Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Introduction. The production and commercialization of raw milk in Nariño, Colombia, follows microbiological and compositional standards on which payment for quality is made. However, quality can be affected during its transport after milking. Objective. To describe the microbiological and compositional quality of raw milk in the highland tropic. Materials and methods. The study was carried out in seven municipalities in the department of Nariño, Colombia, during the rainy season between February and July of 2017. Two milk samples from the same milk can were collected, one after milking (farm; n = 10), and the second at the collection point (tank; n = 10). In each sample, the following variables were evaluated: height above the sea level of the collection site, aerobic mesophilic count (CFU), total coliform count (COL), milk temperature, fat (FAT), protein (PC) and total solids (TS). Results. The temperature of the milk was higher on the farm compared to the tank (30±0.68 vs. 23±0.87 °C, respectively). The aerobic mesophilic count was higher in the tank vs. farm (116,470 vs. 41,388 CFU ml-1, respectively). The temperature of the milk was negatively correlated with the distance and the transport time of the milk (-0.86 and -0.84, respectively). The compositional quality of the milk was not affected by transport conditions. Conclusion. In the high tropic conditions, the microbiological quality of raw milk was negatively affected by the increase in the aerobic mesophilic counts.

Introduction. In Costa Rica, bacterial canker of mango has caused economic losses in most of the productive areas since the mid-1980s. The causal agents have been identified only by phenotypic methods such as Erwinia mangifera and E. herbicola. Objective. To confirm, using a molecular and phenotypic approach, the species of the Enterobacteriaceae the cause bacterial canker of mango in Costa Rica. Material and methods. Fruits, branches, and trunks with symptoms were collected in different orchards in the Alajuela province. Bacterial isolation was performed, and pathogenicity was evaluated by inoculating fruits and trunks of the Tommy Atkins variety. The positive isolates for the pathogenic test were re-inoculated, isolated, and identified in order to fulfill Koch’s postulates. The CIBCM-Mg-115 positive isolate that caused symptoms was analyzed by complete biochemical characterization and molecular identification by phylogenetic analyses of 16S rRNA and the atpD, gyrB, infB, and rpoB housekeeping genes. Results. According to the data obtained from the biochemical and molecular analysis, the CIBCM-Mg-115 strain was identified as Erwinia billingiae. Conclusion. E. billingiae corresponds to one of the causal agents of bacterial canker on mango (M. indica) trees in Costa Rica.

Introduction. The tomato brown rugose fruit virus (ToBRFV) was first reported in Israel and Jordan in 2014, causing damage to tomato crops in protected agriculture. Objective. To collect information on the known distribution, current situation, and detection methods of ToBRFV. Development. Between 2018 and 2019, the presence of the virus was confirmed in Mexico, the United States, China, Germany, Turkey, the United Kingdom, and Italy. Electron microscopy and serological tests have been used to detect the virus, but these cannot differentiate ToBRFV among other tobamoviruses. The most effective diagnostic technique for detection is specific oligonucleotides developed from the isolates from Israel and Jordan. Hygiene protocols are the most important step in preventing infections. Conclusion. Efforts to control ToBRFV are currently focused on the use of strict sanitation and detection practices in seed and plant, using molecular reverse transcriptase polymerase chain reaction (RT-PCR) techniques with specific oligonucleotides, which avoid false positives.

Introduction. Palm cultivation allows oil to be obtained for human and industrial consumption. Some of its development has been achieved through associations of agricultural producers, who have had access to financing to build industrial plants for oil extraction and refinement, which is of great importance to the economy developing countries. Objective. To demonstrate how strategic and risk management influence the profitability and value of the small palm oil industrializer business. Materials and methods. Financial, technical, market, and production indicators were used in a price forecast model. The Monte Carlo simulation method was performed and a time series model was fitted to forecast the international price of palm oil. Subsequently, a univariate structural econometric model was adjusted to forecast revenue based on international price and other variables. Finally, a parameterized cash flow was developed that incorporated the results of the previous models to estimate the value of the business. Results. The international oil price forecast showed high volatility that directly affected the organization’s revenue forecasts and conveyed its effect to cash flows. The value of the business and equity was negative, and in the face of debt restructuring scenarios and the elimination of unproductive assets, they improved considerably. Conclusion. Low-diversified palm oil production companies had a high exposure to changes in international prices which, together with high levels of debt for fixed asset investments with long recovery periods, affect their cash flow, the value of the company, and its assets.

