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

Introduction. In Colombia, horticultural production in the low tropics is limited mainly by biotic factors such as pest attacks, pathogens, and abiotic factors such as extreme values of temperature, solar radiation, wind, and precipitation. Objective. To evaluate two types of anti-insect screens in the ventilation areas of a naturally ventilated Colombian greenhouse in order to analyze the effect on the ventilation rates and the generated microclimate. Materials and methods. The study was carried out in 2019 in the department of Magdalena, Colombia. The methodological approach included the use of a 2-D computational fluid model (CFD) for the development of fifteen steady-state simulations. The CFD model was experimentally validated in the prototype of the real greenhouse evaluated. Results. Goodness-of-fit parameters between measured and simulated data showed absolute mean error (MAE) and root mean squared error (RMSE) values for temperature and relative humidity of 0.15 and 0.32 °C, 2.41 and 2.73 %, respectively. There was an average reduction in ventilation rates between 55.3 and 77.1 % compared to the reference scenario that did not include the presence of anti-insect screens, this reduction generated modifications in the behavior of the temperature and relative humidity variables inside the greenhouse, with a marked heterogeneous spatial distribution. Conclusion. The most inadequate microclimatic conditions occurred in scenarios of low external wind speed; therefore, it is recommended to select and implement some type of anti-insect screen in the ventilation areas of a greenhouse based on the local behavior of this variable.

Introduction. The use of stability estimators for agronomic characteristics of interest allows understanding the behavior of the genotype in relation to those environmental factors that influence its expression. Objective. The objective of this study was to determine genotype by environment (GE) interaction to select cotton varieties with a high seed yield potential and fiber percentage. Materials and methods. Nine varieties of transgenic cotton were evaluated in ten localities distributed in two geographically different ecoregions: geographical valleys of the Magdalena and Cauca rivers, by means of random complete block design, between the months of March and August in 2013. Results. Cotton seed yield had significant GE interaction, where the three principal components (PC) of the Additive Main Effects and Multiplicative Interaction (AMMI) model were significant (p<0.01), with contributions of 86.9, 6.4, and 3.3 %, respectively. The average yield for the two ecoregions were 3.3 t ha-1 (Magdalena river geographical valley) 4.5 t ha-1 (Cauca river geographical valley), and for all the evaluated localities in the ecoregions was 3.9 t ha-1. Fiber percentage did not present significative GE interaction and had an average value of 43,34%. The V004 variety showed the best performance with an average yield of 4.9 t ha-1. The varieties with greater adaptability were V001 and V002. A high correlation was observed between the most productive varieties and the most productive environments. Conclusion. The differential behavior between varieties and localities for yield allowed to select varieties for specific environments, or with phenotypic plasticity for several environments.

Introduction. Colombia is the second producer of panela or non-centrifugal sugar (NCS) in the world, after India. In 2016, the department of Nariño had an area in sugarcane (Saccharum officinarum L.) for harvested sugarcane or NCS of 10 533 ha and an average yield of 7.67 t ha-1 for 6.35 % of total production of panela or NCS in the country. Objective. To evaluate the use of organic and mineral fertilizer on the sugarcane yield for panela or NCS production in its first production cycle. Materials and methods. The study was carried out between the months of November 2008 to March 2010 in the village of Villa Ines, Consaca, Nariño; a randomized complete block design was used, considering continuous sowing systems (SEC) and spacing (SE) ajusted NPK levels according to soil analysis, with chemical (FQ) and organic (FO) sources. The yield was evaluated in cane and panela or NCS, and reducing sugars and phosphates. Results. The treatments (T3) SEC-FQ with 168.20 TCH, (T1) SEC-FA with 167.07 TCH and (T5) SE-AO with 167 TCH showed the highest cane yield compared to the other treatments, and where significantly different from the control treatment (T9). In panela or NCS, the best treatment was (T6) SE-FQ (12.1 % conversion and 18.78 t ha-1). The highest value of reducing sugars was (T8) SE-FA with 13.2 % while in phosphates it was (T9) SEC and SE-SF (753 ppm), and SEC-AO (706 ppm). With 1,500 kg ha-1 of commercial organic fertilizer, cane yields above 100 t ha-1 and panela yields or NCSof 15 and 17 t ha-1 in SEC and SE, respectively, were obtained, similar to those achieved with chemical fertilization. In chemical fertilization, with the mixture of sources the use of nitrogen was reduced by 42 % and phosphorus by 18 %, with cane yields 44 % higher than the regional average and panela yields 20 % higher than the control. Conclusion. It was possible to reduce and supply some nutrients of chemically synthesized nutrients without affecting the sugarcane and panela or NCS yields.

