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Результаты 61-70 из 241
RESIDUAL EFFECTS OF NITROGEN FERTILIZER WITH POLYMER-COATED UREA IN A CORN CROP
2017
TAYENE FRANCO MELLO | SALATIÉR BUZETTI | MARCELO CARVALHO MINHOTO TEIXEIRA | FERNANDO SHINTATE GALINDO | LAIS MENEGHINI NOGUEIRA
The use of nitrogenous fertilizer coated by polymers may reduce losses caused by volatilization, thus exposing this element to plants for a longer period of time. The objective of this work was to evaluate the residual effects of nitrogen in the form of conventional urea and urea coated by polymers in the production components and grain productivity of the first and second corn crops. The experiment was conducted in Selvíria - MS in a clay-type Oxisol during the corn crops of 2011/12 and 2012. The experiment was arranged as a randomized block design with four replications, with a factorial 4 x 4 treatment arrangement as follows: 4 doses of N (0, 40, 80 and 120 kg ha-1) and 4 forms of urea (conventional urea and urea coated by three different polymers). Treatments were applied at the time of corn sowing in the first season (2010/11) and second season (2011). The residual effects of nitrogen fertilization in the corn grown in the first crop season (2011/12) and the second crop season (2012) were then assessed. The polymer -coated urea did not differ compared to the conventional urea.
Показать больше [+] Меньше [-]MOLECULAR IDENTIFICATION OF Liriomyza sp. IN THE NORTHEAST AND SOUTHEAST REGIONS OF BRAZIL
2017
ELAINE CRISTINA BATISTA FERREIRA | MOISES THIAGO DE SOUZA FREITAS | KARLA DIANA DA SILVA SOMBRA | HERBERT ÁLVARO ABREU DE SIQUEIRA | ELTON LUCIO DE ARAUJO | VALDIR DE QUEIROZ BALBINO
In Brazil, species of the genus Liriomyza are widely distributed and have economic importance as they cause damage to at least 14 plant families, especially Solanaceae, Cucurbitaceae, Asteraceae, and Fabaceae. Studies suggest existence of a species complex within this genus, based on the presence of morphological similarities among the species Liriomyza trifolii (Burgess), L. sativae Blanchard and L. huidobrensis (Blanchard). The present study aimed to use DNA barcoding to establish new distribution records of L. sativae in distinct regions in Brazil, determine intra- and inter-population genetic diversity, and reconstruct the phylogeny of Liriomyza species using the DNA barcode sequences. Identity values were between 97% and 99%, confirming that all the examined Brazilian populations belonged to the species L. sativae. Phylogenetic analyses indicated the presence of a single clade of L. sativae, composed of seven populations. Intra-population analysis on individuals of these populations indicated low levels of nucleotide and haplotype diversity. The haplotype network indicated presence of only 14 haplotypes distributed among the Brazilian populations. The genetic similarities shared by the Brazilian populations of L. sativae suggest that these populations are closely related. Genetic patterns observed among populations of L. sativae might be associated with bottleneck events or founder effect during establishment of this leafminer in Brazil.
