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This paper presents a novel semi-supervised approach for accurate counting and localization of tropical plants in aerial images that can work in new visual domains in which the available data are not labeled. Our approach uses deep learning and domain adaptation, designed to handle domain shifts between the training and test data, which is a common challenge in this agricultural applications. This method uses a source dataset with annotated plants and a target dataset without annotations and adapts a model trained on the source dataset to the target dataset using unsupervised domain alignment and pseudolabeling. The experimental results show the effectiveness of this approach for plant counting in aerial images of pineapples under significative domain shift, achieving a reduction up to 97% in the counting error (1.42 in absolute count) when compared to the supervised baseline (48.6 in absolute count).

Ilustraciones (principalmente a color), diagramas, figuras, fotografías Este documento tiene como objetivo la transferencia del conocimiento adquirido acerca de los temas de investigación más relevantes abordados en el proyecto Incremento de la competitividad sostenible en la agricultura de ladera en todo el departamento, Valle del Cauca. De acuerdo con los estudios realizados por la Secretaría de Agricultura en el Plan frutícola para el Valle del Cauca, en dicho proyecto fueron seleccionadas 23 especies frutícolas de las cuales se priorizaron 3 (piña [Ananas comosus], mora [Rubus spp.] y aguacate [Persea americana]) con el fin de realizar proyectos productivos por medio de trabajos participativos de investigación priorizados en los planes de estudio de las brechas tecnológicas que favorecen principalmente a los agricultores, y en los que participaron todos los actores de las cadenas productivas. Los trabajos seleccionados estuvieron liderados por profesionales adscritos al proyecto, jóvenes investigadores, estudiantes de maestría y doctorado, cumpliendo así los objetivos de formación, también por los trabajos realizados con las universidades e instituciones investigativas vinculadas mediante los convenios de cooperación participativa. La edición de cartillas y otros documentos técnicos corresponde al cumplimiento del compromiso de divulgar los resultados obtenidos en las investigaciones del proyecto. (Texto tomado de la fuente). 1° ed.

Anthurium solitarium Schott is a species that might be used both as potted plant and cut foliage, but it is indispensable to have an adequate substrate to achieve desirable growth and commercial standard. Thus, the present research aimed at evaluating the ornamental potential and commercial quality of Anthurium solitarium grown in bamboo compost. The experimental design was in randomized blocks, with six substrates and three replicates with five plants in each experimental plot. Seedlings were grown for 270 days in substrates containing different percentages (v:v) of bamboo compost (BC) and coconut fiber (CF): T1 (100% CF), T2 (75% CF + 25% BC), T3 (50% CF + 50% BC), T4 (25% CF + 75% BC), T5 (100% BC); and a control treatment, T6 - commercial substrate Basaplant® (100% CS). The number of leaves, the leaf area, leaf (LDW) and root dry weight (RDW), root length and volume, LDW/RDW ratio and total dry weight. Leaf nutrient contents were determined. The ornamental potential, commercial acceptance and quality of the plants were also evaluated. Plants grown in substrates with BC showed higher growth, ornamental potential, market quality and acceptance than those grown in CF and CS.

A monitoring network was established in streams within a catchment near the Costa Rican Pacific coast (2008–2011) to estimate the impact of pesticides in surface water (84 samples) and sediments (84 samples) in areas under the influence of melon and watermelon production. A total of 66 (water) and 47 (sediment) pesticides were analyzed, and an environmental risk assessment (ERA) was performed for four taxa (algae, Daphnia magna, fish and Chironomus riparius). One fungicide and seven insecticides were detected in water and/or sediment; the fungicide azoxystrobin (water) and the insecticide cypermethrin (sediments) were the most frequently detected pesticides. The insecticides endosulfan (5.76 μg/L) and cypermethrin (301 μg/kg) presented the highest concentrations in water and sediment, respectively. The ERA revealed acute risk in half of the sampling points of the melon-influenced area and in every sampling point from the watermelon-influenced area. Safety levels were exceeded within and around the crop fields, suggesting that agrochemical contamination was distributed along the catchment, with potential influence of nearby crops. Acute risk was caused by the insecticides chlorpyrifos, cypermethrin and endosulfan to D. magna, fish and C. riparius; the latter was the organism with the overall highest/continuous risk. High chronic risk was determined in all but one sampling point, and revealed a higher number of pesticides of concern. Cypermethrin was the only pesticide to pose chronic risk for all benchmark organisms. The results provide new information on the risk that tropical crops pose to aquatic ecosystems, and highlight the importance of including the analysis of sediment concentrations and chronic exposure in ERA. Universidad de Costa Rica/[802-A8-016]/UCR/Costa Rica Universidad de Costa Rica/[802-B7-508]/UCR/Costa Rica Organismo Internacional de Energía Atómica/[RLA5/050]/IAEA/Austria Organismo Internacional de Energía Atómica/[RLA5/053]/IAEA/Austria Organismo Internacional de Energía Atómica/[RLA5/061]/IAEA/Austria Unión Europea/[690918 H2020-MSCA-RISE-2015]/UE/Paises Bajos UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA)

Resumen (Introducción): Los sistemas de producción agrícola emiten gases con efecto invernadero, por la aplicación de nitrógeno, para incrementar la producción. (Objetivo): Se cuantificó y comparó la emisión de N2O resultante de aplicar diferentes fuentes de nitrógeno (nitrato de amonio (NH4NO3), nitrato de calcio (CaNO3), urea convencional (CO(NH2)2), y recubierta con polímeros, RP). (Metodología): Se aplicaron 250 kg de nitrógeno ha-1 año-1 de cada fuente a plantaciones de café ubicadas en dos zonas productoras de Costa Rica. La recolección de muestras gaseosas se realizó durante todo un año agrícola, utilizándose la técnica de la cámara estática. Se implementó un diseño de bloques completamente al azar con arreglo en parcelas divididas. (Resultados): El patrón de emisión mostró que, en Naranjo, los mayores eventos se determinaron luego de fertilizar en junio, razón por la cual la emisión fue mayor (P

Introducción. El ackee, Blighia sapida, es un árbol originario del continente africano y en Costa Rica, los frutos son consumidos principalmente por los afrodescendientes radicados en el Atlántico. Objetivo. El objetivo de este trabajo fue describir la distribución geográfica, diversidad fenotípica y el manejo del cultivo del ackee, en la Región Huetar Atlántica de Costa Rica. Materiales y métodos. Se realizó una prospección y caracterización vegetativa y reproductiva, además de la medición del índice de rendimiento (IR), de materiales de ackee entre los años 2015 y 2016. Resultados. Se evaluaron 66 árboles que crecían a todo lo largo de la carretera Braulio Carrillo y la carretera hacia el Atlántico sur. Los cantones donde se ubicaron mayor cantidad de genotipos fueron Siquirres y Limón. La gran mayoría de estos materiales se encontraban creciendo cerca de las viviendas, lo que denota un arraigo de esta especie en la cultura culinaria local. De los cuarenta genotipos caracterizados, se encontró poca variabilidad fenotípica en los carácteres vegetativos. En cuanto a los frutos, estos mostraron mayor diversidad, con variación en el peso, tamaño, color y número, y peso y firmeza de los arilos. Un 86,9 % de los genotipos presentaron arilos con consistencia firme antes y después de realizar la prueba de cocción. Los valores de IR estuvieron entre 8 y 20, siendo los mejores genotipos los que presentaron un índice cercano a 8. El manejo agronómico de los árboles en cuanto a fertilización, podas, control de plagas y patógenos, es casi inexistente. Conclusión. Se sugiere validar el uso de los árboles seleccionados por su buen desempeño productivo y establecer las bases para un manejo agronómico simple, que comprenda el uso de fertilización, podas, mayores densidades de siembra, entre otras labores, y medir el impacto sobre la productividad y la calidad de los frutos de esta especie. ntroduction. The ackee, Blighia sapida , is a tree native to the African continent and in Costa Rica the fruits are consumed mainly by Afro-descendants living in the Atlantic. Objective. The objective of this work was to describe the geographical distribution, phenotypic diversity and management of the ackee crop in the Huetar Atlantic Region of Costa Rica. Materials and methods. A vegetative and reproductive prospection and characterization was carried out, in addition to the measurement of the yield index (IR) of ackee materials in the Region, between 2015 and 2016. Results. Sixty-six trees growing along the Braulio Carrillo highway and the road to the South Atlantic, were evaluated. The cantons with the highest number of genotypes were Siquirres and Limon. The great majority of these materials were found growing near the houses, which denotes a rooting of this species in the local culinary culture. Of the forty genotypes characterized, little phenotypic variability was found in the vegetative characters. As for the fruits, they showed greater diversity, with variation in the weight, size, color and number, and weight and firmness of the arils. A 86.9 % of the genotypes presented arils with firm consistency before and after the cooking test. IR values were between 8 and 20, with the best genotypes having an index close to 8. The agronomic management of the trees in terms of fertilization, pruning, pests and pathogens, control is almost non-existent. Conclusion. It is suggested to validate the use of the trees selected for their good productive performance, and to create the bases to establish the simple agronomic management, which includes the use of fertilization, pruning, higher planting densities, among other tasks, and measure the impact on the productivity and quality of the fruits of this species. UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM)

