Vicente Gianluppi

Inoculação de Bradyrhizobium em soja por pulverização em cobertura

The objective of this work was to evaluate a Bradyrhizobium inoculation method on soybean by spraying inoculant over plants. An experiment was conducted in the Cerrado of Roraima. Treatments tested were: control without inoculation; standard inoculation method with two doses of inoculant per hectare applied on seeds; inoculation with threefold standard inoculation dose applied 18 days after plants emergence (DAE); fertilization with 200 kg ha-1 of nitrogen, without inoculation. The inoculation by spraying on covering increased nodulation and plant dry matter in the 45 and 60 DAE. It also increased significantly grain yield and N content, similarly to N fertilization treatment, and was superior to the control, and inferior to the standard inoculation related to grain yield.

Produtividade de forragem e composição química de Stylosanthes capitata cv. Lavradeiro sob níveis de fósforo

The effects of phosphorus levels (0, 40, 80 and 120 kg of P2O5 ha) on green dry matter (GDM), chemical composition and nodulation of Stylosanthes capitata cv. Lavradeiro were evaluated under field conditions in Roraima ́s savannas. Phosphorus fertilization increased significantly (P<.05) GDM yields, nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg) and potassium (K) concentrations and number and dry weight of nodules. Maximum GDM yields and Ca, Mg and K contents were obtained with the application of 89.4; 56.2; 113.1 and 75.6 kg of P2O5 ha, respectively, while the N and P contents and number of nodules were directly proportional to P levels. The P critic level, related to 90% of GDM maximum production, was estimated at 2.43 g kg. The P efficiency utilization was inversely proportional to the P rates applied.

Produtividade de forragem e micorrrização de pastagens de Trachypogon plumosus sob adubação fosfatada

The effect of phosphate fertilization (0, 30, 60, 90 and 120 kg of P2O5 ha) on green dry matter (GDM) yield and the occurrence of arbuscular mycorrhiza fungi (AMF) of Trachypogon plumosus pastures was evaluated under field conditions of Roraima’s savannas. Phosphate fertilization positively and significantly (P<0.05) affected GDM, phosphorus concentrations and extraction, but linearly reduced spore numbers and root colonization rates by AMF. Maximum GDM yields, phosphorus concentrations and uptake were obtained with the application of 91.8; 76.7 and 82.6 kg of P2O5 ha, respectively. The phosphorus efficiency utilization was inversely proportional to the phosphorus rates applied.

POTENCIAL FISIOLÓGICO DE SEMENTES DE GENÓTIPOS DE SOJA PRODUZIDOS EM DIFERENTES AMBIENTES DE CERRADO EM RORAIMA

Several factors can determine the physiological quality of the seeds, among them we can highlight the genotype caused by the physiological maturation, defined by the weight of dry mass, germination and vigor. The objective was to determine the physiological potential of soybean genotype seeds produced in three cultivation ENCICLOPÉDIA BIOSFERA, Centro Científico Conhecer Goiânia, v.15 n.27; p. 2018 232 environments in the cerrado of Roraima. The experiments were carried out in three environments in the cerrado of Roraima and in the Laboratory of Seed Analysis (LAS) of Embrapa Roraima in 2017. Soybean seeds of thirty five genotypes produced in three environments were evaluated (Água boa experimental field / Embrapa RR AB, Fazenda Livramento FL, Fazenda São Pedro FSP) for evaluation of mass of 1000 seeds, productivity, first germination count, germination test, emergence of field seedlings, field emergence velocity and electrical conductivity. The design used in the field was in blocks and in the laboratory was completely randomized formed by the factorial scheme (3x35). The data obtained from the measured variables were submitted to analysis of variance with application of the Scott-Knott test for different genotypes and Tukeys test for different environments at 5% probability. It was verified that there was significant interaction at 5% of probability between environments and the analyzed genotypes. For the variables measured, M. Soy 8372 IPRO produces seeds with greater vigor in the Água Boa environment, while BRASBT13-0225 in Farm Livramento environment, and Sambaiba 05 IPRO in the environment Farm Saint Peter. None of the 35 genotypes present greater vigor in the three environments. The Farm Livramento environment produces more seeds and less vigor.

Produtividade de forragem, composição química e morfogênese de Megathyrsus maximus cv. Mombaça sob períodos de descanso

The effects of rest periods (14, 21, 28, 35, 42 and 49 days) on green dry matter (GDM) yield, chemical composition and morphogenetic and structural characteristics of Megathyrsus maximus cv. Mombaça were evaluated under natural field conditions. GDM yields and regrowth increased consistently with highest rest periods. The leaf appearance and leaf expansion rates are inversely proportional to the rest periods, occurring the inverse for average leaf length, leaf area index and foliar senescence rate. Maximum GDM yields, regrowth yields, number of leaves tiller, average leaf length and leaf area index were obtained with rest periods at 36.4; 39.2; 40.8; 39.6 and 41.3 days. These data suggest that grass grazing at 35 to 42 days of rest period were optimal for obtain maximum yields and regrowth of rich forage.