Показать больше [+] Меньше [-]POTENTIATION OF COPAÍBA OIL-RESIN WITH SYNTHETIC INSECTICIDES TO CONTROL OF FALL ARMYWORM
2017
WALDIANE ARAÚJO DE ALMEIDA | IGOR HONORATO LEDUÍNO DA SILVA | ANA CLÁUDIA VIEIRA DOS SANTOS | AURÉLIO PAES BARROS | ADALBERTO HIPÓLITO DE SOUSA
The control of Spodoptera frugiperda (J. E. SMITH) (Lepidoptera: Noctuidae) has been carried out mainly with pyrethroids and organophosphates insecticides. The continuous and indiscriminate use of synthetic insecticides, for decades, has led to the selection of resistant populations and has caused concerns for human health and the environment. An alternative is the use of botanical insecticides, including through the mixtures with synthetic insecticides. This study aimed to investigate the toxicity of copaiba oil-resin mixtures (COR) with deltamethrin, beta-cyfluthrin, beta-cypermethrin, methomyl, triazophos and chlorpyrifos for S. frugiperda. Bioassays were performed in the laboratory using newly hatched caterpillars on a contaminated surface (filter paper). Initially, concentration-mortality curves were established for each insecticide and COR. Based on the results, experiments were conducted to verify the effect of the COR mixtures with synthetic insecticides in the proportions of 1:1 (LC25 + LC25) on larvae of S. frugiperda. Additionally, COR concentration-response curves were established by adding 1/8 of the recommended rate of each insecticide. Notably, the use of this concentration for all insecticides was previously determined in bioassays, and no significant toxicity was found for S. frugiperda caterpillars. It was found that the toxicity of COR increased substantially by adding synthetic insecticides, especially with lower mixtures with beta-cypermethrin, methomyl and triazophos.
Показать больше [+] Меньше [-]PERFORMANCE OF INOCULATED COMMON BEAN IN RESPONSE TO DIFFERENT COVER CROPS AND DESICCATION TIMES
2017
ANA PAULA SANTOS OLIVEIRA | CEITON MATEUS SOUSA | ENDERSON PETRÔNIO DE BRITO FERREIRA
The common bean requires high levels of nitrogen (N) to achieve high productivity, which can be supplied, at least partially, by the biological nitrogen fixation (BFN). Two field experiments were carried out in the winter season of 2015 aiming to evaluate the effects of different cover crops, desiccation times and the agronomic performance of the common bean inoculated with rhizobia. The experiments were assembled in a randomized block design with four replications, in a factorial split-plot arrangement with two additional treatments (5x4x2+2). The factors were composed of five cover crops, four desiccation times, two seed inoculation treatments and two additional controls (TN = 90 Kg N ha-1 and T0 = without N and without inoculation). The variables analyzed in the cover crops were dry mass (DM) and total nitrogen (Total-N). With the common bean, the chlorophyll content (CC), the number of nodules (NN), the nodule dry weight (NDW), the shoot dry weight (SDW), the root dry weight (RDW) and the grain yield (GY) were evaluated. The results showed that the agronomic performance of the common bean was not affected by the desiccation times of the cover crops, although the amount of Total-N accumulated by cover crops was influenced by sowing times. Inoculation of the common bean promoted an increase in the NN, NDW, CC and SDW. Higher GY of the common bean was achieved with its cropping after Brachiaria brizantha, Brachiaria ruziziensis, millet and fallow.
Показать больше [+] Меньше [-]INTERCROPPING OF CARROT X COWPEA-VEGETABLES: EVALUATION OF CULTIVAR COMBINATIONS FERTILIZED WITH ROOSTERTREE
2017
ARNALDO PANTOJA DA COSTA | FRANCISCO BEZERRA | MAIELE LEANDRO DA SILVA | JAILMA SUERDA SILVA DE LIMA | AURÉLIO PAES BARROS | VÂNIA CHRISTINA NASCIMENTO PORTO
This study aimed to evaluate combinations of cowpea-vegetable cultivars with carrot cultivars in a strip-intercropping system fertilized with roostertree. The work was conducted at the Experimental Farm "Rafael Fernandes" of the Universidade Federal Rural do Semi-Árido (UFERSA) during September 2013 to March 2014. The experimental design was a randomized complete block with four replications and treatments arranged in a factorial 4 x 2 scheme, resulting from the combination of four cowpea -vegetable cultivars (BRS Tumucumaque, BRS Cauamé, BRS Guariba and BRS Itaim) with two carrot cultivars (Brasilia and Alvorada). The characteristics evaluated in cowpea-vegetables were: number of green pods per area, productivity and dry weight of green pods, number of grains per pod, productivity of grains, weight of 100 grains, and dry weight of green grains. In the carrot cultivars, we evaluated total, commercial, and classified productivity of roots. The cultivar combinations were evaluated in terms of land equivalent ratio, productive efficiency index, score of the canonical variable, as well as indicators of gross and net income, rate of return, profit margin, and modified monetary advantage. The intercropping system using the cultivars BRS Guariba (cowpea) and Alvorada (carrot) achieved highest agronomic/biological efficiency. Highest economic efficiency was achieved with the combination BRS Tumucumaque (cowpea) and Brasilia (carrot).
