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| Registros recuperados: 390 | |
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| Sánchez-Olate,Manuel; Sáez,Patricia; Ríos,Darcy. |
| The in vitro introduction of adult walnut (Juglans regia L.) tissue represents an opportunity to clone elite genotypes whose selection occurs in advanced ontogenic states. With the purpose of developing a protocol to allow mass propagation of valuable genotypes from adult material, a comparison was made between two root induction systems of walnut microshoots of the fourth subculture of adult walnut tissue of an in vitro introduction program previously reinvigorated through traditional grafting. Rhizogenic induction by indole-3-butyric acid (IBA) and Agrobacterium rhizogenes was used. The rhizogenic process was analyzed in two phases for both auxinic (T1: 3 mg L-1 IBA; T2: 5 mg L-1 IBA) and A. rhizogenes inductions (T3: A-477; T4: A-478). The first phase... |
| Tipo: Journal article |
Palavras-chave: Rooting; Microshoots; Adult material. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000200019 |
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| Salari,Elham; Ahmadi,Kamal; Dehyaghobi,Reza Zamani; Purhematy,Amin; Takalloozadeh,Haji Mohammad. |
| To reduce the dependence on the sometimes unwise use of synthetic pesticides in fruit and vegetable plantations, the toxicity and repellence of Peganum harmala L. (Zygophyllaceae) acetonic seed extract was assayed against several insect pests. For contact toxicity, 3- to 4-d-old individuals of Aphis fabae Scopoli, A. gossypii Glover, A. nerii Boyer de Fonscolombe, and Myzus persicae (Sulzer) were included, as well as 1- to 7-d-old adult Tribolium castaneum (Herbst). Repellent effect experiments were conducted on adult, 1- to 2- and 3- to 4-d old M.persicae individuals. At 60 mg mL4, the topical bioassay mortality percentage was significantly higher in A. gossypii than in A. fabae and A. nerii after 12-72 h. Mortality of the treatments on M.persicae was... |
| Tipo: Journal article |
Palavras-chave: Topical bioassay; Aphid species. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000100023 |
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| Celis,José; Sandoval,Marco; Barra,Ricardo. |
| The potential toxicity of urban sewage and farmed salmon sludge, as well as their fertilizer potential, was evaluated by a battery of tests carried out with lettuce (Lactuca sativa L.) and annual ryegrass (Lolium multiflorum Lam.) cv. Winter Star. Wastes were evaluated in a Patagonian soil (Andic cryofluvent) and a granitic soil (Ultic Palexeralf). The treatments were municipal sewage sludge (MSS), salmon ground-farming waste (PSW) and salmon lake-farming waste (LSW) at different rates: 25, 50, 75, 100 and 150 t ha-1. Bioassays in lettuce were conducted for germination index (GI), radicle and hypocotyl structure length. Test in ryegrass were conducted for aboveground biomass yield. The phytotoxicological results from Patagonian soil showed significant... |
| Tipo: Journal article |
Palavras-chave: Fish sludge; Salmon waste; Urban sludge; Organic fertilizer; Degraded soil. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000300007 |
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| Claret M,Marcelino; Urrutia P,Roberto; Ortega B,Rodrigo; Best S,Stanley; Valderrama V,Natalia. |
| Consumption of water contaminated with nitrates is associated with important health effects such as methemoglobinemia and gastric cancer. Intensive agriculture, which uses large quantities of N fertilizer, is the main source of nitrates in water systems. There are several strategies to reduce leaching and increase Nitrogen Use Efficiency (NUE). An experiment was conducted with spring wheat (Triticum aestivum L.) under sprinkler irrigation (center pivot) to determine if adjusted N applications using precision agriculture tools and plant demand resulted in a lower groundwater nitrate load. Evaluated treatments were: produced fertilization (Pr), precision agriculture (Pa), chlorophyll meter (Sm), and control without N (W/N). The ceramic capsule methodology... |
| Tipo: Journal article |
Palavras-chave: Nitrates; Precision agriculture; Chlorophyll meter; Wheat. |
| Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392011000100018 |
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| Perea,Alberto Jesús; Meroño,José Emilio; Aguilera,María Jesús. |
