Physiological potential of Brachiaria brizantha cv. Marandu seeds kept in contact with phosphatic fertilizers

Abstract

-The effect of mixture of seeds of Brachiaria brizantha, cv. Marandu, with different sources, granulometry, and phosphatic fertilizer doses during various periods of exposure on the physiological potential of the seeds has been assessed. The treatments consisted in seed exposure during periods of 0, 3, 6, 12, 24, 36, 48, 72, 96, and 120 h to the following fertilizers: ground granulated single superphosphate (SS), and powdered (SSp); and ground granulated ammonium monophosphate (AMP), at doses of 40 and 80 kg P 2 O 5 ha -1 . Tests of germination, tetrazolium, moisture content, and vigor (first count, electrical conductivity, emergence, emergence speed, and fresh mass of seedlings) were performed. It has been concluded that seed physiological potential of B. brizantha cv. Marandu is reduced with increase on the exposure period to phosphatic fertilizer. Such effect, however, is dependent on the product source, granulometry, and dose. SSp was the most harmful to seeds, followed by SSp and AMP, respectively. Moreover, considering a 60% germination rate as acceptable, it may be inferred that seeds can be kept in contact with AMP and SSp, in dose of 80 kg of P 2 O 5 ha -1 , respectively, for periods of 71.2 and 16.2 hours.Index terms: phosphorus, seed-fertilizer mixture, exposure period, vigor. Termos para indexação: fósforo, mistura adubo-semente, período de exposição, vigor. Potencial fisiológico de sementes de1

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“…A proximidade do adubo SS interferiu no IVE e condutividade elétrica da solução do solo em sementes de milho (Belivaqua et al, 1996). Peres et al (2012) ao misturar sementes de braquiária com SS na proporção de 1:20 constataram queda na qualidade Martins (2015) não verificou efeito com a aplicação de 0; 15; 30; 45; 60 e 75 mg L -1 de P na forma de fosfato monoamônio (MAP), em fertirrigação, no diâmetro de coleto de plântulas de tomate produzidas em substrato de fibra de coco. Essas diferenças podem ser devido às espécies envolvidas, genótipos (cultivares/híbridos), condições climáticas, idade das mudas no dia da avaliação; tipo de substrato utilizado e forma de aplicação.…”

Produção De Mudas De Tomate Em Substrato Comercial Enriquecido Com Superfosfato Simples

“…A proximidade do adubo SS interferiu no IVE e condutividade elétrica da solução do solo em sementes de milho (Belivaqua et al, 1996). Peres et al (2012) ao misturar sementes de braquiária com SS na proporção de 1:20 constataram queda na qualidade de P na forma de fosfato monoamônio (MAP), em fertirrigação, no diâmetro de coleto de plântulas de tomate produzidas em substrato de fibra de coco. Essas diferenças podem ser devido às espécies envolvidas, genótipos (cultivares/híbridos), condições climáticas, idade das mudas no dia da avaliação; tipo de substrato utilizado e forma de aplicação.…”

Reduction of the Forage Seeds Physiological Quality by the Contact with Fertilizer in the Crop-Livestock Integration

“…In a tetrazolium test carried out on marandu palisadegrass seeds, submitted to contact with granulated mono-ammonium phosphate, granular superphosphate and superphosphate powder, the authors reported in the reference [16] observed a linear decreasing effect of the contact time of all fertilizers with the seeds on viability.…”

“…The results were because the 05-25-15 fertilizer consisted of mono-ammonium phosphate, single superphosphate, triple superphosphate and potassium chloride, and some of these fertilizers present acid residues or high salt content, which probably caused seed coat rupture and electrolytes release contained in the reserve substances [16] and is indicative of reduced vigor. In addition, in the electrical conductivity results, the fertilizer residue effect on the seeds outer layer can occur, since they were not washed before the beginning of the test.…”