Adubação nitrogenada e consorciação de Trachypogon plumosus com Stylosanthes capitata cv. Lavradeiro sob diferentes densidades de semeadura

The effect of nitrogen levels (0, 40, 80, 120, 160, and 200 kg of N ha1) on pure pastures of Trachypogon plumosus and the sowing densities of Stylosanthes capitata cv. Lavradeiro (1.0; 2.0; 3.0 and 4.0 kg of seeds ha-1) on forage yield, botanical composition and apparent fixation and transfer of nitrogen (N) was evaluated under field conditions. Nitrogen fertilization quadratically affected grass forage yields and its nitrogen content, and the maximum values were estimated by the application of 154.6 and 155.7 kg N ha-1, respectively. The legume forage yield was directly proportional to the densities of its sowing, occurring the opposite for the grass forage yield. The forage yields of the grass-legume mixture, independently of legume sowing density, were higher than those showed by the grass grown alone and for all doses of N evaluated. The use of legume sowing densities between 2.0

Variability among BRS 8381 soybean (Glycine max (L.) Merrill.) yield components under different liming rates and sowing densities on a savanna in Roraima, Brazil

The aim of this research was to evaluate variability among BRS 8381 soybean yield components, under different sowing densities and two amounts of limestone applications on a savanna in Roraima. The seeds were sown to provide five plant populations (10, 14, 18, 22 and 26 linear m-1), in plots with the application of 1.5 and 4.5 t ha-1 of limestone. Experimental plots consisted of four 5-meter long do 5 rows spaced 0.50 cm from each other. The experimental design was of randomized blocks in a factorial scheme with four replications. To evaluate the proposed variables, plants placed within the measurable area of each plot were collected and the following parameters were assessed: plant height, height of insertion of the first pod, stem diameter, number of nodes on the main stem, number of stems per plant, total number of pods per plant, number of grains per pod. Of the total number of plants harvested, 20 were randomly selected and evaluated individually. In addition to the aforementioned parameters, number of pods on the four upper nodes of the plant, dry mass of the plant and dry mass of grain were also evaluated. The apparent harvest index, 100-grain mass and yield estimate were also obtained. The BRS 8381 cultivar grown with 10 plants per linear meter of row presented greater plant dry mass, dry mass of grain, dry mass of hull and number of pods and twigs in both environments. The maximum grain yield was obtained with a plant distribution of 22 plants m-1 of row. The cultivar BRS 8381 is recommended with liming at 4.5 t ha-1 of dolomitic limestone under the edaphoclimatic conditions of the present study, due to its high phenotypic plasticity and higher performance in the production components. Para citar este articulo Smiderle, J., Gianluppi, D., Gianluppi, V. & Souza, A. (2016). Variability among BRS 8381 soybean (Glycine max (L.) Merrill.) yield components under different liming rates and sowing densities on a savanna in Roraima, Brazil. Rev. Colomb. Investig. Agroindustriales, 3(1), 49-55. DOI: http://dx.doi.org/10.23850/24220582.350

Acúmulo de forragem e eficiência de utilização da radiação em pastagens de Axonopus aureus, durante o período seco, nos cerrados de Roraima

O efeito da idade de rebrota (21, 28, 35, 42, 49, 56, 63 e 70 dias) sobre a produtividade de materia seca (MS) e a eficiencia de utilizacao da radiacao (EUR) de Axonopus aureus, durante o periodo seco, foi avaliado em condicoes de campo. O aumento da idade de rebrota resultou em maiores rendimentos de forragem, taxa absoluta de crescimento, taxa de crescimento da cultura, taxa de crescimento relativo e area foliar. As relacoes entre idade de rebrota, rendimento de MS, taxa absoluta de crescimento e EUR foram ajustadas ao modelo quadratico de regressao, sendo os maximos valores registrados aos 62,6; 47,8 e 51,7 dias de rebrota, respectivamente. A resposta da produtividade de forragem a RFA incidente foi quadratica e o maximo valor estimado em 487,7 MJ/m2, o qual correspondeu a 796,7 kg de MS/ha. Visando conciliar produtividade de forragem da graminea com a maximizacao da EUR, o periodo de utilizacao mais adequado de suas pastagens situa-se entre 49 e 56 dias de rebrota.