Revista de Ciencias Agrícolas <p align="justify">The Revista de Ciencias Agrícolas is a recognized means of divulgation and distribution of scientific and technological research nationwide and abroad, biannually publishes original articles written in english, on topics related to Agricultural Sciences, which present in detail results of research in agriculture, forestry, agricultural biotechnology and food which are subject to the assessment process by nationals and foreign peers, and to review and approval by the Editorial Committee of the magazine.</p> <p><strong>DOI:</strong>&nbsp;<a href="" target="_blank" rel="noopener"></a></p> <p>&nbsp;</p> en-US (William Ballesteros Possu) (Leydy Martínez) Sat, 20 Jun 2020 00:00:00 -0500 OJS 60 Water quality index using fuzzy logic Utcubamba River, Peru <p>Water is a fundamental nutrient in the life of any living being. Therefore, it is necessary to estimate its quality, because it is an issue of increasing concern countries around the world for reasons such as the health of the population, regional, national and international economic development, and the environmental quality of the ecosystems. One tool that has been used to know the state of the water is the water quality indexes (WQI). The objective of this research was to develop a WQI based on fuzzy logic, which allows for the estimation of water quality in the Utcubamba River. The methodology used was proposed by Icaga in 2007. To evaluate the proposed WQI called "Diffuse Water Quality Index" (DWQI), sixteen points from the sampling conducted by the Research Institute for Sustainable Development during October 2014 on the Utcubamba River and its tributaries were used. To validate the index, it was necessary to estimate the correlation coefficient R<sup>2</sup> between the results obtained and those of the NSF WQI wáter quality index reported by the Water Research Center. This new index presented results and reasonable correlation, R<sup>2</sup> = 0.81. It is concluded that DWQI can be used as a tool for decision making in the water management of the Utcubamba River.</p> Lenin Quiñones-Huatangari, Luis Ochoa, Manuel Emilio Milla-Pino, José Federico Bazán, Oscar Andrés Gamarra, Jesús Rascón ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500 Agronomic performance of Raphanus sativus L. cultivars grown under different spacings <p>An ideal spacing between plants should be established for the optimization of radish (<em>Raphanus sativus</em> L.) crops since the plant spatial distribution of plants affects the crop yield. &nbsp;This study was conducted aiming to evaluate the agronomic performance of radish cultivars grown under different spacings. The experiment was conducted at the Experimental Field of the Federal Institute of Education, Science, and Technology of Maranhão, in Codó, MA, Brazil, from June to July 2017. The experiment was conducted in a randomized block design with five replications, using a 2×2 factorial arrangement. The factors consisted of 2 cultivars (Sparkler Ponta Branca and Saxa) and 2 spacings between plants (5 and 8cm), totaling 20 experimental plots. Data were collected in &nbsp;6 &nbsp;plants from each experimental plot. The agronomic parameters: total fresh weight (TFW), root fresh weight (RFW), root mean diameter (RMD), root means length (RML), and root yield (RY) of the radish plants were evaluated. The factors (cultivars and spacing between plants) had no significant effect on TFW, RFW, RML, and RMD. The spacing between plants has a significant effect on the yield of radish crops of the cultivar Saxa, and higher yields are found when using the spacing of 5cm.</p> Jorgeana Francis Alvim, Oswaldo Lopes Sobrinho, Erika Kássia Cantanhede, Alvaro Itaúna Pereira, Valdelânia Silva, Leonardo Santos ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500 Phosphated fertilization with organic and inorganic amendments in corn crops (Zea mays L.) <p>The limited availability of phosphorus in most soils in the eastern region of Paraguay restricts the productivity of the chipa corn, where fertilization with phosphates soluble could be one of the alternatives to make up the shortfall nutritional of cultivation. In addition, the combination with amendments makes the use of inorganic fertilizers more efficient in this production system. The work was carried out in the town of Ybyrarobana, Canindeyú, with the aim of to evaluate the effects of phosphorus doses, in combination with organic and inorganic amendments, on corn production. The treatments were distributed in split-plots under a randomized complete block design with 4 blocks. The amendments (bovine manure and ash) and the control occupied the main plots and the doses of P<sub>2</sub> O<sub>5</sub> (0, 40, 80, 120 and 160kg ha<sup>-1</sup>) the subplots. Variables such as post-harvest soil fertility, crop growth and yield were determined. The data were subjected to ANOVA and pair-wise comparisons by the Tukey´s test with 5% of probability. Except for the spike length, the evaluated variables showed significant differences between the amendments used. However, there were no statistical differences among doses of P2O5. The application of bovine manure and soybean expeller ash increased the pH and exchangeable potassium, and decreased exchangeable aluminum, while the levels of calcium, magnesium and phosphorus were not influenced.