Reguladores de crescimento no desenvolvimento de diferentes espécies de grama

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desenvolvimento radicular de híbridos de mamona submetidos à adubação potássica

A deficiency of potassium at the beginning of the season affects the nutritional balance implicating the proper development of plants. The objective of this study was to evaluate the effect of potassium (K) in the root system development and production of dry matter of shoots of hybrid castor. The experiment was a 5 x 2 factorial scheme in a completely randomized design with four replications. The treatments consisted of five doses of K: 0, 25, 50, 100 and 200 ppm and two hybrids of castor (Lyra and Savana). After 45 days after emergence, there was a collection of shoot and root system of plants. The evaluations were: length, area, diameter and dry root and shoot. The addition of potassium caused increased root diameter at the hybrid Savana and reduced at the Lyra. The production of root and shoot dry of the hybrid Savana decreased with doses from 78 and 116 ppm of potassium, respectively.

Sistema radicular de cultivares de painço em resposta à calagem

The root growth is genetically controlled. There is variability among cultivars and soil factors such as toxicant Al and low contents of Ca and Mg can harm it. The objective of this study was to evaluate the root growth and the shoot growth of millet cultivars in response to liming. The experiment was carried out in pots with 13 dm3 of soil, in greenhouse conditions until 62 days after the emergence of the plants. The used experimental design was completely randomized, in a 2x4 factorial scheme, that is to say,two painço cultivars (AL Mogi e AL Tibagi), and four level of calcareous (0,0; 0,83, 1,67 e 3,34 g dm-3 ), with four replications. Liming promotes increase of the root system and of the aerial parts of the cultivars. The AL Tibagi cultivar presents a root system more tolerant to the low saturation by bases in comparison to the AL Mogi, however, the maximum root growth was occurred in saturations at around 64%. Millet cultivars in high acidity conditions reduce root diameter at the expense of the growth in length.

Comprimento radicular e nutrição de cultivares de painço em resposta à calagem

Information on improved cultivars of fall panicum and cultural practices concerning its cultivation is scarce in Brazil. So, the objectives of this research work were to evaluate root length and the mineral nutrition of fall panicum plants as influenced by liming in an acidic soil. The experiment was conducted in vases containing 13 dm3 of soil under greenhouse conditions up to 44 days after seedling emergence. The experimental units were distributed inside the green house according to a completely random design in a 2 X 4 factorial scheme, that is, two fall panicum cultivars (‘AL Mogi’ and ‘AL Tibagi’) and four doses (0.0, 1.67, 2.91, and 4.15 t ha-1 ). The experimental units were replicated 4 times. ‘AL Tibagi’ plants root system showed more tolerance to soil conditions of low base saturation. That cultivar also absorbed more efficiently P, N, Ca, Mg, and K from the acidic soil. Liming brought about increments of P, N, Ca, Mg, and S absorption by the fall panicum cultivars.

Aplicação de doses de vinhaça sob desenvolvimento vegetativo de pastagem degradada e propriedades físicas do solo

The experiment was conducted in the experimental field of the University of GoiásUEG, UNU Ipameri - GO with the objective of evaluating the effect of different doses of vinasse on the vegetative development of degraded pasture and soil physical properties in two seasons. The pasture used in the experiment was in a state of degradation, and had eight years of formation. The experimental design was randomized blocks consisted of eight treatments and four blocks, totaling 32 experimental units. We evaluated the following soil physical properties: density the soil, particle density, total porosity, infiltration velocity, soil water. We also evaluated the following parameters of vegetative development of grassland: green and dry mass of shoots, effective depth of the root system, the grass height. The results were submitted to analysis of variance at 5% significance level and after we performed regression testing. The vinasse promoted significant effect on all parameters related to vegetative development of both grazing during the rainy season as in the dry. In this case, a model that best fit the dataset vegetative pasture was quadratic. It appeared that the vinasse different doses did not cause changes in the physical properties of the soil.

