Eike Luedeling

University of Bonn | Uni Bonn · Institute of Crop Science and Resource Conservation (INRES)

Temperate fruit trees are widely cultivated across the world's temperate regions. These trees are well-adapted to cold-winter climates through their ability to synchronize their phenology with the seasons. In autumn, they enter a dormant state, which allows them to survive the low winter temperatures and lasts until they resume growth in early spri...

Traditional fruit tree cultivars are an important source of agricultural biodiversity. These genotypes are well adapted to the regions where they grow, and their fruits offer distinctive features compared to the commercial cultivars that are frequently grown. We analyzed the adaptation prospects of seven sweet cherry cultivars grown in Zaragoza (Sp...

The present study aims to generalize cultivar-specific tree phenology responses to winter and spring temperatures and assess the effectiveness of the Tabuenca test and various chill and heat accumulation models in predicting bloom dates for a wide range of climatic conditions and years. To this end, we estimated the dates of rest completion and blo...

The wetting behaviour of the spray and the biological efficacy of Cu2+ active ingredients in agrochemical formulations may be enhanced by tank‐mix additives. We investigated how three BREAK‐THRU® additives (BT301: biodegradable, BT133 and BT420: bio‐based and biodegradable) tank‐mixed with commercial copper preparations influenced the spray distrib...

Temperate trees require low temperatures during winter and subsequent warm conditions in early spring to flower and eventually bear fruit. Many parts of the Mediterranean region feature winters with low and sometimes marginal chill accumulation. To assess historic and future agroclimatic conditions for cultivating temperate trees (including almonds...

The wetting behaviour of the spray and biological efficacy of Cu2+ active ingredients in agrochemical formulations may be enhanced by tank-mix additives. We investigated how three BREAK-THRU additives (BT301: biodegradable, BT133 and BT420: bio-based and biodegradable) as tank-mix with commercial copper preparations influence the spray distribution...

Many farmers hesitate to adopt new management strategies with actual or perceived risks and uncertainties. Especially in ornamental plant production, farmers often stick to current production strategies to avoid the risk of economically harmful plant losses, even though they may recognize the need to optimize farm management. This work focused on t...

Farmers’ agricultural practices in Vietnam are highly sensitive to weather, climate variability and climate change. The lack of timely and actionable climate-informed agricultural advice leads to significant input and yield losses, which can render investments in farming unprofitable. Development organizations in Vietnam have provided agro-climate...

Intervening into agricultural systems necessarily includes risks, uncertainties, and ultimately unknown outcomes. Decision analysis embraces uncertainty through an interdisciplinary approach that involves relevant stakeholders in evaluating complex decisions. We applied decision analysis approaches to prioritize 21 farm management interventions, wh...

Phenology models are crucial tools for assessing climate change impacts in forestry, ecology and agriculture. Such models are typically calibrated with observational or experimental data and validated with a set of independent observations. While there have been extensive discussions about validation approaches, systematic studies assessing the eff...

CONTEXT Even though diversification of horticultural production systems allows farmers to cope with risks and uncertainties, strategies for raising profitability usually aim to improve the productivity of monocultures rather than pursuing diversification. Horticultural production systems are often highly diversified in terms of land use and planted...

Decision making in pest management is a challenging task. While pest dynamics are often quite uncertain, such decisions are often based on tenuous assumptions of certainty (economic injury levels and marginal utility approximations). To overcome such assumptions and adequately consider uncertainty, we apply decision analysis to evaluate management...

Voluntary standards can help to ensure the quality of projects eligible for carbon offsetting, i.e., selling carbon certificates. However, in deciding on whether to adopt such standards, the managers of carbon offset projects are faced with uncertainty regarding the costs and risks involved. Decision Analysis provides a helpful set of tools that ca...

Ornamental heather (Calluna vulgaris) production is characterized by high risks such as occurrence of fungal diseases and plant losses. Given the general absence of formal research on this economically important production system, farmers depend on their own approaches to assess plant vitality. We provide a reproducible, affordable and transparent...

National-scale carbon footprints of livestock production are commonly computed from a set of production system characteristics that serve as inputs for greenhouse gas (GHG) emission models. We evaluated the feasibility of using such equations at a finer scale to derive a simple farm-scale indicator of emission intensity (milk yield per head). Using...

Winter chill accumulation plays a crucial role in determining the moment of bud burst in temperate fruit and nut trees, and insufficient chill can greatly limit yield potentials. To assess future cultivation options for such species in South America, we estimated winter chill through a spatial analysis. We used historical data (1980–2017) from 158...

