Search

Strong night frosts in spring have the potential to cause severe damage to fruit trees, causing up to €3.3 billion of damage in Europe in 2017. If temperatures drop below -2.2°C after the growing season starts, this phenomenon is referred to as a False Spring. For The Netherlands, the risk of false spring damage increased during the past 70 years, due to the dates of the last strong night frost and the start of blooming moving closer together. This raises the question whether this trend will continue under future influences of climate change. To analyse the development of false spring damage risks, we developed the False Spring Damage Indicator (FSDI) model. Applying this model to the Dutch KNMI'14 climate change scenarios for 2050 and 2085 showed a decrease in false spring damage risk. The historical risk for 60% bud damage was reduced to around 40% for the moderate scenario in 2050, and to less than 15% for the severe scenario in 2050 and all scenarios in 2080. False spring damage varied spatially throughout The Netherlands. Currently, in the east more severe damage can be expected, while coastal regions in the north and west are less prone to false spring damage. In the future, this is expected to become more uniform over The Netherlands, as the risk in the east is predicted to decrease strongly, becoming similar to the low damage risk in the coastal regions.

SummaryThe 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, leaf uptake and biological efficacy of copper additive mixtures against apple scab and apple powdery mildew under controlled conditions. We quantified the synergetic effects of these additives in foliar applications. In addition, we determined the phytotoxic potential and evaluated impacts on photosynthetic activity, non-photochemical quenching and ROS activity. The additives BT301 and BT420 strongly reduced surface tension and contact angle of copper treatments. The fluorescence observations revealed that BT301 achieved better spreading of copper formulation with more complete coverage of the leaf surface than BT420 and BT133, whereas “coffee-ring” spreading was observed with BT133. The additive BT301 showed an increase in relative fluorescence area, indicating higher ROS production as a signal of intra-cellular tissue activity. The photochemical efficiency of photosystem II (Fv/Fm) was not negatively influenced by copper or additive treatment. Thus, we observed no phytotoxic effects of copper-additive mixtures on apple leaves at treatment doses of 4 g Cu2+L-1. All copper treatments reduced apple scab infestations significantly, by 53-76%. Interestingly, addition of BT301 to copper preparations showed the strongest biological efficacy (83% reduction) againstV. inaequalis, whereas addition of BT420 showed the strongest effect againstP. leucotricha(89% infection reduction). The synergetic effects of additives on the biological efficacy without phytotoxic effects on plants may have potential for reducing copper loads in horticultural production systems.

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 strategies used by farmers in the Colombian Caribbean against the boll weevil (BW). We represent the decision to protect the crop using partial budget analysis. This allows us to capture key properties of BW control strategies, while accounting for uncertainty about pest infestation pressure, control effectiveness and cotton yield and price. Our results indicate that proactive pest management is more efficient than reactive control given the current BW infestation pressure. However, farmers may prefer the reactive strategy, since they have experienced seasons with low infestation pressure where no insecticide applications were required. The proactive strategy, in contrast, requires scheduled pesticide applications in all years. Results show that in seasons with high infestation pressure the expected revenues of the reactive strategy tend to decrease, mainly because more spray applications are required when fields are heavily infested by the weevil. Value of information analysis revealed that uncertainties related to the start of the infestation, loss damage rate and attainable yield have the greatest influence on the decision recommendation for crop protection. Narrowing these key knowledge gaps may offer additional clarity on the performance of the current management strategies and provide guidance for the development of strategies to reduce insecticide use. This is particularly important for the promotion of the proactive strategy, which, under the current infestation pressure, has potential to reduce insecticide use. While economic injury levels can only be applied to responsive measures, our approach of partial budget analysis under uncertainty allows us to assess and compare both responsive and preventive measures in the same methodological framework. This framework can be extended to non-pesticide control measures.