Vanilla planifolia is a neotropical orchid, whose fruits produce the natural vanilla, a fundamental ingredient for the food and cosmetic industry. Because of its importance in the world market, it is cultivated in many tropical countries and recently its cultivation has started in Colombia. This species requires shade for its development; however, the optimal of light conditions are unknown. This work evaluates the effect of different light intensities on CAM photosynthesis, physiology, morphology, and growth of this species. For this, vanilla seedlings were subjected to four treatments of relative illumination (RI) (T1=8%, T2=17%, T3=31% and T4=67%). Most CO2 assimilation occurred along night in all treatments, which confirms that vanilla is a strong CAM species. Plants grown under high lighting (67% RI) had almost half of the photosynthesis in treatments of intermediate lighting (17 and 31%), which is consistent with the lower nocturnal acid accumulation in that treatment. Likewise, the photochemical efficiency of photosystem II (Fv / Fm) showed that in plants of the 67% RI occurred high radiation stress. On the other hand, vanilla plants reached greater length, leaf area, and total biomass when grown under intermediate radiation (17 and 31% RI). These results suggest that high radiation alters the functioning of vanilla plants, inhibiting photosynthesis and growth, and that highly shaded environments not significantly affected the CAM photosynthesis of vanilla; however, in the long-term this species showed higher photosynthesis and growth under intermediate levels of radiation

Los objetivos de este trabajo fueron: evaluar el efecto de dos fungicidas, a fin de disminuir las pérdidas por pudrición de cladodios durante la implantación de Opuntia ficus indica e implantar, simultáneamente, una parcela de multiplicación de esta especie en el campo de un productor familiar. EEA Ingeniero Juárez Fil: Cavallero, María Inés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Ingeniero Juárez; Argentina Fil: Sanz, Patricio Hugo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Ingeniero Juárez; Argentina

Introduction. The ackee, Blighia sapida, is a tree native to the African continent and in Costa Rica the fruits are consumed mainly by Afro-descendants living in the Atlantic. Objective. The objective of this work was to describe the geographical distribution, phenotypic diversity and management of the ackee crop in the Huetar Atlantic Region of Costa Rica. Materials and methods. A vegetative and reproductive prospection and characterization was carried out, in addition to the measurement of the yield index (IR) of ackee materials in the Region, between 2015 and 2016. Results. Sixty-six trees growing along the Braulio Carrillo highway and the road to the South Atlantic, were evaluated. The cantons with the highest number of genotypes were Siquirres and Limon. The great majority of these materials were found growing near the houses, which denotes a rooting of this species in the local culinary culture. Of the forty genotypes characterized, little phenotypic variability was found in the vegetative characters. As for the fruits, they showed greater diversity, with variation in the weight, size, color and number, and weight and firmness of the arils. A 86.9 % of the genotypes presented arils with firm consistency before and after the cooking test. IR values were between 8 and 20, with the best genotypes having an index close to 8. The agronomic management of the trees in terms of fertilization, pruning, pests and pathogens, control is almost non-existent. Conclusion. It is suggested to validate the use of the trees selected for their good productive performance, and to create the bases to establish the simple agronomic management, which includes the use of fertilization, pruning, higher planting densities, among other tasks, and measure the impact on the productivity and quality of the fruits of this species. Introducción. El ackee, Blighia sapida, es un árbol originario del continente africano y en Costa Rica, los frutos son consumidos principalmente por los afrodescendientes radicados en el Atlántico. Objetivo.Describir la distribución geográfica, diversidad fenotípica y el manejo del cultivo del ackee, en la Región Huetar Atlántica de Costa Rica. Materiales y métodos. Se realizó una prospección y caracterización vegetativa y reproductiva, además de la medición del índice de rendimiento (IR), de materiales de ackee entre los años 2015 y 2016. Resultados. Se evaluaron 66 árboles que crecían a todo lo largo de la carretera Braulio Carrillo y la carretera hacia el Atlántico sur. Los cantones donde se ubicaron mayor cantidad de genotipos fueron Siquirres y Limón. La gran mayoría de estos materiales se encontraban creciendo cerca de las viviendas, lo que denota un arraigo de esta especie en la cultura culinaria local. De los cuarenta genotipos caracterizados, se encontró poca variabilidad fenotípica en los carácteres vegetativos. En cuanto a los frutos, estos mostraron mayor diversidad, con variación en el peso, tamaño, color y número, y peso y firmeza de los arilos. Un 86,9 % de los genotipos presentaron arilos con consistencia firme antes y después de realizar la prueba de cocción. Los valores de IR estuvieron entre 8 y 20, siendo los mejores genotipos los que presentaron un índice cercano a 8. El manejo agronómico de los árboles en cuanto a fertilización, podas, control de plagas y patógenos, es casi inexistente. Conclusión. Se sugiere validar el uso de los árboles seleccionados por su buen desempeño productivo y establecer las bases para un manejo agronómico simple, que comprenda el uso de fertilización, podas, mayores densidades de siembra, entre otras labores, y medir el impacto sobre la productividad y la calidad de los frutos de esta especie. &nbsp

Water will become increasingly scarce in the 21st century. Agriculture dominates anthropogenic water use and accounts for about 70% of water withdrawals globally. Unique challenges face tropical small-plot agricultural water management that differs from region to region. This dissertation examines two challenges facing tropical small-plot agriculture. Chapter 2 uses an experimental trial in Western Tanzania to create a unique longitudinal dataset of crop water stress measured over the growing season. The trial tests the effect of seed variety and fertilizer treatment on crop water stress over the growing season and during dry spells. Results demonstrate that hybrid varieties yield significantly more than the locally adapted traditional variety because they are better able to access nutrients and have better stomatal regulation over dry spells. Chapters 3 and 4 shift the focus to India. Chapter 3 characterizes the inter-annual dynamics of anthropogenic water stress across the Central Indian Highlands (CIH), while Chapter 4 examines the hydrological impacts of increasing forest cover on regional water supply and its implications for sustainable irrigation as well as food production. Within Chapter 3, I use extensive data sourced from the Indian government to spatially characterize water demand over the past decade by spatially mapping multiple waves of the Minor Irrigation Scheme Census and Livestock Census collected at the household level, along with monthly power generation datasets. The patio-temporal water demand data is coupled with remotely sensed precipitation and evapotranspiration data to force a customized Sacramento Soil Moisture Accounting Model that computes water supply. Finally, I developed a Groundwater Supply Stress Index to account for the impact of irrigation groundwater withdrawals over the course of the year. Chapter 3 finds that 70% of CIH is water-stressed during some portion of the year and that irrigation makes up approximately 95% of anthropogenic water withdrawals. Chapter 4 extends the findings of chapter 3 in utilizing the infiltration-evapotranspiration trade-off hypothesis to understand the impact of converting croplands to forest on groundwater recharge within the CIH. In this Chapter, I collected and analyzed field data on field-saturated hydraulic conductivity to find that forested land has significantly higher infiltration rates than croplands. These finding are then included in a Spatial Processes in Hydrology model to simulate intra-annual hydrological dynamics of current forest cover versus a forest cover increased to 30% within the river basins of the CIH. Increased forest cover is one of India’s Nationally Determined Commitments at COP21 within the Mission to Green India with a stated aim of improving landscape hydrological functioning. I demonstrate that forest cover increase has the potential to increase groundwater recharge, which could be used to irrigate a second growing season and help offset the loss of cropland through conversion to forest. Collectively, these three chapters harness multiple sources of data and leverage a wide array of innovative methods at multiple scales to shed light on important water management issues faced by small-plot agriculture in the tropics and on opportunities for better agricultural water resource management across two continents.

