Abstract 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.

Abstract 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.

Resumen 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.

Resumen Phytophthora capsici es un oomiceto que causa diversos síntomas como pudrición de raíz, cuello, tallo y fruto, y tizón foliar en diversas especies vegetales que incluye el género Capsicum. Una de las herramientas para contrarrestar este problema biótico, y que tal vez sea más rentable y respetuosa con el medio ambiente a largo plazo, es el uso de biocontroladores como Bacillus, Pseudomonas, Streptomyces (bacterias) y Trichoderma (hongo). Parece que cada uno de estos microorganismos poseen diferentes mecanismos que les permiten inhibir y reducir el crecimiento de P. capsici, afectando negativamente su desarrollo de esporangios, germinación y motilidad de zoosporas, y crecimiento del tubo germinativo. Aunque parecería que esta acción biocontroladora directa sobre el fitopatógeno está correlacionada con la reducción de síntomas en plantas de Capsicum u otras especies vegetales, que también involucraría la activación de respuestas de defensa en plantas contra P. capsici inducidas por los microorganismos. Estos pueden estimular en plantas infectadas o no con P. capsici, la actividad de varias enzimas relacionadas a las vías de isoflavonoides y especies reactivas de oxígeno, así como la expresión de diferentes genes que codifican proteínas relacionadas con la patogénesis, y otras proteínas que pueden activar las vías de señalización del ácido jasmónico, ácido salicílico o etileno. A pesar de los pocos trabajos existentes relacionados con la interacción bioquímica y molecular de Capsicum-P. capsici-biocontrolador, en esta revisión se ha esquematizado y elucidado los posibles efectos y rutas metabólicas relacionadas a ese sistema vegetal tripartito.

Abstract Phytophthora capsiciis an oomycete that causes various symptoms, such as root, neck, stem, fruit rot, and leaf blight, in different plant species, including the genusCapsicum. One of the tools to counteract this biotic problem, which may be more profitable and respectful to the environment in the long term, is using biocontrollers such asBacillus,Pseudomonas,Streptomyces(bacteria), and Trichoderma (fungus). It seems that each of these microorganisms has different mechanisms that allow them to inhibit and reduce the growth ofP. capsici, negatively affecting the development of sporangia, germination and motility of zoospores, and expansion of germ tube. Although this direct biocontrol action on the phytopathogen correlates with the reduction of symptoms in Capsicum plants or other plant species, this would also involve the activation of defense responses in plants against P. capsici induced by microorganisms. The activity of several enzymes related to the isoflavonoid pathways and reactive oxygen species, as well as the expression of different genes that encode proteins related to pathogenesis and other proteins that can activate the jasmonic acid, salicylic acid, or ethylene signaling pathways. Despite the few existing works related to the biochemical and molecular interaction ofCapsicum-P. capsici-biocontroller, in this review, we outlined and elucidated the possible effects and metabolic pathways related to this tripartite pathosystem.

Abstract 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 & 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.

Resumen 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 & 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.

RESUMO As hortaliças estão expostas a constantes infecções por inúmeras doenças, incluindo as causadas pelo oomiceto Phytophthora capsici. Este microrganismo é um patógeno vegetal polífago, capaz de infectar dezenas de espécies de plantas cultivadas ou invasoras. O objetivo desta revisão é abordar tópicos relacionados à etiologia e sintomas das doenças causadas por este oomiceto (queima de folhas, podridão da raiz, podridão da coroa e podridão dos frutos), bem como também a integração e aplicação de diferentes alternativas de controle como genética, cultural, física, biológica e química. É assim que, culturas como pimentão (Capsicum annuum), pimenta (Capsicum spp.), tomate (Solanum lycopersicum), berinjela (S. melongena), cucurbitáceas (Cucumis sativus, Cucurbita spp.), entre outras, estão sujeitas a perdas econômicas consideráveis. Elevada umidade do solo, altas temperaturas, estruturas de resistência do patógeno (oósporos), baixa disponibilidade de cultivares resistentes e reduzida disponibilidade de fungicidas eficazes são condições que dificultam o manejo de doenças causadas por P. capsici no campo. Apesar da importância irrefutável deste patógeno, as informações existentes sobre seu manejo integrado são limitadas. Portanto, uma gestão bem sucedida das lavouras dependerá em grande parte de seu conhecimento e controle. Assim, a aplicação conjunta de diferentes estratégias de controle visa manter o patógeno em níveis populacionais baixos e também manter a epidemia sob o limiar de danos econômicos. No final, um manejo integrado para P. capsici poderá gerar maiores retornos econômicos, colheitas sustentáveis de longo prazo, redução do impacto ambiental e produtos de melhor qualidade para os consumidores.