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, which could be considered in certification schemes for banana production. We estimated their contribution to climate change adaptation and mitigation as well as ecological outcomes. We used a general model that estimated the impacts of each intervention on adaptation (benefits minus costs), mitigation (global warming potential), ecological parameters (e.g., biodiversity and water and soil quality), and farming aspects (e.g., yield, implementation costs and production risks). We used expert and documented knowledge and presented uncertainties in the form of 90% confidence intervals to feed the model and forecast the changes in system outcomes caused by each intervention compared to a baseline scenario without the measure. By iterating the model function 10,000 times, we obtained probability distributions for each of the outcomes and farm management interventions. Our results suggest that interventions associated with nutrient management (e.g., composting and nutrient management plan) positively affect climate change adaptation, mitigation, and ecological aspects. Measures with no direct yield benefits (e.g., plastic reduction) correlate negatively with adaptation but have positive impacts on ecology. Creating buffer zones and converting low-productivity farmland (incl. unused land) also have positive ecological and adaptation outcomes. Decision analysis can help in prioritizing farm management interventions, which may vary considerably in their relationship with the expected outcomes. Additional work may be required to elaborate a comprehensive assessment of the underlying aspects modulating the impacts of a given measure on the evaluated outcome. Our analysis provides insights on the most promising interventions for banana plantations and may help practitioners and researchers in focusing further studies.The online version contains supplementary material available at 10.1007/s13593-022-00809-0.

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 from Libya) by generating 6 past scenarios and 72 future scenarios for 2041–2070 and for 2071–2100, for two Representative Concentration Pathways (RCP4.5 and RCP8.5). We selected three future scenarios representing optimistic, intermediate, and pessimistic outlooks. Safe Winter Chill (SWC; in Chill Portions) was calculated using the Dynamic Model based on data for 100 winter seasons produced with a weather generator. SWC was then mapped for the whole country. Chilling requirements for typical Mediterranean fruit species (almond, pistachio, and peach cultivars) were compared with future SWC to select the best adapted fruit species, and cultivars within species, for each region. Our findings revealed severe SWC decline in the recent past. This decline will continue in the course of the twenty-first century. At the end of the century, we expect few of the studied species and cultivars to be able to fulfill their chilling requirements. By that time, only almonds may remain viable, whereas pistachios and peaches may experience alarming chill shortfalls. While our findings paint a grim picture for Tunisia’s orchards, they also allow insights for many other important fruit-growing regions with Mediterranean climate.

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 climate change impacts on Chilean fruit production in nine major agricultural sites. Using a weather generator, we obtained 100 years of plausible weather data for scenarios produced by 15 climate models for two Representative Concentration Pathways (RCPs). Winter chill, safe winter chill (both quantified in Chill Portions - CP), and the percentage of years with spring frost were estimated for two reference years, 2050 and 2085. Projections show a considerable chill reduction in northern regions in all future scenarios. Relatively stable conditions are projected for southern regions, whereas most of the central sites are expected to lose between 10 and 15 CP by 2050. For 2085, expected chill reduction is much more severe. The percentage of years with spring frost is projected to decrease in all locations, varying according to RCP scenario and year. Results highlight that in northern sites, some species may fail to meet their chill requirements in the future. In other regions, strategies to mitigate the effects of chill shortfalls may become critical to ensure adequate yields. Results may be useful for geneticists, breeders, physiologists, dormancy researchers, and growers making production decisions, e.g., on selection of appropriate species and varieties.

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 can support such decisions by forecasting outcomes under different scenarios. We applied Decision Analysis methods to generate models for the decisions to certify two projects in Costa Rica with the voluntary carbon offset label “The Gold Standard”. We evaluated certifying an additional site of a partially certified reforestation project, as well as the initial certification of an agroforestry project.We calibrated and interviewed decision-makers and stakeholders of the certification projects to identify important parameters and translate these into a decision model. We ran the final decision model as a Monte Carlo simulation to project plausible ranges of decision outcomes, expressed as Net Present Values and annual cash flows. We identified critical uncertainties and research priorities by using the Expected Value of Perfect Information. The results indicate that certification of the two projects would result in a positive Net Present Value. The partially low return on investment of the certification, however, shows the need for projects to undergo thorough evaluation and generate customized strategies before participating in a voluntary carbon offset scheme. The Decision Analysis approaches we describe can help to improve the process of decision making under uncertainty and should be widely adopted for evaluating the potential impacts of certification.

