RESUMO -Neste trabalho avaliou-se durante o período seco do ano o efeito de quatro doses de nitrogênio (100, 300, 500 e 700 kg.ha -1 .ano) e de seis lâminas d'água (0, 20, 40, 80, 100 e 120% da evapotranspiração de referência) sobre o rendimento forrageiro, a densidade de perfilhos, a relação folha/colmo, a altura de plantas e os teores de proteína bruta e fibra em detergente neutro do capim-elefante (Pennisetum purpureum, Schum). O delineamento experimental foi o de blocos casualizados com quatro repetições. Como fonte de adubo nitrogenado utilizou-se ureia, aplicada a lanço. O controle do nível de água e a definição do momento de irrigar foram estabelecidos com base na curva de retenção de água no solo e no teor de água, pelo método gravimétrico de amostras de solo. As lâminas d'água e as doses de nitrogênio aumentaram linearmente a altura das plantas, a produção de matéria seca e a densidade de perfilhos, mas diminuíram os teores de PB. A irrigação teve efeito quadrático no teor FDN, cujo percentual máximo, 69,38%, foi observado quando foi aplicada lâmina d'água de 72,88% da evapotranspiração. A adubação nitrogenada reduziu linearmente o teor de FDN. A menor relação folha/colmo obtida foi de 1,98 quando aplicada lâmina d'água de 65,5% da evapotranspiração com a dose de 300 kg.ha -1 .ano de nitrogênio. As lâminas d'água associadas às doses de nitrogênio elevam a produção de MS de 2.539,08 kg/corte para 6.445,72 kg/corte, diminuindo o efeito da estacionalidade de produção do capim-elefante "pioneiro" no norte de Minas Gerais.Palavras-chave: estacionalidade, evapotranspiração, lâmina d'água, nitrogênio Irrigation depth and nitrogen doses on elephant-grass pastures during the dry season in the north of Minas Gerais StateABSTRACT -This work aimed to evaluate the effect of four levels of nitrogen (100, 300, 500 and 700 kg.ha -1 .year) and six water depth (0, 20, 40, 80, 100 and 120% of the reference evapotranspiration) on the forrage yield, tillers density, relationship leaf/stem, plants height and crude protein content and neutral detergent fiber of the elephant grass (Pennisetum purpureum, Schum), during the dry period. The experimental design was a random block split plot design with four replications.Broadcast urea was used as source of nitrogen fertilizer. The water level control and the definition of the irrigating moment were established based on the soil-water retention curve and on the water level by the gravimetric method in soil samples. Water depth and nitrogen levels increased linearly the plants height, dry matter production and tillers density, however, they decreased the crude protein content. Irrigation had a quadratic effect irrigation on NDF content, with maximum percentage of 69.38%, when water depth of 72.88% of the evapotranspiration was applied. Nitrogen fertilization decreased linearlly the NDF content.The lowest leaf/stem relation (1.98) was obtained with a combination of 65% evapotranspiration and 300 kg.ha -1 .year of nitrogen. Water depth associated to N levels increase dry matter yield ...
The objective was to assess agronomic characteristics of sorghum genotypes and nutritional values of produced silage. A total of 15 sorghum genotypes were used. Planting was carried out through a randomized-block design with three replications per genotype, totaling forty-five (45) plots. Agronomic and nutritional characteristics, besides the quality of the silage, were assessed. There were differences between genotypes for all characteristics analyzed, with the exception of levels of acid detergent unavailable nitrogen (ADUN), acid detergent unavailable protein (ADUP) and water activity (aw). The assessment of the parameters, except for genotypes 1016013, 1016025, 1016037, 1016039, Volumax and BRS 610, which presented protein level below 7%, showed that the other genotypes can be used for silage production, since they have a good profile of fermentation and in vitro dry matter digestibility; however, genotype SF15 is the most favorable one for silage production due to its little participation in the neutral detergent fiber fraction.
