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

Climate change is contributing to the decrease in the production and crop yield of Nicaraguan farmers. The most damaging effect, due to variations in rainfall and temperature, affects food production directly, both for human and animal consumption. This study allowed the evaluation of total and edible biomass production, the survival rate and the identification of biological agents that affect the species Quelite (Cnidoscolus aconitifolium (Mill) LM), Marango (Moringa oleífera (Lam)), as an animal feed alternative under dry tropic conditions, at the Finca Las Mercedes Technological Experimentation and Validation Center, Managua. In order to evaluate the amount of produced biomass, each species was established in a 10.25m² plot and the collected data from two prunings over a period of a year. The species Quelite produced the highest amount of green biomass with 26 572 kg ha-1 in the first pruning and 62 666 kg ha-1 in the second pruning. This same species also produced the best edible dry biomass yields in the first and second pruning with 3 954 kg ha-1 and 11 505 kg ha-1 respectively, the Marango species had a green biomass production of 8 951 kg ha-1 in the first pruning, decreasing in the second pruning to 5 350 kg ha-1. The highest percentages of survival in the first pruning were obtained by the Quelite species with 100 %. Five months later this same species presented yields of 98 %, being classified as very good. Marango presented survival rates of 95 % and 79 %. The biological agents found did not cause damage to the Quelite plants but in Marango they were severe and affected the biomass production and survival of the plants.

The disease known as bacterial blight of rice is caused by Burkholderia glumae, Burkholderia gladiolii and the blight of rice seedlings caused by Burkholderia plantarii, are bacteria considered important in rice cultivation (Oryza sativa L.). The effects have increased in recent years causing large annual economic losses in the countries that produce this grain. The objective of this research was to identify, through phenotypic and molecular tests, Burkholderia species in rice panicles (Oryza sativa L.). The collection of samples was carried out in the municipality of Sébaco, Matagalpa in the TAI-NIC Experimental Center and farm Virginia, Agricola Miramontes in the department of Boaco and farm La Doña, municipality of Malacatoya, Granada. Bacteria were isolated from panicles with symptoms of the disease and species identification was performed by biochemical tests (carbohydrates and differentiation). Confirmation of the Burkholderia species was carried out using the molecular technique PCR (Polymerase Chain Reaction). The isolates of B. gladiolii in the King B medium presented grayish white or yellowish colonies, producing the non-fluorescent diffuse yellow pigment, while B. plantarii showed yellow, translucent, and convex, non-fluorescent colonies, in the case of B. cepacia colonies were translucent, convex, non-fluorescent. Identification with biochemical tests showed the presence of 18 positive isolates for B. gladiolii, two isolates for B. plantarii and one positive for B. cepacia. With the PCR technique, 18 positive samples were identified for B. gladiolii that amplified 479 bp fragments and two positive samples for B. plantarii with 597 bp fragments. In the case of B. glumae, it was not identified by phenotypic or molecular tests.

Planting systems influence crop response in the final product. The objective of this research was to determine the influence of the double furrow planting system and single furrow planting on bean (Phaseolus vulgaris L.) seed yield. The research was carried out during the dry season in the period from February to April 2019 at the bean experimental and development center La Compañía of the Nicaraguan Institute of Agricultural Technology, located in San Marcos, Carazo, Nicaragua. La Compañía is located at an altitude of 470 meters above sea level with an average temperature of 24 °C and annual rainfall between 1 200 and 1 500 mm. A paired plot design was used, comparing plot A (double furrow) with plot B (single furrow). The statistical analysis was a Student's t-test. The cultivar used was INTA Rojo Extrema Sequía, generated by the Nicaraguan Institute of Agricultural Technology. The treatments were two planting systems, the first with a double furrow with 80 cm between rows and 40 cm between rows, the second with a single furrow at 60 cm between rows; both with 12 seeds per linear meter. The variables evaluated were number of pods per plant, number of grains per pod and yield in kg ha-1. There are no statistical differences in yield and its components, so it is concluded that yield and yield components are similar regardless of the planting system.

