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A network of agronomists, researchers, and practitioners associated with cacao farming provided open access to their independent field trials across Latin America and the Caribbean (LAC). A centralized dataset was assembled using qualitative and quantitative data from 25 experimental field trials (hereafter referred to as “CacaoFIT”) spanning several LAC agroecosystems. This dataset was used to document the main traits and agroclimatic attributes of the cacao cultivation model being tested within the CacaoFIT network. By synthesizing data from an entire network of cacao trials, this study aimed to highlight specific design features and management practices that may contribute to better cacao farming sustainability. The CacaoFIT network comprises 200 ha of field trials testing over 150 cacao genotypes and set up under different shade canopy design, management, and research goals. Small-sized trials were common across Mesoamerica, whereas medium to large-size trials were distinct to South America. Cacao trials were 15 years old (on average) and ranged from 3 to 25 years of establishment. Most cacao trials were managed conventionally (i.e., 55%), while 20% were under organic practices, and the remaining 25% presented both conventional and organic management approaches. Most field trials (ca. 60%) planted an average of 10 international clones or national cultivars at high (1,230–1,500 plants ha−1) and medium density (833–1,111 plants ha−1). Mixed shade canopies were the dominant agroforestry model, while timber vs. leguminous shade canopies were also common. The diversity and depth of research domains examined across the CacaoFIT network varied widely. Agronomy and agroforestry topics dominated the research agenda across all trials, followed by environmental services domains. Cacao physiology and financial performance were researched to a lesser extent within the network. Five featured field trials from CacaoFIT offered technical guidelines to inform cacao farming within similar contexts. This collaborative work is a scaffold to encourage public–private partnerships, capacity building, and data sharing amongst cacao researchers across the tropics.

Los sistemas silvopastoriles (SS) combinan productividad con mitigación del cambio climático y mejoran las reservas de carbono (C). El objetivo de la investigación fue estimar las existencias de C en tres sistemas silvopastoriles de la selva alta. Para el estudio se seleccionaron tres sistemas silvopastoriles: Cedrelinga cateniformis (Tornillo), Eucalyptus spp. (Eucalipto) e Inga edulis (Inga). Se recolectaron y analizaron muestras de suelo de 0-15 cm y 15-30 cm para determinar sus características físicas y químicas. La estimación de las reservas de C se realizó a partir de biomasa con ecuaciones alométricas. El análisis estadístico se realizó mediante análisis descriptivo (medias y desviación estándar) y ANOVA y uso de la prueba de Scott Knott. Las propiedades del suelo no mostraron diferencias significativas entre SS, a excepción de P, Al y CIC. Las reservas de carbono fueron mayores en el sistema tornillo. En general, las reservas de C en el SS fueron mayores en el suelo y representaron la principal reserva de C, superando a la vegetación. Los resultados resaltan la importancia del suelo como sumidero de carbono y su papel en la mitigación del cambio climático.

The aim of this research was to show that the absorption of divalent cadmium ions (Cd2+) in Theobroma cacao L. seedlings can be controlled and adjusted by remediation with maghemite (γ-Fe2O3) nanoparticles (NPs), i.e., leading to the low tolerance limits established by the European Union (EU) in 2014 for Cd in products made from cocoa. The research had two stages; the first one involved the medium scale synthesis of 92 g of 15 nm γ-Fe2O3 NPs via room temperature chemical co-precipitation of ferrous salts and their characterizations using diverse physicochemical techniques. In the second stage, and for the first time, three doses of these γ-Fe2O3 NPs (1, 2, and 4 g) were applied to the substrate of cocoa seedlings of genotypes ICS 39, ICS 95, and CCN 51 for three months of exposure. A morphological analysis revealed non-significant toxic effects on the seedlings’ height, leaf area, and stem diameter among the genotypes and tested doses. The results of the atomic absorption analysis of the treatment with 4 g of γ-Fe2O3 NPs showed a concentration of 0.10 mg kg−1 of Cd2+, a limit lower than the control and the recommended value by the 2014 EU regulation. Thus, the transport and/or absorption of the Cd2+ toxic metal were significantly inhibited, since up to 74 % of Cd2+ uptake in the genotype ICS 95 was experimentally observed. Also, the environmental Fe-dynamics in the seedlings and soils demonstrated no transport of γ-Fe2O3 NPs to the seedlings. Thus, the study found that the Cd2+ adsorption in remediated soil using γ-Fe2O3 NPs involves three steps: electrostatic exchange, Fe-oxide adsorption, and substrate-γ-Fe2O3 NPs complexation and precipitation.