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 the economically important and little-researched production system of ornamental heather (Calluna vulgaris) to help farmers find appropriate measures to sustainably improve resource use, plant quality, and profitability despite existing risks. Probabilistic cost-benefit analysis was applied to simulate alternative disease monitoring strategies. The outcomes for more intensive visual monitoring, as well as sensor-based monitoring using hyperspectral imaging were simulated. Based on the results of the probabilistic cost-benefit analysis, the expected utility of the alternative strategies was assessed as a function of the farmer’s level of risk aversion. The analysis of expected utility indicated that heather production is generally risky. Concerning the alternative strategies, more intensive visual monitoring provides the highest utility for farmers for almost all levels of risk aversion compared to all other strategies. Results of the probabilistic cost-benefit analysis indicated that more intensive visual monitoring increases net benefits in 68% of the simulated cases. The application of sensor-based monitoring leads to negative economic outcomes in 85% of the simulated cases. This research approach is widely applicable to predict the impacts of new management strategies in precision agriculture. The methodology can be used to provide farmers in other data-scarce production systems with concrete recommendations that account for uncertainties and risks.

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, pistachios, apricots, sweet cherries and apples), we mapped winter chill throughout this important growing region. We used on-site weather records (1974–2020) to calibrate a weather generator and produced data for historic and future scenarios. To broaden our analysis, we spatially interpolated chill for the whole Mediterranean basin. We supplemented our simulation outcomes by collecting expert knowledge (from farmers and researchers) regarding observed climate change impacts on temperate orchards as well as future risks and concerns generated by climate change. Results showed that northern African growing regions have experienced major chill losses, a likely cause of the irregular and delayed bloom highlighted by experts. The same regions, together with southern Europe, may lose up to 30 Chill Portions by 2050 under a moderate warming scenario. For the future, experts foresee increasing risk of spring frost in early-blooming cultivars, exacerbated bloom-related problems and increasing occurrence of heat waves. Our results provide evidence of likely climate change impacts on temperate orchards. Expert knowledge proved instrumental in interpreting the simulation results as well as in orienting climate change adaptation strategies. The results we present are useful for farmers and orchard managers planning new plantings, as well as for researchers and policy makers developing strategies to adapt fruit orchards to the impacts of climate change.

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 weather stations to calibrate a weather generator and produce temperature data for 10 historical and 60 future scenarios. We computed Safe Winter Chill (SWC, corresponding to the 10th quantile of a chill distribution) for the period 1980–2017 and for all historical and future weather scenarios and developed a framework to interpolate SWC for the continent using the Kriging method. To improve the interpolation, we applied a 3D correction model based on two co-variables (means of daily temperature extremes in July). Our results suggest important chill declines in southern Brazil and central Chile. By 2050 under the global warming scenario RCP4.5 (Representative Concentration Pathway), absolute SWC in these regions may reach a median of 18.7 and 39.6 Chill Portions (CP), respectively. Projections are most alarming for a strong global warming scenario (RCP8.5). In southern South America, adequate SWC levels of about 60 CP may be expected even under the RCP8.5 scenario. Our results highlight the need for climate change adaptation measures to secure temperate fruit production in important growing regions of South America. The procedure we developed may help farmers and practitioners across South America estimate future SWC to adapt their orchards to future challenges.