Показать больше [+] Меньше [-]METHODS FOR INOCULATION WITH Fusarium guttiforme AND GENETIC RESISTANCE OF PINEAPPLE ( Ananas comosus var. comosus )
2017
WANDREILLA MOREIRA GARCIA | WILLIAN KRAUSE | DEJÂNIA VIEIRA DE ARAÚJO | ISANE VERA KARSBURG | RIVANILDO DALLACORT
The objective of this work was to evaluate Fusarium guttiforme inoculation methods and genetic resistance of pineapple accessions. Thus, three experiments were conducted: pathogen inoculation of different leaf types ( B, D and F ) of pineapple (1), pathogen inoculation of pineapple cuttings and detached D leaves (2), and identification of resistance to fusariosis in 19 pineapple accessions (3) sampled in the State of Mato Grosso, Brazil. The cultivars Pérola (susceptible to fusariosis) and BRS - Vitória (resistant to fusariosis) were used as controls. The fusariosis severity was evaluated at 10, 15, 20, 25 and 30 days after inoculation with F. guttiforme . The lesion diameters (severity level) were used in order to calculate the area under the disease progress curve (AUDPC). The inoculation of detached D leaves was the most efficient, fast and inexpensive method, and the one that most satisfactorily reproduced the disease symptoms. The period of 10 to 20 days after inoculation of the D detached leaves with the pathogen is the most suitable to evaluate the resistance of pineapple accessions to fusariosis. The lowest lesion area and AUDPC was found in the accession 1, in all evaluations. Thus, the accession 1 can be used in pineapple breeding programs for resistance to fusariosis.
Показать больше [+] Меньше [-]PYROLIGNEOUS LIQUOR EFFECT ON IN AND EX VITRO PRODUTION OF Oeceoclades maculata (Lindl). Lindl.
2017
CARLOS JOSÉ DA SILVA | ISANE VERA KARSBURG | POLIANA COQUEIRO DIAS | TATIANA PAULA MARQUES DE ARRUDA
Pyroligneous fraction from wood carbonization can be used for several purposes. In this sense, this study aimed to test a pyroligneous liquor extracted during carbonization of forest residues for the vegetative development of the orchid Oeceoclades maculata. The concentrations of pyroligneous liquor used in the treatments were T1 = 0 mL L−1, T2 = 1 mL L−1, T3 = 2 mL L−1, T4 = 3 mL L−1, T5 = 4 mL L−1, and T6 = 5 mL L−1. These treatments were tested together with and without activated charcoal for in vitro and ex vitro propagation. In vitro developed protocorms were assessed according to development or not, the presence of fungus, leaves, and roots. For ex vitro evaluations, leaf size, size, the number of roots, total plant height, and the number of buds were assessed. Possible differences between treatments were tested by means of analysis of variance (ANOVA) and Tukey’s test at 5% significance. The use of pyroligneous liquor at low doses was significant in vegetative tissue development as well as for root and leaf formations in O. maculata seedlings since it presents all the essential mineral elements to the structural development of these plants.
