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Результаты 211-220 из 240
MICROBIAL INTERACTIONS IN THE DEVELOPMENT OF THE BIOMASS OF GLIRICIDIA
2018
TAMIRIS APARECIDA DE CARVALHO SANTOS | GEOVANIA DOS SANTOS MENEZES | JESSICA SILVA SANTOS | LARISSA DE SOUZA GOIS | SÉRGIO LUIZ MENDONÇA NASCIMENTO | REGINA HELENA MARINO
The objective of this work was to evaluate the interaction of microorganisms and phosphorus dosages in the development of gliricidia. The experimental design was completely randomized with six treatments (control, native microbial inoculant, and four arbuscular mycorrhizal fungi isolates: UFLA05 - Gigaspora albida, UFLA351 - Rhizoglomus clarum, UFLA372 - Claroideoglomus etunicatum, and UFLA401 - Acaulospora morrowiae), with four replicates. The parameters evaluated were: height plant, the number of branches, shoot and root dry mass matter, root length and volume, leaf phosphorus, mycorrhizal colonization, the number of spores of the arbuscular mycorrhizal fungi, the number of nodules of nitrogen fixing bacteria, and the presence of endophytic dark septate fungi, after 95 days of inoculation. The high mycorrhizal colonization of gliricidia does not guarantee an increase in biomass, which depends on the interaction of the arbuscular mycorrhizal fungi, the endophytic dark septate fungi, the nitrogen fixing bacteria, and the endophytic bacteria. Gliricidia was responsive to the inoculation of the native microbiota, UFLA372 and UFLA401. Mycorrhizal colonization by UFLA401 was influenced by the presence of nitrogen fixing bacteria. Gliricidia was not responsive to the inoculation of UFLA05 and UFLA351. The presence of the endophytic dark septate fungi did not inhibit mycorrhization and the formation of nodules of nitrogen fixing bacteria in gliricidia.
Показать больше [+] Меньше [-]SUGARCANE CROPS WITH CONTROLLED WATER DEFICIT IN THE SUB-MIDDLE SÃO FRANCISCO VALLEY, BRAZIL
2018
WELSON LIMA SIMÕES | MARCELO CALGARO | MIGUEL JULIO MACHADO GUIMARÃES | ANDERSON RAMOS DE OLIVEIRA | MÍRIAN PAULA MEDEIROS ANDRÉ PINHEIRO
Sugarcane is one of the most affected crops by water scarcity. The efficient use of the irrigation water is an alternative to minimize this problem. The objective of this work was to evaluate biometric parameters, yield, and technological quality of sugarcane plants subjected to different controlled water deficit regimes in the sub-middle São Francisco Valley, Brazil. The experiment was conducted in a randomized block design, in two crop cycles, with three replications, with ten treatments consisted of three controlled water deficits (15%, 30%, and 45% of the crop evapotranspiration - ETc), applied at three development stages of the plant - sprouting and tillering (Stage I), grand growth (Stage II), and maturation (Stage III) - and a control with 100% of the ETc throughout the entire crop cycle. The controlled water deficit did not affect the technological quality of the sugarcane in any development stage. The sugarcane yield was higher when using a controlled water deficit of 30% of ETc in the sprouting and tillering stages of the plants. The water deficit of 15% of ETc is recommended for the grand growth, or maturation stages of the sugarcane plants for a greater water use efficiency of the production system.
Показать больше [+] Меньше [-]GROWTH AND YIELD OF WHEAT IN RESPONSE TO SEED VIGOR AND SOWING DENSITIES
2018
JULIA ABATI | CRISTIAN RAFAEL BRZEZINSKI | CLAUDEMIR ZUCARELI | JOSÉ SALVADOR SIMONETI FOLONI | FERNANDO AUGUSTO HENNING
In wheat crops, it is often observed that the number of plants per area is lower than that of viable seeds used, which may be related to both environmental conditions and seed vigor. The aim of this study was to assess the effect of seed vigor level at different sowing densities on growth, development, and grain yield in wheat cultivars. The experiments were conducted in Londrina and Ponta Grossa, PR, Brazil, under a randomized block design in a 2 × 2 × 3 factorial scheme, with four replications. Two seed vigor levels (high and low), two sowing densities (200 and 400 viable seeds per m2), and three wheat cultivars (BRS Sabiá, BRS Gaivota, and BRS Gralha Azul) were assessed. In order to assess growth and development, plant samples were collected at the phenological stages of seedling growth, stem elongation, booting, and ear emergence. We assessed the emergence of seedlings, height and dry matter of plant shoot, and grain yield. The sowing density of 200 seeds per m2 led to a higher shoot dry matter production per plant at the stages booting and ear emergence. The cultivar BRS Sabiá presented the highest grain yield in Londrina, while BRS Sabiá and BRS Gralha Azul presented the highest grain yield in Ponta Grossa. High vigor seeds favor stand establishment, growth and development of plants at early phenological stages, and grain yield of wheat.
