I. Cassava and Cacao

Colombian Caribbean region contributes significantly in the national cassava production, despite major socioeconomic constraints. Among the latter, Cassava-Bacterial-Blight (CBB), a disease caused by the bacterial pathogen Xanthomonas phaseoli pv. manihotis (Xpm), leads to irreversible damage to plants, impeding growth and productivity. Aspects such as local genetic diversity, the impact of farming practices, and the social context on Xpm epidemiology have yet to be determined. In this sense, we will show, through biocultural approaches, the role played by local knowledge and socioeconomic factors on the occurrence and transmission of CBB within a village where cassava is cultivated at a small-scale. Our findings show that the changes of agricultural practices and the cassava cuttings circulation system strongly impacts the spread and diversity of Xpm. This information can be a key element to improve our understanding of the pathogen population genetic structure and dynamic to improve early detection and sustainable control of CBB in cassava crops.

Yuca (Manihot esculenta Crantz; also called cassava or manioc) is a key subsistence crop throughout the Amazon basin. Archeological and genetic evidence suggest that it was initially domesticated ~10,000 years ago on the southern margin of the region and then dispersed, diversifying under human pressure into myriad landraces. However, the specific influences mediating landrace development remain poorly understood. In this study, we sought to clarify them in a field investigation of cultural and biological variation on five tributaries of the Upper Peruvian Amazon. We identified 45 landraces, which growers propagated clonally, a strategy maintaining landrace integrity. Landraces were also phenotypically distinct and assigned traditional names, reflecting different planned uses. In addition, while most phenotypic measures were statistically associated, nutritional content was independent of others, and may be under independent selective pressure. Finally, we found little evidence of geographic population structure, a pattern likely explained by transportation of landraces by growers.

Research has been conducted about the health benefits of cacao, indigenous uses, and psychoactive effects. However, minimal research has been completed regarding the implications of high-dose cacao consumption in interpersonal settings. People globally who run and attend 'cacao ceremonies' claim that cacao's psychoactive effects lead, in many users, to euphoria, emotional openness, and disinhibition. They assert that these effects make cacao an excellent addition to reflection and connection-building activities done in groups or in pairs; however, claims need to be researched and field tested. If validated, cacao could prove to be a useful complement to a range of interpersonal activities, from corporate team building to community building, to applications for romantic relationships or even therapy. A wealth of anecdotal reports support this notion, though they could very well be the result of confirmation bias. This presentation will present literature background on this topic.