Learning styles refer to how learners perceive, interact with and respond to the learning environment, as a result of heredity, their own life experiences and the demands of the current environment; also to the characteristic affective, cognitive and physiological behavior. The objective of this research is to identify the learning styles shown by the students of the "preparatory functional area for training in agricultural and environmental sciences" of the UNA Camoapa Campus, taught in the face-to-face modality. It is based on Kolb's theoretical model and follows a quantitative-descriptive research methodology. The analysis is approached from the application of the Kolb Learning Styles Test instrument to sixty first-year students of the year 2020. Among the results, it was found that the predominant learning style of the students is the assimilator, characterized by their thought. sequentially, analysis and synthesis of information, and its value system rewards logic and rationality. Since students learn more effectively when they are taught using different pedagogical strategies based on their predominant learning styles, it is incumbent on teachers to structure learning situations that are consistent with all styles.

With the objective of identifying fungi associated with moringa seeds in the state of Monagas, this research was conducted with material obtained from four localities, Caicara de Maturín, Cedeño municipality and seed banks from the Las Avenidas, Brisas del Aeropuerto and Terrenos de Guarapiche, in the Maturín municipality. By origin, the seeds were characterized in physical and intrinsic aspects and 250 units were randomly selected for diagnosis; 125 sown directly in humid chambers, without disinfection, in Petri dishes with absorbent paper, moistened with sterile distilled water and 125 disinfected in a 10 % v/v solution of sodium hypochlorite 3.5 % for 2 minutes, both groups of seeds, incubated in chambers under laboratory conditions. A randomized block design with a 4 x 2 factorial arrangement was used, with five repetitions and five capsules per experimental unit. The frequency of appearance of each fungal colony and the percentage of seed germination at 5, 10 and 15 days after sowing were quantified. The results were analyzed and interpreted by non-parametric statistics. Aspergillus sp. was detected Rhizopus sp., Fusarium sp., Penicillium sp., Monilia sp. and Trichoderma sp., being Aspergillus sp., the most frequent fungal isolate. Recently harvested seeds presented more frequently Fusarium; while in stored seeds the genera Aspergillus, Rhizopus and Penicillium were observed. Aspergillus and Rhizopus caused 100 % infestation levels in seeds without any germination power. Trichoderma sp., was only detected in the treatment without seed disinfection, with a low percentage of detection.

The study was carried out in the Unit for Experimentation and Validation of Technologies El Plantel, belonging to the National Agrarian University (UNA), which aims to characterize the conditions of groundwater through the monitoring of piezometric levels, water balance and water quality for irrigation. Well #1 (main well) and well #3 (reference well) were selected as study objects. To evaluate the flow of groundwater, static water levels were measured in a period from May 2020 to April 2021. To determine the groundwater balance, the principle of entry and exit of water to the aquifer was used, where the entry of water was estimated with potential recharge by the Soil Water Balance method proposed by Schosinsky (2006); water outflows were estimated from groundwater discharges; along with extractions by pumping to irrigate the crops established in El Plantel. Irrigation water quality was evaluated using water quality criteria proposed by the U.S. Salinity Laboratory and the Food and Agriculture Organization of the United Nations (FAO). The results suggest that the fluctuations of piezometric levels have a natural behavior during a hydrological cycle in the area, where it is shown that it is influenced by the variation of rainfall. The groundwater balance shows that the irrigation activities in El Plantel are not causing exploitation of the groundwater resource, since the water output is less than the input to the aquifer; the excess water is part of the storage in the local aquifer. The quality of the groundwater used in El Plantel is suitable for irrigation.

Mangroves are unique ecosystems that grow in brackish waters on the borders of tropical coastlines; represent an enormous scientific, ecological, economic and cultural value. In Nicaragua they represent a great source of economic resources for local populations. The species most affected by logging are Rizophora mangle L, Rhizophora harrisonii Leechm and Rizhophora racemosa G. Mey. Because these species have similar phenotypic characteristics, their separation as a species is difficult. Therefore, aims to this work was to morphophysiologically differentiate the three species of the genus Rhizophora. The foliar samples of the species R. mangle, R. harrisonii and R. racemosa from Juan Venado Island were used. Morphological comparisons and analyzes of pigments and tocopherols were performed. The activity of the photoprotective systems turned out to be highly variable intraspecifically. Total tocopherol content was very different among the three species, with R. racemosa being the highest concentration and R. harrisonii the lowest. The role of g-tocopherol in salinity tolerance could be responsible for the interspecific differences. The different tocopherol composition could be used as a biochemical parameter for interspecific distinction.