While an increasing number of large food companies commit themselves to source only certified cocoa, research on the impacts of certification on cocoa farmers is falling behind. We investigate how Rainforest Alliance (RA) certification of small-scale cocoa farmers in Ghana has affected both the financial and the natural capitals of the farmers. Across two villages, certified farmers were compared to conventional farmers, using both qualitative and quantitative data collected through farmer and key informant interviews and participatory rural appraisals. A combination of the Sustainable Livelihood Framework and the Input-Output-Outcome-Impact Framework was used for the analysis. Results indicate that the RA certification scheme has a positive influence on the certified farmers in terms of cocoa production, yield, income and farmers’ perception of changes in their natural and financial capitals. The positive influence is a result of inputs from the RA certification, including financial support, information and knowledge, technical assistance, and increased access to farm inputs and credit. However, these positive impacts are conditioned by the presence of active farmer organizations and access to agricultural inputs and credit through associations and government institutions, and may be undermined by certified farmers who sell their produce outside the premium value chain. While an increasing number of large food companies commit themselves to source only certified cocoa, research on the impacts of certification on cocoa farmers is falling behind. We investigate how Rainforest Alliance (RA) certification of small-scale cocoa farmers in Ghana has affected both the financial and the natural capitals of the farmers. Across two villages, certified farmers were compared to conventional farmers, using both qualitative and quantitative data collected through farmer and key informant interviews and participatory rural appraisals. A combination of the Sustainable Livelihood Framework and the Input-Output-Outcome-Impact Framework was used for the analysis. Results indicate that the RA certification scheme has a positive influence on the certified farmers in terms of cocoa production, yield, income and farmers’ perception of changes in their natural and financial capitals. The positive influence is a result of inputs from the RA certification, including financial support, information and knowledge, technical assistance, and increased access to farm inputs and credit. However, these positive impacts are conditioned by the presence of active farmer organizations and access to agricultural inputs and credit through associations and government institutions, and may be undermined by certified farmers who sell their produce outside the premium value chain.

El artículo aborda la teoría de la economía institucional desde la perspectiva de su relación con los sectores productivos. El objetivo es dilucidar los principales aportes de la teoría institucionalista en materia de formulación de políticas de apoyo a los sectores productivos de países en desarrollo. Se aborda el rol del Estado y su papel regulador, los bienes públicos y la importancia de las instituciones en el ordenamiento socioeconómico del país. Del análisis realizado surge la conclusión de que un mayor desarrollo institucional dirigido en dos líneas, la primera hacia el fomento del desarrollo integral de las personas, que son quienes conforman la sociedad e integran la fuerza laboral, y la segunda, hacia la promoción de dinámicas innovadoras que incluyan la implementación de nuevas tecnologías, es una de las rutas para el fortalecimiento del desarrollo productivo de los países en desarrollo. Institutional economics theory regarding its relationship with productive sectors is discussed in this article. The main objective of the paper is to clarify the main contributions of institutionalism theory in the formulation of policies to support the productive sectors of developing countries. To this end, the article discusses the role of the State as a regulatory entity, public goods, and the importance of institutions in the socio-economic order of the country. From this analysis, it is concluded that one of the routes to strengthen the productive development of developing countries is having greater institutional development for two purposes: first towards the promotion of the integral development of people, who make up the society and are part of the workforce, and second towards the promotion of innovative dynamics that would include the implementation of new technologies. O artigo aborda a teoria da economia institucional desde a perspectiva de sua relação com os setores produtivos. O objetivo é elucidar as principais contribuições da teoria institucionalista em matéria de formulação de políticas de apoio aos setores produtivos dos países em desenvolvimento. Aborda-se o papel do Estado e seu papel regulador, os bens públicos e a importância das instituições na ordem socioeconômica do país. A partir da análise realizada, conclui-se que um maior desenvolvimento institucional é direcionado em duas linhas, a primeira voltada para a promoção do desenvolvimento integral das pessoas, que compõem a sociedade e integram a força de trabalho, e a segunda, para a promoção de dinâmicas inovadoras que incluam a implementação de novas tecnologias, sendo um dos caminhos para o fortalecimento do desenvolvimento produtivo dos países em desenvolvimento. Universidad Nacional, Costa Rica Escuela de Economía

The world population is expected to increase from 7.3 to 9.7 billion by 2050. Pest outbreak and increased abiotic stresses due to climate change pose a high risk to tropical crop production. Although conventional breeding techniques have significantly increased crop production and yield, new approaches are required to further improve crop production in order to meet the global growing demand for food. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 (CRISPR-associated protein9) genome editing technology has shown great promise for quickly addressing emerging challenges in agriculture. It can be used to precisely modify genome sequence of any organism including plants to achieve the desired trait. Compared to other genome editing tools such as zinc finger nucleases (ZFNs) and transcriptional activator-like effector nucleases (TALENs), CRISPR/Cas9 is faster, cheaper, precise and highly efficient in editing genomes even at the multiplex level. Application of CRISPR/Cas9 technology in editing the plant genome is emerging rapidly. The CRISPR/Cas9 is becoming a user-friendly tool for development of non-transgenic genome edited crop plants to counteract harmful effects from climate change and ensure future food security of increasing population in tropical countries. This review updates current knowledge and potentials of CRISPR/Cas9 for improvement of crops cultivated in tropical climates to gain resiliency against emerging pests and abiotic stresses.

Few archaeobotanical studies have been undertaken on Islamic period sites in eastern Arabia. Excavations conducted by Dr. Axelle Rougeulle (UMR 8167) at Qalh?t in the framework of the Qalh?t Project, have provided the opportunity to improve our knowledge on plant consumption and supply strategies. Samples from the workshop B39 (14th-16th century AD) excavated in 2014-2015 have provided a substantial amount of seed and fruit remains that are the object of this study. First, the distribution of plant remains within B39 provides us with hints to the use of the different spaces. Thus it is suggested that some domestic activities such as food preparation and the cleaning of crops prior to their consumption took place in room E. Most of the remains correspond to crops of tropical origin such as Asian rice (Oryza sativa), finger millet (Eleusine coracana ssp. coracana), mung bean (Vigna cf. radiata), mat bean (Vigna cf. aconitifolia), cowpea (Vigna unguiculata) and sesame (Sesamum indicum). Their presence at the site raises the question of their origin, either as imported goods or crops cultivated locally. In the case of an importation, the Indian subcontinent seems to be the most probable centre of origin although other regions, notably Yemen, may also be considered. Further, we discuss the possibility for the introduction of tropical crops into local agrosystems present near the site.