Introduction. The specialized dairy systems in Colombia represent the most technified sector of the cattle production, nevertheless it has challenges with profitability and competitiveness with the market of imported dairy products, which establishes a disadvantage for local production. However, the rearing of discarded calves for meat production, can be a competitive alternative. Objective. To deepen the management of feeding in the calves rearing stage from dairy farms. Development. Artificial breeding includes the management, care, and feeding of calves until weaning and its objective is to reduce the nutritionally dependent of milk, at the lowest age possible, and to be able to incorporate solid foods into the diet. The basic diet of the calves during rearing includes the colostrum, milk or milk replacer, concentrated feed, and forage. It must be ensured colostrum quality measurement and the offer of quality colostrum, in the first hours postpartum. Milk or milk replacer should be supplied for eight weeks maximum with a tendency to decrease the period without affecting the development of the calves, offering a product of compositional and sanitary quality. The concentrate feed and the forage source can be offered from the first weeks of birth, guaranteeing quality of the diet and removing the feed scraps to avoid gastrointestinal problems. Conclusion. Rearing as a critical stage requires strategic feeding management. The supply of quality colostrum at the right time is the basis of the entire production stage. Liquid diet is essential for the physiological and enzymatic adaptation of the gastrointestinal tract, while solid diet is essential for ruminal development.

Introduction. The cultivated species of the genus Capsicum, among them C. chinense, are known for the pungency of their fruits, however, there are several types of this pepper that do not present pungency. Venezuelan cuisine is defined by the characteristic flavor of a class of peppers that do not present pugency, which are called sweet peppers. Among these, the best known and most used are the cultivars Rosita, Pepon, and Llanero. Objective. To characterize the Rosita, Pepon, and Llanero chilli pepper cultivar by means of 53 morphological characteristics and to determine the phenetic relationship among them. Material and methods. In a randomized block design with three treatments (cultivars) and five repetitions, 45 seedlings of each cultivar were arranged in La Vigia, Jimenez municipality of Lara state, Venezuela, in August 2017. The transplant was carried out in separate rows at 0.50 m, and the seedlings were spaced 0.50 m apart on the row. On the three plants of the central row of each experimental unit (fifteen plants in total for each cultivar) the category or value of attributes of stem, leaf, flower, fruit, and seed were determined. Results. Forty-two percent of these attributes were variable among the plants evaluated, fifteen of them were categorical and seven quantitative, and significant differences (p<0.05) were detected among cultivars. Flower and seed characteristics showed no variation among cultivars, while stem and fruits showed the greatest variation. As a whole, the morphological characteristics that presented variation allowed to identify each one of the cultivars and therefore, to discriminate them. Conclusion. The variation identified in the characteristics of the fruit is indicative of the potential for genetic improvement of the Venezuelan sweet pepper in its commercial part.

Introduction. Risk preference is the situation in which an agricultural producer decides to invest money and there is a probability of obtaining benefits from those desired. Objective. To evaluate risk preference and utility of intensive Angus and Hereford beef production in Rancho Teseachic, La Posta, Chihuahua, Mexico through monetary utility. Materials and methods. The experiment was conducted from March 24th to August 11th 2017. 52 cattle were evaluated and fed for a period of 141 days with rolled corn (53,3 %) and distillers’ grain (37,8 %). The animals were divided into two lots: one with 32 Angus heads with 226.28±28.69 kg of initial live weight and the other with 20 Hereford heads with 191.58±24.23 kg of initial live weight. An econometric model was adjusted, using Ordinary Minimums Squares, to determine the absolute and relative risk preference of the monetary utility in cattle fattening. Results. At the end of the period, the weight was 371.7±43.96 kg for Angus and 320.9±37.99 for Hereford. The production model indicated an optimum live weight at slaughter of 375.5 kg for Angus and 321.5 kg for Hereford. Conclusion. The producer rejected the risk-free preference to the risky preference. Meat production with Angus calves showed a lower risk preference (20 %) than Hereford calves (44 %) and therefore less utility.

