Refinar búsqueda
Resultados 81-90 de 251
NEMATÓIDE DAS LESÕES ASSOCIADO A MUDAS DE MANGUEIRA EM ASSU-RN Texto completo
2015
GUSTAVO RUBENS DE CASTRO TORRES | RUI SALES JÚNIOR | LAUREEN MICHELLE HOULLOU | ANDREIA MITSA PAIVA NEGREIROS
The aim of this study was to report for the first time Pratylenchus brachyurus population asso- ciated to mango cv. Tommy Atkins seedling roots, on naturally infested soil, on Assú municipality, Rio Grande do Norte State. The population of nematode was characterized based on a morphometric study that was done using 20 females collected from the roots. The morphometric data were compared to other data published by different authors in studies concerning to reporters of this species of root - lesion nematode, and it was possible to identify the population as P. brachyurus.
Mostrar más [+] Menos [-]EFFECTS OF HARVEST MANAGEMENT AND MANURE LEVELS ON CACTUS PEAR PRODUCTIVITY Texto completo
2015
JOÃO PAULO DE FARIAS RAMOS | EDSON MAURO SANTOS | GEORGE RODRIGO BELTRÃO CRUZ | RICARDO MARTINS ARAUJO PINHO | POLIANE MEIRE DIAS DE FREITAS
The aim of this paper was to evaluate the cutting frequency and levels of the manure on cactus for-age productivity. The research was conducted at Pendencia Station – The State Agribusiness Reaserch Compa-ny of Paraíba, Soledade – PB –Brazil, from August 2008 to August 2010. It was utilized a factorial arrenge-ment 4x5, 4 crop managements (M1= cactus forage harvested at 12 months after establishment; M2= cactus forage harvested at 12 months after the first regrowth; M3= harvested of the accumulated production in 24 months and M4= sum of the first production and regrowth) and five levels of goat manure: 0; 5; 10; 15 e 20 Mg ha-1. It was evaluated the fresh matter production (FMP) and dry matter production (DMP), water accumula-tion, rainfall use efficiency (RUE) and percentage of the water accumulation in the plant. The largest level of organic fertilizer promoted an increase in FMP of 275, 171, 184, 203% and DMP: 305, 175, 223, 218%, re-spectively, when comparing the highest level of fertilizer with the unfertilized treatment, and an increase in water accumulation 115.60, 102.93, 166.95, 218.53 kg of water ha-1 when comparing the highest level with the unfertilized treatment. The organic fertilization in M1, M2, M3 and M4 managements, despite of the levels, promoted a linear increase in the RUE. Fertilization increases the cactus forage productivity, and its rainfall use efficiency. The annual cut can be employed as a practice in the management of cactus forage.
Mostrar más [+] Menos [-]PRODUÇÃO DE ETANOL DE SEGUNDA GERAÇÃO PROVENIENTE DO BAGAÇO DE PENDÚCULOS DO CAJU Texto completo
2015
EZENILDO EMANUEL DE LIMA | FLÁVIO LUIZ HONORATO DA SILVA | LÍBIA DE SOUSA CONRADO OLIVEIRA | ADRIANO SANT\u2019ANA SILVA | JOSÉ MARIANO DA SILVA NETO
The use of cashew apple bagasse for bioethanol production aimed at taking advantage of a re-gional culture that has about 85% of waste. Due to the complex structure of the material, it is necessary to sub-mit it to physical pretreatments and/or chemicals such as acid prehydrolysis, alkali, steam explosion, CO2 ex-plosion, hot water treatment, pretreatment with microwave, among others, before hydrolysis process for ethanol production. The aim of this paper was to study the prehydrolysis and acid hydrolysis in the cashew bagasse peduncle (Anarcadium occidentale L.), and the removal of toxic compounds from the hydrolyzate liquor using the residual lignin as adsorbent and alcoholic fermentation of liquors for the production of the second genera-tion bioethanol. The cashew bagasse, based on its chemical characterization and physical chemistry, presented itself as a promising source in order to produce bioethanol. The prehydrolysis, is effective in the removal of hemicelluloses mainly in the extraction of arabinose, the temperature being the major variable influencing the process. For the acid hydrolysis done with the following hydrolysis conditions: temperature at 200 °C, acid concentration equal to 6% and ratio of 1:6 has presented the combination of the highest concentration of sugars with a minimum concentration of toxic compounds. During the study of the alcoholic fermentation of liquors with hydrolyzed yeast Saccharomyces cerevisiae, presented yield and efficiency of production of ethanol from cellulosic pulp of processing stalk cashew maximum dry were respectively 0.445 g ethanol/g of pulp and 87.1% hydrolyzed liquor with the addition of cashew apple juice.
