Scientia Agropecuaria

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

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.

Effect of liming and fertilizers on the growth and nutrition of 12-month old Teak (Tectona grandis L.) grown on acidic soil of Peru

Abstract Peru has a great potential for forestry plantations, nevertheless, importations of this type of products are getting very expensive. Soils under forest are acidic and infertile to support sustainable economically valuable forest tree species such as teak. Information is lacking on proper fertility management in forest plantations such as teak. Therefore, the objective of this study was to explore the effect of lime, and organic and inorganic fertilizers on the early growth and nutrient composition of 12-month old teak grown on acidic soil of Peru. The soil under field study was acidic with a pH of 4.99, low in fertility. A factorial design of 2x3: Lime (No Lime and Liming) and fertilizer (organic, inorganic and mixture), with 9 repetitions was adopted. Tree biometric parameters (height, diameter, biomass) and N, P, K, Ca, Mg, Fe, Cu, Mn, Zn foliar concentrations were determined during early the growth of teak. Treatments with addition of dolomite lime favored higher biometric parameters, and use of organic fertilizers promoted more growth than inorganic fertilizers. In the case of nutrients, no major differences were observed between limed and unlimed treatments while organic fertilizer promoted Ca, K and S nutrition. The results show that the application of lime and organic fertilizers is essential for the successful management and establishment of teak plants in acidic soils of Peru.

Plantain peel adsorbent: Simple preparation, and adsorption at phosphate concentrations similar to those of water sources at risk of eutrophication

Abstract There are several investigations on the use of food waste to remove contaminants by adsorption. However, a simple route, without chemical activation reagents, is needed for the development of adsorbents. The aim of this study was to develop an adsorbent from plantain peel, using a simple procedure, and to evaluate its capacity to remove phosphate from aqueous solutions at phosphate concentrations similar to those of water sources at risk of eutrophication (0.30 mg/L). The simple pyrolysis method was used in an electric muffle, without chemical activation, using plantain peel as precursor. The variables evaluated were pyrolysis temperature and solution pH. The specific surface area BET, zero loading point of the developed treatments, was determined. Phosphate adsorption was studied in a batch experiment in the presence of calcium ions in solution. Phosphate adsorption was favorable at all three pyrolysis temperature levels (500, 600 and 700 °C) and two solution pH levels (pH 7 and 10). the pseudo-second order kinetic model was the best fit for the experimental data to describe the adsorption mechanism. The best fit to the experimental equilibrium data was obtained with the Langmuir isotherm model. It was found that a 1 g/L dose of the adsorbent was able to reduce 92% of phosphate in water, with a removal capacity 0.14 mg/g at pH 10 and pyrolysis temperature of 700 °C. This study lays the groundwork for future research on the use of this type of adsorbent in water treatment to facilitate access to clean water for rural populations.

Meat, dairy and vegetable emulsions: Recent innovations in the development of functional, healthy and more stable foods

Abstract Applications of formulations that incorporate emulsified oils offer interesting prospects for producing foods with better characteristics that are in line with the new trends in healthy eating and the new regulations on nutritional claims. This review defines and classifies the types of emulsions according to their drop size, formulation and analyzes the latest research related to the application of emulsions in the food industry. It presents valuable information on the use of micro, nano and macro emulsions for the preparation of meat, dairy and vegetable products as a potential alternative in the transport of bioactive compounds, reformulations with better lipid profiles and substitution ingredients of meat origin by ingredients of plant origin, obtaining foods with acceptable functional and sensory properties. New advances in the emulsion industry open up great possibilities in the delivery of health products, however, there are still limitations in the use of ingredients of plant origin in products formulated in considerable percentages with ingredients of animal origin. There are opportunities to improve the technology of food emulsion, the application at an industrial level is a step that is being taken little by little in congruence with the economic viability of the use of vegetable oils in the reformulation and the demand of current consumers for delivery of products with a clean label. It is suggested to study the economic feasibility of the industrial application of the use of single and double emulsion systems as a substitute ingredient for animal fats.

Cassava torrado-like virus encodes a gene that facilitates the mechanical transmission to Nicotiana benthamiana of Cassava virus X

Abstract Cassava-torrado-like virus (CsTLV) is a bipartite single-stranded RNA virus belonging to the family Secoviridae. The virus has been reported in Brazil and Colombia, and is usually found in mixed infections, and in plants affected by Cassava Frogskin Disease (CFSD), an endemic cassava disease in the Americas. Genome analysis of CsTLV identifies a gene in RNA2 implicated in pathogen movement in other torradoviruses. This gene (RNA2-ORF1) and another one no related to virus movement (Maf/Ham1) were amplified by PCR and cloned into constructs under the 35S promoter of cauliflower mosaic virus (CaMV), which then were transfered to agrobacterium binary vectors. When agro-infiltrated in Nicotiana benthamiana plants, only RNA2-ORF1 had a positive effect on the mechanical inoculation of cassava virus X (CsVX), a potexvirus that has a low rate of mechanical infection in N. benthamiana. Efficiency of CsVX mechanical transmission was measured by the number of infected plants, presence of symptoms, and titers of CsVX as measured by ELISA, two weeks after infection. On average, CsVX could infect 2.3 times more plants when these were previously agro-infiltrated with A. tumefaciens binary vector encoding CsTLV RNA2-ORF1. We conclude that the novel secovirid CsTLV associated with leaf spot symptoms in cassava, encodes a gene that could enhance other viral infections in N. benthamiana. Further studies are required to elucidate this effect and its role in mixed infections, often observed in cassava plants affected by CFSD.