| The objective of this paper was the development of a methodology for the classification of digital aerial images, which, with the aid of object-based classification and the Normalized Difference Vegetation Index (NDVI), can quantify agricultural areas, by using algorithms of expert classification, with the aim of improving the final results of thematic classifications. QuickBird satellite images and data of 2532 plots in Hinojosa del Duque, Spain, were used to validate the different classifications, obtaining an overall classification accuracy of 91.9% and an excellent Kappa statistic (87.6%) for the algorithm of expert classification. |
| Tipo: Journal article |
Palavras-chave: Expert classification; Vegetation index; Land cover; Object-based classification. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000300013 |
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| González Pereyra,Ana Valeria; Maldonado May,Verónica; Catracchia,Carlos Guillermo; Herrero,María Alejandra; Flores,Myriam Celina; Mazzini,Mariana. |
| Grazing animals are exposed to heat stress and there should be conditions to facilitate water intake. Three experiments were carried out to determine the relationship between water intake, water temperature, and heat stress for Holstein pastured dairy cows. Experiment 1: Drinking behavior of 13 cows was evaluated (for 3 consecutive days) and four time periods were established according to the temperature humidity index (THI): (H1:05:00 to 10:59 h, H2:11:00 to 16:59 h, H3:17:00 to 22:59 h, and H4:23:00 to 04:59 h). The highest mean percentage of drinking bouts (53.2%) was registered in H2 (THI: 74.91 to 83.95). Drinking bout means among time periods were different (p < 0.05), thus showing that heat stress conditions influence drinking behavior.... |
| Tipo: Journal article |
Palavras-chave: Drinking behavior; Summer time; THI; Grazing dairy farms. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000200017 |
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| Bastías,Richard M; Manfrini,Luigi; Corelli Grappadelli,Luca. |
| The effect of shading (i.e. reduction of sunlight availability) on fruit growth physiology has been widely studied in apple (Malus domestica Borkh.), but little knowledge exist about fruit growth responses to changes in the light spectrum. The aim of the present research was to study the effect of use of colored nets with differential sunlight transmission in the blue (B, 400-500 nm), red (R, 600-700 nm) and far-red (FR, 700-800 nm) spectra on apple fruit growth and physiological associated responses. Three year old 'Fuji' apple trees were covered with 40% photo-selective blue and red shade nets, 40% neutral grey shade net, and 20% neutral white net as control. Red and blue net reduced in the same proportion (27%) the photosynthetically active radiation... |
| Tipo: Journal article |
Palavras-chave: Sunlight spectrum management; Fruit size; Photosynthesis; Morphogenesis. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000200010 |
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| Garrido,Marco; Román,Luis; Silva,Paola; Castellaro,Giorgio; García de Cortázar,Víctor; Acevedo,Edmundo. |
| The genetic coefficients, representative of a crop, are necessary to use growth models; in many cases the range of the species is known, but there are no specific values for varieties. Durum wheat (Triticum turgidumL. ssp. durum)'Llareta-INIA' and 'Corcolén-INIA' were sown under irrigation in the experiment station Antumapu of the Universidad de Chile on 29 June 2007, 19 May 2009, and 15 June 2010 in order to determinate four genetic coefficients: developmental thermal time, phyllochron (PHLN), extinction coefficient (k), and radiation use efficiency (RUE), and to evaluate the performance of these coefficients. Thermal times to anthesis and from anthesis to physiological maturity were 652 and 541 °C d, respectively. Two PHLN values were found, 46.6 °C d... |
| Tipo: Journal article |
Palavras-chave: Simulation; Thermal time; Radiation use efficiency; Extinction coefficient. |
| Ano: 2013 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392013000200002 |
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| Arumí,José Luis; Rivera,Diego; Holzapfel,Eduardo; Boochs,Peter; Billib,Max; Fernald,Alexander. |
| Agricultural production of high value crops in Chile's Central Valley is highly dependent on surface and groundwater resources. They are connected and together form an integrated hydrological system, the individual components of which have to be studied. This research is addressed to answering two questions: 1) to what extent do irrigation and canal seepage contribute to groundwater recharge and 2) what is the influence of the interactions between the Cachapoal River and ground water. The study was carried out from 2003 to 2007 in Peumo Valley (34.3° S, 71.3° W). In winter, the irrigation canal network intercepts and diverts surface runoff, which flows to flat areas and recharges groundwater. In summer, infiltration from the canals recharges the aquifer... |
