خيارات البحث
النتائج 221 - 230 من 241
PHYSICOCHEMICAL CHARACTERISTICS, ANTIOXIDANT CAPACITY AND PHENOLIC COMPOUNDS OF TOMATOES FERTIGATED WITH DIFFERENT NITROGEN RATES
2017
MARCOS FILGUEIRAS JORGE | KAMILA DE OLIVEIRA DO NASCIMENTO | JOSÉ LUCENA BARBOSA JUNIOR | LEONARDO DUARTE BATISTA DA SILVA | MARIA IVONE MARTINS JACINTHO BARBOSA
The objective of this work was to evaluate the physicochemical and microbiological characteristics, antioxidant capacity and phenolic compounds of organic cherry tomatoes grown under fertigation with organic dairy cattle wastewater (DCW) with different nitrogen rates. Tomato plants, grown in an agroecological farm in Seropédica, State of Rio de Janeiro, Brazil, were subjected to four different nitrogen rates (T1=0, T2=50, T3=100 and T4=150% of N). The moisture, lipids, ashes, protein and total fiber contents, soluble solids (ºBrix), reducing and total sugars (%), pH and total titratable acidity (mg NaOH per 100 g) were evaluated. The total phenolic content (TPC) and the antioxidant capacity was determined by the DPPH and FRAP methods. The different nitrogen rates (%N) affected the pH, protein and soluble solids contents. The increase in %N increased the antioxidant capacities, according to the DPPH assay, and TPC. On the other hand, the tomatoes under fertigation with the highest %N presented lower antioxidant capacities according to the FRAP assay. The fertigation did not affect the microbiological characteristics of the tomatoes, which presented fecal coliforms count <3 NMP g-1 and absence of Salmonella in 25 g.
اظهر المزيد [+] اقل [-]EFFECT OF HYDROTHERMAL AND FREEZING TREATMENT ON THE PHYSICAL AND MECHANICAL PROPERTIES OF EUCALYPTUS WOOD
2017
FABIANA PAIVA DE FREITAS | ANA MÁRCIA MACEDO LADEIRA CARVALHO | ANGÉLICA DE CÁSSIA OLIVEIRA CARNEIRO | WAGNER DAVEL CANAL | RENATO VINÍCIUS OLIVEIRA CASTRO
Wood, in general, is a material with excellent properties; however, some features may limit its use. In this sense, various thermal treatments are emerging as alternatives to improve the technological properties of wood. In this context, this study aims at analyzing the effects of time and temperature (hydrothermal treatment and freezing) on the physical and mechanical properties of Eucalyptus grandis W. Hill ex Maiden. Three trees were selected, and only the heartwood was used to obtain the test body dimensions of 30 × 8 × 3 cm (length × width × thickness). The treatments were carried out at three temperatures of -20, 60, and 100°C, each at three exposure times (5, 10, and 15 h). Temperature treatment at -20°C was conducted in a domestic freezer, while the treatments at 60 and 100°C were administered in a Parr reactor, where the timber was submerged in water. Regardless of the exposure time, the timbers heat-treated at 100°C showed more efficiency, since this treatment unclogged the pores, reduced hygroscopicity, and promoted further darkening and uniformity of color, without changing the density and mechanical strength of the wood.