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 support such decisions by forecasting outcomes under different scenarios. We applied Decision Analysis methods to generate models for the decision to certify two projects in Costa Rica with the voluntary carbon offset label Gold Standard. We evaluated certifying an additional site of a partially certified reforestation project, as well as the initial certification of an agroforestry project. We calibrated and interviewed decision-makers and stakeholders of the certification projects to identify important parameters and translated these into a decision model. We ran the final decision model as a Monte Carlo simulation to project plausible ranges of decision outcomes, expressed as Net Present Values and annual cash flows. We identified critical uncertainties and research priorities by using the Expected Value of Perfect Information. The results indicate that certification of the two projects would result in a positive Net Present Value. The partially low return on investment of the certification, however, shows the need for projects to undergo thorough evaluation and generate customized strategies before participating in a voluntary carbon offset scheme. The Decision Analysis approaches we describe can help to improve the process of decision making under uncertainty and should be widely adopted for evaluating the potential impacts of certification.

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. Dormancy is an intrinsic characteristic of deciduous forest and fruit trees. Release from dormancy and subsequent bud burst occur after chill requirements (CR) have been met. Currently, chilling metrics are poorly interchangeable among climates, probably due to a lack of physiological parameters involved in earlier model development, and, therefore, the reported CR values differ across locations. Here, we propose a way to improve our understanding on physiological markers involved in dormancy of deciduous fruit trees studying the dynamics of starch and hexoses (glucose + fructose) in sweet cherry twigs. Probabilities of bud break were estimated through logistic regression analysis using as independent variable the concentration of carbohydrates. In this experiment, we used 960 twigs and 160 sub-samples of twig portions (~ 2 cm of stem) from 8 sweet cherry cultivars exposed to different amounts of chill in the field. The timing of bud burst in forcing conditions and the concentration of starch and hexoses in the sub-samples were recorded. We found that concentrations of starch and hexoses are closely related to dormancy progression. Specifically, starch concentrations decreased by 43%, while concentrations of hexoses increased by 58% during the transition from 16 to 70 Chill Portions. Responses differed among varieties at the same chill received in the orchard. The logistic regression analysis revealed that the predicted probability of bud break at the moment of recorded bud burst was highest (i.e., up to 0.5) in the varieties Santina, Skeena, Rainier, Lapins, Regina, Kordia and Bing. In contrast, the variety Sweetheart showed the lowest probability (i.e., 0.49) of having met its CR when bud burst was recorded. This may suggest that in this variety, carbohydrate metabolism is not the most important predictor involved in dormancy release. The method presented here improves our understanding on dormancy and might serve to focus further research on dormancy modeling. This is especially important in warm winter regions where the classical way of determining CRs and quantifying chill accumulation is consistently failing.

© 2019 Elsevier B.V. The timing of flowering phenology in most temperate trees results from the interplay of winter chilling and spring heat. As global warming progresses, reduced chilling may gain increasing importance in regulating flowering dates, and eventually offset flowering advances in response to warmer springs. Later onset of flowering events may arise, with negative effects on plant fitness. However, delayed flowering in trees may also reduce the risk from late frosts. Different temperature conditions at both margins of the apple growing areas of Shaanxi in China provide a natural laboratory to examine the responses of trees’ flowering phenology and late frost risk to climate warming. We identified the chilling and heat accumulation periods for apples by Partial Least Squares regression of first flowering dates against daily chilling and heat accumulation rates during 2001–2016. We then analyzed the impacts of temperatures during these periods on flowering timing, and evaluated the frost risk for each site. Results indicated increasing importance of chilling temperatures from north to south, with greatest effects determined for the warmest site, where delayed blossom has been observed during the past 16 years. Since late frosts mostly occurred before tree flowering, only minor frost damage was detected for our study areas, with future delays in flowering likely to reduce the frost risk even further. The redistribution of apple trees to nearby locations with cold winters, either northward or uphill, could be a promising strategy to reduce the risk of insufficient chilling and ensure that production remains viable in a warming future.

