The culture of the giant Malaysian prawn, Macrobrachium rosenbergii, has been recently introduced in Argentina where some tests are carried out, both by the public and private organization. The culture and rearing of the Macrobrachium rosenbergii consists of two phases: the obtainment of larvae from ovate females, and the development and fattening of these postlarvae until they reach a commercial size. Because the need of brackish water for the first phase, many culturists work only on the second phase, i.e., the final production. The complete cycle, from the ovate female to the final harvest, lasts between 6 and 8 months. The most important elements to be taken into account in the M. rosenbergii culture is water quality, controlling the pH, salitness, temperature, NH3 content, dissolved oxygen and turbidness. The processing depends on the requeriments of the chosen markets. They can be sold complete or only the tails, fresh, frozen or peeled. | El cultivo del camaron gigante de la Malasia, Macrobrachium rosenbergii, ha sido recientemente introducido en la Argentina donde se llevan a cabo experiencias a nivel estatal y privado. El cultivo y la cria de este crustaceo consta de 2 etapas: la obtencion de larvas a partir de madres ovadas, y el desarrollo y engorde de estas postlarvas hasta obtener un tamano comercial. Debido a la necesidad de agua salada para la 1ra etapa, muchas camaroneras se dedican a la realizacion de la 2da etapa solamente, es decir, a la produccion final. El ciclo completo desde la madre ovada hasta la cosecha final dura entre 6 a 8 meses. Dentro de los puntos criticos a controlar en el trabajo de una granja acuatica de cultivo de M. rosenbergii esta el cuidado de la calidad del agua, verificando el pH, la salinidad, temperatura, oxigeno disuelto, contenido de NH3 y turbidez. El procesado del camaron depende de la exigencia de los mercados elegidos. Se pueden vender enteros o solamente las colas, frescos, congelados o pelados.

Forestales-Forestería

The purpose of the present research was to study the drought effect, on the hybrid maize AN- 310 and its progenitors and to determine the plant internal water relation. The research was carried out in 1991 in the CIFAP-Aguascalientes Mexico, in a glass fiver green house at 25 C and 50% relative moisture. The drought levels were -1, -4, -6 and -8 bares into plant water potential at the 5:00 a.m. The results were: i.- the water relative content was the best indicator of the plant internal water relation, because of a high correlation with the water potential (r=0.82), leaf elongation (r=0.85) and net transpiration rate (r=0.73); ii.- all genotipes ceased the leaf elongation and net transpiration rate at water potential of -8 bars; iii.- the AN-310 hybrid was the genotype with higher leaf elongation and net rate transpiration; iv.- the VS-201M and AN(2) genotypes were who gave the drought tolerance characteristic of the AN-310. | El objetivo del presente trabajo fue estudiar el efecto de la sequia sobre el hibrido de maiz AN-310 y sus progenitores y determinar en estos las relaciones internas de agua en la planta. El trabajo se desarrollo en 1991 en el CIFAP-Aguascalientes, en un invernadero de fibra de vidrio a una temperatura de 25 C y una humedad relativa del 50(%). Los tratamientos de sequia fueron -1, -4, -6 y -8 bares de potencial hidrico en la planta a las 5:00 a.m. Los resultados fueron: i.- el contenido relativo de agua fue el mejor indicador de las relaciones internas de agua en la planta, correlacionando con el potencial hidrico (r = 0.82), elongacion de la hoja (r=0.85) y tasa transpiratoria (r=0.73); ii.- a h de -8 bares cesa la elongacion de hoja y tasa transpiratoria; iii.- el hibrido AN-310 fue el genotipo que presento mayor elongacion de hoja y tasa transpiratoria; iv.- los genotipos VS-201M y AN(2) fueron los donadores de las caracteristicas de tolerancia a sequia del AN-310.

