Interferência das plantas daninhas na cultura do grão-de-bico cultivado sob doses de adubação nitrogenada

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Crescimento de plantas de Corymbia citriodora (Hook.) K. D. Hill & L. A. S. Johnson sob diferentes doses de potássio e níveis de umidade do solo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atributos físicos e químicos do solo e desenvolvimento de laranja-pera em função de doses de cinza de bagaço de cana-de-açúcar

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Resposta da segunda soqueira da cana-de-açúcar à aplicação de nitrogênio na presença e ausência de silício

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Influência de doses reduzidas de fungicidas no controle da ferrugem asiática da soja

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação agronômica de fontes e doses de fósforo para o capim-Tifton 85

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Efeito do silício aplicado no solo e em pulverização foliar na incidência da lagarta do cartucho na cultura do milho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nutrição do feijoeiro e intensidade da antracnose em função da aplicação de silício e cobre

The objective of this work was to evaluate the effect of calcium silicate and copper sulfate on anthracnose intensity and nutrition of bean plants. The experiment was conducted using an experimental design in randomized blocks following a 4 x 4 factorial arrangement, (four levels of calcium silicate and four levels of copper sulfate) and two additional treatments (plants without inoculation and plants sprinkled with Benomyl). Four evaluations of the incidence and severity of anthracnose were done, in addition to measuring total leaf area. At the end of the evaluations, incidence and severity data were integrated over time, obtaining the area under disease progress curve (AUDPC). Contents of N, P, K, Ca, Mg, B, Cu, Fe, Mn, Zn, Si and lignin were determined in the aerial part. A linear decrease of the intensity AUDPC was observed with the increase of the doses of calcium silicate. The severity AUDPC was influenced by the doses of copper, obtaining a reduction of 35% on the higher dosage. The supply of silicon and copper altered the content of the K, Mg, S, Zn, Ca and Si in the aerial part of the bean plants.

Silicon in plant disease control

All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si) is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.

Avaliação do potencial de uso agrícola da fluorita com óxido silício (AgroSiCa), derivado da fabricação de fertilizantes fosfatados

Phosphate fertilizers are critical for crop production in tropical soils, which are known for having high phosphate-fixing capacity and aluminium saturation, as well as low pH and calcium contents. Fluorine is a component of many phosphate rocks used to make phosphate fertilizers, via a process that generates hexafluorosilicic acid (H2SiF6). While many treatment technologies have been proposed for removal of fluorine in industrial facilities, little attention has been given to a process of neutralizing H2SiF6 with calcium oxide aiming to find out an alternative and sustainable use of a by-product with a great potential for beneficial use in tropical agriculture. This study evaluated the effect of a by-product of phosphoric acid production (fluorite with silicon oxide, hereafter called AgroSiCa) in levels of phosphorus (P), calcium (Ca), silicon (Si), aluminum (Al) and fluorine (F) and some others parameters in soils as on growth of soybean and corn. Experiments were conducted in a greenhouse condition at the Federal University of Lavras (UFLA), Lavras, Minas Gerais, using different types of soils in tropical regions and different doses of AgroSiCa. The application of AgroSiCa resulted in a slight increase in soil pH and significant increases in calcium, phosphorus and silicon in the soil solution and the shoots of corn and soybeans. We also found very low levels of fluoride in all soil leachates. A significant reduction of labile aluminum levels found in all soils after the cultivation of corn and soybeans. In sum, AgroSiCa improved soil properties and contributed to better growth of both cultures. In sum, AgroSiCa improved soil properties and contributed to a better growth of both crops. Our results show that reacting H2SiF6 derived from the wet-process phosphoric acid production with calcium oxide leads to a by-product with potential for agricultural use, especially when applied in highly-weathered soils. Besides providing calcium and silicon to plants, the use of such by-product in soils with high phosphate-fixing capacity and high aluminium saturation delivers additional benefits, since fluoride and silicon can play an important role in improving soil conditions due to the formation of less plant-toxic forms of aluminium, as well as upon decreasing phosphate fixation, thus improving root development and making fertilizer-derived phosphate more available for plant growth.

Exposição à mistura de pesticidas em baixas doses: validação de método e aplicação a tecido adiposo de animais de experimentação (ratos Lewis)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Indução de múltiplas ovulações em éguas utilizando baixas doses de acetato de deslorelina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação dos protocolos de sincronização de estro em ovelhas, com diferentes tempos de exposição aos progestágenos e distintas doses de eCG

Pós-graduação em Medicina Veterinária - FMVZ

Controle químico de Mimosa pudica em pastagem de Brachiaria decumbens com doses reduzidas de herbicidas

Pós-graduação em Agronomia - FEIS

Espaçamentos entrelinhas e doses de nitrogênio em dois cultivares de feijoeiro irrigado no sistema plantio direto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)