Several large-scale metabolic profiling studies have been directed to prospect crops with a major focus on yield-related traits and, ultimately, with the definition of specific markers for plant selection in breeding programs. However, some of these technologies are expensive, time-consuming and not easily feasible for a quick approach. Fatty acid profiling was described as reliable biomarkers and as a chemotaxonomic tool allowing to study not only the diversity in germplasm collections but also to discriminate their geographic origin. We have used fatty acids profiling for a preliminary assessment of Lablab purpureus (L.) Sweet (hyacinth bean) diversity and landraces discrimination. Hyacinth bean displays an enormous variability of agro-morphological traits, probably linked to the multi-purpose uses in different regions, i.e. as pulse, or as food with nutraceutical potential (Africa and Asia), forage (Africa and Australia) and ornamental (Europe and USA). Only two forage cultivars are widely marketed, cv. Rongai and cv. Highworth, with several landraces remaining to be addressed in terms of diversity. We show that fatty acids profiling was able to distinguish landraces, which display shared fatty acids with cultivars from the center of hyacinth bean diversity origin (East Africa). We propose that fatty acid profiling is a tool that may be used not only for nutritional value assessment but also as a chemodiversity tool in crop research.

As part of an ongoing study of Anacardiaceae subfamily Spondioideae, the ten native and one introduced species of Spondias in the Neotropics are revised. The genus is circumscribed. Three new species, Spondias admirabilis, Spondias expeditionaria, and Spondias globosa, are described and illustrated; a key to the taxa found in the Neotropics and distribution maps are provided. The Paleotropical species and allied genera are reviewed. Diagnostic character sets include leaf architecture, habit, flower morphology, and gross fruit morphology. Notes on the ecology and economic botany of the species are provided.

Vanilla planifolia is a neotropical orchid, whose fruits produce the natural vanilla, a fundamental ingredient for the food and cosmetic industry. Because of its importance in the world market, it is cultivated in many tropical countries and recently its cultivation has started in Colombia. This species requires shade for its development; however, the optimal of light conditions are unknown. This work evaluates the effect of different light intensities on CAM photosynthesis, physiology, morphology, and growth of this species. For this, vanilla seedlings were subjected to four treatments of relative illumination (RI) (T1=8%, T2=17%, T3=31% and T4=67%). Most CO2 assimilation occurred along night in all treatments, which confirms that vanilla is a strong CAM species. Plants grown under high lighting (67% RI) had almost half of the photosynthesis in treatments of intermediate lighting (17 and 31%), which is consistent with the lower nocturnal acid accumulation in that treatment. Likewise, the photochemical efficiency of photosystem II (Fv / Fm) showed that in plants of the 67% RI occurred high radiation stress. On the other hand, vanilla plants reached greater length, leaf area, and total biomass when grown under intermediate radiation (17 and 31% RI). These results suggest that high radiation alters the functioning of vanilla plants, inhibiting photosynthesis and growth, and that highly shaded environments not significantly affected the CAM photosynthesis of vanilla; however, in the long-term this species showed higher photosynthesis and growth under intermediate levels of radiation. Vanilla planifolia es una orquídea neotropical, cuyos frutos producen la vainilla natural, un ingrediente fundamental para la industria alimenticia y cosmética. Debido a su importancia en el mercado internacional, se cultiva en varios países tropicales y recientemente ha comenzado su cultivo en Colombia. Esta especie requiere sombra para su desarrollo; sin embargo, se desconocen sus rangos óptimos de condiciones de iluminación. En este trabajo evaluamos el efecto de diferentes intensidades lumínicas sobre la fotosíntesis CAM, la fisiología, la morfología y el crecimiento de esta especie. Para esto, plantas jóvenes de vainilla se sometieron a cuatro tratamientos de iluminación relativa (IR) (T1=8%, T2=17%, T3=31% y T4=67%). La mayor proporción de asimilación de CO2 ocurre durante la noche en todos los tratamientos, lo cual confirmó que la vainilla es una especie CAM fuerte. Las plantas que crecieron bajo alta iluminación (67% IR), tuvieron casi la mitad de la fotosíntesis de las plantas en los tratamientos de iluminación intermedia (17 and 31%), lo cual coincide con la baja acumulación nocturna de ácidos en este tratamiento. Así mismo, la eficiencia fotoquímica del fotosistema II (Fv / Fm) mostró que en las plantas del 67% IR ocurrió estrés por alta radiación. De otro lado, las plantas de vainilla alcanzaron mayor longitud, área foliar, y biomasa total cuando crecieron bajo radiación intermedia (17 y 31% IR). Estos resultados sugieren que la alta radiación altera el funcionamiento de las plantas de vainilla, inhibiendo la fotosíntesis y el crecimiento, y que los ambientes altamente sombreados no afectan significativamente la fotosíntesis CAM de la vainilla; sin embargo, en el largo plazo, esta especie muestra mayor fotosíntesis y crecimiento bajo condiciones intermedias de radiación.

Cassava (Manihot esculenta Crantz) and yam (Dioscorea spp.) are tropical crops consumed by ca. 2 billion people and represent the main source of carbohydrate and energy for the approximately 700 million people living in the tropical and sub-tropical areas. They are a guarantee of food security for developing countries. The production of these crops and the transformation into food-derived commodities is increasing, it represents a profitable business and farmers generate substantial income from their market. However, there are some important concerns related to the food safety and food security. The high post-harvest losses, mainly for yam, the contamination by endogenous toxic compounds, mainly for cassava, and the contamination by external agents (such as micotoxins, pesticides, and heavy metal) represent a depletion of economic value and income. The loss in the raw crops or the impossibility to market the derived foodstuffs, due to incompliance with food regulations, can seriously limit all yam tubers and the cassava roots processors, from farmers to household, from small-medium to large enterprises. One of the greatest challenges to overcome those concerns is the transformation of traditional or indigenous processing methods into modern industrial operations, from the crop storage to the adequate package of each derived foodstuff.

In many tropical countries with agriculture as the mainstay of the economy, tropical crops are commonly cultivated at the plantation scale. The successful establishment of crop plantations depends on the availability of a large quantity of elite seedling plants. Many plantation companies establish plant tissue culture laboratories to supply planting materials for their plantations and one of the most common applications of plant tissue culture is the mass propagation of true-to-type elite seedlings. However, problems encountered in tissue culture technology prevent its applications being widely adopted. Proteomics can be a powerful tool for use in the analysis of cultures, and to understand the biological processes that takes place at the cellular and molecular levels in order to address these problems. This mini review presents the tissue culture technologies commonly used in the propagation of tropical crops. It provides an outline of some the genes and proteins isolated that are associated with somatic embryogenesis and the use of proteomic technology in analysing tissue culture samples and processes in tropical crops.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:40:51Z No. of bitstreams: 1 S1516-89132007000200007.pdf: 64609 bytes, checksum: 405a39237833c078fe9ba07e839bce6a (MD5) Made available in DSpace on 2013-08-22T18:40:51Z (GMT). No. of bitstreams: 1 S1516-89132007000200007.pdf: 64609 bytes, checksum: 405a39237833c078fe9ba07e839bce6a (MD5) Previous issue date: 2007-03-01 Made available in DSpace on 2013-09-30T19:27:02Z (GMT). No. of bitstreams: 2 S1516-89132007000200007.pdf: 64609 bytes, checksum: 405a39237833c078fe9ba07e839bce6a (MD5) S1516-89132007000200007.pdf.txt: 20619 bytes, checksum: be549e4fbdfe07d9c5d9b7ade8b1b3b5 (MD5) Previous issue date: 2007-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:07:32Z No. of bitstreams: 2 S1516-89132007000200007.pdf: 64609 bytes, checksum: 405a39237833c078fe9ba07e839bce6a (MD5) S1516-89132007000200007.pdf.txt: 20619 bytes, checksum: be549e4fbdfe07d9c5d9b7ade8b1b3b5 (MD5) Made available in DSpace on 2014-05-20T15:07:32Z (GMT). No. of bitstreams: 2 S1516-89132007000200007.pdf: 64609 bytes, checksum: 405a39237833c078fe9ba07e839bce6a (MD5) S1516-89132007000200007.pdf.txt: 20619 bytes, checksum: be549e4fbdfe07d9c5d9b7ade8b1b3b5 (MD5) Previous issue date: 2007-03-01 O experimento foi realizado no Departamento de Produção Vegetal da Escola Superior de Agricultura Luiz de Queiroz, ESALQ/USP, Piracicaba, São Paulo, Brasil, utilizando-se as culturas de guaranazeiro (Paullinia cupana Kunth), cafeeiro (Coffea arabica L.), cajueiro (Anacardium occidentale L.), goiabeira (Psidium guajava L.) e seringueira (Hevea brasiliensis Muell. - Arg.). No período de seca (setembro/94) e de chuvas (novembro/94), realizaram-se determinações de resistência estomática (RE) (s cm-1) e transpiração (T) (µg cm-1 s-1) nas diferentes espécies. O delineamento experimental foi em blocos casualizados com cinco repetições. A partir das análises dos dados pode-se concluir: 1. diferenças significativas entre espécies, em termos das variáveis avaliadas no período de deficiência hídrica, com valores decrescentes de resistência estomática e crescente de transpiração na seguinte ordem: guaranazeiro > cafeeiro > cajueiro > goiabeira > seringueira; 2. Nas águas as diferenças entre espécies, para ambas as variáveis, foram menos evidentes, continuando a cultura da seringueira a apresentar menor resistência estomática e maior transpiração dentre as espécies; 3. As culturas de guaraná e café apresentaram maior resistência à perda de água, em relação às demais culturas. During the dry and rainy seasons, determinations of stomatal resistance and transpiration of five tropical crops were carried out: guarana (Paullinia cupana Kunth), coffee (Coffea arabica L.), cashew (Anacardium occidentale L.), guava (Psidium guajava L.) and rubber (Hevea brasiliensis Muell. - Arg.) trees. Experimental design was done at randomized complete blocks with five replications. During the dry season there was a decrease in values of stomatal resistance in the following order: guarana > coffee> cashew> guava > rubber, with values from 2.5 to 30.0 s.cm-1. During the rainy season the stomatal resistance values varied from 1.5 to 3.0 s.cm-1. The guarana and coffee crops showed higher resistance to water transpiration when compared to other crops. During the rainy season, the rubber tree continued to present lower stomatal resistance and, consequently, higher transpiration. Universidade Estadual de Maringá (UEM) Departamento de Agronomia UNESP USP ESALQ Departamento de Ciências Biológicas UNESP