In search of efficient solutions for the treatment of contaminated soils and in favor of the sustainable development of agriculture, this work aimed at developing an efficient method that helps to directly overcome the contamination by nickel in soils and Theobroma cacao L. seedlings. In this study, the genotypes ICS-39, CCN-51, and TSH-1188, which are high-yielding varieties in South America, were studied. The compound used as an adsorbent was commercial zeolite 5A. The zeolite 5A and soil samples were analyzed by X-ray diffraction, Raman microscopy, chemical analysis, electron microscopy techniques, and atomic absorption spectroscopy. This last technique was used for quantitative determination of Ni concentrations in seedlings. Zeolite 5A presented a high adsorption efficiency (95%) among the studied cacao genotypes, making this material a viable adsorbent and inhibitor agent of Ni. In addition, zeolite 5A was found to be not chemically harmful to the plant morphology (root and height), as demonstrated using statistical analysis. Finally, the Ni mechanism was described based on zeolite 5A physicochemical properties, suggesting that this material has remarkable soil remediation application.

Cacao is an important tropical crop and requires high-fertility soils for better growth and productivity; nevertheless, soils where this crop is grown are, in general, acidic and low in fertility. Therefore, germplasm with tolerance to soil acidity is desirable for cacao genetic improvement. The objective of this study was to evaluate cacao germplasm for early growth, nutrient concentration, and potential tolerance to soil acidity. A greenhouse experiment was conducted to evaluate 60 cacao genotypes with diverse geographic origins. Cacao seedlings were grown for six months in acid soil with and without lime. Growth parameters and the total concentration of N, P, K, Ca, Mg, Fe, Cu, Mn, and Zn were measured in shoots after harvest. Our results indicate that the best early growth predictors of acid soil tolerance are the number of leaves and root area. N, Ca, Mg, and K uptake may have a potential role in tolerance to soil acidity. Finally, the results revealed a large difference among cacao genotypes in terms of their responses to acid soil stress, which led to the selection of ten genotypes: CCN-51, PH-21, CCN-10, PAS-91, ICT-1087, ICS-95, UF-667, TSH-565, PH-144, ICT-1189 that are potentially tolerant to soil acidity and could be used for breeding acid soil-tolerant cacao varieties.

Cacao is an understory plant cultivated in full-sun monocultures, multistrata agroforestry systems, where cacao trees are planted together with fruit, timber, firewood, and leguminous trees, or within thinned native forests. In agroforestry systems of cultivation, cacao is subjected to excess shade due to high density, excess growth, and the unmanaged pruning of shade trees. Cacao is tolerant to shade, and the maximum photosynthetic rate occurs at an irradiance of around 400 μmol m−2 s−1. However, excess shade further reduces the irradiance, which is detrimental to photosynthesis and growth functions. Intra-specific variation is known to exist in cacao for the required saturation irradiance. A greenhouse study was implemented with 58 cacao genotypes selected from four geographically diverse groups: (i) wild cacao from river basins of the Peruvian Amazon (PWC); (ii) Peruvian farmers’ collection (PFC); (iii) Brazilian cacao collection (BCC); and (iv) national and international cacao collections (NIC). All of the cacao genotypes were subjected to 50% and 80% shade where photosynthetic photon flux density (PPFD) was 1000 and 400 μmol m−2 s−1, respectively. Intra-specific variations were observed for growth, physiological and nutritional traits, and tolerance to shade. Cacao genotypes tolerant to shade were: UNG-77 and UGU-130 from PWC; ICT-2173, ICT-2142, ICT-2172, ICT-1506, ICT-1087, and ICT-2171 from PFC; PH-21, CA-14, PH-990, and PH-144 from BCC; and ICS-1, ICS-39, UF-613, and POUND-12 from NIC. Genotypes that tolerate excess shade may be useful plant types for maintaining productivity and sustainability in agroforestry systems of cacao management.