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The growth and agricultural yield of common beans (Phaseolus vulgaris L.) is affected, among other factors, by limitations in the availability of water. For this reason, there are working on the search for cultivars tolerant to that abiotic stress. The objective of the research was to determine the effect of different concentrations of PEG-6000 on the in vitro seeds germination of three cultivars of common bean ('ICA Pijao', 'BAT-93' and 'Tío Canela-75') with different responses to water stress. PEG-6000 was used as an in vitro stress-inducing agent at 10, 12 and 14% (m / v) in the liquid culture medium. Deionized water was used as a control. Seeds of each cultivar were placed on a filter paper located in the shape of an M inside the test tube containing the corresponding solution. After three days of culture, the number of germinated seeds was quantified and the percentage of germination was calculated. Subsequently, at seven days the length of the root, hypocotyl and epicotyl, respectively, was measured. In the three cultivars, water stress affected the in vitro germination of the seeds in each of the treatments. There was a significant decrease in the values of the variables evaluated with respect to the control. Specifically, the growth of epicotyl was inhibited. The response to water stress in vitro induced with PEG 600 in each cultivar was specific and differential. The results contribute to the development of early selection strategies in the genetic improvement program of this crop. [ABSTRACT FROM AUTHOR]

An in vitro methodology to estimate the effects of root-growth promotion of soils treated with organic matter and microbial inoculants, in crops, under integrated nutrient management (INM), was developed and validated against data from previous experiments. A soil was prepared with two treatments: a) Control with application of deionized water, and b) INM, comprising the application of humic substances and microbial inoculant. Treated soils were incubated for 72 hours and extracted using five soil to water extraction ratios: 0, 0.05, 0.1, 0.2, and 0.5. Extracts were analyzed for pH and electrical conductivity (EC). Radish and wheat seeds were germinated and irrigated with each solution. Analysis of Variance, Regression and Correlation analyses were performed. Treatment and extraction ratio significantly affected pH and EC of the soil extracts. The application of extracts from soils under INM significantly affected the growth of radish radicles. The growth of radicle and coleoptile of wheat seeds increased when increasing soil proportion in the extract. Maximum growth was obtained with ratios between 1:5 and 2:5. In validation experiments wheat seed growth significantly correlated with soil organic matter content and enzymatic activity, confirming that this method is sensitive to estimate growth- promoting effects. [ABSTRACT FROM AUTHOR]

Hydrogels were synthesized by free radical graft copolymerization of itaconic acid (IA) onto corn starch (Alm-g-IA). The redox initiation system potassium permanganate (KMnO4)-sodium bisulfite (NaHSO3) was used. The effect of varying the acid neutralization grade and the concentrations of monomer and initiator was studied and in each case was compared with the oxidized starch (Alm-ox). Swelling kinetics were obtained in deionized water, saline solution and buffer solutions (pH=4-10,11). In general, copolymers had lower swelling percentage than Alm-ox, which increased with the increment of the monomer concentration and the acid neutralization and with the decrease of the initiator concentration. Hydrogels obtained with the highest neutralization percentage (Alm-g-IA80%) and with the lowest initiator concentration (Alm-g-IA1/2[I]) presented the highest swelling percentage in water, of 1824 and 1562 %, respectively. Hydrogels were sensitive to pH changes due to the presence of carboxylic acid groups grafted onto starch. [ABSTRACT FROM AUTHOR]

En América Latina la Agricultura Urbana y Periurbana viene ganando interés por los procesos migratorios de la población a las ciudades y su periferia, su enfoque ha sido enmarcado dentro de estrategias para mejorar la seguridad alimentaria y nutricional respondiendo a los problemas de pobreza, desempleo, desnutrición, exclusión social, entre otros. La Corporación Colombiana de Investigación Agrosavia desde hace cuatro años viene impulsando sistemas de producción de alimentos urbanos y periurbanos adaptados a climas cálidos a través del establecimiento de dos módulos demostrativos y pedagógicos uno en el C.I. Turipaná en el municipio de Cereté (Córdoba) y el otro en la Unidad Local en el Carmen de Bolívar, con el objetivo de capacitar a personas interesadas en la producción de hortalizas como cebolla, zanahoria, lechugas, rábano, cilantro, solanáceas, rúgula y plantas aromáticas en las ciudades y zonas periféricas principalmente para autoconsumo. La tipología de las capacitaciones fueron talleres con actividades teórico - prácticas relacionadas con la siembra, trasplante, elaboración de semilleros, compost, elaboración de extractos vegetales para el control de plagas y enfermedades comunes en los huertos urbanos y periurbanos. Desde los años 2014 a 2016 se capacitaron alrededor de 1140 personas entre estudiantes universitarios y de instituciones educativas, pensionados, madres cabeza de hogar, docentes, estudiantes SENA, Asistentes Técnicos, representantes de Centros de desarrollo de desarrollo Infantil (CDI), del I.C.B.F, caja de Compensación familiar, FAO, PNUD, FUPAD, productores del DPS Sucre y Bolívar, Fundaciones de Montes de María, asociaciones de pequeños productores, amas de casa, pensionados y capacitadas 2500 personas en el año 2015 en el marco de la feria de AGRONOVA. Por lo anterior los módulos AUP con el método de aprender- haciendo ha sido una forma de enseñar a producir alimentos de forma sencilla, en diferentes condiciones ambientales y grupos de la sociedad como una estrategia para contribuir a la Seguridad Alimentaria y nutricional de la región generando tejido social y promocionando una cultura de alimentación sana y de calidad. [ABSTRACT FROM AUTHOR]

In order to evaluate the influence of some body fluids on the hydrogels (HG) properties, in this work was studied the absorption properties of semi-interpenetrating (IPN) HG obtained from acrylamide (AAm) and chitosan (Q). To achieve this objective we employment a Hanks balanced salt solution, which is a physiological fluid that simulates the blood plasma. The semi-IPN hydrogels synthesized from AAm and Q, were subjected to absorption studies by gravimetric analysis, both in deionized water as in Hanks solution. The results of kinetic parameters indicated that the addition of Q to polyacrylamide (PAAm) hydrogel slightly increases the absorption capacity of the fluid and the Q confers greater affinity with Hanks solution. The X-rays diffraction analysis showed interaction between HG and the constituent elements of the Hanks solution. The results obtained confirm that the HG exhibit good affinity with the simulated body fluid, and therefore have great potential for medical applications. [ABSTRACT FROM AUTHOR]