Evaluación de genotipos ecuatorianos de Capsicum spp. ante infestaciones de Bemisia tabaci

The genus Capsicum, native to tropical and subtropical America, belongs to the Solanaceae family, which includes commercially important vegetables such as chilies and green peppers. The silverleaf whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), causes losses to vegetables including Capsicum species. Among the alternatives of pest control, an effective, economical, and environmentally compatible method is the resistance of the host plant. Infestation by B. tabaci was evaluated in 73 Capsicum genotypes, corresponding to the species C. annuum, C. baccatum, C. sinense, C. frutescens and C. pubescens from an Ecuadorian genebank. Eighty-four percent of the C. baccatum genotypes evaluated showed the highest population densities of B. tabaci, while all the genotypes of C. sinense and C. frutescens had the lowest values (p < 0.05). The non-preference of adults and the scarce oviposition of B. tabaci on genotypes of C. sinense and C. frutescens suggests resistance due to antixenosis. These results could guide breeding programs for the resistance of Capsicum species to B. tabaci infestations.El género Capsicum es nativo de América tropical y subtropical, pertenece a la familia Solanaceae e incluye ajíes y pimientos, que son hortalizas comercialmente importantes. La mosca blanca Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) ocasiona pérdidas en hortalizas incluyendo especies de Capsicum. Entre las alternativas de control de plagas, un método eficaz, económico y ambientemente compatible es la resistencia de la planta hospedera. Se evaluó la infestación por B. tabaci en 73 genotipos de Capsicum nativos de Ecuador, correspondientes a las especies C. annuum, C. baccatum, C. chinense, C. frutescens y C. pubescens, provenientes de un banco de germoplasma ecuatoriano. El 84% de los genotipos de C. baccatum evaluados mostraron las mayores densidades poblacionales de B. tabaci, mientras que los menores valores los tuvieron todos los genotipos de C. sinense y C. frutescens (p < 0.05). La no preferencia de adultos y la escasa oviposición de B. tabaci sobre genotipos de C. sinense y C. frutescens sugiere resistencia por antixenosis. Estos resultados podrían orientar programas de mejoramiento genético para la resistencia de especies de Capsicum ante infestaciones por B. tabaci

Lasiodiplodia theobromae (Pat.) Griffon & Maul [(sin.) Botryodiplodia theobromae Pat] en el cultivo de cacao: síntomas, ciclo biológico y estrategias de manejo

Throughout history, the cocoa crop (Theobroma cacao L.) has been affected by countless diseases, some of these caused by Lasiodiplodia theobromae (Pat.) Griffon & Maul. Although three Lasiodiplodia species have been reported affecting cocoa plants, L. theobromae is the most studied species both in cocoa and other crops. In recent years this phytopathogen has been gaining importance. In cocoa, L. theobromae can survive in soil and culture remains in the form of pycnidia and chlamydospores, spreading by different factors until reaching the plant tissues, remaining there as an endophyte. The pathogenic fungus can cause young twigs death (a characteristic symptom found in field conditions), fruits rot and mummification, and even vascular dieback. In general, the management of pathogens of the Botryosphaeriaceae family is complex, even more so when the pathogen is already present in the crop area. However, there are genetic, cultural, biological, chemical control measures, among others, that could be integrated and used in cocoa crops. As there is little information about L. theobromae in cocoa crops, we believe that this review will be very helpful for both technicians and researchers.A lo largo de la historia, el cultivo del cacao (Theobroma cacao L.) se ha visto afectado por innumerables enfermedades, algunas de estas causadas por Lasiodiplodia theobromae (Pat.) Griffon & Maul. Aunque han sido reportadas tres especies de Lasiodiplodia afectando plantas de cacao, L. theobromae es la especie más estudiada tanto en cacao como en otros cultivos. En los últimos años este fitopatógeno ha venido tomando importancia. En cacao, L. theobromae puede sobrevivir en el suelo y restos de cultivo en forma de picnidios y clamidósporas, diseminándose por diferentes factores hasta alcanzar los tejidos vegetales, permaneciendo ahí como endófito. El hongo patogénico puede causar muerte de ramillas jóvenes (síntoma característico encontrado en campo), pudrición y momificación de frutos, e incluso muerte regresiva. De manera general, el manejo de patógenos de la familia Botryosphaeriaceae es complejo, más aún cuando el patógeno ya está presente en el local de cultivo. Sin embargo, existen medidas de control genético, cultural, biológico, químico, entre otras, que podrían ser integradas y usadas en el cultivo de cacao. Al existir poca información sobre L. theobromae en el cultivo de cacao, creemos que está revisión será de mucha ayuda tanto para técnicos como para investigadores

Enfermedades que afectan el cultivo de café: Elucidando el ciclo de vida de Roya, Mal de Hilachas y Cercosporiosis

