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Cacao (Theobroma cacao L.) has traditionally been considered a crop that requires shade, and consequently it is implemented under agroforestry systems (AFs) in order to regulate the level of incident solar radiation. However, optimal shade levels for this tree crop may vary depending on the climate conditions of where it is grown. Here we analyzed the physiological performance of cacao under three different AFs in the Colombian Amazon that differed in solar radiation patterns: high (HPAR), medium (MPAR), or low (LPAR) mean daily incident radiation. The physiological performance was characterized using photosynthetic variables in leaves such as light- and CO2-response curves, chlorophyll a fluorescence parameters, and total chlorophyll and carotenoid contents, in conjunction with other leaf functional traits. Cacao trees exposed to HPAR showed an improved physiological performance as compared to those from the other two AFs. Compared to MPAR and LPAR, cacao trees in HPAR doubled the rate of net carbon assimilation and reached higher maximum rates of RuBisCO carboxylation and RuBP regeneration. Moreover, cacao trees in HPAR presented photoprotection mechanisms that avoided photoinhibition, which was accompanied by a greater non-photochemical quenching coefficient and biochemical and morphological adjustments (low chlorophyll but higher carotenoid contents and low specific leaf area) compared to cacao trees from the other AFs. Overall, our results show that, due to the high cloud cover in the Colombian Amazon, cacao plantations under conditions of sparse shade maximized their carbon use, showing an improved physiological performance as a result of higher photosynthetic rates and energy dissipation mechanisms. If the crop were managed with sparse shade, the paradigm that favors the cultivation of cacao under shade would be called into question in the Colombian Amazon and other regions with similar climatic conditions.

Colombia's agriculture, forestry and other land use sector accounts for nearly half of its total greenhouse gas (GHG) emissions. The importance of smallholder deforestation is comparatively high in relation to its regional counterparts, and livestock agriculture represents the largest driver of primary forest depletion. Silvopastoral systems (SPSs) are presented as agroecological solutions that synergistically enhance livestock productivity, improve local farmers' livelihoods and hold the potential to reduce pressure on forest conversion. The department of Caquetá represents Colombia's most important deforestation hotspot. Targeting smallholder livestock farms through survey data, in this work we investigate the GHG mitigation potential of implementing SPSs for smallholder farms in this region. Specifically, we assess whether the carbon sequestration taking place in the soil and biomass of SPSs is sufficient to offset the per-hectare increase in livestock GHG emissions resulting from higher stocking rates. To address these questions we use data on livestock population characteristics and historic land cover changes reported from a survey covering 158 farms and model the carbon sequestration occurring in three different scenarios of progressively-increased SPS complexity using the CO2 fix model. We find that, even with moderate tree planting densities, the implementation of SPSs can reduce GHG emissions by 2.6 Mg CO2e ha−1 yr−1 in relation to current practices, while increasing agriculture productivity and contributing to the restoration of severely degraded landscapes.

We present a typology of cacao agroforest systems in Colombian Amazonia. These systems had yet to be described in the literature, especially their potential in terms of biodiversity conservation. The systems studied are located in a post-conflict area, and a deforestation front in Colombian Amazonia. Cacao cropping systems are of key importance in Colombia: cacao plays a prime role in post conflict resolution, as cacao is a legal crop to replace illegal crops; cacao agroforests are expected to be a sustainable practice, promoting forest-friendly land use. We worked in 50 x 2000 m2 agroforest plots, in Colombian Amazonia. A cluster analysis was used to build a typology based on 28 variables characterised in each plot, and related to diversity, composition, spatial structure and light availability for the cacao trees. We included variables related to light availability to evaluate the amount of transmitted radiation to the cacao trees in each type, and its suitability for cacao ecophysiological development. We identified 4 types of cacao agroforests based on differences concerning tree species diversity and the impact of canopy spatial structure on light availability for the cacao trees in the understorey. We found 127 tree species in the dataset, with some exclusive species in each type. We also found that 3 out of the 4 types identified displayed an erosion of tree species diversity. This reduction in shade tree species may have been linked to the desire to reduce shade, but we also found that all the types described were compatible with good ecophysiological development of the cacao trees. Cacao agroforest systems may actually be achieving biodiversity conservation goals in Colombian Amazonia. One challenging prospect will be to monitor and encourage the conservation of tree species diversity in cacao agroforest systems during the development of these cropping systems, as a form of forest-friendly management enhancing sustainable peace building in Colombia.

