Formas de ureia e doses de nitrogênio em cobertura na qualidade fisiológica de sementes de trigo

Besides increasing productivity, nitrogen fertilization may have positives effects on seed physiological quality. The objective of this study was to evaluate the effect of different forms and levels of urea in top dressing fertilization on the physiological quality of wheat seed genotypes. Seeds of three wheat genotypes (BRS 208, BRS Pardela and IWT 04008) were evaluated for four levels of nitrogen fertilization (0, 40, 80 and 120 kg.ha-1) in three forms of urea (conventional urea, urea with urease inhibitor and protected urea). The nitrogen fertilization was applied during tillering, 20 days after emergence. The seed nitrogen content, 1000 seed mass, germination and vigor (germination first count, cold test, seedling emergence in the field, dry weight of seedlings, accelerated aging and electrical conductivity) were evaluated. The IWT 04008 line and the cultivar BRS Pardela had seeds with a higher physiological quality than those of the cultivar BRS 208. The forms of urea and levels of nitrogen in topdressing did not affect seed physiological quality of the different wheat genotypes.

Crescimento inicial e nutrição de cedro (Cedrela fissilis Vell.) em função de doses de nitrogênio

We aimed to evaluate the effects of nitrogen rates in early growth, SPAD index, content and accumulation of nutrients in cedar seedlings. The experiment was carried out in a plastic greenhouse and the seedlings were grown in plastic pots filled with 20 dm-3of Rhodic Hapludox, arranged inrandomized blocks with four replications. Rates of 0, 40, 80, 120 and 160 mg dm-3N were tested. Fertilization up to 160 mg dm-3N promoted increases in SPAD index and early growth of plants, beyond greater absorption of N,P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn. Overall, lower N rates limited growth but not the absorption of nutrients by cedar plants. In leaves, the only nutrien taffected was the B which their content was reduced with increasing of N rate. Increased of nitrogen fertilization changed the Cu distributionin plants, since increased Cu content in roots and reduced their content in stem. Higher N rates promoted higher accumulation of all nutrients due to the increase of dry matter. Nitrogen fertilization changed the dynamic of nutrient absorption in cedar. With 160 mg dm-3N, the amount absorbed followed the order: N>S>Ca>K>Mg>P>Fe>Mn>B> Zn> Cu.

Danos do complexo broca-podridão à produtividade e à qualidade da cana-de-açúcar fertirrigada com doses de nitrogênio

The objective of this work was to evaluate the effect of nitrogen-fertigation on the damage caused by the borer-rot complex to the productivity and quality of fertigated sugarcane. The experiment was carried out in field, using a randomized complete block design, with four replicates and five N doses (0, 50 100, 150, and 200 kg ha-1) applied through drip irrigation. The following variables were determined: number of holes caused by Diatraea saccharalis (Lepidoptera: Crambidae); number of internodes infected with red rot; incidence percentage of red rot; stalk productivity; and sugar content. In laboratory, the attractiveness and the consumption of culm fragments by fourth instar caterpillars, in trials with or without choice, were evaluated. Nitrogen fertigation increased the incidence of D. saccharalis and red rot. The number of holes produced by the larvae was correlated with the occurrence of red rot. Sugar percentage reduced with the increase in the number of red rot affected internodes. Nitrogen doses did not affect the attractiveness of sugarcane culm fragments; however, higher N doses increased the consumption of these fragments by D. saccharalis caterpillars. Despite the damages to quality, nitrogen fertilization expressively enhanced the productivity of stalks and sugar.

Nutrição e produtividade da nogueira-macadâmia em função de doses de nitrogênio

The objective of this work was to evaluate the influence of nitrogen doses on mineral nutrition and yield of macadamia nut (Macadamia integrifolia). The experiment was carried out during three agricultural years, in Jaboticabal, SP, Brazil. The experimental design was a complete block with four replicates. Five doses of N (0, 50, 100, 150, and 200 kg ha-1 per year), applied as urea, were evaluated. The increase in N doses increased the nutrient concentration in the leaves and the yield of nuts and almonds. Ca, Mg, and S contents decreased and the ones of Fe and Mg increased linearly with N fertilization. Nut and almond yields were positively correlated with leaf N concentration, and the range from 14 to 18 g kg-1 allowed the highest yields. The dose of 150 kg ha-1 of N per year provides higher nut yields, without reducing the recovery rate of almonds.

Fontes e doses de nitrogênio na nutrição, produção e qualidade do feijoeiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Doses de nitrogênio na cultura antecessora e do milho em sistema plantio direto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento e produção de Costus productus Maas como planta de vaso em função de doses de nitrogênio

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Doses de nitrogênio no desenvolvimento de girassol ornamental (Helianthus annuus L.) de vaso

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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)

Coberturas vegetais, doses de nitrogênio e inoculação de sementes com Azospirillum brasilense em arroz de terras altas no sistema plantio direto

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

Produtividade do milho e de matéria seca de forrageiras em consórcio e doses de nitrogênio na cultura da soja em sucessão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fontes e doses de nitrogênio antes e após a indução floral em abacaxi cv. Smooth Cayenne, na região noroeste do estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fontes e doses de nitrogênio revestidas ou não por polímeros na cultura do milho

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

Fontes e doses de nitrogênio na adubação do capim-mombaça em cerrado de baixa altitude

Pós-graduação em Agronomia - FEIS

Lâminas de água, inoculação de sementes com Azospirillum brasilense e doses de nitrogênio em arroz terras altas

Pós-graduação em Agronomia - FEIS