Introduction. The percentage of shade and scarification can influence the germination of Ischaemun rugosum Salisb. Knowledge of these aspects would allow establishment of successful measures for an integrated management of this species. Objective. To compare the influence of different percentages of shade on the germination of scarified and not scarified I. rugosum Salisb. Materials and methods. This experiment was carried out in micro-tunnels during the dry season and the transition to the rainy season, at Fabio Baudrit Moreno Agricultural Experimental Station, Alajuela, Costa Rica, during 2016. In the dry season, the following shade percentages were used 0 %, 30 %, 50 % (green saran), and 100 % (black saran). In the transition to the rainy season, the same percentages of shade were used, but the black saran was changed to 70 % white saran, in both experiments scarified and non-scarified seeds of the weed were used and germination was counted. The data were analyzed with logistic regression and a hypothesis test for the regression coefficients with a significance level of 5 %. Results. In the dry season there was greater germination with non-scarified seeds and 50 % shade. During the transition to the rainy season the highest germination occurred at four days after sowing (dds), under 50 % shade and with scarified seed, and fifteen days after sowing the highest germination (odds ratio 8.67 to 1) occurred with 70 % shade, green saran and scarified seed. Conclusion. Scarification allowed an increase in germination in the transition to the rainy season, not in the dry season. In both seasons there was a positive influence on germination with the shade percentages of 50 % and 70 %.

Introduction. Genetically modified crops (GMC) are of particular interest due to their impact on the global economy. Therefore, as a general concern, many countries have established some regulations in regards to genetically modified organisms (GMOs). In Costa Rica, the cultivation of GMOs has been practiced since 1991; however, there´s a lack of studies that monitor the execution and compliance with the biosafety regulations. Objective. The objective of the present study was to identify the presence or absence of transgenicity in processed foods for human and animal consumption, as well as in cotton seeds. Material and methods. The real-time PCR technique was used to target the 35S promoter sequence, derived from the cauliflower mosaic virus (CaMV), as a marker to detect the presence of transgenes in processed foods for human and animal consumption as well as in wild or cultivated cotton seeds collected nearby a GM cotton farm in May 2017. Results. In the analyzed samples there was a high incidence of an 82 bp fragment, corresponding to the 35S promoter sequence, being absent only in organic corn crops and their derivatives (tortillas, corn powder). Results suggest the presence of GMO traces in the Costa Rican food market, additionally it reveals the urgency of implementing adequate labeling for food traceability. Furthermore, the presence of transgenic cotton in the vicinity of a GM cotton farm was identified, suggesting the relevance of surveillance in aspects of biosafety and genetic manipulation of crops. Conclusion. The presence of traces for GMOs in Costa Rican processed food, demonstrates the importance of continuing this monitoring to provide enough elements for a critic discussion about food traceability and potential transgene flow into wild plant material.

Introduction. Granivorous ants have an economic and ecological impact because they are considered agricultural pests that transport seeds and defoliate cultivated plants. Objective. The objective of this work was to evaluate the effectiveness of the insecticides Imidacloprid and Novaluron in mixture with three cornflour-based attractants for the control of Pogonomyrmex barbatus in field trials in Irapuato, Guanajuato, Mexico. Materials and methods. This research was conducted from August to November 2014, six tratments were considered, the first three consisted of the mixture of Imidacloprid with cornflour (in finely milled pellet, in milled pellet and without pelletizing), the fourth was Novaluron combined with cornflour in milled pellet, and the last two consisted only of cornflour (in finely milled pellet and without pelletizing), in addition to an absolute control. Individuals counts per minute were performed before (reading at 0 h), and after the application of the treatments (readings at 1, 24, 72, 144, and 240 h) on the outside of three anthills previously selected for this purpose. The analysis of variance of the design was completely randomized according to sub-subdivided stripes with three repetitions, and three factors that were the following: six treatments and the absolute control, six readings over time including the count prior to the application of the treatments and the three anthills. Results. There were highly significant statistical differences for the factors: treatments and readings, as well as for the interaction between both. Conclusion. The treatments with insecticide showed their maximum control at 72 h of its application, the best were the Imidacloprid combined with cornflour in two presentations (in milled pellet and without pelletizing), showing greater effectiveness after 24 h of its application.