Winter chill is expected to decrease in many mild-winter regions under future climatic conditions. Reliable estimates of the chill requirements (CR) of fruit trees are essential for assessing the current suitability of cultivars and potential climate change impacts on fruit production. We determined chill and heat requirements of ten apple cultivar...

Global warming has modified the phenology of deciduous species. Temperature during the dormancy phase modulates the timing of bloom in temperate trees. Chill and heat requirements represent the climatic needs of trees during dormancy. Partial Least Squares (PLS) regression allows delineating chilling and forcing phases, which in turn allows estimat...

Developing and testing farmers' adoption pathways of agro-climate services

Forecasting spring phenology of temperate fruit trees is of high concern for orchard plannersand fruit producers, particularly in the context of climate change. Responding to this need, horticultural researchers have developed models to estimate chill and heat requirements and project dormancy release. Despite some successes in dormancy modeling, s...

Temperate fruit trees can enter dormancy during autumn-winter and resume active phenological development in spring in response to warm conditions. In a global warming context, recent temperature dynamics are causing changes in phenology and flowering that directly affect fruit production and yield. However, understanding how temperature regulates p...

Voluntary standards help to ensure the quality of projects eligible for carbon offsetting, i.e. selling carbon certificates. However, in deciding on whether to adopt such standards the managers of carbon offset projects are faced with uncertainty regarding the costs and risks involved. Decision Analysis provides a helpful set of tools that can supp...

Agroforestry (AF)-based adaptation to global climate change can consist of (1) reversal of negative trends in diverse tree cover as generic portfolio risk management strategy; (2) targeted, strategic, shift in resource capture (e.g. light, water) to adjust to changing conditions (e.g. lower or more variable rainfall, higher temperatures); (3) veget...

In a global warming context, analyses of historic temperature records are essential to understand the potential impacts of climate change on spring phenology. To estimate flowering trends over recent decades, we analyzed long-term temperature and phenology records of eleven local apple cultivars in Asturias (northwestern Spain) in a temperate ocean...

The boll weevil [BW; Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae)] is the main pest in the cotton-producing regions throughout the Americas from Southern Texas to Argentina. In the Colombian Caribbean, frequent population outbreaks have resulted in cotton planting bans in some localities and in massive applications of insecticides...

Forest and Landscape Restoration (FLR) is carried out with the objective of regaining ecological functions and enhancing human well-being through intervention in degrading ecosystems. However, uncertainties and risks related to FLR make it difficult to predict long-term outcomes and inform investment plans. We applied a Stochastic Impact Evaluation...

Available options for mitigating the impacts of extreme weather events on temperate fruit trees involve a number of risks and uncertainties, leaving growers hesitant about the benefits of implementing new technologies to protect their orchards. We used Decision Analysis approaches, which account for these risks and uncertainties, to assess investme...

Crop models can support agricultural decisions, yet their reliability is necessarily limited when they do not sufficiently represent the complexity and specific circumstances of the target system. In some cases, models have such prohibitively high data requirements that they are only applicable with far-reaching and often questionable assumptions....

The aim of this study is to identify how Africa may transform its potentials into realities and actually secure its supply of food for affordable and healthy diets from the sustainable use of resources. Africa’s food imports amount to about US$ 60 billion per year. In net terms, cereals account for about US$ 25 billion per year, meat and dairy for...

Agroforestry systems dot agricultural landscapes in sub-Saharan Africa (SSA), where they provide food, fuelwood, fibre, fodder and other products that are used at home or sold for income. Agroforestry also provides ecosystem services that are important and critical for improved livelihoods. By combining trees and/or shrubs with crops and/or livesto...

Many actors in agricultural research, development, and policy arenas require accurate information on the spatial extents of cropping and farming practices. While remote sensing provides ways for obtaining such information, it is often difficult to distinguish between different types of agricultural practices or identify particular farming systems....

Future warming predicted for Tunisia may reduce winter chill and affect the production of tree fruits and nuts, one of the key sectors of the country’s economy. To assess past and future chill availability, we used weather records from 1973 to 2019 to simulate historic and future chill for 20 weather stations (16 from Tunisia, 3 from Algeria and 1...

For centuries, traditional high-altitude oases in Oman have depended on the cultivation of deciduous fruit trees. This study explores the effects of climate change on winter chill (estimated as Chilling Hours-CH and Chill Portions-CP), a prerequisite to overcoming dormancy and initiating flowering, in three Omani oases. The results are compared wit...