The rubber tree [Hevea brasiliensis (Willd. Ex Adr. de Juss.) Muell.-Arg] is the main source of natural rubber in the world. However, in the Amazon region, its production is reduced by biotic and abiotic limitations, which have prompted breeding programs in order to identify desirable agronomic and physiological indicators. The objective of this study was to analyze the temporal dynamics of photosynthetic responses based on the parameters of leaf gas exchange and chlorophyll a fluorescence in 10 rubber tree clones during the immature phase (pre-tapping) in three large-scale clone trials, during daily cycles and under two climatic periods (dry and rainy) in the Caquetá region (Colombian Amazon). The variables A, LT, ΦPSII, ETR and qP were significantly higher in the dry period, where the highest values of PAR, AT and VPD were seen. In San Vicente del Caguán and Florencia, the highest averages were estimated for A, E and gs, as compared with Belén de los Andaquíes. In Florencia, the highest fluorescence parameters of chlorophyll a were recorded. At 9:00 h and 12:00 h, the highest means of A, E, ΦPSII and ETR were observed. The majority of the clones displayed the highest Fv/Fm mean (0.82-0.84) in the dry period. The clones FX 4098, FDR 4575, MDF 180, GU198 and FDR 5788 represent genotypes with the best photosynthetic performance (greater photosynthetic rates and better ability of the photosynthetic apparatus to capture, use and dissipate light energy). These desirable genotypes constitute a promising gene pool for expanding the genetic resource of rubber trees in the Colombian Amazon.

The concept of well-being of rural families is part of a theory under construction in which new theoretical elements are constantly being incorporated. This research aims to determine the influence of farmers’ knowledge on the well‑being of cocoa growing families in the departments of Santander, Huila, Meta and Caquetá, Colombia. Four categories of farmers were identified with different levels of knowledge in the management of cocoa cultivation obtained through a cluster analysis. The well-being of cocoa farmers, understood as the balance in the capital endowment of rural households, was obtained through the application of a semi-structured interview with 49 variables of human, cultural, social, political, natural, built, and financial capitals. The results show that cocoa knowledge is heterogeneous in the study area, with a slight improvement towards harvesting, post-harvest and transformation links. There is a positive relationship between cocoa knowledge and the well-being of cocoa farming families. Thus, producers with greater integral knowledge, with emphasis on post-harvest and bean transformation links, showed greater well-being. The Random Forest analysis identified that human capital (political, social, human, and cultural) made the greatest contribution to well-being. The findings show that cocoa knowledge contributes to the well-being of rural households to the extent that it favors vertical relationships (linkages with local governments) and horizontal relationships of producers (participation of association managers, sharing knowledge with friends, neighbors and partners, and cocoa training).

This study evaluated the foliar antioxidant activity in nine Hevea brasiliensis genotypes from the ECC-1 (Élite Caquetá Colombia) selection and IAN 873 cultivar (control) in trees in the growth stage in two large-scale clonal trials in response to different climatic (semi-humid warm and humid warm sites) and seasonal (dry and rainy periods) conditions in the Colombian Amazon. The results indicated that Reactive Oxygen Species (ROS) production increased under conditions of lower water availability (dry period), leading to lipid peroxidation, high defense of photosynthetic pigments, and development of better osmotic adjustment capacity in the ECC 64, IAN 873, ECC 90, and ECC 35 genotypes due to high concentrations of carotenoids (0.40 mg g -1 ), reducing sugars (65.83 μg mg -1 ), and malondialdehyde (MDA) (2.44 nmol ml -1 ). In contrast, during the rainy period, a post-stress action was observed due to high contents of proline and total sugars (39.43 μg g -1 and 173.03 μg g -1 , respectively). At the site level, with high Photosynthetically Active Radiation (PAR) values (1143 moles photons m -2 s -1 ), temperature (32.11°C), and lower precipitation (135 mm), higher antioxidant activity (chlorophylls a, b and total, carotenoids, and proline) was recorded at the humid warm site, demonstrating that the ECC 90, ECC 64, and ECC 66 genotypes are tolerant to water deficit compared to IAN 873. The ECC 64 genotype, independent of seasonal changes and site conditions, presented the highest contents in Chl a, total Chl, reducing sugars, total sugars, and MDA, showing a tendency to adapt to fluctuating conditions. This study showed that water fluctuations do not cause the same metabolic responses, these vary within the same species, depending on their developmental stage and the climatic and seasonal variations characteristic of the Colombian Amazon.