اظهر المزيد [+] اقل [-]QUALITY OF IRRIGATED APPLES IN THE SEMIARID REGION OF THE NORTHEAST OF BRAZIL
2017
CÍNTIA PATRÍCIA MARTINS DE OLIVEIRA | WELSON LIMA SIMÕES | JOSÉ ALIÇANDRO BEZERRA SILVA | PAULO ROBERTO COELHO LOPES | JOSTON SIMÃO ASSIS
The great solar radiation in the Brazilian semiarid region, combined with an adequate irrigation management, favors fruit production and quality of crops that were adapted to this region. The objective of this work was to evaluate the fruit quality of two apple cultivars grown in the Sub-Mid São Francisco River Valley under different irrigation water depths. A complete randomized block experimental design in a split -plot arrangement with five replications was used. The plots consisted of four irrigation water depths (ID) (60, 80, 100 and 120% of the reference evapotranspiration - ETo), the subplots consisted of two apple cultivars (C) (Julieta and Princesa) and the sub-subplots consisted of fruit positions in the tree canopies (FP) (east and west sides). The soluble solids content (SS), titratable acidity (TA), SS/TA ratio, pulp firmness (PF) and fresh weight (FW) of the fruits were evaluated. The factors evaluated showed no triple interaction between the evaluated factors, however, the SS and TA were significantly affected by them; the interaction between ID and C significantly affected the PF; the interaction between ID and FP significantly affected the PF, SS/TA ratio and FW; and the interaction between C and FP significantly affected the SS/TA ratio. The increase in water depth increased the fruit size of both cultivars, without compromising the post-harvest quality. The cultivar Princesa presented the best results regarding SS, TA, PF and FW, however, both cultivars had organoleptic characteristics within the recommended standards for commercialization. The fruits harvested on the west side presented better post-harvest quality.
اظهر المزيد [+] اقل [-]GROWTH AND SEED YIELD OF SUNFLOWER ON SOIL FERTILIZED WITH CASSAVA WASTEWATER
2017
MARA SUYANE MARQUES DANTAS | MARIO MONTEIRO ROLIM | ELVIRA MARIA REGIS PEDROSA | MANASSÉS MESQUITA DA SILVA | DANIEL DA COSTA DANTAS
Cassava wastewater is the liquid residue of the cassava flour processing and its application to the soil as fertilizer for agricultural crops is a good alternative to sources of nutrients for plants. In this context, the objective of this work was to evaluate the growth and seed yield of sunflower on soil fertilized with cassava wastewater. A randomized block experimental design with four replications was used, with six cassava wastewater rates (0, 8.5, 17, 34, 68 and 136 m3 ha-1) and six plant sampling times (15, 30, 45, 60, 75 and 90 days after sowing), using the sunflower cultivar Helio-250. The evaluated variables were total leaf area, leaf area index, leaf area ratio, specific leaf area, leaf weight ratio, shoot dry mass and sunflower seed yield. The use of cassava wastewater rate of 136 m3 ha-1 increases the seed yield, leaf area, leaf area index and shoot dry mass, and results in lower leaf area ratio, specific leaf area and leaf weight ratio of sunflower (cv. Helio-250) crops.
اظهر المزيد [+] اقل [-]INFLUENCE OF POTASSIUM LEVELS ON ROOT GROWTH AND NUTRIENT UPTAKE OF UPLAND RICE CULTIVARS
2017
ANTONIO CARLOS DE ALMEIDA CARMEIS FILHO | CARLOS ALEXANDRE COSTA CRUSCIOL | ADRIANO STEPHAN NASCENTE | MUNIR MAUAD | RODRIGO ARROYO GARCIA
Potassium (K) is an essential nutrient for upland rice growth, but little information on the effects of K on root growth and nutrient uptake capacity of upland rice is found. Therefore, an experiment was conducted under greenhouse conditions to evaluate the influence of soil K levels on root growth and nutrient uptake of four upland rice cultivars. A completely randomized experimental design, in a 4x4 factorial scheme (4 levels of K: 20, 40, 80, and 160 mg dm-3; 4 cultivars: Caiapó, BRS-Primavera, IAC-202, and Maravilha) was used, with four replications. Based on regression equations, the highest values of root length density would be found with 136 mg dm-3 of K. The root diameter and dry matter, shoot dry matter and shoot K concentration increased linearly with the increasing K rates. The shoot K concentration of the upland rice cultivars did not differ. The increased level of K in the soil reduced the shoot Ca concentration of intermediate and modern cultivars, and the shoot Mg concentration of all cultivars. The potassium fertilization increased the plant growth, but the magnitude of this effect varied according to the cultivar..