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 oceanic climate. Our results show that, over a period of 30 years, bloom dates of the local cultivars have experienced relatively minor changes, considering that temperatures increased strongly since 1978, by 0.30 °C per decade. An explanation for this weak phenological response to warming may be that these temperature changes only had a small effect on overall chill accumulation, but possibly delayed the onset date of endodormancy, which may have counteracted phenology-advancing effects of warming in spring. At present, chill accumulation in this area is high, at an average of 96 Chill Portions from November to March, which indicates that chill is not currently a limiting factor for the quality of flowering and fruiting in the study area. We used Partial Least Squares (PLS) regression to delineate an effective chilling period between November 12th and February 9th and effective heat accumulation between March 15th and May 4th. While these periods appear plausible, we noticed that this approach was unable to identify well-known differences in chilling requirements among many of the cultivars, with similar chill needs determined for many of them. This observation may be explained by inaccurate expectations about cultivars’ climatic needs, by inaccuracy of the chill (and possibly heat) model or, most concerning, by inability of the PLS approach to correctly identify the chilling periods of apple cultivars in this region. Bloom dates were similarly responsive to mean temperature during the chill and the heat accumulation phases, indicating that both processes need to be considered when predicting future phenology., Funding was provided by an FPI-INIA fellowship to AD (CPD-2016-0190), AEI-MNECO through project RTA2017-00102-C03-01 and RFP2015-00022. Financial support has been provided by PRIMA, a program supported under H2020, the European Union’s Framework programme for research and innovation ("AdaMedOr" project; grant number 01DH20012 of the German Federal Ministry of Education and Research and grant number PCI2020-112113 of the Spanish Ministry of Science and Innovation)

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 elsewhere (up to 15 insecticide sprays per cotton season). To date, information on boll weevil management strategies in Colombia is only available in the forms of gray literature (technical reports) and informal knowledge held by crop advisors and farmers. This study compiles this information using a standardized protocol for participatory construction of conceptual models for agricultural systems. The conceptual model developed in this study integrates the informal local knowledge of crop advisors and farmers with disciplinary knowledge describing management strategies for boll weevil. The collected data were assessed and organized using a systems approach to facilitate the future development of quantitative models and allow visualization of knowledge gaps. The model includes the description of the biological and technical-decisional subsystems. The latter subsystem explains boll weevil management at two temporal-spatial scales: 1) farm (field) scale management during the cotton season and 2) a regional boll weevil suppression strategy mainly aimed at controlling the insect populations that survived the intercotton season. The development of this conceptual model allowed describing the current management strategies for boll weevil and formulating hypotheses about the effectiveness of these strategies. This conceptual model provides guidelines for future research, and it can serve as a baseline for the development of quantitative models and simulations describing the decision-making process related to the management of boll weevil in the Colombian Caribbean.

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 estimating the trees’ requirements. However, PLS regression requires long-term phenology and weather data, which are scarce in many growing regions. In a two-year experiment, we generated long-term phenology data by exposing potted trees to distinct environments during winter. We obtained records for 66 and 32 experimental seasons in apple and pear, respectively. We recorded tree phenology and hourly temperature. Through PLS regression methods, we determined the impacts of inter-seasonal variation on the outputs, estimated species’ dormancy phases and needs (in Chill Portions – CP and Growing Degree Hours – GDH), and assessed the relationship between bloom and temperature during the chilling and forcing phases. Results suggest inter-seasonal variation may be more important than number of seasons for producing valuable outputs. We delineated the chilling phase from October 19 to January 04 for apple and October 19 to December 27 for pear. The forcing period for both species was January 16 – March 26. Median chill and heat requirements were estimated as 43 CP and 14,845 GDH for apple and 31 CP and 11,816 GDH for pear. Bloom was modulated by temperature during both phases under warm conditions. In cold scenarios, bloom was mostly defined by temperatures during the forcing phase. We expanded the reach of the PLS regression method and made it applicable for cultivars lacking long-term phenology data. Our approach helps dormancy researchers improve their procedures to analyze species’ responses under possible future conditions. This work may assist farmers and orchard managers in adapting their orchards to face future challenges.