Para o estudo da viabilidade do Pacu (Piaractus mesopotamicus) para processamento tecnológico, foram testados os processos de defumação, salga e secagem e enlatamento. Analisou-se também a farinha dos resíduos. Utilizou-se peixes provenientes de tanques de piscicultura do município de Piracicaba-SP e o produto final foi avaliado para o consumo na merenda escolar municipal. Foram feitas análises quanto aos teores de lipídeos, umidade, proteína e cinza. Os produtos processados por salga, defumação e enlatamento foram analisados também quanto ao teor de sal (NaCl); os defumados e enlatados foram submetidos a análise sensorial com avaliação de aparência, cor, aroma, sabor e textura. O pacu "in natura", defumado, salgado seco e enlatado apresentou, em porcentagem, respectivamente, 18,99; 23,80; 52,53; 18,59 de proteína, 3,79; 2,69; 18,31; 14,34 de lipídeos e 1,82; 3,13; 17,76; 2,79 de cinza. Para o pacu enlatado 56% e 33% dos degustadores o classificaram como um produto de excelente e bom sabor. O pacu defumado foi classificado como de excelente sabor por 25% dos provadores e de bom sabor por 55%. | "Pacu" (Piaractus mesopotamicus), a freshwater fish, was used with the purpose of studying its quality when smoked, salted and dried, and canned. Waste flour was also analysed. Fish from a fish farm of Piracicaba,SP was used. The intended final use was children's school meal. The results of the analysis of the final products for moisture, protein, lipids, ash and NaCl, in percent, were, respectively, 11.36; 52.53; 18.31; 17.76; 16.25 for the salted and dried fish; 70.25; 23.80; 2.69; 3.13; 1.17 for smoked fish; 62.19; 18.59; 14.34; 2.79; 1.29 for canned fish and 15.73; 42.94; 20.91; 20.42 (NaCl not available) for the waste flour. The smoked and the canned fishes were submitted to taste panels. For the canned product the results were: aspect in the can: 89% excellent and 11% good; aspect on plate: 56% excellent and 44% good; odor: 67% excellent and 33% good; taste: 56% excellent, 33% good and 11% regular and texture: 22% excellent, 56% good and 22% regular (none of the above got the not acceptable note). For the smoked fish the results were, aspect: 45% excellent and 55% good; odor: 35% excellent, 60% good and 5% regular; taste: 25% excellent, 55% good and 20% regular and texture: 50% excellent and 50% good (none got not acceptable grade).

CONSIDERACIONES GENERALES METODOLOGIA DEL ESTUDIO EVALUACION DE LAS PERDIDAS DE AGUA EN LA CIUDAD DE TACNA EQUIPOS E INSTRUMENTOS CONCLUCIONES Y RECOMENDACIONES BIBLIOGRAFIA | Trabajo de suficiencia profesional

Undisturbed soil samples of a "Terra Roxa Estruturada Latossólica" (Rhodic Kanhapludalf) were taken in Piracicaba,SP from the 25 cm depth, in order to study both methodological and spatial variabilities of the soil water retention curve. The sampling followed a 5 m x 5 m grid of 10 columns and 25 Unes, resulting 250 collecting points. With these samples, 250 retention curves were obtained using porous plate funnels (tensions of 5 x 10²; 1 x 10³; 6 x 10³ and 1 x 10(4) Pa) and Richards pressure chambers (tensions of 3 x 10(4); 8 x 10(4); 3 x 10(5), and 1.5 x 10(6) Pa). The methodological variability was analyzed mainly in the light of the pertinent thermodynamics, using several values of tension. Results have shown that the analytical problems are such that they can lead to erroneous interpret rations, affecting the quality of the experiment and also the comparison of results from several laboratories. For instance, 43% of the samples showed non consistant results, with values of volumetric soil-water content smaller at the tension of 3 x 10(4) Pa than at the tension of 1.5 x 10(6) Pa, which, from the practical point of view, could, lead to subestimated values of available water. | Para estudar a variabilidade tanto metodológica quanto espacial da Curva de Retenção de Água no Solo, coletaram-se amostras de solo com estrutura indeformada à profundidade de 25 cm em uma área de Terra Roxa Estruturada Latossólica (Rhodic Kanhapludalf) em Piracicaba,SP. A amostragem obedeceu a um arranjo com espaçamento regular de cinco metros, resultando numa malha quadriculada de vinte e cinco linhas e dez colunas, totalizando duzentos e cinqüenta pontos. Elaboraram-se 250 Curvas de Retenção por secamento, utilizando-se as tensões de 5 x 10²; l x 10³; 6 x 10³; l x 10(4) Pa (Funil de Placa Porosa) e 3 x 10(4); 8 x 10(4); 3 x 10(5) e 1,5 x 10(6) Pa (Câmara de Pressão de Richards), totalizando oito pontos por curva. Analisou-se a variabilidade metodológica para os vários valores de tensão considerados, principalmente à luz da termodinâmica pertinente. Os resultados evidenciaram que os problemas analíticos são de tal ordem que podem levar a interpretações errôneas, comprometendo a qualidade de experimentos ou mesmo a comparabilidade de resultados provenientes de laboratórios diversos. Exemplificando, 43% das amostras apresentaram resultados inconsistentes, com valores de umidade à base de volume à 3x10(5) Pa menores que a 1,5x10(6) Pa, o que na prática poderia levar, dentre outros, a problemas de subestimativa nos valores de água disponível.