Annona muricata L. is the most important fruit tree of the annonaceae in Mexico. There are several insect pests that cause damage to the crop, including Gonodonta pyrgo Cramer, in tropical crops have been reported lost 100% due to Gonodonta. In Nayarit larvae of Gonodonta pyrgo were observed causing severe defoliations to guanabano in 2004, due to the scarce information of biology and habits, the life cycle in laboratory was determined under controlled conditions of 30.6 ± 0.19 ° C, 70 ± 0.86% RH And 12 h of photoperiod. Likewise, the duration of the biological states of larva, pupa and adult was determined at 27.9 ± 0.22 ° C, 70 ± 1.24% HR and 12 h of photoperiod. With this information, life tables and survival curves were constructed. The insect lived from egg to adult death 26.0 ± 2.11 days at 30.6 ° C and from larva to adult death it lived 30.0 ± 2.03 days at 27.9 ° C. The duration of the larval stage was the same for the two temperatures (12 days), for the biological states the larval was the one that lasted the longest. Insects confined at 30.6 ° C showed a higher mortality rate than those confined at 27.9°C. Annona muricata L. es el frutal más importante de las anonáceas en México. Existen diversos insectos plaga que causan daños al cultivo, entre ellos Gonodonta pyrgo Cramer, en cultivos tropicales se han reportado perdidas del 100 % a causa de Gonodonta. En Nayarit se observaron larvas de Gonodonta pyrgo causando severas defoliaciones al guanabano en el 2004,debido a la escasa información de biología y hábitos, se determinó el ciclo de vida en laboratorio bajo condiciones controladas de 30.6 ± 0.19 °C, 70 ± 0.86 % HR Y 12 h de fotoperiodo. Asimismo, se determinó la duración de los estados biológicos de larva, pupa y adulto a 27.9 ± 0.22°C, 70 ± 1.24 % HR Y 12 h de fotoperiodo. Con esta información se construyeron tablas de vida y curvas de supervivencia. El insecto vivió de huevo a muerte de adultos 26.0 ± 2.11 días a 30.6°C y de larva hasta la muerte de adultos vivió 30.0 ± 2.03 días a 27.9°C. La duración del estado de larva fue el mismo para las dos temperaturas (12 días), de los estados biológicos el larval fue el que más perduro. Los insectos confinados a 30.6°C mostraron mayor tasa de mortalidad que los confinados a 27.9°C.

This paper firstly reviewed development process of UPOV Conventions and briefly introduced current situation of protection of new tropical crop varieties in China. Using SWOT approach, it analyzed internal strengths, weaknesses, external opportunities and threats of breeding R&D of tropical crops if implementing UPOV Convention 1991 Act in China. Internal strengths include rich resources, strategic significance of tropical crops, solid crop breeding foundation, and broad market prospect. Internal weaknesses include insufficient reserve of germplasm resources, weak R&D and protection of new varieties, low market level of breeding R&D entities, unreasonable structure, low input in breeding R&D, and weak protection awareness. Opportunities include bringing into play strengths of rich tropical plant resources, stimulating enthusiasm for new variety R&D and awareness for variety protection, promoting structural optimization of breeding input entities, raising technology level of breeding R&D, and promoting international cooperation of new variety protection. Threats include more strict restriction of intellectual property right, impact to weak fields of new variety R&D, and difficulty in implementing limitation of farmer privileges. Finally, it came up with four recommendations for breeding R&D of tropical crops in China in the contest of implementing UPOV Convention 1991 Act.

The influence of different methods of sample preparation on the aroma profiles of dried Roselle (Hibiscus sabdariffa) was studied. Least amounts of aroma compounds were recovered by analysis of whole dry calyxes (WD) followed by ground dry (GD), blended together with water (BTW), and ground and then mixed with water (GMW). The highest number of aroma compounds was found in Roselle treated in water bath (2hr/40°C) (GMWKB). GMW was chosen as the preparation method because it was shown to be an efficient extraction method without the possibility of excessive chemical changes of the sample.

The process by which different ecological conditions and historical trajectories interacted to create different social and cultural systems resulted in major differences in economic development performance within Southeast Asia. In the late 19th century, Indonesia, the Philippines, and Thailand commonly experienced vent-for-surplus development through exploitation of unused lands. Nevertheless, different agrarian structures were created. Indonesia s development was mainly based on the exploitation of tropical rain forest under Dutch colonialism. It resulted in the bifurcation of the rural sector between rice-farming peasant proprietors and large plantations for tropical export crops based on hired labor. In the Philippines, exploitation of the same resource base under Spanish rule resulted in pervasive landlessness among the rural population. Relatively homogeneous landowning peasants continued to dominate in Thailand, where delta plains that were suitable only for rice production formed the resource base for development. These different agrarian structures associated with different social value systems have accounted for differential development performance across the three economies in the recent three decades.

