Nodulação, nutrição, componentes de rendimento e qualidade de sementes de soja em função do recobrimento de sementes e parcelamento da adubação fosfatada

• Ano de defesa: 2013
• Autor(a) principal: Soares, Marcos Morais
• Orientador(a): Sediyama, Tuneo
• Banca de defesa: Dias, Luiz Antonio dos Santos , Lacerda, Mabio Chrisley , Neves, Júlio César Lima
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Soja; Sementes; Vigor; Fósforo
• Palavras-chave em Inglês: Soybeans; Seeds; Vigor; Phosphorus
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1197

There are several aspects related to the nutrient phosphorus (P), which are likely to become issues regarding its availability and retention in soils, especially in those highly weathered in the tropical regions, particularly in more clay soils, as well as the high cost of phosphate fertilizers therefore, appropriate techniques of application of phosphate fertilizers and use of coated seeds and with higher levels of phosphorus can contribute to greater efficiency in the use of this nutrient by the plants. The objective of this study was to evaluate the effect of P coated seeds and phosphate fertilization split on nodulation, growth and yield components of the soybean crop, in addition to the effect of endogenous P in germination, vigor, concentration of nitrogen, phosphorus, oil and protein in the seeds. The experiment was conducted in three stages. In the first and second stages, it was used a lot of cultivar Valiosa RR, 2010/11 crop seeds. The first stage of the experiment consisted in sowing in pots in a greenhouse where the seeds were treated in the following sequence: Carbendazin + Thiram fungicide, monobasic sodium phosphate, at doses of 0.0 (C1) and 0.7 (C2 ) g hg-1 of seeds followed by peat inoculants application. After treatment, the seeds were sown in plastic pots containing 3.0 dm3 sample of a red yellow latosol. Fertilization with P, potassium and micronutrients was performed according to soil analysis. Five doses of P were used: 50 (P1), 100 (P2), 200 (P3), 300 (P4) and 400 (P5) mg kg-1 of P in the soil, to achieve different levels of P availability, by using triple superphosphate as P source. Each dose of phosphorus was applied as follows: 100% of the total dose at sowing (E1); 50% of the total dose at sowing and more 50% as topdressing fertilization at the V3 stage (E2); 50% of the total dose in sowing plus 25% at V3 and more 25% at the R1 stage (E3). Top-dressing fertilization was performed via two 0.5 cm grooves. In the reproductive stage R2, evaluations of macronutrients contents in the index leaf and the R3 stage were carried out: the dry matter of shoot and root, dry weight of nodules, plant height and number of nodes. The second step was to repeat the first step experiment to perform evaluations after the R8 reproductive stage: number of pods per plant, number of pods without seeds per plant, number of seeds per pod, number of seeds per plant, hundred seeds weight; total weight of seeds per plant and P content in the harvested seeds. In the third step, it was used seeds lot of cultivar Valiosa RR (V1), Msoy 9144RR (V2) and Msoy 8527RR (V3), 2010/11 crop. The seeds of the first cultivar were harvested in the second stage of the experiment. The seeds of V2 and V3 cultivars were treated with the fungicide Derosal Plus followed by application of peat inoculant. After treatment, the seeds were sown in plastic pots containing 3.0 dm3 of soil classified as Yellow-Red Latosol. Treatments consisted of doses of 50, 100, 200, 300 and 400 mg kg-1 P in the soil, using triple superphosphate as P source. Fifteen days after the R8, the seeds were harvested, and determination of phosphorus content in the seeds was carried out after that. After this determination, the seeds were divided into four classes of endogenous P. The following evaluations were performed: germination; first count of germination; seedling length; emergency; speed and speed index of seedling emergence; content determination of nitrogen, protein and oil seeds. The results showed that at lower phosphorus levels added into the soil, the coating of seeds with monobasic sodium phosphate at a dose of 0.7 hg g-1 seed and the phosphate fertilization split, mostly with 50% of the total dose in sowing and 50% topdressing at the V3 stage (season E2) significantly increased most of all variables, with an increase of up to 24.9% on the total weight of seeds. Furthermore, the increased levels of endogenous phosphorus in the seeds of the three cultivars provided greater increases in germination, vigor, contents of nitrogen and crude protein, and reduction in the oil content of the seeds.