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) vegetation-based influences on rainfall patterns; or (4) adaptive, tactical, management of tree-crop interactions based on weather forecasts for the (next) growing season. Forty years ago, a tree physiological research tradition in aboveground and belowground resource capture was established with questions and methods on climate-tree-soil-crop interactions in space and time that are still relevant for today’s challenges. After summarising early research contributions, we review recent literature to assess current levels of uncertainty in climate adaptation assessments in and through AF. Quantification of microclimate within and around tree canopies showed a gap between standard climate station data (designed to avoid tree influences) and the actual climate in which crop and tree meristems or livestock operates in real-world AF. Where global scenario modelling of ‘macroclimate’ change in mean annual rainfall and temperature extrapolates from climate station conditions in past decades, it ignores microclimate effects of trees. There still is a shortage of long-term phenology records to analyse tree biological responses across a wide range of species to climate variability, especially where flowering and pollination matter. Physiological understanding can complement farmer knowledge and help guide policy decisions that allow AF solutions to emerge and tree germplasm to be adjusted for the growing conditions expected over the lifetime of a tree.

Fil: del Barrio, Ricardo. Universidad Nacional de Río Negro, Escuela de Producción, Tecnología y Medio Ambiente. Viedma, Argentina. Fil: Brendel, Andrea. Departamento de Agronomía, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto Argentino de Oceanografía (IADO), Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Argentina Fil: Campoy, José Antonio. Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany. Fil: Fernández, Eduardo.Institute of Crop Science and Resource Conservation (INRES) – Horticultural Sciences, University of Bonn, Auf dem Hügel 6, Bonn, 53121, Germany Fil: Whitney, Cory. Institute of Crop Science and Resource Conservation (INRES) – Horticultural Sciences, University of Bonn, Auf dem Hügel 6, Bonn, 53121, Germany Fil: Luedeling, Eike. Institute of Crop Science and Resource Conservation (INRES) – Horticultural Sciences, University of Bonn, Auf dem Hügel 6, Bonn, 53121, Germany Fil: Campoy, José. Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany 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 of climate change on fruit tree cultivation. We assess winter chill and seasonal heat availability, and the risk of spring frost events based on outputs from 15 Global Climate Models (GCMs) for two Representative Concentration Pathway (RCP) scenarios and two future time periods (represented by central years 2050 and 2085). Metrics were estimated for 47 years of records from the weather stations, as well as typical conditions for 10 past scenarios and 60 future GCM and RCP projections. Scenarios consisted of 100 plausible annual temperature records produced by a weather generator. Results suggest that fruit tree dormancy in Argentinean North Patagonia will not be strongly affected by climate change. Compared to the past, winter chill may only decrease by 9% in the RCP4.5 scenario by 2050 in the northeastern and eastern subregion, while in the central-south and west the reduction seems unlikely to exceed 6% by the same RCP scenario and year. Our models project stable high growing season heat in the northeastern and eastern regions, and major increases in the south by 2085 in both RCP scenarios. Projections of spring frost events varied between 0 and about 25 hours below 0 C depending on the site. Increasing heat availability may create opportunities for fruit and nut growers to introduce new species and cultivars to the region. Our results provide a basis for planning such introductions and for enabling growers to exploit new opportunities for producing temperate orchard crops beyond their traditional ranges. Se espera que el frío invernal disminuya en muchas de las regiones de cultivo adecuadas para árboles de hoja caduca. La Patagonia norte argentina alberga un variado cultivo de árboles frutales, que proporciona una contribución importante tanto a nivel local como global para la seguridad alimentaria. Utilizando registros históricos de 11 estaciones meteorológicas de la Patagonia Norte, evaluamos los posibles impactos del cambio climático en el cultivo de árboles frutales. Evaluamos el frío invernal y la disponibilidad de calor estacional, y el riesgo de eventos de heladas de primavera basados ​​en resultados de 15 modelos climáticos globales (GCM) para dos escenarios de trayectorias de concentración representativas (RCP) y dos futuros períodos de tiempo (representados por los años centrales 2050 y 2085). Se estimaron las métricas por 47 años de registros de las estaciones meteorológicas, así como condiciones típicas para 10 escenarios pasados ​​y 60 proyecciones futuras de GCM y RCP. Los escenarios consistieron en 100 registros de temperatura anuales plausibles producidos por un generador meteorológico. Los resultados sugieren que la dormición de los árboles frutales en el norte de la Patagonia Argentina no se verá muy afectada por el cambio climático. En comparación con el pasado, el frío invernal solo puede disminuir en un 9% en el escenario RCP4.5 para 2050 en la subregión noreste y este, mientras que en el centro-sur y oeste parece improbable que la reducción supere el 6% en el mismo escenario y año de RCP. Nuestros modelos proyectan un calor estable en la temporada alta de crecimiento en el noreste y regiones orientales, y aumentos importantes en el sur para 2085 en ambos escenarios de RCP. Las proyecciones de los eventos de heladas primaverales variaron entre 0 y aproximadamente 25 horas. por debajo de 0 C dependiendo del sitio. El aumento de la disponibilidad de calor puede crear oportunidades para que los productores de frutales y frutos secos introduzcan nuevas especies y cultivares a la región. Nuestros resultados proporcionan una base para planificar tales introducciones y para permitir a los productores explotar nuevas oportunidades para producir cultivos de frutales más allá de sus rangos tradicionales.