The aim of this work was to evaluate changes in growth and productivity parameters of different precocious hybrids and a naturalized variety of papaya under both greenhouse and field cultivation in a temperate climate (the center of the province of Santa Fe, Argentina). In view of the aforesaid, the purpose of our research was to identify further genotypes better suited for the cultivation of this species in temperate climates and demonstrate the need for the use of semi-controlled systems to make possible the cultivation of these promising genotypes in middle latitudes. The average yield was 291% higher in greenhouse than in the field. The average productivity for hybrid genotypes compared with the naturalized variety more than doubled in both environments. Considering behavior in height, leaf area index and yield parameters, hybrids H2 (principally), and H4 showed a great adaptation for use in semi-forced systems. The use of greenhouse and short stature papaya hybrids allows its feasible and surely profitable cultivation in non- tropical climates. El objetivo de este trabajo fue evaluar el crecimiento y los parámetros de productividad en diferentes híbridos precoces de papaya y en una variedad naturalizada bajo dos condiciones ambientales en una zona de clima templado (Centro de la Provincia de Santa Fe, Argentina): al aire libre y en invernadero. A partir de lo anterior, el propósito de la investigación fue identificar, además, los genotipos mejor adaptados al cultivo de esta especie en clima templado y demostrar la necesidad de la utilización de sistemas semicontrolados para hacer factible el cultivo de estos genotipos promisorios en latitudes medias. El rendimiento promedio fue un 291% superior en invernadero que al aire libre. La productividad promedio de los híbridos, comparados con una variedad naturalizada de la zona, aumentó más del doble en ambas condiciones ambientales. Considerando las variables altura, índice de área foliar y rendimiento en fruto, se concluye que los híbridos H2 (principalmente) y H4 presentaron muy buena adaptación para su uso en sistemas semi-forzados. El uso de invernaderos y de genotipos de menor estatura brinda mejores condiciones medioambientales para el crecimiento y la producción. Esto permite que el cultivo de papaya sea factible en zonas no tropicales. Fil: Céccoli, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Panigo, Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina Fil: Gariglio, Norberto Francisco. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina Fil: Favaro, Juan Carlos. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina Fil: Bouzo, Carlos Alberto. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina

La fijación biológica de nitrógeno (FBN) es un proceso que ocurre en la naturaleza y representa la fuente de N más barata para los suelos ácidos del trópico húmedo. El objetivo de este trabajo fue cuantificar la cantidad de N fijado por cuatro especies de fabáceas a través de técnicas isotópicas con 15N, en un suelo de sabana en México. Los tratamientos se establecieron bajo un diseño de bloques completos al azar, con cuatro repeticiones. Las variables evaluadas fueron; biomasa fresca (BF), materia seca (MS), número de nódulos (NN), masa seca de nódulos (MSN), Nitrógeno total (Nt) y Nitrógeno fijado biológicamente (Nf). Los resultados muestran que Mucuna deerengiana L. presentó mayor producción de BF y MS (17,50 y 5,47 Mg ha-1) así como MSN (58,79 mg planta-1) y también mayor contenido de Nt y Nf (526,94 y 522,11 kg ha-1) respectivamente, en comparación con Cajanus cajan L., Phaseolus lunatus L. y Sesbania emerus L., especies que mostraron valores bajos en dichas variables. Se concluye que Mucuna deerengiana L. tolera bien los factores desfavorables que predominan en los suelos ácidos y por ello expresa una eficiencia superior a 500 kg ha-1 de Nf; se considera adecuada para aumentar el nivel de nitrógeno en los suelos de sabana sin aplicar fertilizantes químicos. Biological nitrogen fixation is a process that occurs in nature and is the cheapest source of N for humid tropical acid soils. The aim of this study was to quantify the amount of N fixed by species of fabaceae through 15N isotopic techniques, in a savanna soil in Mexico. The treatments were established under a design of a randomized complete block, with four replicates. The variables evaluated were: fresh biomass (FB), dry matter (DM), nodule number (NN), nodule dry mass (NDM), total nitrogen (tN) and biologically fixed nitrogen (fN). Our results show that Mucuna deerengiana L. had higher production of FB and DM (17.50 and 5.47 Mg ha-1), NDM (58.79 mg plant-1) and higher content of tN and fN (526.94 and 522.11 kg ha-1) respectively, compared with Cajanus cajan L., Phaseolus lunatus L. and Sesbania emerus L., species that showed low values in these variables. We conclude that Mucuna deerengiana L. tolerates unfavorable factors prevailing in acid soils and therefore has efficiency greater than 500 kg ha-1 fN; we consider it appropriate to increase the level of nitrogen in savanna soils, without applying chemical fertilizers. Fil: Córdova-Sánchez, Samuel. Universidad Autónoma de Chiapas (México). Centro Maya de Estudios Agropecuarios Fil: Cárdenas-Navarro, Raúl. Universidad Michoacana de San Nicolás de Hidalgo. Instituto de Investigaciones Agropecuarias y Forestales Fil: Peña-Cabriales, Juan José. Centro de Investigación y Estudios Avanzados (Guanajuato, México) Fil: Castelán-Estrada, Mepivoseth. Colegio de Postgraduados (México). Campus Tabasco. Fil: Lobbit-Phellipe, Cristian. Universidad Michoacana de San Nicolás de Hidalgo. Instituto de Investigaciones Agropecuarias y Forestales Fil: Vera-Núñez, José Antonio. Universidad Michoacana de San Nicolás de Hidalgo. Instituto de Investigaciones Agropecuarias y Forestales

Resumen en español: "El continuo crecimiento de la población humana tiene como consecuencia natural un aumento en la producción de alimentos, situación particularmente evidente en los últimos 40 años (Robertson y Swinton 2005; Godfray et al. 2010). Esto ha motivado a los productores a buscar prácticas agrícolas que aumenten la producción de sus cultivos y que sufran menos por plagas (Hails 2002). Algunos cultivos son particularmente susceptibles a las malezas, por lo que la introducción de organismos genéticamente modificados, o transgénicos (soya, algodón, maíz, canola y alfalfa), resistentes a herbicidas como el glifosato permite la aplicación de esta sustancia sin que se reduzca la producción, afectando únicamente a las plantas indeseables. Sin embargo, una de las consecuencias derivadas de la aplicación de glifosato es la contaminación de agua, suelo y sedimentos (Arregui et al. 2004; Byer et al. 2008; Peruzzo et al. 2008; Hanke et al. 2010). Otro problema es la reducción de recursos necesarios para algunos organismos polinizadores como las mariposas, abejas, abejorros y otros insectos (Goulson et al. 2008; Brower et al. 2012), ya que el glifosato al ser de amplio espectro, afecta a las plantas que usan como refugios o fuente de recursos. Además se han reportado afectaciones directas, como problemas en la reproducción, alteraciones endócrinas, malformaciones y disminución de la diversidad de especies en aves, anfibios e insectos (Relyea 2005; Evans et al. 2010; Jones et al. 2011; Séralini et al. 2012). A pesar de los problemas que se originan por el uso de glifosato, la aceptación de los cultivos transgénicos a nivel mundial ha sido enorme y sigue en aumento, ya que en la actualidad se cultivan más de 100 millones de hectáreas en 22 países (James 2006), comparado con 1.7 millones de hectáreas que se cultivaban en 1996 (James 2003), un un aumento de casi 50 veces en 10 años. Con la introducción de estos cultivos también se ha incrementado la demanda de glifosato a nivel mundial. En el año 2011 se utilizaron alrededor de 650,000 toneladas de productos a base de glifosato, cifra que podría duplicarse para el año 2017 debido al creciente uso de estos cultivos (CCM international 2012). Por ejemplo, en Argentina (Brindraban et al. 2009) y Brasil (Riesemberg y Silva 2009) se ha observado un incremento en el uso de glifosato debido a que los cultivos transgénicos alientan a los agricultores a realizar aplicaciones continuas, lo que ya ha ocasionado la aparición de resistencia (James 2003). En México, el glifosato es uno de los herbicidas más vendido (Albert 2005; Salazar y Aldana 2011). Sus ventas se han asociado con la introducción de cultivos transgénicos resistentes a este herbicida lo que implica un aumento en la contaminación de fuentes de agua y otros recursos (Arregui et al. 2004; Landry et al. 2005; Peruzzo et al. 2008). De esta manera se empeora el panorama para especies de importancia ecológica y económica como las abejas, que brindan el servicio de polinización y la elaboración de productos como la miel. Los objetivos de este trabajo fueron (1) determinar las concentraciones de glifosato presentes en cuerpos de agua cercanos a zonas agrícolas en la región Soconusco, Chiapas, México y (2) medir los efectos tóxicos agudos de las concentraciones de glifosato encontradas sobre las abejas Apis mellifera y Tetragonisca angustula. Se colectaron muestras en el periodo de secas y de lluvias de 2013 y se analizaron mediante inmunoensayo enzimático. Se detectó glifosato en todas las muestras. Para la temporada de secas la concentración más alta fue 36.71 μg/L, y para la de lluvias fue 1.32 μg/L. La mayoría de las muestras presentaron concentraciones superiores a los límites permisibles por las normas de Europa y Australia. Con base a la concentración más elevada encontrada (36.71 μg/L) se prepararon soluciones de agua-miel y se realizaron las pruebas de toxicidad oral a 24 horas sobre los polinizadores, resultando que las concentraciones encontradas en campo no generaron efectos agudos sobre la mortalidad en estas especies. "