</p> Alder-Delosantos Duarte-Monzón, Eugenio González-Caceres, Jimmy Walter Rasche-Álvarez, Carlos Leguizamón-Rojas, Diego-Augusto Fatecha-Fois ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500 Biochemical quality of cowpea grains grown under water-deficit maintained with hydrogel use <p>Investigations related to the effects of the hydrogel use in a water-deficit condition on the biochemical composition of the harvested products are scarce. The aim of this study was to verify the influence of hydrogel on the biochemical quality of cowpea beans produced under water-deficit in southern Tocantins. The experiment was a randomized complete block design with four replications. The treatments were obtained in a 2x5 factorial scheme, being: two sources of hydrogel (Hydroplan-EB HyC and Polim-Agri PP) and five concentrations (0, 5, 10, 15, and 20 kg ha<sup>-1</sup>). After harvesting, the grains of cowpea, BRS Vinagre cultivar, were ground and chemically analyzed. The oil content of the grains agreed with the reference values. The use of Polim-Agri PP promoted the best levels of amino acids (0.38 mg g<sup>-1</sup>) and proteins (243.22 mg g<sup>-1</sup>) of grains. The carbohydrate content of the grains (Ȳ= 81.44 mg g<sup>-1</sup>) was better using Hydroplan-EB HyC, regardless of the concentration applied. The application of 6.28 kg ha<sup>-1 </sup>of Polim-Agri PP provided the highest starch content (842 g mg<sup>-1</sup>) of grains. The use of hydrogel improves the biochemical quality of cowpea beans produced under water deficit in southern Tocantins.</p> Rodrigo Ribeiro Fidelis, Guilherme Sousa da Silva, Wagner Augusto Rauber, Larissa Urzêdo Rodrigues, Vitor L. Nascimento, Susana Cristine Siebeneichler ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500 Effect of supplementation with organic acids on productive and reproductive parameters in guinea pigs <p>Guinea pig production systems demand organic alternatives to improve their productivity, due to the increased demands of this type of livestock operations. The present study aimed to evaluate the effect of organic acids on the productive and reproductive indices in reproductive Guinea pigs in an intensive breeding farm in Lima. 60 pools were used with 10 Guinea pigs in each one (9 females and one male). &nbsp;They were randomly divided into 4 treatment groups: T1: 1mL/L, T2: 2mL/L, T3: 4mL/L; all with 15 pools in total (5 pools each with dosage of 5, 10 and 15 days, respectively), and T4: Control (15 pools without dosage); the observation period was 3 months. No significant difference was found (p&gt; 0.05) between treatments for weight gain, percentage of maternal mortality, percentage of abortions, percentage of pregnancy, number of offspring born and percentage of viability. For the percentage of mortality of pups and average weight of the offspring, a significant difference was found (p &lt;0.05), demonstrating that T3 reached a higher weight index at birth of offspring (T3: 147.7 / 142.7 / 146.8g) and lower percentage of mortality in rabbits (T3: 0 / 1.8 / 3.0%). No significant difference was found in terms of dosing days. It is concluded that supplementation with organic acids with T3 (4mL/L) improved the weight at birth of the offspring and the mortality percentage in kits.</p> Christian Vela, Siever Morales-Cauti ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500 Quantification of carbon capture in different soil uses <p>Carbon sequestration by soils in different production systems contributes greatly to the reduction of greenhouse gases. The objective of this study was to quantify the carbon stored in four land uses at different soil depths. To this end, a 2<sup>2</sup> factorial experiment in complete randomized block design (CRBD) was carried out. The factor A: land uses (natural pastures, shelterbelts, fodder banks, and potato crop) and the factor B: two soil depths (30 and 60cm), with three replications.&nbsp; . As a result, statistical differences were found among soil uses (p&gt;0.0573) and between depths of 30 and 60cm (p&lt;0.0061). However, no statistically significant differences were found in the interaction land-use and depth (P &gt; 0.0659). The fodder bank presented a higher organic carbon content (139.85tC.ha<sup>-1</sup>) at 60cm depth and the potato monoculture (63.32tC.ha<sup>-1</sup>) at 30cm depth while, at both depths, natural pasture reported lower values (54.45 and 60.02tC.ha<sup>-1</sup>). Hence, the importance of productive systems to accumulate more carbon at greater depths of soil (60cm) compared to lower depths (30cm), which may be linked to agricultural opperations made on the soi surface, generating carbon leakage.