The common bean ( Phaseolus vulgaris L.) is a major food legume cultivated by smallholder farmers in the tropics of Latin America and eastern and southern Africa. Acid soil and high temperature limit its production. Here we quantify differences in agronomical, phenological and physiological performance of common bean lines in order to identify promising lines with adaptation to acid soils and high temperatures in the Amazon region of Colombia. A field study was conducted using a 6 × 6 Alfa Lattice design with four replications consisting of 30 genotypes and one control genotype (Calima) which was repeated six times in each block (with a total of 36 plots) to cope with the spatial variability within the experimental site. During the growing period of the crop, maximum and minimum average temperatures were 32 and 23 °C, respectively while the total precipitation was 933 mm and the soil was acidic with aluminum toxicity. Differences in agronomical (grain yield, canopy biomass, number of seeds and pods per area), phenological (days to flowering and days to physiological maturity) and physiological (biomass partitioning, photosynthetic ability and pollen viability) attributes among the genotypes tested were quantified. The results obtained on the relationships between different plant attributes indicated that adaptation to acid soils and high temperatures is related to pollen viability, earliness, greater values of canopy biomass and better mobilization of plant reserves to the formation of pods and grains. Two common bean lines (BFS 10 and NCB 280) were identified as better adapted to the combined conditions of acidic soil and high temperatures in the Amazon region of Colombia.

Cocoa is a food product with sensory and organoleptic attributes that depends on postharvest processes such as fermentation. This process affects not only the sensory profile, but also chemical reactions and therefore, the quality of the product. Hence, the aim of this study is to carry out a chemical and sensory characterization of cocoa (Theobroma cacao L.) samples from different cocoa farms in the department of Huila, Colombia. Moreover, a bromatological analysis was performed, secondary metabolites (caffeine and theobromine) and total polyphenols were determined, as well as volatile fraction compounds using gas chromatography by solid phase microextraction in the headspace mode (HS-SPME); finally, the samples were classified (acceptable, unpleasant and contaminated) according to a tasting panel. In general, bromatological characteristics of cocoa samples showed acceptable levels, presence of special volatile compounds (linalool and linalool oxide) that affected sensory attributes (floral). Likewise, levels of caffeine and theobromine had adequate levels that resulted in bitter taste. A relationship was found between volatile fraction compounds and bromatological analysis variables, secondary metabolites and total polyphenols that affected the quality of the product.

Cupuassu (Theobroma grandiflorum (Willd. ex Spreng.) K.Schum.) is an evergreen tree in the family Malvaceae, with nutritional qualities of interest in the food and cosmetic industry. It is necessary for its processing, in addition to other processes, to perform a fermentation, affecting its chemical composition. Therefore, the effect of fermentation time on the phenolic content and antioxidant activity of Cupuassu (T. grandiflorum) beans, was determined. During this process, the chemical properties of the beans and the phenolic content were evaluated every two days; also quantifying the secondary metabolites Catechin, Epicatechin, Theobromine and Caffeine by high performance liquid chromatography (HPLC). The antioxidant activity was analyzed using the ABTS, DPPH, and FRAP assays. Analysis of phenolic content and antioxidant activity showed a decrease after 6 days of fermentation. Therefore, it is not recommended to continue fermentation after this period due to a negative influence of the process on the bioactive substances (Catechins) content, and the reduction of the ability to inhibit free radicals, exhibited by Cupuassu beans. 

Cacao cultivation has great socioeconomic importance for the development of rural areas of Colombia, especially for the approximately 52,000 rural households that depend on it. Therefore, is important to analyze the relationship that the capitals endowment of cacao-growing rural households has with the agronomic status of the crop. To establish this relationship, we determined the endowment of community capitals in 22 rural households and the agronomic status of their cacao crops, grown in 83 plots. In each of these plots, these components were characterized: (1) floristic composition and crop structure; (2) soil quality; (3) pest attack status and diseases in the crop; (4) sensory quality of cacao beans, and (5) production. We found a positive correlation between the tree structure and physicochemical indices of the soils (p < 0.05). Crops with greater shade showed a greater impact of pests and diseases (shade range 2.2–85.7%). Estimated cacao bean yield (kg ha−1 yr−1) were higher where cacao cultivation was the main livelihood (961 kg ha−1 yr−1 in Cacao Farmers and 774 kg ha−1 yr−1 in Diversified Farmers with Cacao). Crops demonstrating less damage caused by pests and diseases and less diverse tree structures obtained a higher cacao bean yield (kg ha−1 yr−1). Households with greater knowledge, experience and interaction with institutions that offer training, had more diverse tree structures and better soils physicochemical conditions. Households with greater capitals endowment had better agronomic conditions in cacao cultivation and had crops that generated additional products.