In Kenya potato is an important food crop, second after maize. Potatoes are grown on 128,000 ha per year with average yields of about 8 tonnes per ha. The yield is far below its po-tential and should be improved to enhance food security. Of all potato growers in Kenya, 98% are characterised as small-scale farmers, producing less than 0.4 ha of potatoes per year per farm (total of two planting seasons). They produce 83% of the national production. Lack of good quality seed is a main reason for low yields. The fast-track seed project aims to improve availability of certified seed. Imported seed needs to be multiplied locally once or twice to reduce the cost price and make it affordable for small-scale growers. It is estimated that there is potential for at most 1,000 ha of professional seed production in Kenya to meet the market demand for certified seed. In Kenya about 98% of ware potatoes are sold for 'fresh' consumption. For industrial processing the most favourable opportunities are the production of crisps and fresh - not frozen - French fries. To change the low-input low-output strategy of many small-scale farmers linkages between producers and markets need to be improved. In the short term, improvement of potato growing and crop management should receive higher priority than storage and mechanisation. Storage and mechanisation should be adapted to local conditions and needs. Two cases have been indicated in which investments in professional cooled storage facilities are necessary; - storage of seed potatoes of varieties with a long dormancy period; - storage of ware potatoes for processing industry and some high-end retailers. Long-term seed storage in modern stores required for varieties with long dormancy increases the cost price of seed by 50% compared with short-term storage in diffused light stores. This makes short dor-mancy an important trait for potato varieties in Kenya, where potatoes are planted during two growing seasons. Machinery supplied for potato growing in Kenya should be geared to local needs. Higher yields and more multiplications of imported seed reduce the cost price of seed potatoes produced in Kenya. The cost price of imported seed after two multiplications is competitive with locally produced seed from minitubers after three multiplications. This report describes the current situation of the potato sector in Kenya and opportunities for further de-velopment. The study focuses on possibilities of the Dutch agribusiness to facilitate these developments. Existing information has been collected, although information on potato production was not easily availa-ble. In addition, during a mission to Kenya stakeholders were visited and interviewed. This resulted in cost- price calculations for seed potato production (short and long-term storage, imported seed and minitubers) and market information.

In Kenya potato is an important food crop, second after maize. Potatoes are grown on 128,000 ha per year with average yields of about 8 tonnes per ha. The yield is far below its po-tential and should be improved to enhance food security. Of all potato growers in Kenya, 98% are characterised as small-scale farmers, producing less than 0.4 ha of potatoes per year per farm (total of two planting seasons). They produce 83% of the national production. Lack of good quality seed is a main reason for low yields. The fast-track seed project aims to improve availability of certified seed. Imported seed needs to be multiplied locally once or twice to reduce the cost price and make it affordable for small-scale growers. It is estimated that there is potential for at most 1,000 ha of professional seed production in Kenya to meet the market demand for certified seed. In Kenya about 98% of ware potatoes are sold for 'fresh' consumption. For industrial processing the most favourable opportunities are the production of crisps and fresh - not frozen - French fries. To change the low-input low-output strategy of many small-scale farmers linkages between producers and markets need to be improved. In the short term, improvement of potato growing and crop management should receive higher priority than storage and mechanisation. Storage and mechanisation should be adapted to local conditions and needs. Two cases have been indicated in which investments in professional cooled storage facilities are necessary; - storage of seed potatoes of varieties with a long dormancy period; - storage of ware potatoes for processing industry and some high-end retailers. Long-term seed storage in modern stores required for varieties with long dormancy increases the cost price of seed by 50% compared with short-term storage in diffused light stores. This makes short dor-mancy an important trait for potato varieties in Kenya, where potatoes are planted during two growing seasons. Machinery supplied for potato growing in Kenya should be geared to local needs. Higher yields and more multiplications of imported seed reduce the cost price of seed potatoes produced in Kenya. The cost price of imported seed after two multiplications is competitive with locally produced seed from minitubers after three multiplications. This report describes the current situation of the potato sector in Kenya and opportunities for further de-velopment. The study focuses on possibilities of the Dutch agribusiness to facilitate these developments. Existing information has been collected, although information on potato production was not easily availa-ble. In addition, during a mission to Kenya stakeholders were visited and interviewed. This resulted in cost- price calculations for seed potato production (short and long-term storage, imported seed and minitubers) and market information. In Kenia zijn aardappelen na mais het belangrijkste voedselgewas. Het areaal aardappelen ligt op ongeveer 128.000 ha per jaar met een gemiddelde opbrengst van circa 8 ton per ha. De opbrengsten zijn aanzienlijk lager dan de potentieel haalbare opbrengsten en moeten worden verhoogd om de voedselzekerheid te vergroten. Van alle aardappelproducenten in Kenia is 98% te karakteriseren als kleine producenten die minder dan 0,4 ha per jaar per bedrijf telen (totaal van twee groeiseizoenen). Gezamenlijk produceren ze 83% van de nationale aardappelproductie. Het 'fast-track seed project' heeft als doel de beschikbaarheid en kwaliteit van pootaardappelen te verhogen. Geïmporteerde pootaardappelen zouden in Kenia één of twee keer vermeerderd moeten worden om de kostprijs te reduceren tot een voor kleine boeren aanvaardbaar niveau. Geschat wordt dat in Kenya mogelijkheden liggen voor de professionele teelt van hoogstens 1.000 ha pootaardappelen om aan de potentiële vraag naar gecertificeerd pootgoed te voldoen. In Kenia wordt 98% van de consumptieaardappelen verkocht voor verse consumptie. Voor de verwerking zijn de kansen het beste voor chips en koelverse frites.

The global database developed as an integral part of the World Bank's research project on Distortions to Agricultural Incentives, which is publicly available, provides around 30,000 estimates of nominal rates assistance to agricultural industries (NRAs) and associated consumer tax equivalents for 75 countries that together account for between 90 and 95 percent of the world's population, farmers, agricultural output and total Gross Domestic Product (GDP). They also account for more than 85 percent of farm production and employment in each of Africa, Asia, Latin America and the transition economies of Europe and Central Asia as well as all Organization for Economic Co-operation and Development (OECD) countries. More than 70 products are included (an average of 11 per country), which represents around 70 percent of the gross value of agricultural production in each of the focus countries, and just under two-thirds of global farm production valued at undistorted prices over the period covered. Not all countries had data for all of the entire 1955-2007 period, but the average number of years covered is 41 per country. This paper provides details of the coverage of the database. It also summarizes the distributions of the NRAs by showing two sets of Box plots for 1955-84 and 1985-2007, one set for various regions of the world, the other for all the covered products for each focus country.

This working paper summarizes annual estimates of covered product Nominal Rate of Assistance (NRAs), for each of the focus economies of Europe's transition economies, their key distortion indicators defined in Anderson et al. (2008), and provides some summary statistics for the region's estimates. Four tables are provided for each country: (a) the NRA to individual farm products covered in the study and their weighted average, using as weights production valued at undistorted prices; (b) the RRA to producers of agricultural tradable, again using as weights production valued at undistorted prices, and the component parts of the RRA calculation; (c) the weights themselves for individual covered farm products and for the residual non-covered group of products, shown as percentages and so they sum to 100 percent; and (d) the trade status of each covered product each year. The NRA in the case of a product having just its output price distorted by government policies is the percentage by which the domestic producer price exceeds the price that would prevail under free markets, that is, the border price appropriately adjusted to account for differences in product quality, transport costs, processing costs, etc. A negative value indicates the domestic price is below that comparable border price.

