Revista de Investigación Agraria y Ambiental

13-19

Authors: Luis Felipe Orozco, Katherin Castro-Ríos & Gonzalo Taborda Ocampo

Coffee pulp and mucilage are semi-liquid by-products involved in the generation of residual waters with a high concentration of organic matter and diverse species of microorganisms which negatively affect the efficiency of traditional treatment and require up to five months for total decontamination of these waters. This demands the testing of different treatment methods that can improve the efficiency of traditional processes. Electrocoagulation was tested with Fe/Al electrodes, 2.3 A and natural pH in a reduction in chemical oxygen demand and other microorganisms present in the coffee mucilage. The electrochemical process produced a maximum removal of 93% for coliform bacteria, molds and yeasts with a treatment time of 50 min. The reduction in chemical oxygen demand was 32% for the undiluted sample, 45% for the sample diluted to 50% (v/v), and 51% for sample diluted to 25% (v/v); indicating there is an increase in efficiency with a decrease in organic matter. The energy consumption was less than 0.083 kWh/m3 for the samples analyzed. This method is a viable alternative for the pre-treatment or reutilization of waters contaminated with coffee mucilage.

31-40

Authors: Carlos Iván Cardozo Conde & César Augusto Posada Tique

Ricinus communis L., commonly known as the castor- oil plant, is important for its use in biofuels production. With the objective of learning about its current status, in 40 villages influential to the oil complex of Caricare (municipality of Arauquita) and Caño Limón (municipality of Arauca) in Arauca, Colombia (where five years earlier the crop had been established), a collection of sexual seed was carried out between December 2011 and January 2012. The variables studied include passport data as a collection resource, local name, relief, and soil type among others. A Garmin map76CSx was used in order to identify the transects and record data such as geographic location and elevation. Simple descriptive statistics were used to identify the variables of greatest variation. Using the qualitative variables of greatest importance, a contingency table analysis with a significance level of 5%, a multiple correspondence analysis(MCA) and principal component analysis (PCA) were performed for quantitative and qualitative variables, in addition to a classification analysis through a similarity matrix. The castor-oil plant was found in 25% of the villages visited. 12 introductions were collected, four from Caricare and eight from Caño Limón. Although the environmental conditions were favorable for its cultivation, there are no castor-oil plant crops in the locations visited. The absence of grain commercialization and oil extraction equipment is the main limiting factor. A garden was established using collected materials for the purpose of research, breeding and propagation.

49-64

Authors: Carmen Mireya Lapo Pauta & Rafael Pérez García

This paper presents research completed with the intention of finding the most economical solution in the design of pressurized irrigation networks, while efficiently meet service delivery. A systematic methodology is proposed that combines two optimization techniques through a “hybrid method” in, which linear programming, nonlinear programming and genetic algorithms are fused. The overall formulations of the problem of optimal dimensioning consist of minimizing an objective function constituted through the asociated cost of the pipes that form the network. This methodology was implemented in three networks a fictitious irrigation and two irrigation networks (Tuncarta and Cariyacu) located in the cities of Loja and Chimborazo which yielded optimal design solutions. Finally different scenarios were simulated in both models to obtain an overview of the operation of the hydraulic variables

81-88

Authors: René Aguilar Anccota, Raquel Briggit García Raymundo, José Antonio Dulanto Bejarano & Edgar Abraham Maldonado Duque

The department of Piura is the principal banana-producing zone in Peru, sharing 87% of exportations.In this zone, one of the most important postharvest diseases is crown rot. The economic loses attributed to this disease are estimated to be between 25 and 30% of organic bananas exported. The objective of this study was to identify the causal agents associated with this disease. Samples taken refrigerated fruit from the areas of Querecotillo, Salitral and Mallares were taken and selected after the fact. Thielaviopsis paradoxa, Lasiodiplodia theobromae, Colletotrichum musae and Fusarium verticilloides. In order to demonstrate the pathogenicity of the isolated species, inoculations were given in the area of the crown of the fruit on healthy bananas. These fungi caused symptoms of infection in different proportions, concluding that crown rot is a disease with a complex etiology.

101-111

Authors: Walter Alfredo Salas-Zapata & Leonardo Alberto Ríos-Osorio

The transition toward sustainability is the set of changes and decisions a group of people make in order to resolve problems of sustainability. To address these problems a scientific trend has emerged called sustainability science, which has been considered to be a science inspired by the use of knowledge and must have characteristics such as transdisciplinarity, participation, social learning, coproduction of knowledge, as well as consider multiple perspectives and scales of problems and the uncertainty inherent to them. However, scientific research plays a particularly important role in the decision making processes. The chances of success greatly increase when permits interaction and communication between researchers and decision makers, or other actor. This paper analyzes how the characteristics in question contribute to the promotion of changes toward sustainability