Growth regulation of bermudagrass (Cynodon dactylon) and zoysiagrass (Zoysia japonica) with glyphosate.

Glyphosate can generate positive effects on turfgrass maintenance as a form of growth control by decreasing the expenses associated with mowing. However, there is little information about the effects of this herbicide on turfgrasses. This study aimed to evaluate the response of bermudagrass and zoysiagrass to the herbicide glyphosate as a growth regulator. Two studies were performed in a greenhouse and repeated at different times. The treatments involved application of glyphosate at 10 different rates (0, 5.625, 11.25, 22.5, 45, 90, 180, 360, 720, and 1.440 g ae ha-1) with four replicates. Evaluations of green cover by digital analysis, injury, and plant height were performed at 7, 14, 21, and 28 days after application, and shoot dry matter of clippings was determined for the last evaluation period. Bermudagrass and zoysiagrass presented variedtolerance to glyphosate toxicity. Overall, the digital analysis showed that green content was negatively influenced by the increase in visual injury caused by glyphosate application. Moreover, increasing the glyphosate rate decreased plant height and shoot dry matter in both turfgrasses. Glyphosate application rates up to 45 g ae ha-1 for bermudagrass and 90 g ae ha-1 for zoysiagrass decreased plant growth without affecting the factors analyzed in this study.

Effects of gibberellic acid on Tifton 85 bermudagrass (Cynodon spp.) in constructed wetland systems.

This study aimed to evaluate 1) the influence of gibberellic acid (GA3) in the development of Tifton 85 bermudagrass grown in constructed wetland systems (CWs) and 2) the plant's capacity to remove nutrients and sodium from synthetic municipal wastewater (SMW). The experiment was carried out in Viçosa, Minas Gerais, Brazil, and consisted of foliar applications of GA3 set in randomized blocks design, with four replicates and 6 treatments as following: NC (control with plants); 0 µM GA3; N1: 5 µM GA3; N2: 25 µM GA3; N3: 50 and N4: 100 µM GA3 per CWs, NC* (control with no plants): 0 µM GA3. The study was conducted over two crop cycles in the spring 2016. The parameters used to evaluate the performance of the Tifton 85 bermudagrass were its plant height, productivity, chlorophyll measurement, number of internodes, nutrients and Na removals. Chemical analyses of the effluents were conducted. In response to the application of GA3, the increase in height of Tifton 85 bermudagrass in the first crop cycle was higher than the increase in height in the second crop cycle. The decrease in plant growth in response to GA3 in the second crop cycle may be linked to the age of the plant tissue and climatic conditions. The greater growth of the plants cultivated in the CWs allows a more efficient removal of pollutants, using simple management and low cost. The results suggest that applying 50 µM of GA3 to the development of Tifton 85 bermudagrass provides higher dry matter yield and removal of nitrogen, phosphorus, and sodium for the first crop cycle in CWs. However, in the second crop cycle, the application of GA3 had no effect on dry matter production and nutrient removal by Tifton 85 bermudagrass in CWs.

Características estruturais, produtivas e bromatológicas dos capins Tifton 85 e Jiggs fertilizados com alguns macronutrientes / Structural, productive and bromatologic characteristcs of Tifton 85 and Jiggs grasses fertilized with some macronutrients

