significant decrease in genetic diversity was observed in this study. Lastly, a parentage analysis was performed to check parental relationships based on historical research. Out of 128 parent-child trios, 110 trios resulted in significant relationships and reconfirmed the information from the literature. In some cases, the information from the literature was disproven. This analysis also allowed for readjusting the trueness-to-type criteria for previously undetermined cultivars. Overall, the importance of authenticity evaluations for gene bank cultivars was highlighted. Furthermore, the direct use of the dataset was shown by relevant investigations on the genetic diversity and structure of the apple cultivar collections of the GFG.

Genetic and Pomological Determination of the Trueness-to-Type of Sweet Cherry Cultivars in the German National Fruit Genebank

Genebank collections preserve many old cultivars with ancient breeding history. However, often, cultivars with synonymous or incorrect names are maintained in multiple collections. Therefore, pomological and genetic characterization is an essential prerequisite for confirming trueness-to-type of cultivars in gene bank collections. In our study, 1442 single sweet cherry (Prunus avium L.) trees of the German Fruit Genebank were evaluated according to their trueness-to-type. For this purpose, pomological analysis was performed, in which the accessions were assigned totheir historical cultivar names. The pomological identifications were based on several historical reference sources, such as fruit references from historical cherry cultivar and fruit-stone collections, as well as historical pomological literature sources. In addition, the cherry trees were genetically analyzed for cultivar identity using 16 SSR markers. Based on pomological characterization and genetic analysis for the majority of the trees (86%), cultivar authenticity could be confirmed. Most markers were highly discriminating and powerful for cultivar identification. The cherry collection showed a high degree of genetic diversity, with an expected heterozygosity He = 0.67. Generally, high genetic admixture between cultivars of different geographic origin and year of origin was obtained after STRUCTURE analysis, demonstrating the extensive exchange of genetic information between cherry cultivars in the collection over time. However, the phylogenetic tree calculated by DARwin reflected the geographic origin of selected cherry cultivars. After parentage analysis with CERVUS, paternity could not be confirmed for three cultivars, indicating the necessity of further pedigree analysis for these cultivars. The results of our study underlined the general importance of evaluating the authenticity of cultivars in genebank collections based on genetic and pomological characterization.

Can new healthy luxury food products accelerate short food supply chain formation via social media marketing in high-income countries?

Social media marketing is a promising tool for successful product placement of new healthy luxury food products, a subcategory of superfoods. Despite its growing popularity, no studies have investigated how social media marketing affects consumers' quality perception process for such superfoods and whether this provides opportunities for farmers to gain a competitive advantage in direct marketing channels. Therefore, we integrate media richness theory into the food quality guidance model, compile a data set of 697 German fruit consumers from May to June 2020, and analyze this sample via partial least square analysis. Results show that social media marketing is a viable tool for new healthy luxury food products if media content is highly experience providing. Furthermore, it offers opportunities for the formation of shorter food supply chains as farmers could, through the provision of engaging social media marketing content, sell new healthy luxury food products directly to the final consumer. This research provides implications to farmers, retailers and policy makers to exploit the social media marketing potential of new healthy luxury food products.

Compliance with pre-harvest interval rules in apple production—A comparative analysis of green nudges among fruit growers and agricultural students in Germany

Using an incentivized single-player multi-period business management game in which the participants have to manage a virtual apple farm as an experimental device, this study examines how nudges can improve compliance with regard to the 14-day pre-harvest interval rule after the pesticide application. Two different samples were examined, namely German fruit growers and agricultural students. Two different green nudge treatments were investigated: A nudge with facts and pictures which imply environmental and health damages that are presumably caused by breaching the 14-day pre-harvest interval rule, and a nudge with an additional social comparison suggesting that the majority of fruit growers in the same region comply with the rule. The core result of the study is that nudging has a preventive effect and reduces participants' non-compliance behavior in the business management game. The results are of interest to (agricultural) policy makers dealing with regulatory strategies in the context of pre-harvest intervals in apple production, as it is widely documented that nudging is an effective low-cost supplement to controls. Furthermore, the results are of interest for further research in the field of (experimental) economics and nudging, as we provide novel insights into the application of nudges.