Показать больше [+] Меньше [-]AGRONOMIC CHARACTERISTICS OF THE PACOVAN ORGANIC BANANA IN IRRIGATION SYSTEMS IN THE AÇU-RN VALLEY
2018
JÚLIO JUSTINO DE ARAÚJO | VANDER MENDONÇA | MARIA FRANCISCA SOARES PEREIRA | MATHEUS DE FREITAS SOUZA
The banana tree is grown in an extensive tropical region throughout the world, usually by small producers. The present work had the objective of evaluating irrigation systems in banana production in the Açu-RN Valley, aiming at alternatives so that they can be recommended to farmers in the Açu Valley region. The experiment was carried out in the area of the School Farm of the IFRN Campus Ipanguaçu, located in the municipality of Ipanguaçu-RN. The experiment was carried out in a randomized complete block design with subdivided plots and eight replications. The irrigation systems were: irrigation, drip irrigation, micro sprinkler and alternative irrigation. The plots were composed of eight useful plants with spacing in double rows 4 x 2 x 2 m. Eight characteristics related to production were evaluated: bunch mass (MC); number of leaves (NP); number of fruits per cluster (NFC); mean mass of the leaves (MMP); diameter of the fruit of the second seed (DF2P); length of the fruit of the second seed (CF2P); mean fruit mass (MMF); productivity (Prod). The data were submitted to analysis of variance and the means were compared by the Tukey test at 5% of probability. In the first cycle of production the sprinkler irrigation system was the one that presented better results the productivity of the Pacovan banana tree; in the 3rd cycle the alternative irrigation system was the one that showed better results the productivity of the banana tree; where the electrical conductivity correlated with the sodium adsorption ratio in the irrigation water, contributed to a moderate limitation of use.
Показать больше [+] Меньше [-]MICROBIAL BIOMASS AND ENZYMATIC ACTIVITIES IN SANDY SOIL CULTIVATED WITH LETTUCE INOCULATED WITH PLANT GROWTH PROMOTERS
2018
Marcele de Cássia Henriques dos Santos Moraes | Erika Valente de Medeiros | Dayane da Silva de Andrade | Leandro Dias de Lima | Ivonaldo Carlos da Silva Santos | Argemiro Pereira Martins Filho
Plant growth promoter microorganisms have been studied as important tools for increasing crop production. Lettuce is the most consumed hardwood crop in the world. Numerous microorganisms are capable of acting in a beneficial way in the growth of this culture. The objective of the present study was to evaluate the efficacy of Trichoderma and Pseudomonas on the microbial biomass, enzymatic activities in sandy soil and lettuce production. The experimental design was completely randomized with ten replicates and treatments: CONT (absolute control); CM (control with cattle manure fertilization); CMB (with fertilization and Pseudomonas sp.); CMF (with fertilization and T. aureoviride) and CMBF (with fertilization and the two microorganisms combined). The fertilizer used was organic with cattle manure in a dose recommended for the culture. This study evaluated the production of lettuce, microbial biomass and the enzymatic activity of acid phosphatase, alkaline phosphatase and urease. The combined application of CMBF was efficient in increasing lettuce production, because it increased 85% of the cv. Veronica cultivated on sandy soil. The combined use of plant growth promoting microorganisms resulted to an increase in microbial biomass. In lettuce crops, it is recommended to use T. aureoviride URM 5158 and Pseudomonas sp. UAGF 14 in lettuce crops, because improved lettuce production, improves the biochemical quality of soils measured by absolute and specific enzymatic activities per unit of microbial biomass.