This research was aimed to study the morphometric, faneroptic dimorphism and variability of crossbred goats from rural communities in the municipality of Nindirí. From a total population of 208 animals, 35 adult individuals were evaluated by random sampling, from which 13 morphological measures, 13 phaneroptics, 9 zoometric indices and the biological variables, age and live weight, were determined. Age and live weight in males presented the lowest values, but with the highest level of variation. The cephalic measurements raised and the longitudinal (DL) and dorsal sternal (DDE) diameters did not present a very marked dimorphism between sexes. Chest width (AP) and rump measurements, width (AG) and length (LG), were slightly greater in females, with high levels of variability. The thoracic and cane perimeters did not show very marked differences between both sexes. The morphostructural homogeneity of these animals is high, 76.92 % of the variables present a coefficient of variation between medium to low (coefficient of variation less than 10 %), being the raised those that present the lowest proportions of variability. Based on the ethnological and productive capacity indices, the animals would be morphologically, dolichocephalic, not very compact, medium-sized, convexilinear and Brachymorphic. The values of the pelvic indices longitudinal (IPEL) and transversal (IPET), reveal a lack of specialized productive attitude. The phaneroptics were dominated by: layers, mucous membranes and dark hooves, hair of medium length and absence of raspil, breeches, goatee and mamellas. In the morphological characteristics, the straight nasal fronto profiles, horizontal medium ears, acorn, depigmented udders, and bagged, nipples with normal numbers and parallel position stood out. Less than 50 % of the positive and significant correlations were found, so this population can be considered a morphostructural model that is not very harmonious. Four main components (PCA) explained 77 % of the total variation, highlighting within them seven variables with greater discrimination power

Climate change is contributing to the decrease in the production and crop yield of Nicaraguan farmers. The most damaging effect, due to variations in rainfall and temperature, affects food production directly, both for human and animal consumption. This study allowed the evaluation of total and edible biomass production, the survival rate and the identification of biological agents that affect the species Quelite (Cnidoscolus aconitifolium (Mill) LM), Marango (Moringa oleífera (Lam)), as an animal feed alternative under dry tropic conditions, at the Finca Las Mercedes Technological Experimentation and Validation Center, Managua. In order to evaluate the amount of produced biomass, each species was established in a 10.25m² plot and the collected data from two prunings over a period of a year. The species Quelite produced the highest amount of green biomass with 26 572 kg ha-1 in the first pruning and 62 666 kg ha-1 in the second pruning. This same species also produced the best edible dry biomass yields in the first and second pruning with 3 954 kg ha-1 and 11 505 kg ha-1 respectively, the Marango species had a green biomass production of 8 951 kg ha-1 in the first pruning, decreasing in the second pruning to 5 350 kg ha-1. The highest percentages of survival in the first pruning were obtained by the Quelite species with 100 %. Five months later this same species presented yields of 98 %, being classified as very good. Marango presented survival rates of 95 % and 79 %. The biological agents found did not cause damage to the Quelite plants but in Marango they were severe and affected the biomass production and survival of the plants.

ABSTRACT The present research addresses morphological aspects of the plant and evaluates the behavior of vegetative development of oregano (Plecthranthus amboinicus (Lour.) Spreng) through the establishment of stems at nursery level using a Randomized Complete Block design, over a period of 90 days. Each block was composed of 30 plants, with three replications for a total of six blocks with 180 plants. Three measurements were made at 30-day intervals. The variables were: survival, number of leaves, plant height, and leaf length and width. Three types of substrates were used; 1) 100 % soil, 2) a mixture of 35 % soil, 30 % sand, 30 % bokashi and 5 % lime, 3) 35 % soil, 35 % rice husk and 30 % sand. In the laboratory, the percentage of biomass in green and dry weight (root and aerial) was calculated to check the moisture content of the plant. The bokashi substrate presented the best results in terms of organic matter and nitrogen. Plant growth was better with the bokashi substrate when obtaining the highest values; in terms of stem survival, a general average of 64% was recorded, with no difference between the factors or in the interaction; in terms of the number of leaves, the bokashi substrate in large bag obtained 41 leaves, in length and width of the leaf, 6.07 cm and 5.32 cm were recorded respectively, and 32.46 cm in plant height, all these results obtained in the moisture content of the plants was higher (86%) with the bokashi substrate.