Market power and food loss at the producer-retailer interface of fruit and vegetable supply chains in Germany

Food loss and waste are associated with an unnecessary consumption of natural resources and avoidable greenhouse gas emissions. The United Nations have thus set the reduction of food loss and waste on the political agenda by means of the Sustainable Development Goal Target 12.3. The German Federal Government committed itself to this goal by implementing the National Strategy for Food Waste Reduction in 2019. However, this policy approach relies heavily on voluntary action by involved actors and neglects the possible role of power imbalances along the food supply chain. While current research on food loss and waste in industrialised countries predominantly focuses on the consumer level, this study puts emphasis on the under-researched early stages of the food supply chain from the field to retailers’ warehouses. Based on 22 expert interviews with producers, producer organisations and retailers, this article identifies major inter-stage drivers of food loss in the supply chains for fresh fruit and vegetables in Germany. Its main novelty is to demonstrate how market power imbalances and risk shifting between powerful and subordinate actors can reinforce the tendency of food loss on the part of producers further up the supply chain. Results indicate that prevalent institutional settings, such as contractual terms and conditions, trading practices, ordering processes, product specifications, and communication privilege retailers and encourage food loss. The mechanisms in which these imbalances manifest, go beyond the European Commission’s current legislation on Unfair Trading Practices. This study suggests a research agenda that might help to formulate adjusted policy instruments for re-structuring the German fruit and vegetable markets so that less food is wasted.

Consumer Acceptance and Market Potential of Iodine-Biofortified Fruit and Vegetables in Germany.

Biofortification of food crops with iodine is a novel approach to preventing iodine deficiency in humans. The present study analyses the consumer target groups and the market potential of iodine-biofortified fruit and vegetables in Germany. For this purpose, an online survey of 1016 German fruit and vegetable consumers was conducted to investigate the acceptance of different product categories as well as relevant criteria for the market launch. The results show that iodine-biofortified fruit and vegetables are particularly attractive to consumers who purchase at farmers’ markets, organic food shops, and farm stores. Out of this group, 39% of consumers rate such iodine-rich foods as very appealing. They attach importance to food that naturally contains iodine and prefer produce from integrated domestic cultivation. With their focus on sustainability and naturalness, this group of consumers clearly differs from typical users of dietary supplements, who are primarily concerned with health benefits. However, overall about 85% of respondents would prefer biofortified fruits and vegetables to supplements to improve their iodine supply. The greatest market potential for iodine-biofortified fruit and vegetables is to be expected in supermarkets, as this is the preferred food shopping location for most consumers. A total of 28% of those who buy here rate the biofortified foods presented as very appealing. Nevertheless, a successful market launch requires that the benefits of the new products are communicated according to the potential consumer group needs.

Preservation of fruit genetic resources in Germany

The preservation of fruit genetic resources has a long-lasting tradition in Germany. It dates back to the early decades of the 20th century. Ever since, a multitude of cultivars of different fruit crop species is preserved in federal and state governmental institutions as well as in communities and towns, non-governmental organizations, and by private individuals. The German Fruit Genebank has been established as a decentralized network with the aim to coordinate the preservation in the different germplasm collections in Germany to minimize the risk of losing cultivars of fruit species and therefore to maintain a part of the cultural heritage. Currently, the German Fruit Genebank is composed of six species-specific networks consisting of 48 different collections. In addition to the cultivar collections, the Fruit genebank of the Institute of Breeding Research on Fruit Crops, Dresden-Pillnitz includes collections of crop wild relatives of the fruit species important for fruit production in Central Europe. Special emphasis is given on the genera Malus and Fragaria representing 46 and 22 taxa respectively. These accessions are valued for their diverse alleles but also for their specific genotypes. Different cryopreservation protocols were elaborated. For Fragaria a protocol combining vitrification with cold acclimation and for Malus a protocol based on dormant winter buds can now be realistically used to build up a Cryo bank as a duplicate collection. Based on the results provided, a combination of the traditional ex situ conservation approach and cryopreservation approach has a great potential to improve conservation of fruit genetic resources contributing to the National Program for Genetic Resources of Agricultural and Horticultural Crops in Germany.