Показать больше [+] Меньше [-]WOODY NECROMASS STOCK IN MIXED OMBROPHILOUS FOREST USING DIFFERENT SAMPLING METHODS
2018
KARINA HENKEL PROCEKE DE DEUS | AFONSO FIGUEIREDO FILHO | ANDREA NOGUEIRA DIAS | IZABEL PASSOS BONETE
The objective of this study was to quantify the necromass stock in a Mixed Ombrophilous Forest (MOF) fragment in the National Forest of Irati, State of Paraná, Brazil. Two sampling methods were tested: FA1, consisting of a fixed area (FA) approach with sample units measuring 2,500 m2 (50 m × 50 m); and FA2, consisting of fixed area sampling units measuring 500 m2 (10 m × 50 m) and line intercept sampling (LI) using 50 m lines. Data were collected on permanent sample plots installed in the area, consisting of 25 square blocks of 1 ha. Fallen dead wood pieces with a diameter = 10 cm were used in the analysis. The dead wood was classified into three degrees of decomposition, and masses were calculated as the corresponding density at each class. The tested sampling methods were evaluated using coefficient of variation and relative sampling error, and the nonparametric Kruskal-Wallis test was used to compare the results between the methods. Volume size of fallen dead wood did not statistically differ between the methods, but variation in necromass volume was lower in the FA1 method, whereas the FA2 method had a smaller sampling error. Overall sampling error ranged from 23.4-27.92%; lowering the sampling error to 15% would require a high sampling intensity (FA1: 42 area units a.u., FA2: 99 a.u., and LI: 236 a.u.). Total necromass weights amounted to 4.67 Mg.ha-1 (FA1); 5.16 Mg.ha-1 (FA2) and 4.58 Mg.ha-1 (IL), and carbon stock estimates were 2.00 Mg.C.ha-1 (FA1); 2.20 Mg.C.ha-1 (FA2) and 1.96 Mg.C.ha-1 (IL).
Показать больше [+] Меньше [-]EXPLAINING THE WATER-HOLDING CAPACITY OF BIOCHAR BY SCANNING ELECTRON MICROSCOPE IMAGES
2018
RUBENS SONSOL GONDIM | CELLI RODRIGUES MUNIZ | CARLOS EDUARDO PACHECO LIMA | CARLOS LEVI ANASTÁCIO DOS SANTOS
Biochar is a solid material formed during biomass thermochemical decomposition processes. This organic compound has particular properties that may cause effects on soils depending on its feedstock and processing conditions. Thus, the characteristics and purpose of use of this material must be recognized prior to its use. Two types of biochar, derived from different wood sources, were compared, one from caatinga biome species and another from cashew trees. Two species from caatinga biome were used, jurema-preta (Mimosa tenuiflora Willd. Poir.), and marmeleiro (Croton sonderianus Müll. Arg.). This study aimed to identify the best biochar material regionally available to increase water-holding capacity in the soil, based on laboratory tests and microstructural porosity evaluation. Biochar from Caatinga wood demonstrated an improved water-holding capacity if compared to cashew wood biochar. The particle diameters of 2 and 4 mm showed the highest levels, which were 2,268 g.g-1 for caatinga wood and 0.574 g.g-1 for cashew wood biochars, respectively. While the smaller quantities of macropores and a larger number of micropores (smaller radius) could explain the higher water-holding capacity for biochar from caatinga wood, the thick lignified cell walls of biochar from cashew wood support the idea of a hydrophobic effect contributing to water lower holding capacity.