ResumoObjetivou-se por meio deste trabalho avaliar o efeito de nitrogênio sobre a morfogênese e rendimento forrageiro do capim-elefante cv. Pioneiro. O delineamento experimental utilizado foi em blocos casualizados com cinco repetições, totalizando 20 unidades experimentais. Os tratamentos corresponderam a quatro doses de nitrogênio (100, 200, 300 e 400 kg ha -1 ano -1 ). O experimento foi mantido sob condições irrigadas. Foram realizados cortes avaliativos a 50 cm do solo com valores de interceptação luminosa (95%) sem intervalos pré-definidos. Observou-se que a adubação nitrogenada aumentou significativamente (P<0,05) a produção de matéria seca por hectare, taxa de aparecimento foliar (folhas dias -1 perfilho -1 ), taxa de alongamento foliar (cm folha -1 dia -1 ) e taxa de alongamento de colmo (cm perfilho -1 dia -1 ). O processo de senescência foliar nesta forrageira é acelerado com o aumento das doses de nitrogênio e taxa de aparecimento foliar, consequentemente reduzindo o filocrono. É necessário um estudo sobre a viabilidade econômica de doses mais elevadas de nitrogênio em pastos de capim elefante cv. Pioneiro. Palavras-chave: Alongamento de colmo, aparecimento foliar, filocrono, Pennisetum purpureum AbstractObjective of this work by evaluating the effect of nitrogen on forage yield and morphogenesis of elephant grass cv. Pioneer. The experimental design was randomized blocks with five replications, totaling 20 experimental units. Treatments consisted of four nitrogen levels (100, 200, 300 and 400 kg ha -1 yr -1 ). The experiment was conducted under irrigated conditions. Evaluative cuts were made at 50 cm soil with values of light interception (95%) without pre-defined intervals. It was observed that N fertilization increased significantly (P<0.05) the production of dry matter per hectare, leaf appearance rate (leaves days -1 tiller -1 ), leaf elongation rate (cm tiller -1 day -1 ) and stem elongation rate (cm day -1 ). The process of
RESUMO-Nas fruteiras caducifólias, o metabolismo de carboidratos constitui-se no principal mecanismo que garante a sua sobrevivência no período de dormência, estando, também, relacionado ao seu potencial produtivo em safras subseqüentes. Conhecer a forma como a planta utiliza esses carboidratos durante o seu desenvolvimento é um passo importante para o entendimento das suas relações fonte-dreno e para fundamentar algumas práticas de manejo, como a poda e o raleio de frutos. Caracterizar a variação dos teores de amido e de carboidratos solúveis totais em órgãos lenhosos do caquizeiro (Diospyros kaki L.), no decorrer do seu desenvolvimento fenológico, foi o objeto de investigação do presente estudo. O trabalho foi conduzido em um pomar de caquizeiros localizado na área experimental da Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), em Piracicaba, Estado de São Paulo, durante o ciclo 2002/ 2003. A fenologia das plantas foi caracterizada pelo período de ocorrência e duração do alongamento dos ramos, florescimento, desenvolvimento dos frutos e das folhas e do abortamento natural de frutos. A variação dos teores desses carboidratos em ramos e em raízes foi analisada tendo por base os diferentes estádios fenológicos. Ocorreram variações significativas no teor desses carboidratos no período de estudo. A mobilização do amido nos ramos teve grande importância na sustentação de um novo ciclo de brotações. O maior consumo de amido ocorreu durante a abscisão foliar, e a reposição no seu estoque, nos ramos e nas raízes ocorreu, principalmente, entre o florescimento e a abscisão foliar. Termos para indexação: fenologia, desenvolvimento, amido. CARBOHYDRATE CONTENT IN PERSIMMON TREE WOODY ORGANS IN TROPICAL CLIMATEABSTRACT-In deciduous fruit trees, the carbohydrate's metabolism are recognized as the main mechanism that ensures their survival during the rest period. Besides it, the very same metabolism is related to the productive potential in subsequent harvest seasons. Knowing how the plants use those carbohydrates during their development and growth is an important step in the right direction to understand the relation source-drain more effectively along with building up the fundamentals of some handling practices, for instance, the pruning and fruit thinning. The objective of the present study was to characterize how the total soluble sugars content and the starch vary in woody organs of the persimmon tree (Diospyros kaki L) in elapsing of its phenological development. This study was carried out in the experimental area of the Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ) in Piracicaba -SP, during the cycle 2002/2003. The phenology of persimmon tree was described by the occurrence period and prolongation of shoot growth, flowering, fruit growth, leaf expansion and natural abortion of fruits. The carbohydrates content in stems and roots were analyzed based on different phenological stages. The results showed a significant variation in the starch and total soluble sugars content in the sampled organs. The ...
The objective was to evaluate the effect of inclusion of acetic acid during the ensiling of sugarcane (Saccharum officinarum) on fermentation quality and nutritional value. The treatments consisted of sugarcane silages, variety (IAC 86-2480) additives with four inclusion levels of glacial acetic acid (1.5, 3.0, 4.5 and 6.0 % in natural matter) plus the control. A completely randomized design was used, being 5 treatments and 6 replicates. The glacial acetic acid showed a pH 2.9 (0,1M). There was a reduction of 0.07 units in the pH of the sugarcane silage for each 1% inclusion of acetic acid (P < 0.01). The N-NH3 concentration was not modified in the ensiled mass of the treatments, with a mean of 0.45% in dry matter (P =0.91). The averages of effluent losses were adjusted to the quadratic regression model with the application of acetic acid (P < 0.01). There was a reduction in the yeast population in the order of 0.44 log UFC/g of silage (P < 0.01). The addition of acetic acid in sugarcane silage reduces fermentative losses, the yeast population and improves the nutritional value in doses from 1.5% of natural matter.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.