| Tipo: Journal article |
Palavras-chave: Agriculture; Chile; Groundwater; Irrigation seepage; MODFLOW; Surface water-groundwater interactions. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000100002 |
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| Iqbal,Muhammad Asif; Khalid,Muhammad; Shahzad,Sher Muhammad; Ahmad,Maqshoof; Soleman,Nawaf; Akhtar,Naeem. |
| Maintenance of high bacterial population in the rhizosphere improves the efficiency of these organisms. This high bacterial population can be maintained by the application of enriched compost which supports their growth and activities. Thus integrated use of Rhizobium, plant growth promoting rhizobacteria (PGPR) containing 1-aminocyclopropane-1-carboxylate deaminase (ACC-deaminase) and P-enriched compost (PEC) could be highly effective for promoting growth, nodulation, and yield of lentil (Lens culinaris Medik.). A field study was conducted to evaluate the potential of Rhizobium, PGPR containing ACC-deaminase and PEC for promoting growth of lentil. For this study, the soil type was sandy clay loam soil having pH 7.6; EC (electrical conductivity) 2.8 dS... |
| Tipo: Journal article |
Palavras-chave: Co-inoculation; Biological N fixation; Rhizobium; ACC-deaminase; P-enriched compost; Nodulation; Yield. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000100017 |
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| Wong,Wendy; Barba,Paola; Álvarez,Catalina; Castro,Álvaro; Acuña,Manuel; Zamora,Pablo; Rosales,Marlene; Dell´Orto,Paola; Moynihan,Michael R; Scorza,Ralph; Prieto,Humberto. |
| The transgenic plum (Prunus domestica L.) C5, in which the coat protein (CP) gene of the Plum pox virus (PPV) is inserted, represents a unique example of the use of genetic engineering for fruit crop improvement in Prunus spp. Field trials in Poland, Romania, and Spain have demonstrated resistance of C5 to several D and M strain PPV isolates. In Chile, the quarantine regulations for PPV and for genetically modified (GM) plants require that the testing of C5 for resistance to Chilean PPV isolates be done under controlled isolated conditions. To carry out these tests C5 shoots were multiplied in vitro and micro-grafted onto four Adesoto101 (Prunus insititia L.) rootstock populations that had been previously infected each with one of four Chilean PPV-Ds.... |
| Tipo: Journal article |
Palavras-chave: C5; Chilean isolates; Micro-grafting. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000300004 |
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| Khaliq,Abdul; Matloob,Amar; Riaz,Yasir. |
| Weed control program should be environmentally benign and cost-effective so that reduced herbicide use can help meet these goals. Field trials were conducted to assess the bio-economic and qualitative impact of reduced doses (25 and 50% of label dose) of a postemergence pyrimidinyloxybenzoic acid herbicide (bispyribac-sodium) applied alone or in combination with multipurpose tree (eucalyptus Eucalyptus camaldulensis Dehnh., mango Mangifera indica L., and mulberry Morus alba L.) water extracts in direct seeded rice (Oryza sativa L.) fields. The label dose of bispyribac-sodium and penoxsulam along with weed control were included for comparison. Tank mixing of multipurpose tree water extracts with reduced herbicide doses accounted for > 55% suppression in... |
| Tipo: Journal article |
Palavras-chave: Reduced dose; Weed suppression; Yield; Kernel quality; Oryza sativa. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000300008 |
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| Carrasco-Letelier,Leonidas; Mendoza,Yamandu; Ramallo,Gustavo. |
| This work studies the acute contact toxicity of oxalic acid (OA) on a honeybee polyhybrid subspecies (Apis mellifera), which is the dominant biotype in southwestern zone of Uruguay (SWZU) and the country's most important honey-producing region. We determined the mean lethal dose (LD50), as well as the no observed effect level (NOEL) and the lowest observed effect level (LOEL) values. We also estimated the total number of honeybees per hive in the test area. The aim was to assess the relationship between the maximum OA dose used in Uruguay (3.1 g OA per hive) and the toxicological parameters of honeybees from SWZU. The current dose of 3.1 g OA per hive corresponds to 132.8 OA per honeybee since determined NOEL is 400 OA per honeybee; our results indicate... |