Показать больше [+] Меньше [-]REACTION OF BANANA CULTIVARS TO THE Meloidogyne javanica X Fusarium oxysporum f. sp. cubense COMPLEX
2018
LEANDRO DE SOUZA ROCHA | ROBERT FELIX DE SANTANA | ANA CRISTINA FERMINO SOARES | FERNANDO HADDAD
The interaction Fusarium oxysporum f. sp. cubense (Foc) x nematode and the genetic variability of Foc are the main problems with potential to affect the use of resistant varieties in the management of the Panama disease. The objective of this work was to evaluate the interaction between Foc and Meloidogyne javanica on the banana of the Prata Anã, Grande Naine and BRS Princesa cultivars. The experiment was conducted in a randomized block design, with six treatments and ten replications, which differed in the inoculation time of each pathogen. Simultaneous inoculation with Foc and M. javanica, inoculation with Foc one week before inoculation with M. javanica, and inoculation with M. javanica one week before inoculation with Foc. In addition to the controls, Foc isolated, M. javanica isolated, and cultivars without the pathogens. The seedlings were transplanted in 3-liter pots with sterile soil infested with 40 grams of Foc inoculum at the concentration of 1x106CFU/gram and 1000 eggs and J2 of M. javanica. At the end of 56 days, the treatments with 'Grande Naine' presented the highest reproduction factors of M. javanica. In the 'Prata Anã' no interaction was observed between Foc x M. javanica. The treatments with simultaneous inoculation of the two pathogens, and with Foc a week before, in the 'BRS Princesa', presented the highest external disease indices (DI), which promoted the highest AUDPC. The highest internal DI were observed in the treatments Foc+Mj+Grande Naine, Foc+Mj+BRS Princesa, Mj+Grande Naine+Foc and Foc+BRS Princesa+Mj. The simultaneous presence of M. javanica and Foc increases the severity of the Panama disease in Grande Naine and BRS Princesa cultivars.
Показать больше [+] Меньше [-]PARASITISM BY VARROA AND Nosema sp. IN BEEHIVES USED FOR APPLE TREE POLLINATION
2018
LUCAS DE ALMEIDA BIZOTTO | REGIS SIVORI SILVA DOS SANTOS | MARI INÊS CARISSIMI BOFF
The apple tree depends on cross-pollination for adequate fruiting. The objective of this study was to evaluate the rate of parasitism by Varroa destructor mites and the infection rate of Nosema sp. in hives of Apis mellifera (Linnaeus) used in pollinating services in apple orchards in the municipality of Vacaria, Rio Grande do Sul state, Brazil. The study evaluated the sanitation of beehives before, during, and after apple orchard pollination. Natural parasitism by V. destructor and the presence of Nosema sp. spores were evaluated in hives from areas of forest and canola cultivation (in the 2014/2015 harvest), and from areas of forest and eucalyptus reforestation (2015/2016 harvest). In both harvests, the average rate of parasitism in the hives by V. destructor ranged from 3.0 to 6.7%. The levels of parasitism increased during the pollination period in hives from canola-cultivated areas (2014/2015 harvest), but not in those from the forest and eucalyptus reforestation areas. Spores of Nosema sp. were observed in hives in the 2014/2015 harvest but not in the 2015/2016 harvest. The levels of natural parasitism by V. destructor in A. mellifera hives used in pollination services remained low, and was within the levels reported for the southern region of Brazil. Additionally, the levels of Nosema sp. infection in the hives was low.
Показать больше [+] Меньше [-]USE OF TREATED SEWAGE AS WATER AND A NUTRITIONAL SOURCE FOR BEAN CROPS
2018
CLEY ANDERSON SILVA DE FREITAS | JOSÉ ADEILSON MEDEIROS DO NASCIMENTO | FRANCISCO MARCUS LIMA BEZERRA | RONNEY MENDES MAGALHÃES DE LIMA
Considering the relevance of the reduction or replacement of fresh water supplies for irrigation, to mitigate the use of agricultural fertilizers and to improve sustainability, this study aimed to evaluate water and nutritional efficiency of treated sewage in cowpea plots. The experiment was conducted in the city of Tianguá-CE, on land belonging to the Water and Sewage Treatment Company of Ceará. It used a randomized block design for the arrangement of split plots. The plots contained two water sources (treated sewage and well water). The subplots contained four irrigation levels based on potential evapotranspiration (50%, 75%, 100%, and 125% of ETc) and the sub-subplots contained four nitrogen, phosphorous, and potassium (NPK) levels (0%, 33%, 66%, and 99% of the nutritional recommendations for cowpea cultivation). The yield variables, number of pods per plant, bean numbers per pod, and bean production, were improved with increased irrigation, regardless of the water source. Examining NPK levels in particular, yields differed depending on the water source. The use of treated domestic wastewater for bean irrigation can replace up to 100% of commercial fertilizers.
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