ABSTRACT Vegetable crops are exposed to constant infection by numerous diseases, including those caused by the oomycete Phytophthora capsici. This microorganism is a polyphagous plant pathogen, capable of infecting dozens of plant species, including cultivated plants and weeds. The aim of this review is to address topics related to etiology and symptoms of the diseases caused by this oomycete (leaf blight, root rot, crown rot and fruit rot), as well as the integration and application of different control alternatives, such as genetics, cultural, physical, biological, and chemical. Crops such as sweet pepper (Capsicum annuum), chili pepper (Capsicum spp.), tomato (Solanum lycopersicum), eggplant (S. melongena), cucurbits (Cucumis sativus, Cucurbita spp.), among others, are subject to considerable economic losses induced by this pathogen. High soil humidity, high temperatures, resistance structures of the pathogen (oospores), scarce availability of resistant cultivars and a reduced range of effective fungicides are conditions that difficult the management of diseases caused by P. capsici in the field. Despite the irrefutable importance of this pathogen, the existing information regarding its integrated management is limited. Therefore, a successful management will depend to a great extent on its knowledge and its control. Thus, the joint application of different control strategies seeks to maintain the pathogen at low population levels and also keeping the epidemics under the threshold of economic loss. At the end, an integrated pest management approach for P. capsici could result in higher economic returns, long-term sustainable harvests, reduction of the environment impact and better quality products for consumers.

Abstract 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.

Resumen 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.

Summary Soybean [Glycine max (L) Merrill.] in Ecuador is one of the main short-cycle crops in the coastal region, and it is an important economic component for the country. Seven soybean genotypes developed at the University of Guayaquil, Ecuador, and a commercial variety were studied to know their adaptability and phenotypic stability, grain productivity and resistance to Asian rust (Phakopsora pachyrhizi). In seasons 2015, 2016 and 2017, eight trials were planted in representative environments at the province of Los Ríos, Ecuador under a randomized-complete-blocks design with four replications. Agronomic characteristics of the plants and yield and its components were evaluated and analyzed by analysis of variance and multiple range comparisons by Tukey tests (P ≤ 0.05). Additionally, the association between yield and its components was studied through Pearson correlations and linear regression. To evaluate genetic stability, the model of additive main effects and multiplicative interaction (AMMI model) was used. The So ITAV 7 line had the highest grain yield and was the most stable. Soybean genotypes established in the Vinces locality displayed the lowest severity of Asian rust.

Resumen La soya [Glycine max (L) Merril.] en el Ecuador es uno de los principales cultivos de ciclo corto en la región de la costa, y constituye un importante rubro económico para el país. Se estudiaron siete genotipos de soya desarrollados en la Universidad de Guayaquil, Ecuador, y una variedad comercial para conocer su adaptabilidad y estabilidad fenotípica, productividad de grano y resistencia a la roya asiática (Phakopsora pachyrhizi). En las temporadas 2015, 2016 y 2017 se sembraron ocho ensayos en ambientes representativos de la provincia de Los Ríos Ecuador, bajo un diseño experimental de bloques completos al azar con cuatro repeticiones. Se evaluaron características agronómicas de la planta y rendimiento y sus componentes, a los que se les realizó un análisis de la varianza y comparaciones múltiples de medias por la prueba de Tukey (P ≤ 0.05). Adicionalmente, se estudió la asociación entre los componentes del rendimiento mediante correlaciones de Pearson y regresión lineal. Para evaluar la estabilidad genética se empleó el modelo de efectos principales aditivos e interacción multiplicativa (modelo AMMI). La línea So ITAV 7 obtuvo el mayor rendimiento de grano y fue la más estable. Los genotipos de soya establecidos en la localidad de Vinces obtuvieron la menor severidad de la roya asiática.

The aim of this study was to determine the effect of seeding density on sanitary and agronomic characteristics of promising peanut genotypes, in Quevedo, Ecuador. The following promising peanut lines were used: CB-02, CB-16 and CB-23, Runner type, with a standard distance of 0,50 m between rows and 3,6; 5 and 10 plants m-1 for each cultivar. The disease intensity of leaf spot and rust were determined, furthermore, agronomic variables such as plant height, number of pods and seeds, pod weight per plant, weight of 1000 seeds, weight of pods per parcel and pod yield (kg ha-1). The experiment was carried on a Completely Randomized Block design with 9 treatments and four replications, using a factorial arrangement 3 (lines) x 3 (plants m-1). Tukey’s test at 5% of significance level was used for separation of means. The smallest number of leaf spot and rust lesions was observed on the peanut line CB-23. On the one hand, at plant densities of 3,6 and 5 plants m-1 lead to the highest number of pods per plant (321,83 and 286,50 respectively). On the other hand, the highest plant height (47,24 cm), weight of pods per parcel (2,00 kg) and pod yield (1809,42 kg ha-1) were observed at 10 plants m-1. The interaction between factors was significant for the following variables: number of seeds per plant (p<0,05) and yield (p<0,01), showing the dependence between the analyzed factors

