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Результаты 1161-1170 из 1,862
VARIABILIDADE ESPACIAL DE CARACTERÍSTICAS FÍSICO-HÍDRICAS DE UM CAMBISSOLO CULTIVADO COM MAMÃO NO SEMI-ÁRIDO DO RN
2006
José Alexsandro Guimarães Lima | Alessandra Monteiro Salviano Mendes | Gustavo Pereira Duda | Cristiano Vieira Ferreira
This work had as objective to evaluate spatial variability of physical characteristics of a Typical Haplocambids (CX), under papaya culture, by means of the geostatistic. The analyzed area presented 43 sampling points , where soil samples were collected, in the layer of 0 ¿ 0.2 m. In the soil samples granulometry, soil bulk density, particles density, water content at tension of 0.03 and 1.5 MPa were measured. From these analyses the total porosity and water availability were calculated. Data were evaluated by descriptive statistics and by analysis of the spatial dependence based in semivariograms adjustment. The variation coefficient indicated low variability for total and coarse sand contents, water content at tension of 0.03 and 1.5 MPa, soil bulk and particles density and total porosity; and medium for clay, silt e available water contents. Except for water content at tension of 0.03 and 1.5 MPa and particles density, the other variables presented space dependence, being the spherical and exponential models adjusted to all the semivariograms. The nugget effect had small contribution in the data total variance, indicating strong spatial dependence for fine sand and clay contents, total porosity and available water. The other variables showed moderate dependence. There was a great variation in the distance until where the physical characteristics of the ground present spatial dependence (reach).
Показать больше [+] Меньше [-]FUNGOS MICORRÍZICOSARBUSCULARES EMÁREAS NO ENTORNO DO PARQUE ESTADUAL DA SERRA DO MAR EM UBATUBA (SP)
2006
Cristiane Figueira da Silva | Marcos Gervasio Pereira | Eliane Maria Ribeiro da Silva | Maria Elizabeth Fernandes Correia | Orivaldo José Saggin-Júnior
This work was carried out in order to evaluate the mycorrhizal fungi in four surrounding areas of Parque Estadual da Serra do Mar, in Ubatuba (SP), with the following covering vegetation: banana plantation interposed at forest, cassava plantation, capoeira area and secondary forest. Soil samples were collected in July 2003 and March 2004. Regarding arbuscular mycorrhizal fungi (AMFs), the crop areas of banana and cassava showed higher spore number than forest and capoeira areas in the winter. In the summer, only cassava area showed high spore production. The rainy season provided a higher number of AMFs species compared to the dry season, in both forest and banana areas. However, regarding the occurrence of different AMFs species there was no clear pattern as to wet or dry season.
Показать больше [+] Меньше [-]TAMANHO AMOSTRAL PARA ESTIMAR O TEOR DE SÓLIDOS SOLÚVEIS TOTAIS EM TALHÕES DE MELÃO AMARELO
2006
Glauber Henrique de Sousa Nunes | José Erivan Torquato | Rui Sales Júnior | Hailson Alves Ferreira | Francisco Bezerra Neto
The purpose of the present work was to determine the size sample in order to estimate soluble solid contents in yellow melon plot. Samples of fifty fruits were taken of fifteen yellows melon plots grown in Mossoró- Assu Agricultural Pole. Evaluation for total soluble solid contents was done in all fruit samples. The procedures used for sample size estimation were bootstrap method and classical expression with 5% and 10% of error limit. The sample sizes estimated by bootstrap method, in average, yielded estimates close to those observed in the classical expression with 10% of error limit, although in ten plots these sample sizes were greater in the bootstrap method. The sample size recommended to estimate the total soluble solid contents in cultivated plots of melon fruits is fifteen.