Introduction. Milk production systems are affected by climate change, presenting seasonality in forage production, and added to this, breeds with high nutritional requirements predominate, which leads producers to permanently use concentrates that increase the costs of production. Objective. The objective of this work was to evaluate milk production and quality in cows supplemented with espadrille bean (Vicia faba L.) and fodder beet (Beta vulgaris L.) silage. Materials and methods. The study was conducted at the Obonuco Research Center of AGROSAVIA, municipality of Pasto, Nariño, Colombia. Twelve cows of the F1 breed (Kiwi Cross X Holstein) were used, of first childbirth (93 days of breastfeeding), with an average live weight of 460 kg. Cows were kept in paddocks with grasses, legumes, and water ad libitum. For three periods of fifteen days each, three levels of silage inclusion (0, 4 and 8 kg day-1) of bean and beet were evaluated, using a 3x3 Latin square experimental design for each species. Daily production of each animal was recorded and the compositional quality of the milk (fat, protein, total solids and milk urea nitrogen MUN) was determined. Results. With the highest level of inclusion (8 kg cow-1 day-1), the alpargata bean silage had an effect (p<0.05) on the protein percentage, while the fodder beet silage influenced (p<0,05) in the percentage of fat. Both species did not influence production, total solids, and MUN. Conclusion. The supply of bean and beet silage influenced the compositional quality of milk, providing food alternatives in the milk production systems of the upper tropics of Nariño, allowing seasonality and the replacement of common sources to be reduced.

Introduction. The management of shade trees in a production system is considered an ecosystem-based adaptation practice capable of providing multiple ecosystem services. Objective. Contribute to the understanding of the effects of trees in coffee plantations on ecosystem services for provisioning and regulation and how the analysis of relationships between services can contribute to improve the design and management of these systems. Development. The study was carried out between July and October 2017. Shade trees have an effect on coffee yield, attributed to their influence on the regulation of fruit load. This effect can have positive results with an adequate agroforestry management, as it would reduce extreme biennial fluctuations in coffee production. The trees also regulate the climate within the coffee plantation (microclimate), in addition, they have positive effects on soil fertility, the amount of organic matter, the recycling of nutrients, decrease soil evaporation, reduce erosion and sequester carbon. However, there are some aspects that are still complex and sometimes contradictory. Overall, the documentation of the positive aspects of the trees on provisioning and regulation services is greater than the negative ones. Conclusion. This review shows an effect of shade trees on ecosystem services. Knowledge of these effects, considering the interest and expectations of the social systems, must be complemented with analysis of relationships between services with the aim to identifying best agroforestry practices or model systems that can provide multiple services simultaneously.

Introduction. Sweet potato (Ipomoea batatas) is a root crop very susceptible to viral diseases, which have been associated with crop yield reductions of over 50 %. In the Costa Rican sweet potato plantations the presence of feathery mottle virus (SPFMV), chlorotic stunt virus (SPCSV), and leaf curl virus (SPLCV) have been reported, for the development of adequate control programs, early detection and identification is necessary through the use of sensitive and efficient techniques. Objective. The objective of this research was to estimate the incidence of SPFMV, SPCSV, and SPLCV in sweet potato plantations using qPCR. Materials and methods. In 2018 foliar tissue samples were collected from eighty plants showing viral symptoms from twenty-five sweet potato plantations distributed in four provinces in Costa Rica. The detection of the three viruses was performed by qPCR with the use of primers and specific hydrolysis probes. Results. In 92 % of the plantations studied, the presence of virosis was found. The Sweet potato virus disease (SPVD) defined as the combined infection of SPFMV and SPCSV, was the most common viral disease found in all plantations. The plantations located in Sabanilla, El Cacao, and La Guacima were the only ones to present the three viruses studied. The SPLCV virus was only detected in the Limón and Alajuela provinces. Conclusion. It is possible to make an early detection of three of the most frequent sweet potato viruses with the use of qPCR which would contribute to certified seed production programs.  

Introduction. Jatropha curcas L. (JC) is a specie with the potential to use its oil as a biofuel and its quality is recognized by the composition of the fatty acids present. Objective. The objective of this work was the identification and quantification of fatty acids of JC genotypes of the Jatropha Colombia Collection. Materials and methods. During the years 2012-2014 the experiment was conducted in Espinal-Tolima, Colombia, in a randomized complete block design with fifteen genotypes. The lipid profile of the genotypes was determined by chromatography GC-MS and GC-FID. Results. Ten types of fatty acids were detected in the oil: five saturated (myristic, palmitic, margaric, stearic, arachidic); three monounsaturated (palmitoleic, oleic and eicosenoic), and two polyunsaturated (linoleic and linolenic). The proportion was higher in monounsaturated acids (45.44 %) and polyunsaturated acids (34.18 %) and lower in saturated acids (20.37 %). In the monounsaturated, the oleic predominated (44.62 %); in polyunsaturated linoleic (33.95 %) and in saturated palmitic (12.41 %) and stearic (7.43%). The results found allowed the classification of JC oil as monounsaturated-polyunsaturated (oleic-linoleic), which coincided with what was reported worldwide. Conclusion. Based on the lipid profile, it can be inferred that the oil of the fifteen genotypes evaluated in Colombia is suitable for use as biodiesel.