Objetivou-se avaliar o efeito da fertilização dos capins Tifton 85 e Jiggs com alguns macronutrientes sobre as características estruturais, produtivas e bromatológicas. Avaliaram-se duas forrageiras (Cynodon dactylon cv. Tifton 85 e C. dactylon cv. Jiggs) e cinco fontes de fertilizantes (três formulações NPK: 08-28-16, 30-00-20 e 20-10-10 e duas fontes de nitrogênio: ureia e super N), em esquema fatorial 2 x 5, distribuídos em delineamento inteiramente casualizado, com quatro repetições. O plantio dos capins foi realizado sem adubação, simulando uma pastagem implantada em condições de baixa fertilidade natural. As maiores produções (P = 0,009) e proporções de folhas (P 0,001) foram verificadas no capim-Tifton 85, resultando em menor proporção de colmos quando comparado ao capim-Jiggs. As fontes de fertilizantes empregadas na adubação dos capins Tifton 85 e Jiggs alteraram o peso e a proporção de folhas e colmos, bem como a relação folha/colmo, número de perfilhos e produção de massa. Houve interação significativa entre os fatores de estudo (capim e fertilizante) quanto aos teores de MS (P = 0,024), FDA (P = 0,012), hemicelulose (P = 0,007), DMS (P = 0,012), NDT (P = 0,012), ED (P = 0,012) e EM (P = 0,012) das folhas, além do teor protéico (P = 0,016) do colmo. De maneira geral, a aplicação do fertilizante 30-00-20 resultou em menor teor de FDA nas folhas do capim-Tifton 85 e maior digestibilidade da MS, com maior teor energético também, e o fornecimento de super N implicou em menor teor de FDA e maior digestibilidade da MS das folhas do capim-Jiggs. Considerando-se a planta inteira, o capim-Jiggs apresentou maior teor de FDN (P = 0,017) em relação ao Tifton 85, entretanto, a concentração de FDA nesse capim foi menor (P < 0,001) do que o Tifton 85, o que implicou em maior digestibilidade da MS (P < 0,001) e aporte energético (P < 0,001).(AU)

The aim this study was to evaluate the effect of fertilization of Tifton 85 and Jiggs grasses with some macronutrients on the structural, productive and bromatologic characteristics. Were evaluated two grasses (Cynodon dactylon cv. Tifton 85 and C. dactylon cv. Jiggs) and five sources of fertilizer (three formulations NPK: 08-28-16, 30-00-20 and 20-10-10, and two sources nitrogen: urea and super N) in a factorial scheme 2 x 5, distributed in a completely randomized design with four replications. The planting of grasses without fertilization was performed to simulate a pasture located in low natural fertility. The highest yields (P = 0.009) and ratios of leaves (P 0.001) were observed in Tifton 85 grass, resulting in a lower proportion of stems when compared to Jiggs grass. The sources of fertilizers used changed the weight and the proportion of leaves and stems, as well as the leaf/stem ratio, number of tillers and mass production of Tifton 85 and Jiggs grasses. There was a significative interaction between the study factors (grass and fertilizer) for concentrations of DM (P = 0.024), ADF (P = 0.012), hemicellulose (P = 0.007), DMD (P = 0.012), TDN (P = 0.012), DE (p = 0.012) and ME (P = 0.012) leaves and the protein content (p = 0.016) of the stem. In general, the application of 30-00-20 fertilizer resulted in lower ADF content in the leaves of Tifton 85 grass and higher DM, with higher energy content also, and providing super N implied lower ADF content and higher DM digestibility of Jiggs grass leaves. In the whole plant, the Jiggs grass had higher NDF (P = 0.017) compared to Tifton 85 grass, however, the concentration of ADF that grass was lower (P < 0.001) than Tifton 85 grass, which resulted in higher DM (P < 0.001) and energy intake (P < 0.001). The application of super N decreased the ADF content (P = 0.026) of grasses, mainly from Jiggs, implying an increase in the digestibility of DM (P = 0.026) and energy content (P = 0.026).(AU)

Acúmulo de forragem em pastos de Tifton 85 adubados com nitrogênio e manejados sob lotação contínua / Biomass of the forage in Tifton 85 pastures fertilized with nitrogen and managed under continuous stocking

O presente ensaio foi realizado na Unidade de Pesquisa e Desenvolvimento de Adamantina, SP, da Agência Paulista de Tecnologia dos Agronegócios (APTA) Polo da Alta Paulista, com objetivo de avaliar o efeito da adubação nitrogenada na composição morfológica, densidade populacional de perfilhos, índice de área foliar, interceptação luminosa e acúmulo de forragem em pastos de Tifton 85 submetidos ao regime de lotação contínua. Os tratamentos corresponderam a três doses de nitrogênio e o controle (0, 100, 200 e 400 kg/ha/ano de N), dispostos em delineamento experimental de blocos casualizados com quatro repetições. Não foi constatado efeito da época de avaliação na densidade populacional de perfilhos vegetativo, morto e total de Tifton 85 em lotação continua com carga variável. Os parâmetros avaliados nos pastos de Cynodon cv. Tifton 85 sofrem influência da época de avaliação e das doses de nitrogênio com efeito marcante na composição morfológica do pasto, índice de área foliar e interceptação luminosa que são determinantes no acúmulo de forragem. O capim Tifton 85 alcançou as condições necessárias para atingir a taxa de crescimento da cultura máxima quando manejado sob lotação continua mantendo-se o pasto a 15 cm de altura.(AU)