اظهر المزيد [+] اقل [-]COWPEA LEAF AREA, BIOMASS PRODUCTION AND PRODUCTIVITY UNDER DIFFERENT WATER REGIMES IN CASTANHAL, PARÁ, BRAZIL
2017
PAULO JORGE DE OLIVEIRA PONTE DE SOUZA | VIVIAN DIELLY DA SILVA FARIAS | MARCUS JOSÉ ALVES DE LIMA | THAYNARA FERNANDES RAMOS | ADRIANO MARLISOM LEÃO DE SOUSA
This work evaluated the effect of soil water availability on growth and productivity variables of cowpea in northeastern Pará, Brazil. The experiment was carried out in a field of 2,100 m2 at the experimental site of the Federal Rural University of Amazon, during the driest season of the years 2011, 2012 and 2013, in a completely randomised design with two treatments (irrigated and non-irrigated), both with 12 replications in the reproductive phase (2012 and 2013). Growth and productivity data were submitted to analysis of variance with two variation factors (water regime and experimental year) at 5% probability. Student's t -test at 5% probability was used in the means of the stomatal conductance data, since this was monitored only in 2012. Final biomass production presented a reduction of 54.3% in 2012 and 26.4% in 2013 as a result of water deficit (DEF) of 76 and 26 mm, respectively. Mean stomatal conductance was reduced by 73% in the grain-filling stage as a result of the lower water availability during this period. Average cowpea productivity under water deficit reached 1,257 kg ha-1 in 2012 and 1,396 kg ha-1 in 2013. The reduction in water supply over the reproductive period significantly decreased production by 72 and 41% (F test, p < 0.05) in 2012 and 2013, respectively. An accumulated water deficit during the reproductive phase caused a maximum LAI reduction of 47% in 2012 (DEF of 76 mm) and of 13% in 2013 (DEF of 26 mm).
اظهر المزيد [+] اقل [-]AGRONOMIC PERFORMANCE OF COWPEA CULTIVARS DEPENDING ON SOWING SEASONS IN THE CERRADO BIOME
2017
FERNANDO DA SILVA ALMEIDA | FÁBIO LUIZ CHECCHIO MINGOTTE | LEANDRO BORGES LEMOS | MÁRCIO JOSÉ DE SANTANA
The objective of this work was to assess the agronomic performance of cowpea cultivars depending on sowing seasons in the Cerrado biome. Thus, an experiment was conducted in Uberaba, State of Minas Gerais, Brazil, in a complete randomized block design, in a 6x3 factorial arrangement, using six cowpea cultivars ( BRS - Itaim , BRS - Guariba , BRS - Potengi, BRS - Cauamé , BRS - Novaera and BRS - Tumucumaque ) and three sowing seasons (Dec 14, 2012; Jan 14, 2013; and Feb 14, 2013), with four replications. The interaction between the cultivars and sowing seasons was assessed regarding the number of days for full flowering, number of days for pod maturation, number of trifoliate leaves, height of the first pod - bearing node, pod length, number of pods per plant, final plant population, 100 - grain weight and grain yield. The cowpea cultivars sown in December produced the lowest numbers of pods per plant and grains per pod, resulting in the lowest grain yields. The cultivar BRS - Tumucumaque had the highest grain yield in the January sowing. The highest grain yields were found in the February sowing, especially when the cultivars BRS - Itaim (3,439 kg ha - 1 ), BRS - Novaera (3,435 kg ha - 1 ), BRS - Guariba (3,168 kg ha - 1 ) and BRS - Potengi (3,107 kg ha - 1 ) was used.
اظهر المزيد [+] اقل [-]PROXIMATE COMPOSITION AND TECHNOLOGICAL CHARACTERISTICS OF DRY PASTA INCORPORATED WITH MICRONIZED CORN PERICARP
2017
JOÃO RENATO DE JESUS JUNQUEIRA | FAUSTO ALVES DE LIMA JUNIOR | GISELE SOUZA FERNANDES | MARIA CRISTINA DIAS PAES | JOELMA PEREIRA
Pastas are generally accepted all over the world, mainly because they are versatile, cheap and easy - to - prepare. They are not nutritionally balanced, since they provide mainly carbohydrates. As a result of this, it is important to use ingredients which could improve the nutritional deficiencies, without affecting the technological and sensorial characteristics. This study evaluated the effect of using wheat semolina and micronized corn pericarp (MCP), on the proximate composition, cooking quality and color of spaghetti type pasta. Spaghetti pasta was produced using wheat semolina with the incorporation of micronized corn pericarp, at levels of 0, 10, 20 and 30%. There were no significant differences (p > 0.05) between the formulated samples with regards to the contents of moisture and lipid, cooking time, weight gain and volume increase. As observed, supplementation with micronized corn pericarp presented significant difference on the contents of proteins, minerals, dietary fiber and solid soluble loss of the spaghetti pasta (p < 0.05). With increase in micronized corn pericarp concentration, the color difference became accentuated. The use of MCP appears to be viable, providing a nutritionally enriched product without further impairment on pasta quality.
