Revista de Investigación Agraria y Ambiental

15-24

Authors: Ingrith Marcela Romero Méndez, Yovanka Pérez Ginoris, Cristina Celia Silveira Brandão & Marcely Ferreira Nascimento

In the present study were performed up-flow in-line filtration experiments, in pilot scale, to evaluate the performance of the natural coagulant chitosan on the removal of polystyrene microspheres with similar dimensions to the Cryptosporidium oocysts in the natural water treatment with turbidity around 30 uT, with kaolinite-induced. The parameters evaluated were the turbidity, organic matter (absorbance 254 nm) and microspheres concentration. Initially, were performed jar tests for the coagulation diagram construction and definition of the conditions to be adopted in the filtration experiments. The up-flow in-line filtration experiments were effectuated in the optimal coagulation conditions, over-optimal and sub-optimal dosages. The coagulation diagram showed a region of optimal performance of chitosan, corresponding to effluent turbidity values from 0.5 uT to 0.25 uT at doses between 0.9 e 1.5 mg/L and pH values between 5 and 6. In the filtration experiments conducted in optimal coagulation conditions the mean effluent turbidity was 0.29 uT during the regular operation of the system. In this coagulation condition the microspheres removal ranged between 4.3 log e 4.9 log. The over optimal and suboptimal coagulation conditions, affected the filter performance with increases in the effluent turbidity and was accompanied by removal reduction of microspheres with respect to the optimal coagulation condition of the order of 0.65 to 0.98 log, respectively, during the regular operation of the system, indicating that these coagulation conditions lead to increases the number of particles with similar dimensions to the Cryptosporidium oocysts in the filter effluent, which can compromise the microbiological quality of the water produced. Finally, in all investigated coagulation conditions the mean absorbance(UV254 nm) removal was 50%.

39-49

Authors: José Omar Cardona Montoya & Jaime Eduardo Muñoz Flórez

The physiological fluctuation of organic constituents about its environmental response has two components, intra-inter individual variation. This study assessed the components of biological variation based on a matrix of presence-absence, generating precision values inter-intra individual/population based on a sample of 58 accessions of L. alba. Chemical intra-individual variability was high (WI=2.06 [98%]) and the inter-population, was low (AP=0.033), with FST=0.023 p(rand>data=0.07) and 2% proportion. There were no high values of Estimates of variance [Est.Var.] leading to establish chemical variability among individuals and populations. The results generated by the test point to the presence of two subpopulations, defined each by local environmental conditions.

73-85

Authors: Renan Borgiani, Yury Baldo De Arruda, Juliana Sanchez Carlos, Marcos Vinícius Bohrer Monteiro Siqueira & José Dorival Coral.

The rapid growth of cities has resulted in several environmental problems. Seeking to minimize such problems, the afforestation in urban areas has become indispensable and it is considered a quality of life parameter for the population. In this context, the present study aimed to diagnose the status of urban trees of the neighborhood Jardim Brasil, in the city of Bauru - São Paulo, Brazil, through a qualitative and quantitative survey of shrubs and arboreal individuals. It was possible to record 23 families and 41 species in a total of 510 trees and shrubs, from which 11 were found dead. The neighborhood has a relatively low variety of species, mostly exotic ones (60.98%). The most common species are: Licania tomentosa (31.87%), Caesalpinia peltophoroides (11.16%), Lagerstroemia indica (9.56%), Murraya paniculata (6.57%) and Terminalia catappa (5.98%). Most of the problems found are due to the lack of planning of urban forestry, which creates conflicts with the electrical wiring and construction; however, few are the cases of conflict with the street lighting and traffic signs. We also highlight a large number of trees attacked by termites and ants (59.34%). Studies like these become useful for decision making and planning of urban trees of a city.

99-106

Authors: Sandra Bibiana Aguilar Marín, Laura Alexandra Laitón Jiménez, Fernando Esteban Mejía García & Carlos Felipe Barrera Sánchez

Due to the cross-pollinated condition of the plant, which causes variation in the sweetener’s composition and in the morphological characteristics in terms of shape and color of the leaves, seed propagation is limiting for commercial purposes, so it is convenient to use asexual propagation systems. In this study, a protocol for In Vitro establishment of Stevia rebaudiana was developed, for which eight disinfection treatments were applied using 5% and 4% concentrations of sodium hypochlorite (NaClO) with different exposure times, 5, 10, 15 and 20 minutes. The best disinfection percentage (76.75%) and sprouting (58.91%) was obtained using a 5% concentration of NaClO with 20 minutes of exposure.

121-127

Authors: María del Pilar Romero-Lozada, Christian Felipe Enciso Murillo, Sandra Marcela Garcia, Juan José Wagner Guerrero, Yina Jazbleidi Puentes-Páramo & Juan Carlos Menjivar-Flores

The proper handling of a crop nutrition involves efficient use of nutrients. Therefore, this research had as objective determine the efficiency agronomic (EA) and of recovery of the fertilizer (ERF) for nitrogen, phosphorus and potassium in Chili habanero and pepper tabasco and its influence in the performance. The experimental design consisted of complete blocks at random with four treatments and four replications. The treatments were T1: witness, T2: fertilization according to the program that manages the Experimental Center of the National University of Colombia (CEUNP) for n-p - K, T3: fertilization of CEUNP 50% and T4 program: CEUNP 100% fertilization program. For pepper tabasco (C. frutescens L.) and habanero (C. chinense J.) the analysis of variance gave differences highly significant (p < 0.001) by effect of them treatments both for the efficiency agronomic (EA) as of recovery of the fertilizer (ERF). The results show that the highest values of EA, and ERF for n-p - K in tabasco were presented in the T4 treatment, and habanero presented in the T3 treatment, except for the ERF of phosphorus. Thus, these enable observe that tabasco chili presents low efficiencies agronomic and recovery of nutrients to the habanero type. The best yields of tabasco and habanero are presented in the T4 and minors in T1, which suggests a clear influence of genotype.

157-169

Authors: Darío Alberto Pinto Medina, Yesenia Fernández Varga & Efrain Martinez Quintero

The Colombian agro-industry is seen like an option for use agricultural raw materials efficiently, especially those with quality parameters that do not know in the market yet and generate huge losses to farmers and ranchers. This research was mainly based on the apple (Pyrus malus L.) use. The nectar was prepared from three varieties of apple which are produced in the department of Boyacá, Colombia.These apple varieties are Anna, Pensilvania and Winter. It was a study to test the extraction pulp productivity with losses of 18.4% for Pensilvania, 21,4% for Anna and 30% for Winter. Sensory tests were carried out to determine the acceptability degree of these products. Significant differences were observed in texture, and similarities in odor, color and flavor. In this analysis, the three apple varieties were compared with a commercial apple néctar. It was concluded that the unit production cost for 900 ml of nectar from the Pensilvania variety is $4.999, Anna $5.100 and Winter $5. 296 (Colombian pesos), due to better prodution in extraction of pulp for the variety Pensilvania, showing that the products are competitive in price and quality.