Valdemício F. de Sousa

Freqüência de irrigação em meloeiro cultivado em solo arenoso

The objective of this work was to evaluate the effect of five irrigation frequencies in the productivity and efficience of water use of melon crop cultivated under fertirrigation by drip irrigation in a sandy soil of the Coast Plains of Piaui, Brazil. The experiment was allocated in a randomized complete block design, with five treatments and six replications. The treatments were: F1, F2, F3, F4 and F5, irrigation frequency of 0.5, 1, 2, 3 and 4 days, respectively. The irrigation frequency affected the marketable and total yield of the melon crop. The highest total (70.73 t ha-1; 77.99 t ha-1 and 64.21 t ha-1) and marketable (62.20 t ha-1; 63.88 t ha-1 and 53.67 t ha-1) yields were obtained with the frequencies of 0.5 and 1 day, respectively. It was observed that for the leastest frequent of water applications there was a significative reduction (P<0.01) of the marketable and total fruit yield of melon crop. The average fruit weight was not affected by the frequency of water application. The highest and the lowest efficiency of water use, 24.40 kg m-3 and 14.14 kg m-3, were obtained with the frequencies of F1 and F5, respectively. The irrigation frequency twice a day, daily and two days are indicated for melon crop cultivated in sand soil by drip irrigation. The efficiency of water use for the melon crop is higher when the irrigation frequencies are higher.

Produtividade do maracujazeiro amarelo sob diferentes níveis de irrigação e doses de potássio via fertirrigação

The objective of this work was to study the effect of four irrigation levels and five K doses applied through fertirrigation by drip irrigation system in the yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg.) yield. A complete randomized block design in plot subdivided with four replications was used. The treatments resulted from the combination of four irrigation levels [0.25V (926.76 L), 0.50V (1,528.20 L), 0.75V (2,117.28 L) and 1.00V (2,706.36 L), where V is the average volume of water applied in lysimeter with passion fruit plant] with five K doses (0.000, 0.225, 0.450, 0.675 and 0.900 kg plant-1 year -1 of K2O). The commercial yield was affected by irrigation levels, K doses and by the interaction irrigation levels vs. K doses. The majors values of passion fruit commercial yield were obtained with the application of 0.450 to 0.675 kg plant-1 year -1 of K2O, and water levels of 1,528.20 to 2,117.28 L plant-1 year -1, respectively.

Produtividade de frutos do meloeiro sob diferentes níveis de salinidade da água de irrigação, com e sem cobertura do solo

The number and the yield of fruits from two hybrid of muskmelon, submitted to different saline levels of irrigation water and soil covering was evaluated. A factorial outline was used 3 x 2 x 2 in a complete randomized blocks design with four replications. The factors were three levels of salinity of irrigation water, with electric conductivity of 1.2 dSm-1; 2.5 dSm-1 and 4.4 dSm-1 respectively, two hybrids, Gold Mine and Trusty, with and without soil covering using black-silvery double face polyethylene film. The hybrids reacted in different ways to the salinity of irrigation water. Reduction on the total number of fruits was observed only in the hybrid Trusty. The marketable yield of fruits was similar in both hybrids, being reduced with the increase of the electric conductivity. For the usage of soil covering the hybrids also reacted in a different way. The hybrid Trusty produced greater number of fruits and higher yield in treatments using soil covering.

Distribuição de fertilizantes em um sistema de fertirrigação por gotejamento

The aim of this study was to evaluate the spatial and temporal fertilizer distribution uniformity in a drip fertigation system, installed in an experimental area with passion fruit crop in Piracicaba, SP, Brazil. The discharge of emitter was 2.4 L h-1 and a fertilizer injector pump of hydraulic action was used. The injection time of solution was of one hour. To evaluate the uniformity of nutrients distribution samples of solution were collected 2, 12, 22, 32, 42, and 52 min after the start of fertigation in the emitters from the first plant (2 m) and in the emitters localized at 1/3 (10 m) and 2/3 (22 m) distance of lateral line length and those installed on last plant (34 m) of each lateral line. The fertilizer concentration in the samples was determined by the electrical conductivity of the solutions. The relation between the minimum and the mean electrical conductivity values was used to evaluate the fertilizers distribution uniformity. The distribution uniformity indexes in the lines washed before the fertigation were higher compared to others. It was observed that the uniformity increased with time until 42 min after the injection and maintained constant thereafter.