</p> Jesús Geovanny Solarte-Guerrero, Dayana Marcela Males, Angela Natalia Ortiz ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500 Physical properties of soil in the stage of establishment an agroforestry system in the high Andean zone <p>In Nariño, the change to the ground has generated some problems such as erosion, compactation, lack of fertility, and others, so it was necessary to look up alternatives to reduce these impacts. The objective of this study was to evaluate some physical properties to the ground in an agroforestal system with <em>Morella pubescens</em> (Humb. &amp; Bonpl. ex Willd.) Wilbur with <em>Smallanthus</em> <em>sonchifolius </em>(Poepp.) H.Rob in the experimental farm Botana, in the municipality of Pasto, where the parental density was analyzed, real density, total porosity, structural stability properties and distribution of aggregates, the results were obtained in two phases, f1 before the implementation to the crop and f2 according to harvest period <em>S. sonchifolious.</em> A randomized complete blocks design with three treatments ant three repetitions was used. The treatments had corresponded to harvest densities, T1: <em>S sonchifoliuos</em>, sowed to 1x1 m, T2:0,8x0,8m y T3:0,5x0,5m, with three repetitions.<em> M pusescens</em> was stablished to 4x4 m between seedlings and 9 m between lines and the control (f1). The Tukey test had significant stadistics differences between f1 (control) and f2 (treatments), to the structural stability properties and distribution of aggregates. The results showed that the ground has suffered a structural stability change to stable lightly (0,97 D.P.M) in f1 to a stable moderate (2,53 D.P.M), in f2. The distribution of aggregates passed to 60 % in f1 to 70,3 % in f2, with a media aggregation status. The different agroforestal systems management could help in long term by improving the ground´s structure through the vegetal material of arboreal component, the application of a minimums farming and the addition of organic material.</p> <p>&nbsp;</p> Jennyfer Cristina Guerrero Jurado, Anyi Valeria Andrade, Martin Alonso Muñoz, Iván Andrés Delgado ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500 Evaluation of pre-germination treatments on four native species of the High Andean forest <p>High Andean forests are strategic ecosystems with high diversity of native and endemic plants; however, these natural ecosystems are affected by agricultural expansion. Knowledge on the propagation of native plants is essential to restore these environments. This research aimed to evaluate germination in the following native species: <em>Viburnum triphyllum </em>Kunt. (Caprifoliaceae)<em>, Oreopanax floribundum </em>Kunth, (Araliaceae)<em>, Weinmannia tomentosa </em>L.f. (Cunoniaceae), and <em>Tournefortia fuliginosa</em> Benth. (Boraginaceae) in Botana experimental farm of Universidad de Nariño. This study was conducted between October (2016) and February (2017). For each species, an unrestricted randomized split-plot design was established. The main plot included the substrates (S), and the sub-plots included the different pre-germination treatments (PM) with three repetitions. The results showed statistically differences in germination percentage among pre-germination treatments for <em>O. floribundum. </em>The highest germination percentage (42%) for this species was achieved with seed imbibition for 48 hours at 22°C. Moreover, <em>W. tomentosa</em> showed statistical differences for S and PM, with a germination percentage of 74% with imbibition for 48 h at 22°C and sand substrate. <em>T. fuliginosa </em>did not show relevant differences; however, it had a germination percentage of 47%. <em>V. triphyllum </em>did not germinate; therefore, further evaluations of pre-germination treatments should be required.</p> Pedro Pablo Bacca, Diana Lucía Burbano, Angélica Sofía Moreno Muñoz ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500 Multiple mechanisms in which agricultural insects respond to environmental stressors: canalization, plasticity and evolution <p>Insects are a paramount component of biodiversity in terms of taxonomic richness, ecological functions and ecosystem services. However, many human activities have negative consequences on such organisms, causing changes in their morphology, physiology, behaviour, and even causing mass deaths leading to the well-recognized insect decline phenomenon. Although the effects of some environmental stressors (e.g. global warming and pesticides) on insect biology are fairly well understood, there is a plethora of stressors that that have only recently been considered. Additionally, although the exposure to multiple stressors is a common scenario in natural conditions, our knowledge on insect responses in this regard is still incipient. Knowledge that is in much need to inform policy makers in the fight against global change. Here, a short review on prominent environmental stressors, and the known responses that insects may exhibit, which are summarized as canalization, plasticity and evolution is provided. Furthermore, an outlook and recommendation for future studies aiming to elucidate the effects of environmental stressors (both lone and mixed) on insect biology is given. This manuscript advocates for controlled (lab or semi-field) manipulative experiments that implement realistic environmental conditions and that ideally combine several stressors.</p> Yeisson Gutiérrez ##submission.copyrightStatement## Sat, 20 Jun 2020 00:00:00 -0500