Показать больше [+] Меньше [-]FOAM-MAT DRYING KINETICS OF KEITT MANGO PULP
2017
MARY KARLLA ARAÚJO GUIMARÃES | ROSSANA MARIA FEITOSA DE FIGUEIRÊDO | ALEXANDRE JOSÉ DE MELO QUEIROZ
This study aimed to assess the foam-mat drying kinetics of mango pulp (cv. Keitt) adding 1% Emustab® and 1% Super Liga Neutra®, for a whipping time of 20 minutes, dried in a forced-air convection oven at different temperatures (50, 60 and 70oC) and foam layer thicknesses (0.5, 1.0 and 1.5 cm). Drying kinetic data were used to build drying curves and then fit to Page, Henderson, Henderson and Pabis, Logarithmic and two-term Exponential models. Both temperature and foam layer thickness influenced drying time, which reached the shortest value at the highest temperature and smallest thickness. The Page model provided the best fit to the experimental drying curve data.
Показать больше [+] Меньше [-]MORPHOPHYSIOLOGICAL RESPONSES OF COWPEA GENOTYPES TO IRRIGATION WATER SALINITY
2017
JOÃO PEDRO ALVES DE AQUINO | ANTÔNIO AÉCIO DE CARVALHO BEZERRA | FRANCISCO DE ALCÂNTARA | CARLOS JOSÉ GONCALVES DE SOUZA LIMA | RAYLSON RODRIGUES DE SOUSA
Cowpea is broadly cultivated worldwide, especially in semi-arid or arid regions where soil or irrigation water salt contents can negatively influence the species’ productive capacity. The objective of this study was to evaluate the morphophysiological responses of cowpea genotypes to irrigation water salinity. The experiment was conducted in a greenhouse, under a completely randomized design with nine replications and in a 5x3 factorial scheme. Treatments consisted of five levels of irrigation water electrical conductivity - EC (EC0: 0.55; EC1: 1.60; EC2: 3.20; EC3: 4.80 and EC4: 6.40 dS m-1), applied from the 15th day after sowing (DAS), and three cowpea genotypes (G1: BRS Imponente; G2: MNC04-795F-168 and G3: MNC04-795F-159). EC increases at 35 DAS promoted stem diameter reductions of 8.0% (G1), 11.4% (G2), and 7.7% (G3), indicating different resistance to salinity by each genotype. Leaf area reductions at 25 and 38 DAS were 30.9% and 38.8% for EC0 and EC4, respectively. The BRS Imponente cultivar presented a performance superior to those of G2 and G3 in relation to stem diameter and stem dry matter at 25 DAS, and root-shoot and root-leaf ratios at 38 DAS.
Показать больше [+] Меньше [-]GENOTYPIC VARIATION ON THE ANTIOXIDATIVE RESPONSE OF COWPEACULTIVARS EXPOSED TO OSMOTIC STRESS
2017
EDILENE DANIEL DE ARAÚJO | ALBERTO SOARES DE MELO | MARIA DO SOCORRO ROCHA | REBECA FERREIRA CARNEIRO | MAURISRAEL DE MOURA ROCHA
The cowpea Vigna unguiculata (L.) Walp., also known as cowpea, is of fundamental socioeconomic importance to the northeast of Brazil, and has become one of the main sources of protein in the diet of the rural population. However, in this region, it has become necessary to identify genotypes that are better adapted to drought. In addition, research is needed regarding the action of substances that promote tolerance to stress factors. The aim of this study was to evaluate the antioxidative response of cowpea cultivars under osmotic stress conditions using potassium nitrate as an attenuator. Five osmotic potentials were tested in the substrate (0.0, −0.2, −0.4, −0.6, and −0.8 MPa), and three seed treatments (pre-soaking in distilled water, pre-soaking in potassium nitrate, and without pre-soaking) were tested in three cowpea cultivars (BRS Itaim, BRS Aracê, and BRS Potengi). The design was randomized with 45 treatments and four replications. The data were submitted to analysis of variance (P < 0.05), and in cases of significance, regression analysis was conducted to quantitate the factors. Our results indicate that an increase in proline content in cowpea plants may be seen as indicative of the intensity of water stress on germination and the initial stages of growth of the plant. The BRS Itaim cultivar best tolerates drought conditions with the application of potassium nitrate, given the increased activity of antioxidant enzymes such as superoxide dismutase, catalase, and ascorbate peroxidase.
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