Examinando por Autor "Torres de la Cruz, Magdiel"

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In vitro biological activity of Beauveria bassiana, Beauveria peruviensis, and Metarhizium sp. against Hypothenemus hampei (Coleoptera: Curculionidae)
(Hindawi, 2023-09-30) Chuquibala Checan, Beimer; Torres de la Cruz, Magdiel; Leiva, Santos; Hernandez Diaz, Elgar; Rubio, Karol; Goñas Goñas, Malluri; Arce Inga, Marielita; Oliva Cruz, Manuel
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.
The Germination and Subsequent Development of Cocoa Seedlings (Theobroma cacao L.) Are Subject to Influence From the Pregerminative Methods Employed
(John Wiley & Sons Ltd., 2025-12-20) Chuquibala Checan, Beimer; Torres de la Cruz, Magdiel; Mendoza Merino, Jani Elisabet; Tineo Flores, Daniel; Arce Inga, Marielita; Álvarez Robledo, Yeltsin Abel; Atalaya Marin, Nilton; Gómez Fernández, Darwin; Goñas Goñas, Malluri
In Peru, cocoa production has increased significantly, thereby establishing a prominent position for this crop in the country's agricultural landscape. The effect of different pregerminative methods on seed germination of cocoa ecotypes and their influence on seedling development in nursery were evaluated. Three cocoa ecotypes were used INDES 24, INDES 31, and INDES 67, and five pregerminative methods were applied to the seeds with mucilage, mucilage removal, tegument removal, water immersion, and immersion in Trichoderma harzianum solution. Parameters such as germination percentage GP, mean germination time GT50, mean germination rate GR50, and plant growth characteristics in terms of cotyledon height, plant height, number of leaves per plant, and stem diameter were evaluated. The results revealed that the treatments INDES 24 removal tegument, INDES 67 removal tegument, INDES 67 water immersion, and INDES 67 immersion in T. harzianum showed the best GPs of 100% at 72 h. Additionally, the INDES 67 tegument removal showed the best mean germination time and rate GT50 and GR50 with 24 h and 8 seeds/24 h, respectively. For growth parameters, INDES 67 mucilage removal showed the highest values for cotyledon height and the number of leaves per plant with 4 cm and 13.33 leaves/plant; for plant height and stem diameter, the treatments INDES 31 tegument removal and INDES 24 mucilage removal obtained the highest average values with 30.21 cm and 6.65 mm, respectively. These findings demonstrate that pregerminative methods significantly impact the germination and growth of cocoa plants. This insight can enhance cocoa propagation practices and improve the success rate of their establishment in the field.