RESUMO A couve-flor é uma brássica bastante produzida e consumida no Brasil, cujo cultivo é dependente do suprimento adequado de água e nutrientes. Portanto, objetivou-se com este estudo, avaliar o efeito da aplicação de lâminas de irrigação e doses de nitrogênio nos componentes de produção e na produtividade da água da cultura da couve-flor híbrida ‘Barcelona CMS’. Foram avaliadas as lâminas de 0, 75, 100, 125 e 150% da evapotranspiração da cultura combinadas com cinco doses de nitrogênio (0, 75, 150, 300 e 450 kg ha-1). O experimento foi conduzido em delineamento inteiramente casualizado com arranjo em parcelas subdivididas. Os efeitos da desses fatores foram avaliados pela metodologia de superfície de resposta. Observou-se que a produtividade da água pela cultura apresenta relação decrescente com a lâmina de água aplicada; portanto, a produtividade é maior quando a reposição de água é menor que o recomendado. A maior produtividade total da couve-flor estimada é de 24.547,80 kg ha-1, com diâmetro médio de 19,60 cm, altura média de 12,25 cm e massa fresca da inflorescência de 858,90 g por planta, obtida com irrigação equivalente a 132,09% da evapotranspiração da cultura e 450 kg ha-1 de nitrogênio. Para obtenção do maior diâmetro e altura de inflorescência é necessária lâminas de irrigação equivalentes a 128,70 e 108,20% da evapotranspiração da cultura, respectivamente, na dose de 450 kg ha-1 de nitrogênio. Portanto, a melhor resposta da produtividade da couve-flor híbrida ‘Barcelona CMS’ pode ser obtida com lâmina de irrigação superior à evapotranspiração da cultura, independentemente da dose de nitrogênio aplicada.

ABSTRACT Cauliflower is a brassica produced and consumed in Brazil, whose cultivation depends on the adequate supply of water and nutrients. The objective of this study was to evaluate the effect of irrigation depths and nitrogen doses on the production components and water yield of cauliflower hybrid Barcelona CMS. The treatments consisted of five irrigation water depths (0, 75, 100, 125 and 150% of the crop evapotranspiration) combined with five nitrogen doses (0, 75, 150, 300 and 450 kg ha-1). The experiment was conducted in a completely randomized design with a split-plot arrangement. The effects of these factors were evaluated using the response surface methodology. The water yield of the crop decreases with increasing irrigation water depth; therefore, the yield is higher when water replenishment is lower than the recommended. The highest estimated total inflorescence yield is 24,547.80 kg ha-1, with a inflorescence mean diameter of 19.60 cm, a inflorescence mean height of 12.25 cm, and an inflorescence fresh weight of 858.90 g plant-1, obtained with an irrigation water depth equivalent to 132.09% of the crop evapotranspiration (ETc) and a nitrogen dose of 450 kg ha-1. The highest inflorescence diameter and height are obtained with an irrigation depth equivalent to 128.70 and 108.20% of ETc, respectively, and a nitrogen dose of 450 kg ha-1. Therefore, the best productivity response of the Barcelona CMS cauliflower hybrid can be obtained using an irrigation depth greater than the crop evapotranspiration, regardless of the nitrogen doses.

RESUMO Devido à importância socioeconômica do feijoeiro no Brasil, estudos que permitem estabelecer condições favoráveis ao não comprometimento da lavoura com o mofo-branco tornam-se vitais para a agricultura brasileira, haja vista os enormes prejuízos causados por este fungo, , razão por que se objetivou, neste trabalho, avaliar a incidência e severidade do mofo-branco na cultura do feijoeiro-comum (Phaseolus vulgaris L.), cultivar Madrepérola, submetido a diferentes turnos de rega, densidades de plantio e aplicação de fungicida. A pesquisa foi conduzida em Viçosa, nos anos 2011 e 2012. Na análise estatística foi utilizado o esquema de parcelas sub-subdivididas. Nas parcelas foi alocado o efeito do fungicida (com ou sem fungicida), nas subparcelas os turnos de rega (3, 6, 9 e 12 dias) e nas sub-subparcelas as densidades de plantio (6, 9, 12 e 15 plantas por metro linear), no delineamento experimental em blocos casualizados, com três repetições. A variação do turno de rega não colaborou significativamente para o controle do mofo-branco. Recomenda-se a utilização de menores densidades de plantio a fim de minimizar os danos ocasionados pela doença. A utilização do fungicida foi o principal método de controle do mofo-branco nos dois anos consecutivos.

ABSTRACT Due to the socioeconomic importance of common bean in Brazil, studies that allow establishing favorable conditions for not compromising the crop with white mold, in view of the enormous damages caused by this fungus, become vital to Brazilian agriculture. Therefore, the aim of this study was to evaluate the incidence and severity of white mold in common bean (Phaseolus vulgaris L.), cultivar ‘Madrepérola’, subjected to different irrigation intervals, planting densities and fungicide application. The research was conducted in Viçosa-MG, Brazil, in the years 2011 and 2012. The statistical analysis used the split-split-plot scheme. The fungicide applications (with or without fungicide) were allocated to plots, the irrigation intervals (3, 6, 9 and 12 days) to sub-plots and planting densities (6, 9, 12 and 15 plants per linear meter) to sub-subplots, in a randomized block design with three replicates. The variation of the irrigation intervals did not contribute significantly to the control of white mold. It is recommended to use lower planting densities in order to minimize the damages caused by the disease. The use of the fungicide was the main method of white mold control in two consecutive years.

ABSTRACT In the correct pasture management, nutritional factors such as nitrogen and potassium fertilization play an important role in the forage production and quality. The aim was to evaluate the effects of the application of water levels, nitrogen and potassium doses in the Xaraés grass in the south of the State of Tocantins. For this, Xaraés grass was cultivated in the experimental field of the Federal University of Tocantins, municipality of Gurupi, TO. We used a mixture of fertilizer, combinations of N and K2O following the 1 N: 0.8 K2O ratio. To evaluate the effect of irrigation water levels and combinations of N and K2O doses in Xaraés grass, the plant height, the crude protein content and neutral detergent fiber were determined. The greatest height observed in the grass was 61.6 cm, with the dose application of 700 kg ha-1 yr-1 of N: 0.8 K2O and a water level of 120% of the ETc. The highest protein content was 11.7%, with the highest dose application of fertilizer and absence of irrigation. The highest fiber content in neutral detergent was 64%, with the estimated amount of 385.5 kg ha-1 yr-1 of N: 0.8 K2O and a water level of 120% of ETc. The conclusion was that the plant height, fiber detergent and crude protein content were influenced by the change in water level of irrigation and fertilizer doses. The values of plant height and crude protein increased with the increase of water levels and manure dose, while the fiber content of neutral detergent decreased with the increase of irrigation and varied little with the increase of fertilizer dose.