El objetivo del estudio fue determinar el efecto de la densidad de siembra en las características fitosanitarias y agronómicas de genotipos promisorios de maní, en Quevedo, Ecuador. Se utilizaron las líneas promisorias de maní CB-02, CB-16 y CB-23, tipo Runner, con distanciamiento estándar de 0,50 m entre hileras y una población de 3,6; 5 y 10 plantas m-1 para cada cultivar. Se cuantificó la intensidad de cercosporiosis y roya, así también las variables agronómicas altura de la planta, número de frutos y de semillas, peso de frutos por planta de 1000 semillas, frutos por parcela, y rendimiento de frutos (kg ha-1). Fue empleado un Diseño de Bloques Completos al Azar con nueve tratamientos y cuatro réplicas, con arreglo factorial 3 (líneas) x 3 (plantas m-1). Para la comparación entre las medias de los tratamientos se empleó la prueba de Tukey al 5 % de probabilidad del error. La línea de maní CB-23 obtuvo menor número de lesiones para cercosporiosis y roya. Con 3,6 y 5 plantas m-1 fue obtenido el mayor número de frutos por planta (321,83 y 286,50, respectivamente), y con 10 plantas m-1, la mayor altura de planta (47,24 cm), peso de frutos por parcela (2,00 kg) y rendimiento de frutos (1809,42 kg ha-1). Se observó interacciones entre los factores, solamente para el número de frutos por planta (p<0,05) y para el rendimiento (p<0,01), mostrando dependencias entre ellos

Cocoa (Theobroma cacao L.) is one of the main crops of economic importance in Ecuador since small and medium farmers on the coast rely on this income. However, fungal diseases decreases yield. In this research 10 experimental cocoa clones of National type and two commercial control varieties (EET-103 and CCN-51) were evaluated from 2008 to 2011, at plantations located in Quevedo and Tenguel. The objective of this research was to identify disease tolerant clones to frosty pod rot (Moniliophthora roreri) and witches' broom (Moniliophthora perniciosa), while maintaining high production levels. Experimental design was a randomized complete blocks in a factorial arrangement with four replications. Variables measured were number of branches showing witches' broom per tree; percentage of diseased pods; number of healthy pods; total number of pods; and yield of dried cacao almonds (kg ha-1). Commercial clone CCN-51 exhibited the lowest incidence of diseases and the highest production of healthy pods and average almond yield (1047.7 kg ha-1). Four experimental clones showed desirable traits: L46-H57 had the highest number of healthy pods and total pod number; L21-H43, L46-H57 and L46-H88 yielded more than 550 kg ha-1 of almonds; L18-H58 presented fewer number of witches' broom (7.3), and L21-H43 had the lowest incidence of diseased pods (37.0 %). These clones might be used for breeding programs and genetic conservation. The Quevedo location showed higher incidence of fungal diseases and yield of dry cocoa beans than Tenguel.

El cacao (Theobroma cacao L.) es uno de los principales cultivos de importancia económica en el Ecuador, principalmente para los pequeños y medianos agricultores del litoral. Sin embargo, las enfermedades fungosas reducen el rendimiento de este cultivo. Durante los años 2008 a 2011 se evaluó en las localidades Quevedo y Tenguel, el comportamiento de 10 clones experimentales de cacao tipo Nacional con el objetivo de seleccionar los de mayor productividad y tolerancia a dos enfermedades: moniliasis (Moniliophthora roreri) y escoba de bruja (Moniliophthora perniciosa), en comparación con dos testigos comerciales (EET-103 y CCN-51). El diseño experimental fue de bloques completos al azar con arreglos factorial, con cuatro repeticiones. Se registró el número de escobas de bruja vegetativas, porcentaje de mazorcas enfermas, número de mazorcas sanas y totales, así como el rendimiento de almendras secas de cacao. El clon comercial CCN-51 presentó la menor incidencia de enfermedades, así como la mayor producción de mazorcas sanas y rendimiento promedio de almendras (1047.7 kg ha-1). Cuatro clones experimentales presentaron características deseables: L46-H57 con una mayor producción de mazorcas sanas y totales, L21-H43, L46-H57 y L46-H88 con un rendimiento de almendras superior a 550 kg ha-1, L18-H58 con el menor número de escoba de bruja (7.3), y L21-H43 con la menor incidencia de mazorcas enfermas (37.0 %). Estos clones pueden ser utilizados en programas de mejoramiento y conservación. La incidencia de enfermedades fúngicas y el rendimiento de almendras secas de cacao fueron mayores en Quevedo que en Tenguel.