El café (Coffea spp.) es el segundo producto básico de mayor importancia a nivel mundial, siendo C. arabica su especie más representativa. El cultivo de café es afectado por diferentes enfermedades fúngicas que reducen el área fotosintéticamente activa de sus hojas y la producción de granos. Por orden de importancia se destacan la Roya causada por el patógeno biótrofo Hemileia vastatrix que es de difícil manejo por su tipo de reproducción. Otra no menos importante, el Mal de hilachas ocasionada por los basidiomicetos Ceratobasidium noxium (Sin. Corticium koleroga) y C. chavesanum, que afectan todos los tejidos aéreos de las plantas. La tercera enfermedad, la Cercosporiosis causada por Cercospora coffeicola infecta tanto hojas como granos lo que dificulta su manejo. Aunque hay basta información científica sobre la Roya, muy poco se conoce sobre la etiología, sintomatología, ciclo de vida y manejo de Mal de hilachas y Cercosporiosis. Se utilizaron fotografías y micrografías de alta resolución y se las relacionó con la información científica disponible. Además, se recopiló información científica actualizada sobre cada enfermedad, y con eso se elaboraron los ciclos de vida. Así mismo, en este manuscrito se describe el manejo de las tres enfermedades basado principalmente en el uso de medidas genéticas, culturales, físicas, biológicas y químicas, y su integración como una alternativa sostenible en el agroecosistema de café. Entre los principales desafíos actuales y futuros en café están la evaluación de cultivares, diversidad genética de Ceratobasidium spp. y C. coffeicola, interacciones planta-patógenos, y prácticas de manejo agroecológicas

Forecasting occurrence of palm weevil Rhynchophorus palmarum L. (Coleoptera, Curculionidae) using Autoregressive Integrated Moving Average modeling

Oil palm (Elaeis guineensis L.) is a crucial crop in Ecuador, considerably affected by black palm weevil Rhynchophorus palmarum L. (Coleoptera: Curculionidae) for several years. Despite its importance, the behavior of the black weevil in Ecuador is not well comprehended presently. Therefore, this study aimed to predict infestation patterns of the black palm weevil in Ecuador using a mathematical model based on monitoring data. Data on the number of insects per trap from a commercial oil palm farm in Quinindé, Ecuador, was collected every two weeks for five years (2016-2020) and analyzed using the Classical Fourier (CF) spectrum and the Dickey-Fuller test to determine seasonality. The trend component of the data dropped from 16.33 in January 2017 to 11.96 in January 2019, with a fluctuation ranging from -0.11 to 2.50 observed for the entire data set. The results obtained after fitting the model ranged from -0.11 to 3.19, with a maximum of 5.30. The augmented Dickey-Fuller (ADF) test for the black weevil time series yielded a result of -5.60 (P<0.01). The partial autocorrelation ranged from -0.35 to 0.1. Based on our model, we projected the occurrence of black palm weevil from 2021 to 2024, with a fluctuation in the number of insects per trap ranging from 12.68 in January 2021 to 13.023 in November 2023. This model can be used to predict future insect occurrences in Ecuador, providing valuable insights into the behavior of the black weevil and using it for effective development control measures for this pest

<em>Phytophthora capsici</em> on <em>Capsicum</em> Plants: A Destructive Pathogen in Chili and Pepper Crops

Capsicum from tropical and subtropical America, is an important genus for the nutritional, economic and cultural values of its species. At the same time, the Capsicum species are affected by diseases caused by viruses, bacteria, fungi and pseudofungi, in particular the oomycete Phytophthora capsici. This phytopathogen causes great damage and losses in different Capsicum species, because it infects all plant organs causing root, crown and fruit rot; and, leaf blight. The polycyclic dispersion through zoospores and sporangia, the limited availability of resistant genotypes, and the reduced diversity of effective oomyceticides (fungicides), make P. capsici one of the most complex phytopathogens to be managed worldwide specially in field conditions. However, successful management of P. capsici depends on the knowledge of the pathogen, its interaction with the susceptible host and the methods of control used. Thus, this chapter addressed the etiology, symptomatology, occurrence and management of the disease. Additionally, the cycle of the disease is discussed in a holistic and simple way

Can Mathematical Models Describe Spear Rot Progress in Oil Palm Trees? A Five-Year Black Weevil-Disease Assessment from Ecuador