Mostrar más [+] Menos [-]CRESCIMENTO DE CULTIVARES DE CAFEEIRO CONILON SUBMETIDAS AO ESTRESSE SALINO-HÍDRICO Texto completo
2015
AMANSLEONE DA SILVA TEMOTEO | ANTÔNIO DE PADUA SOUSA | CÍCERO MANOEL DOS SANTOS | ÉRICO TADAO TERAMOTO
The culture of coffee is quite important on the national scene and in the country's economy. Though, the crop response to salt stress is not well known. The objective of this paper was to evaluate compar-atively the initial growth of seedlings of two Conilon coffee cultivars under different conditions of soil salinity, and low water availability in the soil. The experiment followed a randomized block design in factorial arrange-ment with two Conilon cultivars (clones 120 and 14), two levels of water in the soil (50% and 70% of available soil water) and four levels of soil salinity (0; 2.0; 4.0 and 6.0 dS m-1). The physiological characteristics of growth: leaf area (Area F), stem height (Height. C), Stem diameter (Dia. C), reproductive branches numbers, shoot biomass and root were evaluated. Among the growth variables, leaf area and leaf dry mass and root are the best indicators of the presence of saline-hydric stress. The cultivar clone 120 is moderately tolerant of soil salinity, with less reduction in leaf area and leaf dry mass when subjected to salt stress.
Mostrar más [+] Menos [-]ADUBAÇÃO POTÁSSICA EM HÍBRIDOS DE SORGO FORRAGEIRO CULTIVADOS EM SISTEMAS DE MANEJO DO SOLO NA AMAZÔNIA ORIENTAL Texto completo
2015
JESSIVALDO RODRIGUES GALVÃO | ANTONIO RODRIGUES FERNANDES | VICENTE FILHO ALVES SIVA | DANIEL PEREIRA PINHEIRO | NILVAN CARVALHO MELO
Sorghum is grown in areas and environmental situations very dry and/or too hot, where produc- tivity of other cereals is uneconomical. Aiming to evaluate the production of three sorghum hybrids, because of potassium and management systems, grown in Oxisol with low productive capacity, an experiment was con- ducted in the field, in the area of the Federal Rural University of Amazonia/UFRA, Belém campus The experi- mental design was randomized in blocks, arranged in a factorial 4 x 3 x 2 with four replications. The factors were: four doses of potassium (50, 100, 200 and 300 kg ha - 1 ) as KCl, three sorghum hybrids (Qualimax, Volumax and AG 2005 - E) and two tillage systems (no - till and conventional). The tillage produced a higher shoot dry weight of sorghum, and the hybrid and Volumax and Qualimax had incomes above the AG2005 - E. The contents of the elements N, P, K, Ca and Mg in the leaves of sorghum grown with tillage were higher than those found in conventional tillage. Doses of potassium resulted in greater increase in MSPA tillage using 40% less potash fertilizer with the conventional system.