اظهر المزيد [+] اقل [-]DEFINING MANAGEMENT ZONES BASED ON SOIL ATTRIBUTES AND SOYBEAN PRODUCTIVITY
2017
FABRICIO TOMAZ RAMOS | RAUL TERUEL SANTOS | JOSÉ HOLANDA CAMPELO JÚNIOR | JOÃO CARLOS DE SOUZA MAIA
Demarcating soil management zones can be useful, for instance, delimiting homogeneous areas and selecting attributes that are generally correlated with plant productivity, but doing so involves several different steps. The objective of this study was to identify the chemical and physical attributes of soil and soybean plants that explain crop productivity, in addition to suggesting and testing a methodological procedure for defining soil management zones. The procedure consisted of six steps: sample collection, data filtering, variable selection, interpolation, grouping, and evaluation of management zones. The samples were collected in an experimental area of 12.5 ha cultivated with soybean during the 2013/14 crop in Dystrophic Red Latosol, in Mato Grosso, Brazil. A total of 117 pairs of plant and soil samples were collected. Student’s t - test was used ( α = 0.02) to verify that the number of samples was adequate for correlation analysis. Results showed that only the P and Mn content in the grains explained (based on R 2 values) the variation in soybean grain productivity the area. Based on the interpolation of these contents by ordinary kriging, the fuzzy C - means algorithm was used to separate them into groups by similarity. Division into two groups was the best option, which could be differentiated by Mann – Whitney test (P < 0.05), resulting in a map with 10 management zones.
اظهر المزيد [+] اقل [-]GENETIC DIVERSITY IN ACCESSIONS OF Passiflora cincinnata Mast. BASED ON MORPHOAGRONOMIC DESCRIPTORS AND MOLECULAR MARKERS
2017
TIAGO VINÍCIUS BATISTA DO CARMO | LUIZA SUELY SEMEN MARTINS | ROSIMAR DOS SANTOS MUSSER | MAIRON MOURA DA SILVA | JOSÉ PEROBA OLIVEIRA SANTOS
Passiflora cincinnata Mast. has become more popular in the market because the unusual flavor of its fruits and natural beauty of its flowers, and has great potential for breeding programs of Passiflora edulis f. flavicarpa, because its resistance to diseases and drought. The objective of this work was to evaluate seven wild passion fruit (P. cincinnata) accessions, using morphological and agronomic descriptors and molecular markers type ISSR, to identify their morphoagronomic and genetic variabilities and potential for use in breeding programs. A randomized block experimental design was used with five replications and two plants per plot. Thirteen qualitative and twenty-one quantitative, vegetative and floral characteristics were used for morphoagronomic characterization. Twelve ISSR primers were evaluated for molecular characterization. Among the qualitative characteristics, only the color variations were significantly different between the accessions. According to the mean squares of the quantitative characteristics evaluated, obtained from analysis of variance, the means of accessions showed significant differences (p<0.01) for all characteristics. The IAL (internode average length) was the morphological descriptor that most contributed to diversity, with 43.12%, followed by DH5 (stem diameter at 5 cm height) and SW (sepal width). The average genetic similarity found was 68%. Despite the low genetic variability found among accessions, the primers UBC-887 and UBC-841 stood out with high percentage of polymorphism with 14 and 11 polymorphic fragments, respectively, and higher values of polymorphism information content (PIC), resolving power (RP) and marker index (MI), denoting suitability for use in diversity studies of P. cincinnata. Low variability was found among accessions evaluated.
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