The present study, carried out at the Division for Research and Development of Adamantina, SP/Brazil, at Agência Paulista de Tecnologia dos Agronegócios (APTA) Polo da Alta Paulista, aimed to evaluate the effect of nitrogen fertilization on the morphological composition, tiller density, leaf area index, light interception and forage accumulation of Tifton 85 pastures subjected to continuous grazing. Treatments corresponded to three nitrogen and control doses (0, 100, 200 and 400 kg N/ha/year), arranged in a randomized block design with four replications. No effect of time of evaluation was verified on the vegetative, dead and total tiller densities of Tifton 85 under continuous grazing with variable stocking rate. The pastures of Cynodon cv. Tifton 85 were affected by the time of evaluation and nitrogen doses, with marked effect on the pasture morphological composition, leaf area index and light interception, which are determinant to forage accumulation. Tifton 85 grass reached the necessary conditions to achieve the maximum growth rate of the culture when managed under continuous grazing keeping the pasture at a height of 15 cm.(AU)

Características estruturais, produtivas e bromatológicas dos capins Tifton 85 e Jiggs fertilizados com alguns macronutrientes / Structural, productive and bromatologic characteristcs of Tifton 85 and Jiggs grasses fertilized with some macronutrients

Objetivou-se avaliar o efeito da fertilização dos capins Tifton 85 e Jiggs com alguns macronutrientes sobre as características estruturais, produtivas e bromatológicas. Avaliaram-se duas forrageiras (Cynodon dactylon cv. Tifton 85 e C. dactylon cv. Jiggs) e cinco fontes de fertilizantes (três formulações NPK: 08-28-16, 30-00-20 e 20-10-10 e duas fontes de nitrogênio: ureia e super N), em esquema fatorial 2 x 5, distribuídos em delineamento inteiramente casualizado, com quatro repetições. O plantio dos capins foi realizado sem adubação, simulando uma pastagem implantada em condições de baixa fertilidade natural. As maiores produções (P = 0,009) e proporções de folhas (P 0,001) foram verificadas no capim-Tifton 85, resultando em menor proporção de colmos quando comparado ao capim-Jiggs. As fontes de fertilizantes empregadas na adubação dos capins Tifton 85 e Jiggs alteraram o peso e a proporção de folhas e colmos, bem como a relação folha/colmo, número de perfilhos e produção de massa. Houve interação significativa entre os fatores de estudo (capim e fertilizante) quanto aos teores de MS (P = 0,024), FDA (P = 0,012), hemicelulose (P = 0,007), DMS (P = 0,012), NDT (P = 0,012), ED (P = 0,012) e EM (P = 0,012) das folhas, além do teor protéico (P = 0,016) do colmo. De maneira geral, a aplicação do fertilizante 30-00-20 resultou em menor teor de FDA nas folhas do capim-Tifton 85 e maior digestibilidade da MS, com maior teor energético também, e o fornecimento de super N implicou em menor teor de FDA e maior digestibilidade da MS das folhas do capim-Jiggs. Considerando-se a planta inteira, o capim-Jiggs apresentou maior teor de FDN (P = 0,017) em relação ao Tifton 85, entretanto, a concentração de FDA nesse capim foi menor (P < 0,001) do que o Tifton 85, o que implicou em maior digestibilidade da MS (P < 0,001) e aporte energético (P < 0,001).