Resumen En los sistemas de producción de hortalizas del Caribe colombiano, la diversificación en el uso de la tierra y productos a comercializar incrementa la complejidad del sistema. Estos sistemas requieren cuantificar la productividad y el riesgo asociado a cada uno de los cultivos seleccionados e identificar los factores limitantes de estos que afectan el retorno económico a fin de priorizar las opciones de inversión de recursos por parte de los agricultores e investigadores dedicados a estos sistemas. Para orientar este propósito, este estudio usó un enfoque de modelamiento participativo usando información cualitativa y cuantitativa del sistema de producción provista por agricultores del Valle del Sinú. La información cualitativa provista en grupos focales y entrevistas individuales fue organizado usando un enfoque de sistemas. La información cuantitativa relacionada con las variables del sistema fue extraída como probabilidades distribución después que los agricultores fueron entrenados para proveer estimaciones cuantitativas de variables. Modelo y valores de entrada para las variables fueron usados para construir una simulación probabilística que permitió i) estimar los ingresos esperados en los cultivos de hortalizas, e ii) identificar las incertidumbres críticas del sistema de producción. Los cultivos analizados fueron berenjena, ají dulce, papaya y habichuela. La simulación muestra que existe traslape de los rangos de distribución para ingreso (valor presente neto) y la relación costo-beneficio para estos cultivos. En consecuencia no existen ventajas de un cultivo sobre otro en términos de mayores beneficios y menores riesgos. La preferencia de un cultivo en particular podría ser explicada por las diferencias en la inversión requerida para cada cultivo, donde los agricultores con menor capacidad financiera prefieren sembrar cultivos de escasa inversión y ciclos más cortos (habichuela larga). El análisis de valor de la información permitió identificar las variables que más afectan los ingresos esperados del sistema de producción: precio de venta de los productos, pérdidas asociadas a plagas y enfermedades y rendimiento; se determinó que las variables asociadas a ají dulce son las de mayor importancia sobre el rendimiento esperado del sistema irrigado de producción de hortalizas en el Valle del Sinú.

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 livestock, agroforestry diversifies both farm and nonfarm activities. This creates diverse livelihood strategies that help households to deal with recurrent shocks, such as droughts and lean periods, and can make livelihoods more sustainable over time. Based on the literature on agroforestry in SSA, we describe major tree-based systems that are widely practised in SSA and that have received much attention in terms of their contribution to sustainable livelihoods. We show that agroforestry systems are typically multifunctional, although the type of goods and services produced vary depending on the components of agroforestry and the way these are managed in the landscape. Broadly, agroforestry supports food production, health and nutrition, wood-based energy and income. We discuss the current state of knowledge, present case studies to provide the evidence base and highlight gaps in knowledge and barriers to harnessing agroforestry-based livelihoods.