Mostrar más [+] Menos [-]PALMA (OPUNTIA FICUS INDICA MILL) CV. GIGANTE EM SUPLEMENTOS PARA FÊMEAS LEITEIRAS EM CRESCIMENTO A PASTO Texto completo
2015
GLEIDIANA AMÉLIA PONTES DE ALMEIDA | JOSÉ MAURÍCIO DE SOUZA CAMPOS | MARCELO DE ANDRADE FERREIRA | ANA LÚCIA VANDERLEY CORREIA | ALBERÍCIO PEREIRA DE ANDRADE
This study aimed at evaluating the effect of replacing corn by palm in the supplements for dairy females in grazing at levels of 0, 33, 66 and 100%. Intake of pasture and apparent nutrient digestibility, animal performance, intake of nitrogenous compounds, nitrogen balance, synthesis and microbial efficiency and bioe-conomy system were evaluated. The study was conducted at Farm Roçadinho, municipality of Capoeiras Wasteland region of the State of Pernambuco in the period from 30/09/2012 to 19/01/2013, in a completely randomized design with four treatments and six replications, using 24 dairy females growing initial weight of 180 pounds. Consisted of 112 days, and 28 for adaptation. The intake of DM, DM/pasture, OM, CP, NDFap. NDFi intake and increased ADF because of the NFC, EE, and TDN decreased (P <0.05). PUN levels in plasma did not change. The apparent digestibility of DM, OM, NDF, ADF, NFC, EE and TDN decreased linearly, and CP increased (P <0.05). Weight gains decreased since the FC increased (P <0.05). No effect was observed in nitrogen intake and nitrogen excreted in the urine. A reduction in nitrogen excreted in the faeces nitrogen bal-ance and percentage of ingested nitrogen, urea-N excreted in the urine increased (P <0.05). The replacement of corn by palm reduces the performance of dairy females in pasture growth. Thus the total or partial replacement is conditioned to the projection of age at first calving on the production system and economy of use.
Mostrar más [+] Menos [-]MOBILIDADE DO HERBICIDA IMAZAQUIN EM DIFERENTES SOLOS Texto completo
2015
FLAVIA FLORIDO | ANA CAROLINA RIBEIRO DIAS | PATRICIA ANDREA MONQUERO | VALDEMAR TORNISIELO
Imazaquin is an herbicide widely used in Brazil to control weeds associated with the soybean crop. This work aimed to study the mobility and leaching of imazaquin in soils with different characteristics. In both experiments, a completely randomized block design was used; with tree replicates. We study the mobility of imazaquin in Red Eutrophic Latosol, clayey; Alfisol Haplic Eutrophic, medium texture; Alfissol Eutrophic, medium texture; and Orthic Psament, sandy texture. To obtain the mobility rate (Mr), a solution of 14Cimazaquin with the activity of 304,75 Bq/mL was applied to plates containing different soils. All Mr values range between 0.803 and 1, indicating that imazaquin has a relevant mobility in our soils. In the leaching study, the soils were classified as Rhodic and differed chemically. The herbicide imazaquin (14C + imazaquin technical product) was applied to the highest recommended dose ( 161 g a.i. ha-1 ), directly on the soil surface of each column. After that, was done a rainfall simulation of 200 mm. Nearly 100% of the herbicide was in the 0- 10 cm layer, however, the soil with higher pH, the herbicide was distributed to 15-20 cm depth. The herbicide imazaquin has greater mobility in soils with low organic matter and clay and soils with high Ph.