Uso de estimulantes de crescimento radicular associado a doses de fósforo na cultura do feijoeiro

O trabalho teve como objetivo avaliar o efeito da aplicação do Stimulate e Forth Seed associados a cinco doses de fósforo(P) no desenvolvimento do sistema radicular e parte aérea de plantas de feijão. O experimento foi desenvolvido em condições de casa de vegetação nas dependências do Departamento de Recursos Naturais – Ciência do Solo, da Faculdade de Ciências Agronômicas (FCA), UNESP, Campus de Botucatu, SP. O solo usado foi um Latossolo Vermelho Escuro de textura média. As unidades experimentais foram vasos contendo 8 dm3 de solo mantendo-se a umidade correspondente a 60% do Volume Total de Poros (VTP) ocupados por água. Utilizou-se a cultivar de feijão IAC-Carioca, em um delineamento experimental inteiramente casualizado, sendo os tratamentos constituídos de dois produtos (Stimulate e Forth Seed) nas respectivas doses 5 e 3 mL Kg-1 de sementes e uma testemunha sem biofertilizante, e 5 doses de P (0, 16, 32, 64 e 128 mg dm-3), com três repetições. Foi avaliada, também, a qualidade fisiológica das sementes usadas no experimento por meio de: a) primeira contagem do teste padrão de germinação; b) emergência; c) vigor, mediante a contagem de emergência; d) velocidade de emergência e determinação do crescimento das plântulas. O uso de Stimulate e Forth Seed agregados a doses de P causou redução no peso seco final das plantas.

Fisiologia e bioquímica do tomateiro submetido à irrigação salina parcial do sistema radicular

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Comportamento do carbono orgânico e de atributos químicos, físicos e microbiológicos de um solo arenoso em área de conversão pastagem - Eucalipto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fluxo do grupo de renormalização dos modelos-'alfa' e as álgebras de Lie contínuas

Pós-graduação em Física - IFT

Doses de Bradyrhizobium japonicum e Azospirillum brasilense no desenvolvimento das plantas, na produção e na qualidade fisiológica de sementes de soja

Pós-graduação em Agronomia - FEIS

Effects of RegCM3 parameterizations on simulated rainy season over South America

The impacts of change in the Grell convective scheme and biosphere-atmosphere transfer scheme (BATS) in RegCM3 are described. Three numerical experiments (RegZhang, RegClaris and RegArain) are conducted to reduce the RegCM3-Grell rainfall underestimation over tropical South America. The simulation referred to as RegZhang follows modifications made by Zhang et al. (2008) in the BATS. The RegClaris combines the RegZhang BATS parameters with a reduction of water drainage at the bottom of the subsoil layer in the regions covered by the tropical rain forest and a shorter convective time period for the Grell scheme. The RegArain considers this same modification in the Grell scheme, but uses a deeper total soil column and a deeper root system in the BATS. After the first year of simulation, the soil water content in RegZhang is progressively drained out of the soil column resulting in a deficit of rainfall in the Amazon. The RegClaris and RegArain, on the other hand, simulate a similar rainfall annual cycle in the Amazon, showing substantial improvement not only in phase but also in intensity. This improvement is partially related to an increase in evapotranspiration due to a larger availability of water in the soil column. A remote effect is also noted over the La Plata Basin region, where the larger summer rainfall rate may be related to the increase in moisture transport from the Amazon. Wind- and rainfall-based indices are applied to identify South American monsoon (SAM) timing. The RegClaris rainfall rates are adequate to identify the onset and the demise of SAM according to the observed data, whereas the rainfall deficit in RegZhang is associated with a delay in the onset and an early demise of the SAM.

Efeitos gênicos de caracteres associados à eficiência no uso de nitrogênio em milho

Os objetivos deste trabalho foram determinar o controle genético da eficiência no uso do nitrogênio (EUN), identificar a importância das eficiências na absorção (EAN) e na utilização (EUtN) na sua composição,  e quantificar relação entre produção de matéria seca da parte aérea (MPS) e do sistema radicular com a EUN e  com seus componentes. Foram avaliadas 41 combinações híbridas em duas disponibilidades de N: baixa (BN)  e alta (AN). Utilizou-se o delineamento de blocos ao acaso com duas repetições, em arranjo fatorial simples  (combinação híbrida x disponibilidade de N). As análises estatísticas foram realizadas por meio das equações  de modelos mistos. Correlações de elevada magnitude foram detectadas entre EAN e EUN, bem como entre  essas eficiências e a MPS, tanto em BN como em AN. Em ambas as disponibilidades de N, efeitos genéticos  aditivos apresentaram maior importância para os caracteres associados à EUN. Dessa forma, a seleção baseada  no desempenho individual de linhagens quanto à MPS pode possibilitar a obtenção de genótipos com alta  EUN. Independentemente da disponibilidade de N, a EAN é o componente mais importante da EUN.