La fertilidad de los suelos es el problema más importante en los trópicos, siendo altos niveles de aluminio y bajo fósforo (P) los factores más limitantes de la producción. Se inicio la evaluación de la variabilidad genética para la tolerancia a bajo P utilizando 457 líneas del CIMMYT. Se encontró variabilidad genética para la tolerancia y se seleccionaron 78 líneas con diferente respuesta. Con 12 líneas contrastantes se hizo un dialélico y se evaluó en 2 ambientes con bajo (4 ppm) y alto (15 ppm) P. Habilidad combinatoria general (ACG) y específica (ACE) fueron altamente significativas en los dos ambientes, siendo ACE 3 veces más grande, lo que sugirió que en la tolerancia a bajo fósforo son más importantes los efectos genéticos no aditivos. La tolerancia mostró ser un carácter poligénico. Con 6 líneas contrastantes de hizo un análisis de medias generacionales y se evaluó en alto y bajo P en un diseño de bloques completos al azar con 3 repeticiones. La eficiencia en la toma y uso de P, y la tolerancia genética se ajustan a un modelo aditivo dominante en donde los efectos genéticos aditivos y no aditivos son importantes, siendo los últimos los de mayor importancia relativa. La epistásis no mostró ser significativa en la tolerancia a bajo P. La tolerancia es poligénica e involucra de siete y 26 genes, dependiendo del estrés. La heredabilidad en sentido estrecho está entre 13.3 y 29.7%. //Abstract. Soil fertility is important for low maize production in the tropics being aluminum toxicity and phosphorus (P) deficiency the most important limiting factors. Four hundred and fifty seven CIMMYT’s maize inbreds were evaluated in a low P (4 ppm) soil using a lattice design and 78 inbreds were selected. From these, 12 inbreds contrasting for their reaction for P uptake and use efficiency were selected and a diallel was generated. The diallel was evaluated in low (4 ppm) and high (15 ppm) P environments I a diallel design. General (GCA) and specific (SCA) combining abilities were significant in both environments, being the SCA sum of squares (SS) 3 fold the GCA SS; which suggest that non-additive gene effects were more important that the additive. A set of the most contrasting inbreds was selected for a generation mean analysis study that was evaluated on low (4ppm) and high (15 ppm) P environments. P uptake and P use efficiency was explained by an additive-dominant model, being the additive effects more important. This trait is polygenic and includes fro 7 to 26 genes depending upon the P stress. Narrow sense heritability varied from 13.3 to 29.7%. Doctorado

PROTA programme, Wageningen University

PROTA programme, Wageningen University

According to Myint's "vent-for-surplus" theory, development of the economies of Indonesia, the Philippines, and Thailand from the nineteenth century on depended on the natural advantage of large tracts of unused "empty land" with low population density and abundant natural resources of the type typically found in Southeast Asia and Africa at the outset of Western colonization. When these economies were integrated into international trade, hitherto unused natural resources (primary commodities the indigenous people had not valued) became the source of economic development, commanding market value because of high import demand in Western economies. The major delta of Chao Phraya River was the resource base of vent-for-surplus development with rice in Thailand; tropical rain forests filled that role in Indonesia and the Philippines with respect to the production of tropical cash crops. This basic difference underlay differences in the distribution of farm size: the unimodal distribution of peasants or family farms in Thailand and the coexistence of peasants and large estate farms or plantations specializing in tropical export crops in Indonesia and the Philippines. Differences in agrarian development were also shaped by different policies toward the elites preemption of unused land. Under Spanish colonialism, the elite preempted unused land in the Philippines wholesale, bifurcating land distribution between non-cultivating landlords and sharecroppers in lowland rice areas, and between plantation owners and wage laborers in upland areas. In Indonesia, the Dutch government granted long-term leases for uncultivated public land to foreign planters, but prevented alienation of cultivated land from native peasants, to avoid social instability. In Thailand, concessions were granted for private canal building, but the independent kingdom preserved the tradition of giving land to anyone who could open and cultivate it. Relatively homogenous land-owning peasants dominated Thailand's rural sector. As frontiers for new cultivation closed, the plantation systems initial advantage (large-scale development of land and infrastructure) began to be outweighed by its need to monitor hired labor. The peasant system, based on family labor needing no supervision, allowed Thailand's share of the world market in tropical cash crops to grow, as Indonesia and the Philippines lost their traditional comparative advantage. Moreover, land reform in the Philippines made land markets inactive, with resulting distortions in resource allocation and serious underinvestment in agriculture.

Crop drying in the Caribbean is carried out mainly by small farmers and estates, the normal technique being by simply spreading the material out in the sun. This method however, suffers from a number of disadvantages which could be alleviated by the use of solar or mechanical dryers. The paper describes an approach which identifies two basic types of simple, natural convection solar dryers well suited for the small farmer situation, where only small quantities would be dried at any time. Experimental results are presented which demonstrate dryer performance for both types. In the case of drying produce from the larger estates where much larger quantities are being harvested, the packed bed dryer is projected. This type of dryer can operate using either solar energy, hydrocarbon fuel or biomass as an energy source or, alternatively, can utilise any convenient combination of these sources. For the drying of timber and forages, greenhouse type solar dryers, working either by natural or forced convection are described.

Tropical smallholder agriculture is undergoing rapid transformation in nutrient cycling pathways as international development efforts strongly promote greater use of mineral fertilizers to increase crop yields. These changes in nutrient availability may alter the composition of microbial communities with consequences for rates of biogeochemical processes that control nutrient losses to the environment. Ecological theory suggests that altered microbial diversity will strongly influence processes performed by relatively few microbial taxa, such as denitrification and hence nitrogen losses as nitrous oxide, a powerful greenhouse gas. Whether this theory helps predict nutrient losses from agriculture depends on the relative effects of microbial community change and increased nutrient availability on ecosystem processes. We find that mineral and organic nutrient addition to smallholder farms in Kenya alters the taxonomic and functional diversity of soil microbes. However, we find that the direct effects of farm management on both denitrification and carbon mineralization are greater than indirect effects through changes in the taxonomic and functional diversity of microbial communities. Changes in functional diversity are strongly coupled to changes in specific functional genes involved in denitrification, suggesting that it is the expression, rather than abundance, of key functional genes that can serve as an indicator of ecosystem process rates. Our results thus suggest that widely used broad summary statistics of microbial diversity based on DNA may be inappropriate for linking microbial communities to ecosystem processes in certain applied settings. Our results also raise doubts about the relative control of microbial composition compared to direct effects of management on nutrient losses in applied settings such as tropical agriculture.

The inventory model 'PestLCI Consensus', originally developed for temperate conditions, estimates initial pesticide emission fractions to air, to off-field surfaces by drift deposition, and to field crop and field soil surfaces according to crop foliar interception characteristics. Since crop characteristics and application techniques differ in tropical conditions, these aspects need to be included in the model in support of evaluating pesticide emissions under tropical conditions. Based on published literature, a consistent set of crop foliar interception fractions was developed as function of crop characteristics and spraying techniques for tropical crops. In addition, we derived drift deposition fractions from published drift experiments specifically conducted under tropical conditions. Finally, we compiled a consistent set of pesticide emission fractions for application in life cycle assessment (LCA). Foliar interception fractions are strongly influenced by the spraying technique, particularly for hand-operated applications. Drift deposition fractions to off-field surfaces were derived for air blast sprayer on papaya and coffee, for boom sprayer on bean and soybean, for aerial application on soybean, sorghum, millet, corn and cotton, and for hand-operated application on cotton. Emission fractions vary for each combination of crop and application method. Drift deposition curves for missing crop-application method combinations can only partly be extrapolated from the set of considered combinations. Overall, our proposed foliar interception fractions and drift deposition fractions for various crops grown under tropical conditions allow to estimate pesticide emissions in support of assessing the environmental performance of agrifood systems in LCA with focus on tropical regions.