Botanical diversity, structure and composition in cocoa agroforest systems in Alta Verapaz, Guatemala

Abstract The tree composition in cocoa agroforestry systems (CAFS) in Guatemala is valued for providing a number of ecosystem services. Despite the importance of the trees in these systems, little is known about the tree species richness and its contribution to the conservation of diversity. We studied the botanical composition of CAFS of different ages in the Alta Verapaz department of Guatemala. In total, 70 survey plots with a size of 2500 m2 were established. An inventory was carried out in each sampling unit, recording the tree species present and measuring the diameter at breast height (DBH 1.30 m) and the height of each tree. The Importance Value Index (IVI) was calculated and species richness and the similarity between sites were evaluated. A total of 2519 trees, belonging to 59 species and 34 families were identified. The species with the highest IVI was Gliricidia sepium (Jacq.) Kunth. The CAFSs with the highest and lowest species richness were those of 9-12 and 27 years old, respectively (H´=1.99, H´=0.34). This behavior can be explained by the fact that growers work to enrich the agroforestry systems with a broad diversity of species in the first years which they then begin to harvest at around 16 years of age. A discriminant analysis of principal components (DAPC) and the Jaccard Similarity Index were used to show that several AFS were similar in terms of composition and botanical diversity. Given the tree diversity within the CAFS, these can be acknowledged as areas with good potential for the conservation of overall biodiversity. We recommend education programs for local growers about the benefits of shade management during the production cycle of cocoa to preserve the botanical composition and structural complexity of the AFS.

Emotions and visual preferences of consumers towards native and classic potato (Solanum tuberosum) chips: Comparative study using neurogastronomy and neuromarketing

Resumen El uso de herramientas tecnológicas, en adición a las técnicas tradicionales, para conocer las emociones y preferencia de los consumidores a productos alimenticios es muy importante para que los desarrolladores de productos tengan mejor información para la toma de decisiones. El objetivo del presente estudio fue utilizar herramientas de la neurogastronomía y neuromarketing para estudiar las emociones y preferencias visuales de los consumidores hacia hojuelas de papas (Solanum tuberosum) nativas y clásicas. Se utilizaron dos tipos de hojuelas frita, papa clásica y papa nativa, con un costo de S/ 6,60 (1.79 USD) y S/ 7,00 (1.90 USD), respectivamente. En una primera etapa se utilizó la tecnología de Seguimiento Ocular y el Análisis de Emoción utilizando una aplicación para teléfono móvil. En una segunda etapa, cada participante respondió una encuesta cognitiva, mediante el uso de formulario Google. Se utilizaron 100 consumidores con edades entre 14 y 63 años. La encuesta mostró que un 45% de los consumidores mostraron su intención de comprar el producto nativo más que el producto clásico. Los resultados de neuromarketing mostraron principalmente una mayor proporción de neutralidad, y un poco menor, en emociones negativas de “escepticismo”, “tristeza” y “disgusto”, especialmente sobre el factor nutricional y el precio. Estos resultados, más que contradictorios son complementarios, ya que las herramientas tecnológicas nos permiten conocer más detalles de las preferencias y elecciones. Los consumidores pretenden consumir más productos nativos, siempre que sean más nutritivos, más sustentables, más baratos y beneficien al productor local.

Abstract The use of technological tools, in addition to traditional techniques, to understand consumer emotions and preferences for food products is very important so that product developers have better information for decision-making. This study aimed to use neurogastronomy and neuromarketing tools to study consumers' emotions and visual preferences toward native and classic potato flakes (Solanum tuberosum). Two types of fried flakes were used, classic potato and native potato, with a cost of S/ 6.60 (1.79 USD) and S/ 7.00 (1.90 USD), respectively. Eye Tracking technology and Emotion Analysis were used in the first stage using a mobile phone application. In the second stage, each participant answered a cognitive survey, using the Google form. A hundred consumers aged between 14 and 63 years were used. The survey showed that 45% of consumers indicated their intention to buy the native product rather than the classic product. The neuromarketing results mainly showed a higher proportion of neutrality, and a little lower, in negative emotions of "skepticism", "sadness" and "disgust", especially on the nutritional factor and price. These results, more than contradictory, are complementary since technological tools allow us to know more details about preferences and choices. Consumers intend to consume more native products, if they are more nutritious, more sustainable, cheaper, and benefit the local producer.