| Tipo: Journal article |
Palavras-chave: LD50; Uruguay. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000200019 |
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| Francescangeli,Nora. |
| Because of the increasing and diversified demand for potted plants, there is interest in Argentina in commercial iris production (Iris x hollandica Tub.). Two experiments were performed at the Instituto Nacional de Tecnología Agropecuaria (INTA), San Pedro Agricultural Experimental Station (33º41 S, 59º41 W), Buenos Aires Province. The effects of increasing concentrations of paclobutrazol (PBZ) and combinations of PBZ and 6-benzylaminopurine (BA) were compared. Height, length of the cycle and rate of flowering were registered. Experiment 1: the bulbs were subjected to immersion in nine concentrations of PBZ: 0, 10, 20, 30, 40, 50, 60, 70 or 80 mg L-1 for 24 h. Experiment 2: the bulbs were immersed in three concentrations of PBZ: 0, 10 or 20 mg L-1 for 24... |
| Tipo: Journal article |
Palavras-chave: Bulbous; Growth regulator; Height. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000400005 |
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| Rupp,David E; Reckmann,Oscar; Vergara,Jorge; Uribe,Hamil; Selker,John S.. |
| In the dryland of the Libertador General Bernardo O'Higgins Region in Chile, most farmers rely on wide and shallow hand-dug wells as their primary source of water during the dry summer. Few of these wells have sufficient yield for more than domestic use (human consumption, livestock, and irrigation of a subsistence garden). To more accurately assess available groundwater resources, saturated hydraulic conductivity (K) of aquifers in the eight counties that comprise this regions dryland was estimated using evacuation and recovery tests in 353 hand-dug wells. K followed a log-normal distribution and ranged over nearly five orders of magnitude. County median K varied by a factor of 5 and a slight increasing K trend in the southward direction. In one northern... |
| Tipo: Journal article |
Palavras-chave: Groundwater; Well recovery; Slug-test. |
| Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392011000200012 |
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| Toledo T,Roger; Engler P,Alejandra. |
| Decisions are strongly influenced by risk and risk preferences of decision makers; however, in Chile there are few studies in the agricultural sector focused on this topic. The present paper analyzes the risk preferences of small producers of raspberries (Rubus idaeus L.) and the production function associated with their production system in the Bio-Bio Region of Chile. Under a mean-variance approach, the estimation procedure uses a flexible utility function to incorporate a variety of risk preference alternatives. Three different estimation procedures were used: Least Squares Estimation, Seemingly Unrelated Regression and Full Information Maximum Likelihood, which revealed the same conclusions. Results showed that small farmers are risk averse (γ... |
| Tipo: Journal article |
Palavras-chave: Risk aversion; Mean-variance utility function; Production function. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000200007 |
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| Flores P,Fabiola; Lillo S,Mario. |
| Agricultural studies on a regional scale about water balance and evapotranspiration estimation, among others, require estimating air temperature (Ta) spatial variation since the generally low density of weather stations does not allow obtaining such data for a specific area. The aim of this study was to estimate air temperature through atmospheric profiles provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on a regional level. One of the present-day methodologies estimates Ta through vertical temperature profiles, which is why modifications to this methodology were proposed for zoning, surface elevation, and pressure/altitude ratios. By applying this new methodology, better Ta estimates were obtained by replacing the MODIS sensor... |
| Tipo: Journal article |
Palavras-chave: MODIS; Atmospheric profile; Digital elevation model. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000300011 |
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| Registros recuperados: 390 | |
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