Approaches to Reduce Food Losses in German Fruit and Vegetable Production

Food losses occur in all agricultural value chains, but are especially high in the fruit and vegetable sector. This study quantifies losses of selected fruits (strawberries, apples) and vegetables (lettuce, carrots), identifies the main reasons for food losses, and assesses effective measures for the reduction of these losses. Data were collected in structured interviews with value chain actors from production to food retail and validated in regional expert workshops. Results show that in average years, about 25% of the analysed vegetables are lost at farm level. The range of fruit losses differs widely, from 15% to 20% for strawberries and only 6% to 16% for apples. Weather is a major factor for crop losses, since it can strongly affect product appearance and hence marketability in the food retail sector. There is a lack of alternative market channels for products, which do not meet the high-quality standards for fresh products in the retail sector. Effective measures to reduce food losses are protected cultivation in greenhouses or under hail nets, continuous cooling systems, improved packaging and training of staff. More cooperation and coordination between producers, wholesalers and retailers could also increase the share of marketable products.

Do pro-environmental values, beliefs and norms drive farmers' interest in novel practices fostering the Bioeconomy?

A transition towards a bio-based economy is accompanied by a growing demand for biomass resources as fossil fuels need to be replaced for the more sustainable production of consumer goods, chemicals and energy. To increase the supply of renewable biomass and avoid a conflict with food production, currently underutilized by-products (i.e. leaves, stems) from horticultural production could be valorised as feedstock. The success of this approach depends on farmers' willingness to adopt novel practices like the collection and treatment of plant leaves. However, literature on factors influencing farmers' decisions to adopt novel practices aimed to foster the Bioeconomy is limited. This paper addresses this gap by exploring drivers of farmers' interest in the valorisation of by-products. To this aim, the Value-Belief-Norm theory was used and expanded by contextual factors, such as the perceived market demand for biomass and future environmental policies. A survey with German fruit and vegetable farmers (N = 96) has been carried out and data have been analysed with a Structural Equation Model. Findings suggest that the Value-Belief-Norm theory is a relevant framework for the agricultural domain to predict farmers' interest in the valorisation of horticultural by-products. Results further indicate that an internal ecological worldview is potentially relevant for farmers' perception of contextual conditions aimed to foster the Bioeconomy. These outcomes could have managerial and policy implications associated with the identification of potential lead users to trigger the diffusion of innovative sustainable practices and generally foster the Bioeconomy.

Evaluation of Rubus genetic resources on their resistance to cane disease

Raspberry cane disease, caused by a complex of fungi, is amongst the most devastating problems for raspberry production. Using resistant or highly tolerant genotypes is a promising strategy. However, until now, cultivars with good field resistance for German fruit growers as well as the primary causal pathogens of cane disease present in the eastern part of Germany, Saxony state are still unknown. The primary objective of this study was to identify the primary disease causing organisms and resistant Rubus germplasm for future breeding efforts. From 2012 to 2014, we evaluated the degree of susceptibility to cane diseases on 213 raspberry cultivars at two different locations using a rating scale. We also identified the main fungi growing on infected canes. Our results suggest that Fusarium avenaceum is the main fungus causing cane disease in Saxony. The Rubus hybrid cultivars ‘Tayberry’ (2n = 6x = 42), ‘Buckingham Tayberry’ (2n = 6x = 42) and ‘Dorman Red’ (2n = 2x = 14) displayed the highest levels of field resistance at both locations. Moreover, we established an in vitro assay for resistance evaluation which correlates significantly with field data and is particularly suitable for quick assessment of resistance against F. avenaceum in breeding material. Future breeding programs, aiming at cultivars with enhanced resistance towards cane diseases can use the presented data for parental selection and may employ our in vitro F. avenaceum inoculation method for parental testing and progeny selection.