Thiamethoxam on the histological characteristics of sugarcane young roots

Thiamethoxam is a systemic insecticide from the neonicotinoid group, nitroguanidin family which affects the nicotinic receptor acetyl choline in the insect membrane, wounding the nervous system and causing the death of the insect. It was used with success in the control of initial pests of several crops. It was considered that thiamethoxam has a bioactivator effect, because in the absence of insects promoted increase in vigor, development and productivity of crops. This work was carried out to verify if thiamethoxam causes histological changes in sugarcane roots. In this work, it was used optical microscopy, images arrest, tissue biometrics and statistical analysis, in young roots of sugarcane RB 83 5486 after the treatments with different thiamethoxam concentrations. It was determined changes in histological structure of tissues 7, 14, 21 and 28 days after the treatments, establishing its effects on root plant anatomy. It was verified that thiamethoxam increased root cortex width, increasing the vascular cylinder and the metaxylem vessel elements number in the vascular tissue until 21 days after application.

Water use in a sugarcane plantation

The evapotranspiration (E) from a sugarcane plantation in the southeast Brazil was measured by the eddy-covariance method during two consecutive cycles. These represented the second (393 similar to days) and third year (374 similar to days) re-growth (ratoon). The total E in the first cycle was 829 similar to mm, accounting for 69% of rainfall, whereas in the second cycle, it was 690 similar to mm, despite the total rainfall (1353 similar to mm) being 13% greater. The ratio of E to available energy, the evaporative fraction, exhibited a smaller variation between the first and second cycles: 0.58 and 0.51, respectively. The estimated interception losses were 88 and 90 similar to mm, respectively, accounting for approximately 7% of the total rainfall. The sugarcane yield in the second cycle (61.5 similar to +/-similar to 4.0 similar to t similar to ha-1) was 26% lower than the first cycle, as well as lower than the regional average for the third ratoon (76 similar to t similar to ha-1). The below average yield was associated with less available soil water at the beginning of the cycle, with the amount of rainfall recorded during the first 120 similar to days of re-growth in the second cycle being 16% of that recorded in the first (203 similar to mm).

ARBUSCULAR MYCORRHIZAE AND RHIZOBIUM IN ROOTING AND NUTRITION OF ANGICO-VERMELHO SEEDLINGS

The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizae fungi (AMF) and rhizobium on rooting, growth and nutrition of seedlings of angico-red (Anadenanthera macrocarpa (Benth) Brenan) propagated by minicutting. Six progenies were used, of which were prepared cuttings with a pair of complete leaves. It was used a 55 cm(3)container filled with commercial substrate Bioplant (R). Four treatments were tested: 8 kg m-3 of superphosphate (SS) added to substrate; 4 kg m-3 SS added to substrate; 4 kg m-3 SS added to substrate and adition of a suspension solution containing rhizobium; 4 kg m-3 SS and suspension solution containing rhizobium plus 5 g of soil contaminated by AMF spores. There was no interaction among treatments for survival rate of cuttings and roots observed at bottom of the container, evaluated in the greenhouse exit (30 days) and the shade house exit (40 days), probably because the root system was still in formation. There were differences among the progeny for survival rate of the shoots, the percentage of cuttings with roots observed at bottom of the container, height, stem diameter and shoot dry weight. The evaluations of the growth characteristics of the cuttings in, particularly with respect to survival at full sun (140 days), demonstrate the efficiency of rhizobium and AMF on seedling production of this species. We conclude that the symbiotic association with rhizobium and / or FMA favors the production of seedlings of A. macrocarpa by minicutting.