Indalécio Dutra

Resposta do meloeiro à fertigação controlada através de íons da solução do solo: desenvolvimento vegetativo

Fertigation management is done by the use of the uptake nutrients curves. However, the tracking of the soil solution nutrients concentration appears to be a promising technique. The objective of this work was to study the response of melon plants subjected to controlled concentrations of nitrogen and potassium in the soil solution. 13 treatments were adapted, disposed in fully randomized design with 4 replications. The treatments resulted from the management of controlled concentrations of nitrogen and potassium in the soil solution. The crop was drip irrigated and fertigation was carried out only when necessary. The length of the main stem, stem diameter, leaf number, leaf area, average leaf area and dry matter were evaluated, and analysis of variance and regression using the SAS were performed. At 30 days, the best concentrations of nitrogen and potassium were 336 and 84 mg L-1, respectively. At the end of the cycle, the best concentration of nitrogen in soil solution was of 336 mg L-1 and potassium ranged from 35 and 44 mg L-1.

Determination of the soil cover factor for melon grown under different depths and irrigation water salinities

Two experiments were carried out with the objective of comparing methodologies for determination of the soil cover factor of melon when submitted to different conditions of water depths and salinity, in Mossoro, RN. The experimental design was of completely randomized blocks in a 2 x 2 x 6 factorial scheme. Two methods were tested (Stockings and ruler), two salinity levels (0.55 and 2.65 dS m-1) and six water depths (0.55, 0.70, 0.85, 1.00, 1.15 and 1.30 of the ETc). Both methods of measurement were efficient, with significant effects for both irrigation water depths and salinity in the melon crop being observed. The results obtained by the ruler method differed from Stockings method in the melon only during the initial and rapid growth stages.

Resposta do meloeiro à fertigação controlada através de íons da solução do solo: parâmetros produtivos

A fertigacao tem-se desenvolvido muito e seu manejo que, e feito atraves do uso de curvas de absorcao de nutrientes, comeca a mudar para o monitoramento dos nutrientes na solucao do solo. Buscou-se estudar, aqui, a resposta do meloeiro submetido a concentracoes controladas de nitrogenio e potassio na solucao do solo, atraves da adocao de 13 tratamentos dispostos em delineamento inteiramente aleatorizado com 4 repeticoes em que cada um foi aplicado atraves do manejo controlado das concentracoes de nitrogenio e potassio na solucao do solo. A cultura foi irrigada por gotejamento e a fertigacao realizada somente quando necessario. Avaliaram-se o numero de frutos, a producao, o peso medio dos frutos, a porcentagem de rendilhamento da superficie dos frutos, o diâmetro dos frutos, a espessura e a firmeza da polpa e os solidos soluveis totais e se realizou analise de variância e de regressao com o uso do SAS. Constataram-se baixa producao, peso medio de frutos e, em geral que, os frutos colhidos tiveram baixa qualidade. Obtiveram-se as melhores caracteristicas de qualidade dos frutos em concentracoes de nitrogenio na solucao do solo entre 240 e 260 mg L-1, tendo o potassio variado entre a nao aplicacao em fertigacao e 84 mg L-1.

Área irrigada e métodos de irrigação no Estado do Ceará, segundo o Censo Agropecuário de 1995-1996

Com este estudo, objetivou-se analisar estatisticas sobre a area irrigada total no Estado do Ceara, em funcao dos grupos de area total e dos Agropolos, alem do metodo de irrigacao utilizado pelos estabelecimentos informantes, de acordo com o Censo Agropecuario de 1995-96. Observa-se que o metodo de irrigacao por superficie e o mais utilizado, equivalendo a 61,2% dos estabelecimentos agricolas do estado, seguido pela aspersao (37,2%) e pelos demais metodos (12,6%). O maior percentual de area irrigada se encontra nos estabelecimentos com area menor que 100 ha, representando 53,9% da area total irrigada do Estado, e aqueles com mais de 10.000 ha apresentam o menor percentual, equivalendo a apenas 1,3%. Nos Agropolos encontram-se 61,7% (68.753 ha) da area irrigada do Estado (108.998 ha), sendo o Agropolo do Baixo Jaguaribe o que apresenta maior area irrigada, com 34,4% da area irrigada nos Agropolos. O Agropolo do Baixo Acarau tem a menor area, equivalente a 5,8%. A irrigacao superficial tambem predomina nos Agropolos, sendo utilizada em 60,0% dos estabelecimentos, contra 33,9% da aspersao, e 13,5% dos outros metodos, predominando tambem por grupos de area total.

Efeito da lâmina de irrigação na conservação pós-colheita de melão Pele de Sapo

The occurrence of effects of cultivation conditions on the postharvest quality and conservation of fruits is already known, but the studies are scarce, in the literature, which relate the use of irrigation with postharvest quality and conservation of melon. Thus, the objective was to evaluate the irrigation effect in the postharvest conservation of Piel de Sapo melon. An experiment was carried out in Mossoro, Rio Grande do Norte state, Brazil, from September to December 2004 in which three irrigation levels tested: L1= 281 mm, L2= 349 mm and L3= 423 mm, the soil being fertilized according to the crop needs. The fruits were harvested at physiological maturity (60 days after transplantation). After the harvest, the fruits were transported to the laboratory of the Universidade Federal Rural do Semiarido, where the fruits were washed and selected. A sampe was evaluated previously and the other fruits were identified and placed in cardboard boxes. They were stored in a cooler with temperature at 10+1oC and 85+2% RH where they remained for 35 days. The experimental design was completely randomized in a 3x2 factorial, representing respectively three irrigation levels (L1, L2 and L3) and two fruits storage periods (0 and 35 days), with five replications. Significant differences were detected between the irrigation levels and storage time to vitamin C. There occurred an increase on the pH value and a decrease on vitamin C content and on fruits pulp firmness with higher irrigation levels. The pulp firmness, acidity and soluble solids of fruits decreased after storage time.