Strategies to manage hail risk in apple production

PurposeHail risk management is essential for successful farm management in German fruit production, particularly because hail events and associated losses have increased in recent years. The purpose of this paper is to conduct a detailed risk analysis comparing different strategies to manage hail risk, taking into account farmers’ risk aversion and farm-specific conditions.Design/methodology/approachWithin an expected utility framework, two different strategies for managing hail risk are compared: one belonging to the group of financial instruments (hail insurance) and the other to the group of technical instruments (anti-hail net). A unique data set comprising a ten-year time series of orchard-specific hail damage and hail insurance data is used.FindingsFor orchards with low local hail risk and low yield potential, not using hail risk mitigation is most efficient. For orchards with high local hail risk and high yield potential, anti-hail nets provide the highest certainty equivalents. For orchards with high local risk, but low yield potential, hail insurance is most efficient. For orchards, with low local risk, but high yield potential, the certainty equivalents are higher for anti-hail net, when the farmer is risk neutral or slightly risk-averse. With increasing risk aversion, hail insurance is most efficient, which can be explained by the greater degree of the instrument’s flexibility.Originality/valueThe novelty of the study lies in the direct comparison of the risk effects of anti-hail nets and hail insurance in fruit production.

RISK MANAGEMENT OF GERMAN FRUIT PRODUCERS

Horticultural farms in Germany face substantial business risks. However, fruit farms often struggle to implement appropriate risk management processes, and the risk management literature widely has ignored this farm type. The aim of the study was to improve the assessment of risks by farmers and the choice of suitable risk management instruments. Therefore, a risk management process based on subjective probabilities and suitable for small and medium-sized farms was developed, considering the specific needs of family run businesses. An online survey was conducted to achieve a comprehensive view of the risk perception and risk management practices of German fruit producers. Price and production risks are the most relevant risk categories for fruit farmers. However, among single risk sources, those in the people risk category were seen as the most important. Results show significant interactions among risk categories and a significant correlation between loss experience and the rating of risk categories. The assumption that risk averse farmers generally rate risks higher than risk neutral or risk seeking farmers cannot be confirmed. Diversification seems to be the most important risk management instrument for many fruit producers, especially diversification of marketing channels, farm income, and production activities. Further research should focus on the apparent inconsistency between the satisfaction with instruments reported by farmers and the actual implementation of many of them (e.g., hail insurance and anti-hail net). Furthermore, there is a need for research, to develop decision models considering the interactions of risks and risk management instruments, loss experience and risk seeking attitudes.

Cryopreservation of fruit germplasm

Most temperate fruit species are genetically heterozygous and vegetatively propagated. Active collections of fruit genetic resources in Germany are generally maintained in the field, e.g., as potted plants for Fragaria and as trees for pome and stone fruit species. The plant material in active collections should be kept in duplicate to ensure security in case of disease or environmental disaster. The aim of this study was to develop an efficient complementary conservation strategy for fruit genetic resources. Although costly, fruit tree cultivars can be duplicated as field collections at a second site within the framework of the German Fruit Genebank, which is a decentralized fruit-specific network. Wild species accessions, particularly those of the genera Malus spp. (apple) and Fragaria spp. (strawberry) as well as strawberry cultivars, can also be duplicated by means of cryopreservation. In the current study, long-term cryopreservation was initiated for 194 Fragaria genotypes. A protocol combining vitrification with cold acclimation was effective and highly reproducible, with an average regrowth rate of 86%. In Malus, a general cryopreservation protocol based on dormant winter buds was adopted. Based on the results provided in this study, a combination of traditional ex situ conservation and cryopreservation can greatly improve the stability and security of fruit germplasm conservation.

Producer price volatility in the German fruit and vegetable industry

Producer price volatility in the German fruit and vegetable industry

Preparatory work for the pest categorisation of three bacteria listed in the annexes of the Council directive 2000/29/EC Erwinia amylovora Winslow et al. Xylophilus ampelinus (Panagopoulos) Willems et al. Clavibacter michiganensis subsp. insidiosus(McCulloch) Davis et al

Preparatory work for the pest categorisation of three bacteria listed in the annexes of the Council directive 2000/29/EC Erwinia amylovora Winslow et al. Xylophilus ampelinus (Panagopoulos) Willems et al. Clavibacter michiganensis subsp. insidiosus(McCulloch) Davis et al

Price versus Non-price Incentives for Participation in Quality Labeling: The Case of the German Fruit Juice Industry