Oil palm (Elaeis guineensis Jacquin) tree yields may be negatively affected by biotic factors such as Black weevil (Rhynchophorus palmarum L.; Coleoptera: Curculionidae) and Spear rot (Fusarium spp.). This study aimed to identify, model the temporal progress, and correlate Black weevil (BW) and Spear rot (SR) in the highly susceptible varieties INIAP-Tenera and IRHO, under field conditions in Ecuador between 2016 and 2020. Morphological analysis of BW and morphomolecular study of the causal agent of SR allowed us to identify Rhynchophorus palmarum and Fusarium solani, respectively, as biotic factors that affect oil palm trees in Ecuador. The number of adults increased in both genotypes over the years, but much more in INIAP-Tenera (in 2017 and 2019). The logistic model, having a smaller mean square of the residue, was the non-linear model that best explained the SR epidemic in both susceptible genotypes. The incidence of dead palms was higher in INIAP-Tenera trees compared to those of IRHO in the year 2020. Dead plants and the number of insects, and these with the fresh fruit bunches, were correlated significantly. To our knowledge, this is the first report on the positive correlation between dead plants (%) by SR and BW, and the study of both biotic factors in Ecuador

Avances en la comprensión de la interacción entre Ceratocystis cacaofunesta y Xyleborus ferrugineus (Coleoptera: Curculionidae: Scolytinae) en árboles de cacao

Cocoa (Theobroma cacao L.) is one of the main crops in Latin American and African countries, its almonds being marketed to produce chocolate. However, different biotic factors can negatively affect the crop production, especially on small farms where management by farmers is scarce or nonexistent. Lethal wilt (Ceratocystis cacaofunesta Engelbrecht &amp; Harrington) together with beetle borers (Coleoptera: Curculionidae: Scolytinae), continue to be the main problems affecting cocoa. It has been observed that both organisms interact intrinsically inside the trunks of cacao trees. Despite the importance of this interaction, in general, the countless research and review articles carried out to date have focused mainly on studying each biotic factor separately or have been addressed in a general way. Thus, in this review we mainly focus on the interaction between the Lethal wilt and the borer beetles, especially how and which is the insect that transmits the disease in cocoa plants. Additionally, an exhaustive characterization of Xyleborus ferrugineus as a possible vector of C. cacaofunesta in cacao trees has been made. From this review, we can say that Ceratocystis species still need to be fully identified and differentiated, a deeper understanding of the ecology of the scolithid X. ferrugineus, to study the interaction between C. cacaofunesta and vectors from the host response and generate new studies, and the chemical ecology of the fungus-vector-tree still needs to be understood.El cacao (Theobroma cacao L.) es uno de los principales cultivos de países latinoamericanos y africanos, siendo comercializadas sus almendras para la elaboración de chocolate. Sin embargo, diferentes factores bióticos pueden afectar negativamente la producción del cultivo, especialmente en pequeñas fincas donde el manejo por parte de los agricultores es exigua o nula. El Mal del machete (Ceratocystis cacaofunesta Engelbrecht &amp; Harrington) junto a coleópteros barrenadores (Coleoptera: Curculionidae: Scolytinae), siguen siendo los principales problemas que aquejan el cacao. Se ha podido observar que ambos organismos interactúan intrínsecamente dentro de los troncos de árboles de cacao. A pesar de la importancia de esta interacción, por lo general, el número de artículos de investigación como de revisión realizados hasta la presente fecha, se han enfocado principalmente en estudiar cada factor biótico por separado, o han sido abordados de forma general. Así, en esta revisión objetivamos principalmente la interacción entre el Mal del machete y los coleópteros barrenadores, especialmente cómo y cuál es el insecto que transmite la enfermedad en plantas de cacao. Adicionalmente, se ha hecho una caracterización exhaustiva de Xyleborus ferrugineus como posible vector de C. cacaofunesta en árboles de cacao. A partir de esta revisión, nosotros podemos decir que aún falta identificar y diferenciar completamente las especies de Ceratocystis, comprender más a profundidad la ecología del escolítido X. ferrugineus, estudiar la interacción entre C. cacaofunesta y vectores a partir de la respuesta del huésped, y generar estudios en el campo de la ecología química del hongo-vector-árbol

Ecosystem services valuation in the Abras de Mantequilla wetland system: A comprehensive analysis

The Abras de Mantequilla Wetland System (ADMW) in Ecuador provides a variety of ecosystem services, including erosion control, flood regulation, nutrient retention, and habitat provision. This study used a multi-level combined model to assess the potential of ADMW to provide these services. The results showed that ADMW has the potential to store a significant amount of organic carbon (3.1 million Tg C), retain nutrients (154,000 kg N and 73,000 kg P annually), and control erosion (mean surface runoff of 1100 L year−1). The study also found that the potential of ADMW to provide ecosystem services is influenced by the slope of the land, the presence of water bodies, and the vegetation cover. The results of this study have important implications for the management of ADMW and for the sustainable use of wetlands in Ecuador.The study suggests that ADMW should be managed by a variety of stakeholders, including government agencies, local communities, and private landowners, in a way that protects its ability to provide ecosystem services, such as by protecting the wetland from pollution, maintaining the vegetation cover, and preventing the development of infrastructure that could damage the wetland