The genus Beauveria is considered a cosmopolitan anamorphic and teleomorphic genus of soilborne necrotrophic arthropod-pathogenic fungi that includes ecologically and economically important species. Species identification in Beauveria is difficult because of its structural simplicity and the lack of distinctive phenotypic variation. Therefore, the use of multi-locus sequence data is essential to establish robust species boundaries in addition to DNA-based species delimitation methods using genetic distance, coalescent, and genealogical concordance approaches (polyphasic approaches). In this regard, our study used multilocus phylogeny and five DNA-based methods to delimit species in Beauveria using three molecular makers. These polyphasic analyses allowed for the delimitation of 20–28 species in Beauveria, confirming cryptic diversity in five species (i.e. B. amorpha, B. bassiana, B. diapheromeriphila, and B. pseudobassiana) and supporting the description of B. peruviensis as a new taxon from northeastern Peru. The other five species were not evaluated as they did not have enough data (i.e. B. araneola, B. gryllotalpidicola, B. loeiensis, B. medogensis, and B. rudraprayagi). Our results demonstrate that the congruence among different methods in a polyphasic approach (e.g. genetic distance and coalescence methods) is more likely to show reliably supported species boundaries. Among the methods applied in this study, genetic distance, coalescent approaches, and multilocus phylogeny are crucial when establishing species boundaries in Beauveria.

Cacao is a commodity crop from the tropics cultivated by about six million smallholder farmers. The tree, Theobroma cacao, originated in the Upper Amazon where it was domesticated ca. 5450–5300 B.P. From this center of origin, cacao was dispersed and cultivated in Mesoamerica as early as 3800–3000 B.P. After the European conquest of the Americas (the 1500s), cacao cultivation intensified in several loci, primarily Mesoamerica, Trinidad, Venezuela and Ecuador. It was during the colonial period that cacao diseases began emerging as threats to production. One early example is the collapse of the cacao industry in Trinidad in the 1720s, attributed to an unknown disease referred to as the “blast”. Trinidad would resurface as a production center due to the discovery of the Trinitario genetic group, which is still widely used in breeding programs around the world. However, a resurgence of diseases like frosty pod rot during the republican period (the late 1800s and early 1900s) had profound impacts on other centers of Latin American production, especially in Venezuela and Ecuador, shifting the focus of cacao production southward, to Brazil. Production in Brazil was, in turn, dramatically curtailed by the introduction of witches’ broom disease in the late 1980s. Today, most of the world’s cacao production occurs in West Africa and parts of Asia, where the primary Latin American diseases have not yet spread. In this review, we discuss the history of cacao cultivation in the Americas, and how that history has been shaped by the emergence of diseases.

Cadmium (Cd) contamination threatens cocoa farming in the province of Bagua in Amazonas, Peru. This study reports our assessment of Cd concentrations in cocoa farm soils, and in cocoa roots, leaves, testa, and cotyledon, thus evaluating the magnitude of the problem caused by Cd exposure. For our analysis, we sampled agricultural soil, cocoa roots, leaves and pods at 29 farms in the province of Bagua. Concentrations of Cd in each of the samples were measured and correlated with selected variables at each sampling site. Within our collection of samples, Cd levels showed great variability. In soil, Cd concentrations ranged between 1.02 and 3.54 mg kg−1. Concentrations of this metal within cocoa trees measured from roots, leaves, testa, and cotyledon, Cd ranged from 0.49 mg kg−1 to 2.53 mg kg−1. The cocoa trees exhibited variable degrees of allocation Cd from the soil to their tissues and thus considerable variation among themselves. We found that Cd amounts in roots were up to five times more concentrated than Cd levels in the soils and 2.85 times [Cd] the amounts found in cotyledon. Soil pH is a key variable enabling the uptake of this metal. Most importantly, our evaluation determined that measurements from the majority of farms exceeded the maximum permissible limits established by Peruvian and European legislation.

El riego por melgas es la modalidad de riego por superficie que se adapta mejor a los cultivos forrajeros en siembra directa, pero las condiciones de alta pendiente y baja velocidad de infiltración de la mayoría de los suelos del sur de Uruguay hacen difícil su adaptación cuando se pretende aplicar las recomendaciones de la bibliografía internacional. El objetivo del estudio fue determinar indicadores de desempeño del riego por melgas para los suelos del sur del Uruguay y plantear escenarios de optimización para identificar estrategias de manejo. Se instaló un ensayo de riego por melgas orientadas en el sentido de la máxima pendiente, variando la dirección entre grupo de melgas para minimizar la pendiente transversal. La buena conformación de los bordos de las melgas favoreció las medidas de los indicadores de desempeño. Para poder evaluar situaciones diferentes a las ensayadas a campo se planteó el uso del modelo WinSRFR. Los caudales con mejor desempeño fueron más bajos que los recomendados por la bibliografía internacional. Para el suelo evaluado y largo de ladera de 50-60 m el caudal 0,2 L/s/m tuvo la mejor respuesta a la optimización por tiempo de corte. El caudal 0,5 L/s/m alcanzó las mejores eficiencias con largos en el entorno de 170 m. El caudal 0,33 L/s/m podría ser la mejor solución en zonas donde la ladera tiene longitud variable, permitiendo alcanzar alta eficiencia de aplicación mediante la modificación del tiempo de riego. El modelo predijo muy bien el volumen infiltrado y escurrido.

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