Subtropical areas such as the major fruit production zone of Chile are among the most vulnerable environments to climate change. Increasing frequencies of unusual weather events, e.g. excessive rainfall or hail and frost episodes, during the growing season can cause severe fruit losses. This can threaten the viability of farm. and have implications...

Farmers' agricultural practices in Vietnam are highly sensitive to variable weather and vulnerable to the impacts of climate change. The lack of timely and actionable weather forecasts and agricultural advisories can lead to significant yield loss and unprofitable investments in agricultural inputs, which can have severe consequences for resource-c...

Winter chill, which temperate trees require in order to overcome dormancy, is expected to decrease substantially in the future in most deciduous fruit tree growing areas. Several mathematical models have been developed in different regions to quantify chill requirements of tree species and cultivars. The Dynamic model has emerged as the most plausi...

Tunisia is among the most vulnerable countries to climate change in the future with increasing temperatures and frequencies drought years. In Tunisia, fruit growing is one of the key sectors of the national economy. It occupies 2 million hectares, contributes about 30% to total agricultural production and 60% to agricultural exports. Fruits rich in...

Agroforestry interventions have the potential to benefit the livelihoods of farmers and communities worldwide. However, given the high system complexity, the long-term benefits of agroforestry are difficult to anticipate. This study aimed to integrate uncertainty into long-term performance projections for agroforestry interventions in the highlands...

Agricultural management decisions are usually made without perfect knowledge. Decision Analysis (DA) approaches translate available uncertain information on costs, benefits and risks involved in decisions into actionable management recommendations. We illustrate the use of DA procedures to inform decisions on disease management strategies in orname...

Winter chill is expected to decrease in many of the suitable growing regions for deciduous trees. Argentinean North Patagonia hosts extensive fruit tree cultivation, which provides an important contribution to both local and global food security. Using historic records from 11 weather stations from North Patagonia, we evaluate the possible impacts...

In Mediterranean climates, many deciduous fruit trees are unable to meet their seasonal chill requirements, a situation that may be exacerbated by global warming. Modeling approaches can be used to assess the impacts of climate change on tree crops for the past and forecast possible impacts for the future. We apply modeling approaches to assess cli...

Sustainable land management is at the heart of some of the most intractable challenges facing humanity in the 21st century. It is critical for tackling biodiversity loss, land degradation, climate change and the decline of ecosystem services. It underpins food production, livelihoods, dietary health, social equity, climate change adaptation, and ma...

Climate change may result in increasingly frequent extreme events, such as the unusually dry conditions that occurred in Germany during the apple growing season of 2018. To assess the effects of this phenomenon on dormancy release and flowering in apples, we compared irrigated and non-irrigated orchard blocks at Campus Klein-Altendorf. We evaluated...

The perennial life strategy of temperate trees relies on establishing a dormant stage during winter to survive unfavorable conditions. To overcome this dormant stage, trees require cool (i.e., chilling) temperatures as an environmental cue. Numerous approaches have tried to decipher the physiology of dormancy, but these efforts have usually remaine...

Agricultural landscapes are increasingly being managed with the aim of enhancing the provisioning of multiple ecosystem services and sustainability of production systems. However, agricultural management that maximizes provisioning ecosystem services can often reduce both regulating and maintenance services. We hypothesized that agroforestry reduce...

Winter chill, which temperate trees require to overcome dormancy, is expected to decrease substantially in the future in most deciduous fruit tree growing areas. Several mathematical models have been applied in different regions around the world to quantify this chill requirement. While the 'Dynamic' model has emerged as the most plausible and reli...

Key message High starch concentrations in woody tissue of sweet cherry trees were associated with deep stages of dormancy, while increasing concentrations of hexoses were related to the dormancy release process. Abstract Dormancy is an intrinsic characteristic of deciduous forest and fruit trees. Release from dormancy and subsequent bud burst occu...

This data article provides the datasets that are used in the holistic ex-ante impact evaluation of an irrigation dam construction project in Northern Ethiopia [1]. We used an expert knowledge elicitation approach as a means of acquiring the data. The data shared here captures all the parameters considered important in the impact pathway (i.e. the e...

Irrigation plays a significant role in achieving food and nutrition security in dry regions. However, detailed ex- ante appraisals of irrigation development investments are required to efficiently allocate resources and optimize returns on investment. Due to the inherent system complexity and uncertain consequences of irrigation develop- ment inter...