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.

The use of native Trichoderma strains has been proposed as a sustainable alternative to control cocoa diseases. The aim of this study was to assess indigenous Trichoderma strains from Bagua Province, Peru, with reference to their antagonistic characteristics in vitro and their potential for in vitro biocontrol against frosty pod rot (FPR) disease. A total of 199 strains were assessed for in vitro mycoparasitism, antibiosis, and potential antagonism. The effect of four strains was evaluated in vitro using epidemiological variables, yield, and efficacy at two sites (Copallín and La Peca). Significant differences (p < 0.05) were reported for all variables evaluated in vitro and in vitro. Mycoparasitism ranged from 32% to 100%, antibiosis from 33.36% to 57.92%, and potential antagonism from 42.36% to 78.64%. All strains were found to affect the in vitro-assessed parameters in addition to enhancing the productive yield. The efficiency ranged from 38.99% to 71.9% in Copallín, and 45.88% to 51.16% in La Peca. The CP24-6 strain showed the highest potential for biocontrol under field conditions when considering its effect on both sites.

Frosty pod rot, caused by the fungus Moniliophthora roreri, is one of the most important diseases of cacao in Peru. Sustainable alternatives to control it include timely cultural practices such as pruning, and the application of biological control agents such as Trichoderma spp. We isolated 234 Trichoderma strains native to the department of Amazonas in Northern Peru from soil samples in cacao farms. These strains belong to at least eighteen species within four phylogenetic clades in the genus (Harzianum, Longibrachiatum, Hamatum, and Brevicompactum clades). We aimed to assess the in vitro biocontrol potential of these strains against M. roreri. We evaluated their mycoparasitism, antibiosis, and potential antagonism to select candidate strains for efficient biocontrol of M. roreri. We found evidence (Kruskal–Wallis test, p < 0.005) that strains belonging to the Harzianum clade tend to have higher mycoparasitism, antibiosis, and potential antagonism levels than strains in the Longibrachiatum and Hamatum clades. Additionally, this study constitutes the first report for antagonistic behavior against M. roreri for T. parareesei, T. lentiforme, T. orientale, T. asperelloides, T. inhamatum, T. zelobreve, T. afarasin, T. ghanense, T. rifaii, and T. breve. These results will be foundational for further M. roreri biocontrol studies.

Although the coffee berry borer (CBB) is the most important coffee pest worldwide, controversies remain regarding basic aspects of its behavior, such as how this is influenced by abiotic factors of the coffee agroecosystem. In this study, we compared the level of infestation and total population per fruit under three different levels of shade (full sun, up to 40%, and >40%), for two varieties of coffee (Caturra and Catimor) and at two different altitudes (1200 to 1700 m above sea level) in Rodríguez de Mendoza, Peru. We found that the infestation percentage increases with the shade levels of the plot. The average percentages of infestation according to shade levels were 10.52% for coffee in full sun, 12.56% with up to 40% shade, and 17.99% for coffee growing in more than 40% shade; however, maximum infestation values of 68.421%, 84.127%, and 95.238% were obtained for coffee plantations in full sun, up to 40% shade, and more than 40% shade, respectively. The Catimor variety was found to be more susceptible to CBB infestation than Caturra. In addition, CBB infestation per fruit was found to decrease with increasing altitude.

Coffee (Coffea arabica) is the main commodity in Peru and is the economic support for thousands of small farmers. However, coffee production is affected by the coffee berry borer (Hypothenemus hampei). Currently, H. hampei is the most important pest in whole coffee-growing regions in Peru. This study aimed to evaluate in vitro biological activity of Beauveria bassiana, Beauveria peruviensis, and Metarhizium sp. against Hypothenemus hampei in two trials at different times. Conidia production, Conidia viability, and pathogenicity against H. hampei were evaluated at three concentrations (1 × 10⁵, 1 × 10⁷, and 1 × 10⁹ conidia/mL⁻¹). In addition, lethal times (LT₅₀ and LT₉₀) and lethal concentrations (LC₅₀ and LC₉₀) were calculated. There were significant differences in conidia production ( < 0.001) and conidia viability ( < 0.041). The highest conidia production and conidia viability were reached by B. bassiana and B. peruviensis, respectively. Likewise, there were differences in the pathogenicity of the strains in the two tests carried out (test 1: < 0.0009 and test 2: < 0.0001). The highest mortality occurred in the treatments of B. bassiana 1 × 10⁹ conidia/mL⁻¹, B. bassiana 1 × 10⁷ conidia/mL⁻¹, and B. peruviensis 1 × 10⁹ conidia/mL⁻¹. The treatments with lower LT₅₀ and LT₉₀ were B. bassiana 1 × 10⁹ conidia/mL⁻¹ and B. peruviensis 1 × 10⁹ conidia/mL⁻¹, and the strains with the lowest LC₅₀ and LC₉₀ were B. peruviensis and B. bassiana. The in vitro characteristics shown by B. bassiana and B. peruviensis conditions suggest they should be evaluated in the field to determine the capability of these strains to reduce populations of H. hampei.

Existe una gran diversidad de especies forrajeras en las praderas naturales de la región Amazonas, y son escasos los estudios referentes a la identificación de las mismas. Con objeto de profundizar los conocimientos en especies forrajeras, se realizó la identificación de las especies de pastos presentes en las principales microcuencas ganaderas y pisos altitudinales de la región Amazonas. Las microcuencas ganaderas identificadas fueron Shocol, Leyva, Ventilla, Alto Imaza, Pomacochas, Condechaca y Leymebamba. Sobre la base de las microcuencas ganaderas y praderas naturales se definió dos variables referentes a los sistemas de producción (sistemas silvopastoriles, SSP, y sistemas pastoriles a campo abierto, SPCA) y cuatro rangos altitudinales < 1900 m.s.n.m., 1900 – 2400 m.s.n.m., 2400 – 2900 m.s.n.m. y > 2900 m.s.n.m. Se usaron transectos, identificándose un total de 34 familias y 113 especies entre forrajeras y no forrajeras, de las cuales 27 especies fueron clasificadas como especies forrajeras que agrupan un total de 05 familias. Se encontraron diferencias porcentuales de abundancia y diversidad entre especies respecto a las variables estudiadas.