Mostrar más [+] Menos [-]DISTRIBUIÇÃO ESPACIAL DA QUALIDADE FISIOLÓGICA DE SEMENTES DE SOJA EM CAMPO DE PRODUÇÃO Texto completo
2015
ALEXANDRE GAZOLLA-NETO | MARCIABELA CORREA FERNANDES | ALINE DUARTE GOMES | GIZELE INGRID GADOTTI | FRANCISCO AMARAL VILLELA
The objective of this study was to identify and determine the spatial distribution of the physiological quality of soybean seeds in a field of 39 hectares with production through precision farming techniques. Soil sampling and harvest seeds, georeferenced points for determining soil fertility, seed quality and range of spatial dependence were performed. The results were submitted to analysis of descriptive statistics, Pearson correlation, and geostatistics. The data presented coefficient of variation of 1,63% for emergency, 1,74% for germination, 1,63% for viability, 2,59% for accelerated aging and 4,28% vigor evaluated by the tetrazolium test. Soil pH was negatively correlated with germination, emergence, and viability. The grid point per hectare and a georeferenced grid sampling, spacing of 100 meters between points, was efficient in assessing the spatial variability. Physiological quality is not uniform, particularly in nexion of vigor, providing better diagnosis through interpolation maps. Precision agriculture allows one to determine the spatial distribution of seed physiological quality in a production area of soybean seeds, facilitating decision-making, in what refers to the areas to be harvested.
Mostrar más [+] Menos [-]CARACTERIZAÇÃO FOTOSSINTÉTICA DA ESPÉCIE ISOHÍDRICA PATA-DE-ELEFANTE EM CONDIÇÕES DE DEFICIÊNCIA HÍDRICA Texto completo
2015
SUZANA CHIARI BERTOLLI | JULIANO DE SOUZA | GUSTAVO MAIA SOUZA
The maintenance of a plant water status is essential for keeping of its development in environments with limited water availability. Different species have different mechanisms that provide greater ability to survive under drought conditions. The objective of this study was to evaluate physiological parameters changes of the isohydric species Beaucarnea recurvate Lem. under irrigation suspension. The study involved experiments with slow dehydration (SD) performed by withholding water followed by plants rehydration, and with rapid dehydration (RD), where individual leaves were detached and placed to dehydrate in the laboratory bench. The results showed that although of the soil water content (% H2O) reach critical values (12%) in the first days of the irrigation suspension, the plants showed maintenance of the relative water content (≅80%) over the 54-day SD period, when the net photosynthesis (PN) reached null values. Throughout SD, it was observed that the PN, stomatal conductance (gs), instantaneous carboxylation efficiency, the electrons transport rate, the potential quantum efficiency of PSII and chlorophyll content were reduced. In RD, experiment was observed a high correlation between PN and gs . The results suggest that the reduction in photosynthesis was initially caused by a stomatal adjustment that culminated in an imbalance between photochemical energy production and its consumption by biochemical apparatus of photosynthesis. However, after rehydration, all gas exchange parameters were recovered, indicating that the isohydric behavior of this species contributed to the plants did not suffer extensive damage during a prolonged period of irrigation suspension.
Mostrar más [+] Menos [-]QUALIDADE DE CEBOLA EM FUNÇÃO DE DOSES DE NITROGÊNIO E ÉPOCAS DE PLANTIO Texto completo
2015
GARDÊNIA SILVANA DE OLIVEIRA RODRIGUES | LEILSON COSTA GRANGEIRO | MARIA ZULEIDE DE NEGREIROS | ANA CLÁUDIA DA SILVA | JOSÉ NOVO JÚNIOR
The classification of the onion made based on the diameter of the bulbs and the quality measured by soluble solids, titratable acidity, relation soluble solids /acidity e a pungency due to nitrogen and planting times were evaluated in two experiments conducted from december 2011 to April 2012 and August tha december to 2012, horta in the Department of Plant Sciences Universidade Federal Rural do Semi-Árida em Mossoró-RN. The experimental design was a randomized block with four replications. The treatments consisted of N rates: 0, 34, 67, 101, 134 and 168 kg ha -1 N. Each experimental unit consisted of a bed of 3,0 x 0,8 m, satisfaction eight rows of plants spaced 0.10 x 0.10 m. Was used as floor area, the six central rows of plants in the flowerbed. The bulb pungency increased with the supply of nitrogen to the dose of 93 kg ha-1 . Acidity and soluble solids reduced with the application of nitrogen. The onion planting in August 2012 favored the production of better quality bulbs.
Mostrar más [+] Menos [-]