Quality assurance and labeling play an important and increasing role in firms’ marketing strategies. In almost all cases, a price incentive has been stressed as the major incentive for firms to participate in such schemes. We argue here that important non-price incentives for participation in quality labeling may exist, too. In German retailing, it can be observed that discount retailers are listing more and more foods with quality labels. Processors may then participate in voluntary quality labeling in order to enter the large and growing market of discount retailers. The price-premium versus the market-entry hypothesis are analyzed theoretically. We investigate then in an empirical hedonic pricing model for the German fruit juice market and for participation in the quality label of the Deutsche Landwirtschafts-Gesellschaft (DLG) which of the two hypotheses is consistent with the data. There is strong support for the market-entry hypothesis.

Bioactive components in forced sweet cherry fruit (Prunus avium L.), antioxidative capacity and allergenic potential as dependent on cultivation under cover

Five early maturing varieties of Prunus avium L. on dwarfing rootstock were forced at Bonn, Germany in spring under transparent plastic cover without additional heating to ripen at a time before field-grown German fruit become available, with better fruit quality than imported sweet cherries; trees grown outside without cover served as control. The cover reduced the incident radiation by up to 54% PAR, UV by up to 22% UV-A and UV-B up to 2% and increased day temperature indoors. Fruit were as firm in the early varieties grown under cover as those in the field and slightly softer than in the late harvesting cultivars. Sugar content was slightly less in four of the five varieties; no differences in acidity and sugar/acid ratio as a taste indicator were found. Fruits were up to 3 mm larger when grown under cover in cvs. ‘Burlat’ and ‘Souvenir’, but no differences were observed in cvs. ‘Earlise’ and ‘Prime Giant’. Fruit of three cultivars, ‘Burlat’, ‘Samba’ and ‘Prime Giant’ can be classified as premium quality with 28 mm–30 mm diameter, when grown under cover. Overall, all cherry fruit were of the market, i.e. consumer- preferred, dark red colouration in line with enhanced anthocyanin contents. In two cultivars, the cover induced healthier fruit. Antioxidative capacity was larger in cv. ‘Samba’, while ascorbic acid (Vitamin C) was increased in cv. ‘Souvenir’; phenols were enhanced in all cultivars and attributed to heat stress. Allergenic protein (Pru av 1) in cherry fruits of both cultivation types were below the detection level at harvest time, indicating that cultivation under cover had no adverse effects on this particular health component.Overall, forcing successfully resulted in 2 weeks earlier ripening, thereby providing the first fresh and healthy (low allergen, high phenolic compounds and high anthocyanin) German cherries of high fruit quality on the market in spring.

Die Deutsche Genbank Obst, ein dezentrales Netzwerk zur nachhaltigen Erhaltung genetischer Ressourcen bei Obst

The preservation of fruit genetic resources is the basis for ensuring a sustainable fruit production in Germany. The preservation of fruit cultivars has a long-lasting tradition in Germany, which reaches back to the early decades of the 20 th century. Since that time, a multitude of cultivars of different fruit crop species are preserved in public and private germplasm collections. However, the loss of individual cultivars can not be excluded using such form of preservation. The German Fruit Genebank has been recently established to minimize the risk of losing fruit genetic resources. The German Fruit Genebank is a decentral network, which is aimed on the coordination of different germplasm collections in Germany. The work will be organized in species specific networks (e.g. apple network, strawberry network etc.). Preservation guidelines for each fruit species will be developed within the species specific networks. The first three networks for strawberry, cherries, and apple recently have taken up their activities. The establishment of networks for further fruit crops has been scheduled.

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.

The Cost of Climate Change to the German Fruit Vegetation Sector

This paper applies the concept of damage coefficients introduced in Houba and Kremers (2008) to provide an estimate of the cost of climate change - in particular the cost of changes in mean regional temperature and precipitation - to the fruit vegetation sector. We concentrate on the production of apples in the German 'Alte Land' region. The estimated cost of climate change on apple-growing in the 'Alte Land' is dependent on the assumptions regarding developments in the rentability of land not related to climate change in the fruit sector.