Effect of five cooking methods on the physicochemical, nutritional and sensory characteristics of rainbow trout (Oncorhynchus mykiss)

Resumen El objetivo de este estudio fue evaluar el efecto de cinco métodos de cocción (vapor, plancha, horno, microondas, fritado) en las características fisicoquímicas, valor nutricional y aceptabilidad sensorial de trucha arcoiris (Oncorhynchus mykiss) de origen piscícola. Se aplicó una encuesta a 307 consumidores para definir la formulación de la solución de adobado constituida por sal, ajos, comino y pimienta. Los filetes marinados en esta solución fueron cocinados por cada método y se registraron fotografías para la determinación de los perfiles sensoriales mediante el método CATA (Check All That Apply), así como la aceptabilidad de la apariencia mediante la evaluación virtual (n = 289) y presencial (n = 100). En ambas modalidades se encontró una similitud entre los mapas de atributos sensoriales para el fritado, horneado y a la plancha. Se evidenciaron diferencias significativas (p < 0,05) en la composición proximal entre las técnicas estudiadas como consecuencia de los parámetros tecnológicos de cocción. El fritado y microondas obtuvieron la mayor aceptabilidad en apariencia y ocasionaron un incremento del índice de peróxido. La relación n-6/n-3 para ambas técnicas (3,62 y 2,05) se ubicó dentro del requerimiento, siendo mayor en la fritura debido al predominio de ácidos grasos Omega 6 incorporados por el aceite empleado. La elección de estos dos métodos demuestra que el consumidor peruano aprueba técnicas caracterizadas por la facilidad de preparación y un marcado desarrollo de atributos de color y textura.

Abstract This study aimed to evaluate the effect of five cooking methods (steam, grill, oven, frying and microwave) on farm-raised rainbow trout's sensory acceptability, physicochemical characteristics, and nutritional value. A survey was conducted with 307 consumers to create a marinade made with salt, garlic, cumin and pepper. The fillets marinated in this mixture were cooked, and photographs were taken to determine their sensory profile using the Check All That Apply (CATA) method, as well as their appearance through both visual (n = 289) and virtual (n = 100) surveys. Similarity was found between the sensory attribute maps for frying, oven and grilling in both evaluation methods. Significant differences (p < 0.05) in proximal composition were observed between the cooking techniques studied because of their technological parameters. The methods with the best visual acceptability were frying and microwave, and they caused an increase in the peroxide index. The n-6/n-3 ratio for both techniques (3.62 and 2.05) was within the requirement, being higher in frying due to the predominance of Omega 6 fatty acids incorporated by the oil used. This study demonstrated that the Peruvian consumer prefers cooking techniques characterized by ease of preparation and marked the development of color and texture attributes.

Massive production of Hemileia vastatrix uredospores for inoculation of coffee seedlings

Abstract Coffee leaf rust (Hemileia vastatrix) is the most important disease in coffee crops around the world. Currently, there is limited knowledge about mass production methodologies and ex-situ infection of H. vastatrix that lead to the development of different health characterization studies of Coffea or disease phenotyping. In this context, the aim of this research was to develop a simple protocol for the mass production of coffee rust uredospores under controlled conditions and to determine their infection in coffee seedlings. Uredospores of H. vastatrix were collected from infected plants in the “Chontal” coffee-growing area in San Martín, Peru. The viability of uredospore germination was evaluated, and a uredospores suspension (2 x 105 uredospores/mL) was prepared to inoculate coffee seedlings. Incidence and sporulation rates were evaluated after 43 days of inoculation. During the multiplication process of H. vastatrix uredospores, using controlled conditions (23±1 °C, ≈ 80% relative humidity and photoperiod of 16 hours of light) under an innovative system, the first symptoms of chlorosis were observed on coffee leaves 20 days after inoculation. Our findings show a 100% incidence of inoculated coffee plants with an average of 54 mg of H. vastatrix uredospores per plant and a 1.38 x 10-1 mg/cm2 sporulation rate. Finally, here we report a protocol that allows mass multiplication of H. vastatrix uredospores under controlled conditions, that would be useful in any time for coffee leaf rust bioassays.

Geolashon (Teloschistes flavicans), a natural yellow dye from the Peruvian Andes: traditional uses, bioactive extraction, and potential applications

Abstract Recently, interest in studying pigments from lichens has been aroused due to their bioactive properties and health benefits. The Geolashon (Teloschistes flavicans) is a thousand-year-old lichen from the Peruvian Andes characterized by its yellow filaments, traditionally used by the Peruvian inhabitants as a natural pigment for making handicrafts and medicinal purposes. In this sense, this article aims to compile all the studies on Geolashon as a source of natural yellow pigments, starting from its importance and applications by the Andean population to research on obtaining, characterizing, and properties of its extracts. Although studies on this lichen are limited, it was observed that the obtained from lichen are rich in 3-[1’-(2”,3”-dihydroxy-phenyl)-propyl]-7-hydroxy- chroman-4-one, vicanicin, parietin, other compounds and has antidiabetic, antibacterial, antileukemic, antimicrobial, anticancer and termiticide activity that would be interesting for use in the pharmaceutical, cosmetic, food and agricultural industries, generating added value in the final product. Aspects such as processing, functional properties, and toxicology of the bioactive components of Geolashon must be studied for its correct use.