Evaluation of soil hydraulic parameters for soil water distribution models under drip irrigation

As solucoes analiticas de distribuicao de agua para ponto fonte e regime de fluxo nao- permanente sao dependentes de parâmetros de solos considerados constantes em suas deducoes. Erros na determinacao desses parâmetros implicam insucesso dessas solucoes. Este trabalho teve por objetivo avaliar o comportamento dos parâmetros ada equacao de Gardner k(h) = Ks eah e o parâmetro de linearizacao k = dK(q)/dq em diferentes posicoes do bulbo molhado, considerando os processos de infiltracao isolado e seguido de redistribuicao de agua, a semelhanca de um ciclo de irrigacao. Dados de potencial matricial foram coletados em diversas posicoes do bulbo molhado em duas situacoes:(i) inicio da irrigacao ate atingir regime permanente em todo o bulbo molhado (infiltracao); e (ii) durante dois ciclos de irrigacao envolvendo infiltracao e redistribuicao de agua. Os resultados mostraram que os parâmetros a e k variaram nas posicoes do bulbo molhado em relacao ao gotejador, de acordo com o regime de umidade a que tais posicoes estiveram sujeitas. A obtencao desses parâmetros pelo metodo inverso requer testes que considerem as fases de infiltracao e redistribuicao em pelo menos dois ciclos de irrigacao.

Desenvolvimento de plantas de crisântemo cultivadas em vaso em resposta a níveis de condutividade elétrica

In floriculture market, the competition is intense and the productivity differential consists in an appropriated nutritional management which provides a large impact in quality, productivity and longevity of the flowers and plants. This present work aimed to evaluate the effects of electrical conductivity (EC) levels in chrysanthemum plant (Dendranthema grandiflora Tzvelev.) development. These plants were planted in pots and cultivated in a greenhouse. The experiment was carried out in Paranapanema city, Sao Paulo State. The experimental design was made in randomized blocks with four repetitions and split plots. The plots were constituted according to the sample times, and the split plots according to the different EC levels which were determined in the applied water irrigation solution: 1.42; 1.65; 1.89; 2.13 and 2.36 dS m-1 (vegetative stage); 1.71; 1.97; 2.28; 2.57 and 2.85 dS m-1 (bud stage). The plant height and the bouquet diameter were weekly evaluated, and every 14 days the leaf area and the dry mass of the aerial portion of the plant were measured. The treatment which applied the EC level of 2.13 dS m-1 during the vegetative stage and 2.57 dS m-1 during the bud stage provided the best visual aspect in plants, as well as the higher aerial part if the dry mass, higher leaf area and the best formation and coloring.

Produtividade do meloeiro fertirrigado com potássio em ambiente protegido

We studied the effects of three kalium doses applied via fertigation on the yield of melon plants (Cucumis melo L.). The experiment was carried out in a greenhouse installed in Limoeiro do Norte County, Ceara State, Brazil. Plants were irrigated from April to August, 2002 by a regular or a subsurface drip irrigation system. Seeds of the hybrid Bonus 2 were sown at 0.5 x 1.0 m. Streaks were installed to induce the vertical growth of the plants, up to 2.0 m height. The experimental design followed a 2 x 3 factorial random blocks design. The treatments consisted of the combination of three kalium doses (40; 120 and 200 kg ha-1) and tof two depths of application (0.0 m - surface and 0.20 m - subsurface) with four replications per treatment. The total dry matter, leaf dry matter, average fruit weight, soluble solid content of fruits and yield of fruits were evaluated. The subsurface drip irrigated plants produced higher total dry matter and leaf dry matter. The applied kalium levels, however, resulted in no statistic difference for all evaluated variables.