Показать больше [+] Меньше [-]WATER AND SODIUM CHLORIDE EFFECTS ON Mimosa Tenuiflora (WILLD.) POIRET SEED GERMINATION
2006
Ivonete Alves Bakke | Antonio Lucineudo de Oliveira Freire | Olaf Andreas Bakke | Alberício Pereira de Andrade | Riselane de Lucena Alcântara Bruno
Water shortage and saline soils of the Brazilian semi-arid northeastern region are limiting factors to the development of many plants. Jurema preta (Mimosa tenuiflora (Willd.) Poiret) is a small, multiple use tree that abundantly colonizes unfavorable sites, including environments with severe water stress. This work had the objective of investigating the tolerance of jurema preta seeds to water and salt stresses during germination. Seeds germination in polyethylene glycol (PEG-6000) and sodium chloride (NaCl) solutions was analyzed under five different osmotic potentials (0.0; -0.3, -0.6, -0.9 and -1.2MPa), in order to simulate water and salt stress, respectively, in four 100-seed replications for each treatment. Seeds were placed into 10cmx10cmx4cm boxes, and germination accomplished in BOD germinator adjusted to 30oC. The number of germinated seeds was monitored every 24 hours, and percentage and speed of seed germination were generated from these data. Mean percentage germination in the control treatment was ~95%, reducing to 63-53% at -0.9 to -1.2-MPa PEG solutions, and to 27- 9.5% at NaCl solutions at equivalent osmotic potentials. Velocity of germination index was more affected, and decreased up to 1/8 of the control, at -0.6 MPa. Jurema preta seeds showed lower tolerance to NaCl than to water stress, and this species can be classified as a glycophyte.
Показать больше [+] Меньше [-]ATIVIDADE ENZIMÁTICA DE FUNGOS ENDOFÍTICOS E EFEITO NA PROMOÇÃO DO CRESCIMENTO DE MUDAS DE MARACUJAZEIRO-AMARELO
2006
Jaqueline Silva Luz | Roberta Lane de Oliveira Silva | Elineide Barbosa da Silveira | Uided Maaze Tiburcio Cavalcante
From leaves, stems and roots of healthy yellow passion fruit plants 93 isolates of endophytic fungi were obtained, with the colonization rates varying from 59.8 to 92.4% (leaves), 27.2 to 90% (stems) and 2.4 to 87.2 (roots). Twenty-nine of these isolates were evaluated for extracelular hydrolitic enzymes production (amylolitic, cellulolitic, lypolytic and proteolytic) and capacity to promove growth of yellow passion fruit seedlings. The isolates were identified as Fusarium (44.82%), Colletotrichum (37.93%), Acremonium, Glomerella, Curvularia, Alternaria and Aspergillus (3.45% each). The isolates EM11, EM50, EM172, EM20, EM81, EM72, EM135 and EM24 presented lypolytic activity with halos varying from 1.52 to 3.74 cm, and no isolate produced proteolytic, cellulolytic and amylolitic enzymes. Fifteen endophytic isolates promoted growth of yellow passion fruit seedlings, being the best EM173 (Alternaria), EM155 (Fusarium), EM139 (Curvularia), EM20 (Colletotrichum), EM6 (Acremonium) and EM151 (Colletotrichum) that increased aerial and root fresh biomass and root dry biomass of until 108.4, 204.4 and 70.2%, respectively, 90 days after the inoculation.
Показать больше [+] Меньше [-]EMERGÊNCIA E SOBREVIVÊNCIA DE PLÂNTULAS DE IMBUZEIRO (Spondias tuberosa Arruda) NA CAATINGA
2006
Nilton de Brito Cavalcanti | Geraldo Milanez de Resende | Marcos Antônio Drumond | Luiza Teixeira de Lima Brito
This work had as objective to evaluate the emergency and the survival of seedlings of imbu tree (Spondias tuberosa Arruda) in caatinga. The assay was carried through of January of 2001 the December of 2004 with 37 plants of imbu tree, selected to perhaps in area of caatinga of the Embrapa Semi-Árido, Petrolina - PE. In each plant four quadrants of 1 m2 had been demarcated randomized below of the pantry for counting of the emergency and survival of seedlings. The comments had been carried through to each 15 days in the rainy station and 30 days in the dry station. A rain gauge was installed in the area of the experiment for attainment of the values of the occurred precipitation during the period of evaluation. The biggest indices of emergency had occurred in the period of bigger precipitation with 57,89 plântulas.m-2, in average, for plant-mother in the rainy station of 2004. Few seedlings had survived until the end of the period of evaluation. The stadium seedling is most critical for the survival and development of the imbu tree in caatinga. The biggest volume of precipitation significantly contributed for a bigger tax of germination and emergency of seedlings of imbu tree.