Introduction. The use of biological controllers as alternatives to traditional chemicals is an ecological and economic option for farmers. Fungi of the genus Trichoderma can confer resistance to plants and increase the absorption of nutrients, reducing a wide variety of crop diseases. Objective. To evaluate pineapple stubble wastes as a substrate for the solid fermentation growth of two Trichoderma strains to produce a spore solution for agricultural purposes. Materials and methods. The experiment was carried out at the Laboratory of Research in Chemistry and Applied Biosciences of the Universidad Tecnica Nacional of Costa Rica, in the period between April 2018 and October 2019. Two variants of fungus T. viride and T. harzianum were used, these were grown in natural potato dextrose agar (PDA) and pineapple stubble. A conidia count was performed in a 1/10 mm Neubauer chamber. Results. T. viride and T. harzianum showed uniform growth in reseeding plates with color changes in time, from white to green. T. viride showed better development in wet substrate, while T. harzianum in low moisture stubble. The maximum cell concentration in the liquid solution of T. harzianum and T. viride was 1 132 750 cell ml-1 and 1 023 250 cell ml-1, respectively. Conclusion. Both strains of Trichoderma developed adequately in the pineapple stubble, however, the efficient growth of the strains is associated with the management of external factors such as the amount of substrate, oxygen, and moisture.

Introduction. Rambutan productivity depends on satisfying its nutritional demand through the use of fertilizers. Knowing the quantity and the times of greatest demand for nutrients by the plant allows the producer to improve fertilization programs. Objective. To evaluate the content and distribution of macronutrients in different ages of the rambutan crop. Materials and methods. An experiment was established in the Atlantic coast of Honduras under a completely randomized design with six treatments (sampling at 2, 3, 4, 8, 10, and 17 years of establishment) and three repetitions. The study was carried out between the months of March and December 2017. At harvest time, leaves, branches, shells, and seeds were collected to analyze the concentrations of N, P, K, Ca, Mg, and S in each one. Results. It was recorded that the macronutrient concentration differed significantly among the organs and ages of the plant, finding the highest concentration of N, Ca, Mg, and S in leaves, P in seed and K in the shell. The total concentration (leaf + branch + shell + seed) of the nutrients registered fluctuations over time and increased the demand for P, K, Ca, and Mg in years 2 and 3, to then decline in years 8 and 10. While the demand for N and S were constant during the development stages. In addition, N (41 %) was required in greater quantities, followed by K (24 %) and Ca (20 %) and finally P (6 %), Mg (5 %) and S (4 %). Conclusion. The content and distribution of macronutrients were variable according to the age of the plant, allowing the identification of which nutrients and when they were most required and the plant organ where it was accumulated.

Introduction. The guava (Psidium guajava L.) is considered a commercially important fruit in more than sixty countries, which is used in the agro-industry and fresh consumption, due to its nutraceutical properties, since it is considered an important source of vitamin C, thus improving the health of consumers. Objective. To determine the current status of research for the guava cultivation in Colombia. Development. The cultivation of guava in Colombia presents inadequate yields in the different producing regions, mainly due to the lack of knowledge on the part of the producers and the use of technologies that are not suitable for intensive production. However, there are currently a number of technological offers that can be implemented to address the main limitations of the crop, achieving as a result to improve the production of guava in a profitable and environmentally sustainable way. Conclusions. The technical recommendations and technological offers related to the use of improved varieties, agronomic, and phytosanitary management of the guava crop could be implemented by the producers, in order to position Colombia as an international reference to supply the domestic and export markets.