The aim this study was to evaluate the effect of fertilization of Tifton 85 and Jiggs grasses with some macronutrients on the structural, productive and bromatologic characteristics. Were evaluated two grasses (Cynodon dactylon cv. Tifton 85 and C. dactylon cv. Jiggs) and five sources of fertilizer (three formulations NPK: 08-28-16, 30-00-20 and 20-10-10, and two sources nitrogen: urea and super N) in a factorial scheme 2 x 5, distributed in a completely randomized design with four replications. The planting of grasses without fertilization was performed to simulate a pasture located in low natural fertility. The highest yields (P = 0.009) and ratios of leaves (P 0.001) were observed in Tifton 85 grass, resulting in a lower proportion of stems when compared to Jiggs grass. The sources of fertilizers used changed the weight and the proportion of leaves and stems, as well as the leaf/stem ratio, number of tillers and mass production of Tifton 85 and Jiggs grasses. There was a significative interaction between the study factors (grass and fertilizer) for concentrations of DM (P = 0.024), ADF (P = 0.012), hemicellulose (P = 0.007), DMD (P = 0.012), TDN (P = 0.012), DE (p = 0.012) and ME (P = 0.012) leaves and the protein content (p = 0.016) of the stem. In general, the application of 30-00-20 fertilizer resulted in lower ADF content in the leaves of Tifton 85 grass and higher DM, with higher energy content also, and providing super N implied lower ADF content and higher DM digestibility of Jiggs grass leaves. In the whole plant, the Jiggs grass had higher NDF (P = 0.017) compared to Tifton 85 grass, however, the concentration of ADF that grass was lower (P < 0.001) than Tifton 85 grass, which resulted in higher DM (P < 0.001) and energy intake (P < 0.001). The application of super N decreased the ADF content (P = 0.026) of grasses, mainly from Jiggs, implying an increase in the digestibility of DM (P = 0.026) and energy content (P = 0.026).

Acúmulo de forragem em pastos de Tifton 85 adubados com nitrogênio e manejados sob lotação contínua / Biomass of the forage in Tifton 85 pastures fertilized with nitrogen and managed under continuous stocking

O presente ensaio foi realizado na Unidade de Pesquisa e Desenvolvimento de Adamantina, SP, da Agência Paulista de Tecnologia dos Agronegócios (APTA) Polo da Alta Paulista, com objetivo de avaliar o efeito da adubação nitrogenada na composição morfológica, densidade populacional de perfilhos, índice de área foliar, interceptação luminosa e acúmulo de forragem em pastos de Tifton 85 submetidos ao regime de lotação contínua. Os tratamentos corresponderam a três doses de nitrogênio e o controle (0, 100, 200 e 400 kg/ha/ano de N), dispostos em delineamento experimental de blocos casualizados com quatro repetições. Não foi constatado efeito da época de avaliação na densidade populacional de perfilhos vegetativo, morto e total de Tifton 85 em lotação continua com carga variável. Os parâmetros avaliados nos pastos de Cynodon cv. Tifton 85 sofrem influência da época de avaliação e das doses de nitrogênio com efeito marcante na composição morfológica do pasto, índice de área foliar e interceptação luminosa que são determinantes no acúmulo de forragem. O capim Tifton 85 alcançou as condições necessárias para atingir a taxa de crescimento da cultura máxima quando manejado sob lotação continua mantendo-se o pasto a 15 cm de altura.

The present study, carried out at the Division for Research and Development of Adamantina, SP/Brazil, at Agência Paulista de Tecnologia dos Agronegócios (APTA) Polo da Alta Paulista, aimed to evaluate the effect of nitrogen fertilization on the morphological composition, tiller density, leaf area index, light interception and forage accumulation of Tifton 85 pastures subjected to continuous grazing. Treatments corresponded to three nitrogen and control doses (0, 100, 200 and 400 kg N/ha/year), arranged in a randomized block design with four replications. No effect of time of evaluation was verified on the vegetative, dead and total tiller densities of Tifton 85 under continuous grazing with variable stocking rate. The pastures of Cynodon cv. Tifton 85 were affected by the time of evaluation and nitrogen doses, with marked effect on the pasture morphological composition, leaf area index and light interception, which are determinant to forage accumulation. Tifton 85 grass reached the necessary conditions to achieve the maximum growth rate of the culture when managed under continuous grazing keeping the pasture at a height of 15 cm.