Показать больше [+] Меньше [-]METODOLOGIA DO TESTE DE GERMINAÇÃO EM SEMENTES DE ALGODÃO, COM LÍNTER E DESLINTADA
2006
Sebastião Medeiros Filho | Sérgio Oliveira da Silvas | Alek Sandro Dutra | Salvador Barros Torres
The research was conducted in order to compare the methodology recommended on Seeds Analysis Rules, regarding substrate and temperature, for the germination test of linted and delinted cottonseeds. Seeds of the cultivar 7MH from the 98/99 season of Morada Nova-CE were divided into two samples. Two assays were done: inthe first, seeds were delinted with sulfuric acid (98%), for three minutes, being later washed in current water, while in the second, seeds were maintained with linter. Both samples were put to germinate on towel paper, cotton cloth and sand substrates, on fixed temperatures at 25ºC, 30ºC and alternated temperatures of 20-30ºC (20ºC/16h and 30ºC/8h). For each treatment, 400 seeds were used, being eight sub-samples of 50 seeds for paper and cloth substrates. The analysis were done in a seven days interval, being the first counting done at the fourth day and the final at the seventh day after the sowing. Two experiments were done to evaluate linted and delinted seeds, using the completely randomized design, with four replications, in a 3x3 factorial scheme. One concluded that for delinted seeds the germination test must be conducted on cloth cotton or paper towel substrate, atfixed temperature of 25ºC or 30ºC or alternated of 20-30ºC; for linted seeds, the best was cloth at alternated temperature of 20-30ºC.
Показать больше [+] Меньше [-]INFLUÊNCIA DA TEMPERATURA NA GERMINAÇÃO DE SEMENTES DE Ocimum canum SIMS
2006
Ana Carla Brito | Douglas de Almeida Pereira | Cláudio Lúcio Fernandes Amaral
The aim of this work was to examine the effect of different temperatures on germination of the seeds in O. canum. The seeds had been washed in under water and after immersed for 30s in water with environmenttemperature, 25, 30 (control), 50, 75 and 100ºC. After that it was immersed per 5 minutes in fungicidal solution and later washed by 10s with water and placed to germinate in plates of Petri conditioned in germination chamber regulated to provide temperature of 25 ± 1,0ºC and photoperiod of 12 hours. The completely randon design was used in experiment, with 5 treatments and 10 repetitions, resulting in 50 parcels. Each experimental unit wasconstituted of a plate of Petri contends 10 seeds. The averages had been compared by the Scott-Knott test at 5% level of probability. The germination rate was statistically equal in the control and the temperatures of 25, 50 and 75ºC, being superior to that one gotten to 100ºC. The temperature of 30ºC was the one that provided the biggest rate of germination, while that of 100ºC is not indicated for the breaking in dormancy of thisspecies, since it promoted the death of the embryo.
Показать больше [+] Меньше [-]DESEMPENHO DE BEZERROS MESTIÇOS LEITEIROS SUBMETIDOS A DIFERENTES SISTEMAS DE ALEITAMENTO ARTIFICIAL
2006
Alexandre Paula Braga | Hildeberto Uchoa Ribeiro | Flávio Andrade da Câmara | Zilah Claudia Alves da Costa Braga
The experiment was accomplished in a completely randomized block design, using 25 cross bred bullocks nursed in the periods of 35, 42, 49, 56 and 63 days of life. Effect of the breastfeed periods was not observed on the weight development of the bullocks. The consumption of daily and total milk was influenced by the weight when being born and for the breastfeed period (P < 0,05). The adjustment of the averages for the variation analysis showed an increase tendency in the consumption of proportional milk to the breastfeed periods. The wean at 35 days was shown economically viable.
Показать больше [+] Меньше [-]CULTIVARES DE ALFACE AMERICANA EM SEGUNDO CULTIVO NOS SISTEMAS SOLTEIRO E CONSORCIADO COM CENOURA
2005
ANTONIO MARCOS DE OLIVEIRA | FRANCISCO BEZERRA NETO | MARIA ZULEIDE DE NEGREIROS | ELIANE QUEIROGA DE OLIVEIRA