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The purpose of this work was to evaluate the response of coffee (Coffea Arabica L.), cv. Tupi (Rubiaceae) crop to water supplied by the polyacrylamide polymer denominated of superabsorbent polymer. The experiment was conducted on greenhouse, in the experimental area of the Centro Técnico de Irrigação, at the Universidade Estadual de Maringá, state of Paraná, from August to October/1998. It was conducted in a 4 x 4 factorial way, with 16 treatments and 5 repetitions. Each treatment was obtained by combinations of two variation sources: irrigation frequency and percentage of polymer on substrate. Irrigation was done every 10; 20; 30 and 40 days (four levels). Polymer was added to substrate to make four levels: 0; 15; 30 and 45% of total mass. Crop response to treatments was measured using two variables. The height and the dry matter of the plants increased with the addition of the polymer to the substratum and they decreased with the increase in the interval between irrigations. The use of polymer in the substratum allows greater intervals between irrigation without damage to the coffee plants growth and increase of dry matter O trabalho teve por objetivo avaliar a eficiência do polímero de poliacrilamida denominado de polímero superabsorvente, adicionado ao substrato de transplantio no armazenamento de água para o cafeeiro (Coffea arábica L.), cv. Tupi (Rubiaceae). O experimento foi conduzido em casa de vegetação no Centro Técnico de Irrigação da Universidade Estadual de Maringá, Estado do Paraná, no período de agosto a outubro de 1998. O delineamento experimental foi inteiramente casualizado, com 16 tratamentos e 5 repetições, na forma de fatorial 4 x 4. Os tratamentos consistiram na utilização de quatro turnos de regas T1 = 10; T2 = 20; T3 = 30 e T4 = 40 dias e quatro níveis de polímero de poliacrylamida hidratado, P1 = 0; P2 = 15; P3 = 30 e P4 = 45, adicionados ao substrato de transplantio. A altura e o peso seco da planta aumentaram com a adição de polímero superabsorvente no substrato de transplantio e diminuíram com o aumento do intervalo entre irrigações. A presença de polímero no substrato de transplantio permite aumentar o intervalo entre as irrigações, sem comprometer o crescimento, o acúmulo e a matéria seca do cafeeiro

Nutritious solutions, outflows and quality of the hydroponic lettuce. This experiment was carried out in a vegetation environment at the irrigated agriculture unit of the State University of Maringa, State of Parana in order to study the effect of three nutritious solutions with distinct electrical conductivities, applied to two different outflows, on the lettuce cultivation. The following production variables were analyzed: number of useful leaves, number of non-useful leaves, and length of the stem. The treatments consisted of a factorial combination of three nutritious solutions with different concentrations (S1=1.2 mS cm -1 , S2=2.5 mS cm -1 , and S3=0.8 mS cm -1 ) and two application outflows (O1=1.2 L min -1 and O2=0.8 L min -1 ) in the cultivation channels. The delineation was performed at random with 3 replications. Thus, the following treatments were used: S1O1 - nutritious solution 1 applied to outflow 1, S1O2 - nutritious solution 1 applied to outflow 2, S2O1 - nutritious solution 2 applied to outflow 1, S2O2 - nutritious solution 2 applied to outflow 2, S3O1 - nutritious solution 3 applied to outflow 1, S3O2 - nutritious 3 applied to outflow 2. The increase in the concentration of the nutrients with different outflows of the solutions did not provide a significant increase in the number of useful leaves. However, when analyzing the solution treatment separately, there were significant differences in the number of non-useful leaves between solutions I and II, in relation to solution III. Solution 1 (CE = 1.8 mS cm -1 ) provided the longest length of the stem, which was significantly different from the other solutions.

The hydrogel use in the brazilian agriculture, mainly in the forestation, fruits field, and growth media, is being consolidated by its capacity of holding and release water (nutrient solution) to plants. This work aimed to study the holding capacity of nutrient solutions by hydrogel when submitted into differents solutions from sulphates. This study was conducted out the Irrigation Technical Center of Universidade Estadual de Maringa, Maringa, Parana State. It was conducted in a 5 x 5 factorial way (with 26 treatments and 04 replications) and the randomized design. It was used as treatments 05 fertilizers sulphates base (ferrous sulphate, ammonium sulphate, zinc sulphate, copper sulphate, and magnesium sulphate) and 05 doses (0.4; 0.8; 1.2; 1.6, and 2.0 g to each 500 g of distilled water). The distilled water treatment and hydrogel were used as control treatment. The hydrogel was hydrated for 24 hours for a later measure of holding capacity of nutrient solution. We noticed that besides the electric conductivity of nutrient solution the different fertilizer interfered with the holding capacity of nutrient solution.

RESUMO. O presente estudo foi realizado para o municipio de Maringa, Estado do Parana, (latitude de 23o27'S, longitude de 51o57' e altitude de 542 metros). Nele, utilizou-se o modelo de simulacao de crescimento e desenvolvimento da cultura do feijao, Cropgro-Drybean. Esse modelo simula o desenvolvimento fenologico e crescimento da cultura, considerando o balanco de agua no solo. As simulacoes foram realizadas durante o periodo de 1980 a 2000, em um total de vinte safras, considerando-se a semeadura da cultivar Iapar 57, nas seguintes datas: 1, 10 e 20 de marco, 1 de abril, 20 e 30 de julho, 10 e 30 de agosto e 1 de setembro. Os dados de entrada para as simulacoes foram dados meteorologicos diarios de temperaturas maxima e minima, precipitacao e radiacao solar global, caracteristicas fisico-hidricas do solo correspondentes a capacidade de campo, ponto de murchamento permanente, densidade, etc. Os resultados revelaram maiores produtividades nas semeaduras em 10 e 20 de agosto e 1 de setembro, e menores em 1 de abril e 20 de julho, sendo estas, em media, 25% inferiores. Palavras-chave: Cropgro-drybean, feijao, simulacao.