916 Pretransplant biopsy in expanded criteria donors. Do we really need it

Introduction. Renal transplantation is the best treatment for end-stage renal disease, including when using expanded criteria donors (ECD) kidneys. However, these suboptimal kidneys should be evaluated rigorously to meet their usefulness. Opinions differ about the best way to evaluate them. Materials and Methods. We retrospectively reviewed kidneys from ECD harvested by a single academic institution between January 2008 and September 2013. Needle biopsies were performed at the time of the harvest when considered relevant by the transplant team. Two pathologists where responsible for their analysis; the Remuzzi classification has been used in all cases. Results. We evaluated 560 ECD kidneys. Biopsies were made in 197 (35.2%) organs, 20 of which were considered not usable and 36 good only for double transplantation. Sixty-three kidneys (11.3%) were discarded by the transplant team based on the biopsy result and clinical criteria. Donors who underwent a biopsy were older (P < .001) and had a worse glomerular filtration rate (GFR; P 1⁄4 .001). Comparing donors approved and rejected by the biopsy, the rejected donors were heavier (P 1⁄4 .003) and had a lower GFR (P 1⁄4 .002). Cold ischemia time was longer for the biopsy group (P < .001). Regarding graft function, the biopsy overall score correlated with the transplant outcome in the short and long term. Separately, glomeruli and interstitium scores were correlated with recipient’s GFR in the earlier periods (3 months; P 1⁄4 .025 and .037), and the arteries and tubules correlated with GFR in the longer term (at 3 years P 1⁄4 .004 and .010). Conclusion. The decision on the usability of ECD grafts is complex. At our center, we chose a mixed approach based on donor risk. Low-risk ECD do not require biopsy. In more complex situations, especially older donors or those with a lower GFR, prompted a pretransplant biopsy. The biopsy results proved to be useful as they relate to subsequent transplant outcomes, thereby allowing us to exclude grafts whose function would most probably be less than optimal.

Densidade de plantas e número de drenos influenciando a produtividade de roseiras cultivadas em vaso

The cultivation of flowers in Ceara State has expanded during the last years, especially in highland areas with a favorable climate for several crops. However, there exist only limited research in this area, so that producers work empirically with those crops. Consequently, this research aimed to evaluate the effects of the number of plants (2, 3 and 4) and the amount of drains (1 and 8) per pot on the number of stems per pot, in a protected environment. The experiment was carried out in Sao Benedito, Ceara State, Brazil, following a 3 x 2 factorial randomized block design with four repetitions. The number of stems with 35, 40, 50, 60 cm and, the total number of stems per pots of 12.0 L were evaluated. The highest number of plants per pot provided the greatest number of stems per pot, but with a predominance of lower commercial value. On the other hand, the least number of plants per pot resulted in few stems per area which were better evaluated commercially. The use of pots having more drains reduced the total number of stems per pot.

Fertirriego por goteo superficial y enterrado del melón (Cucumis melo L.) en invernadero

Este trabajo tuvo como objetivo determinar el efecto de dos posiciones de instalacion de tubos porta goteros, tres laminas de riego y cuatro dosis de potasio sobre la productividad comercial de frutos de melon en invernadero. El experimento fue realizado en un invernadero de 420,0 m2, localizado en Piracicaba - Sao Paulo – Brasil. El diseno experimental fue en bloques completos al azar en esquema factorial de 2x3x4. Las posiciones de instalacion de tubos porta goteros fueron superficial y enterrado a 0,2 m, las laminas de riego fueron 33, 67 y 100 % de la evaporacion diaria de un mini tanque evaporimetrico y las dosis de potasio fueron 0, 6, 9 y 12 g de K2O planta-1. El fertirriego fue realizado basandose en la curva de absorcion de N y K del cultivo. La evaporacion total del mini tanque evaporimetrico durante la epoca de riego fue de 417,32 mm. La productividad comercial fue influenciada significativamente (P<0,01) por las dosis de potasio, laminas de riego y posicion de los tubos porta goteros. Las dosis de potasio 6 y 9 g de K2O planta-1, combinadas con la lamina de 100% y la posicion de los tubos porta goteros enterrados, alcanzaron mayor productividad comercial, 61.428 y 66.224 kg ha-1, respectivamente.