Fraze mowing offers a new tool used in both overseeding establishment and removal of perennial ryegrass (Lolium perenne L.). Research objectives were to determine the most effective timing of fraze mowing in overseeding establishment and removal, as well as to compare fraze mowing to other establishment and removal methods. Fall overseeding studies suggest that fraze mowing and scalping in mid-October provides the fastest establishment of ryegrass. However, by mid-March all treatments led to visually similar results. When evaluating removal timings, fraze mowing performed in early- and late-May led to faster visual bermudagrass recovery than March and April timings. Early-season application of glyphosate for ryegrass removal was fairly ineffective; whereas, late-season application was damaging to bermudagrass. Rimsulfuron removed ryegrass more quickly late in the season. Repeated scalping gradually removed ryegrass providing a slower, but complete, bermudagrass recovery. Overall, late-May fraze mowing resulted in the best bermudagrass cover 5 weeks after treatment.

Perennial ryegrass (Lolium perenne L.) is commonly overseeded into hybrid bermudagrass [Cynodon dactylon (L.) Pers. X C. transvaalensis Burtt Davy] turfs during autumn in the southern United States. Overseeding can provide a green, actively-growing turf throughout the winter dormancy period. Improved persistence of perennial ryegrass cultivars has increased management inputs during the spring transition period. Lower input turf systems that provide acceptable winter overseeding quality are preferred, and research aimed at evaluating alternative overseeding species are warranted. Grooming reel attachments allowing for threedimensional clipping management (3DCM) have become increasingly used by turf managers for reducing grain and thatch, but scientific information on best management practices and canopy effects of 3DCM-grooming are lacking. A field study was conducted at the Texas A&M Turfgrass Field Laboratory in College Station, TX (30.6191 degrees N, 96.3576 degrees W), to investigate the effects of overseeding using annual (Lolium multiflorum Lam.) and perennial ryegrasses on 3DCM-groomed and non-groomed fairway turfs of 'Tifway' hybrid bermudagrass, zoysiagrass [Zoysia matrella (L.) Merr. 'Cavalier'], and seashore paspalum (Paspalum vaginatum Sw. 'Sea Isle 1'). The study was arranged as a randomized complete block split-split-plot with three replications. Species whole main plots were split into three grooming intervals, which were further split into four overseeding treatments. Data were collected assessing visual turf quality, visual turf cover, leaf area index, clipping yield, shoot density, and biomass partitioning. Results indicate annual ryegrass alone and an annual/perennial ryegrass overseeding mix provided acceptable turf quality, but did not improve turf recovery over perennial ryegrass alone in 'Tifway' or 'Sea Isle 1' turfs. In 'Cavalier' turfs, summer quality was affected by overseeding treatment as follows: control > annual > annual/perennial > perennial. The overseeding tolerance of the warm-season turfgrasses was as follows: 'Sea Isle 1' > 'Tifway' > 'Cavalier'. Differences in canopy architecture of warm-season turfgrasses were related to the overseeding tolerance of each species and used to explain plant competition during the spring transition period. Grooming by 3DCM improved late-season turf quality and reduced scalping in 'Tifway'. Overseeding establishment and canopy architecture were not affected by 3DCM.

Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-01-14Bitstream added on 2014-06-13T20:48:03Z : No. of bitstreams: 1 bertolote_lem_me_botfmvz.pdf: 359265 bytes, checksum: 3b37fd0d739b8724b336a7e443f13ee2 (MD5) / Universidade Estadual Paulista (UNESP) / O objetivo deste trabalho foi avaliar o efeito da densidade de semeadura de aveia e altura de corte do capim-Tanzânia sobre a produção, emergência de plantas, proteína bruta (PB) e digestibilidade in vitro da matéria seca (DIVMS) das espécies em sobressemeadura. Foram avaliados três taxas de semeadura de aveia (60, 90 e 120 kg.ha-1 de sementes puras viáveis) e duas alturas de corte do capim-Tanzânia (10 e 30 cm). A taxa de semeadura não teve efeito sobre a produção ou valor nutritivo tanto da espécie tropical como de clima temperado. A produção de aveia foi de 313,04 e 232,94 kg MS.ha-1 e de capim-Tanzânia de 366,06 e 214,51 kg MS.ha-1, para as alturas de 10 e 30 cm, respectivamente. Foram observados teores de PB na aveia de 22,40% e 21,28% e no capim-Tanzânia de 17,23% e 15,85%, para alturas de 10 e 30 cm, respectivamente. Os teores de DIVMS obtidos para aveia foram de 81,66% e 78,09% e para capim-Tanzânia foram de 64,95% e 68,65% pra as alturas de 10 e 30 cm, respectivamente. A densidade de semeadura mais adequada foi a de 60 kg.ha-1, por ser a menos onerosa e a altura de corte de 10 cm do capim-Tanzânia no momento da sobressemeadura proporcionou melhor produção de forragem e valor nutritivo das pastagens de aveia e de capim-Tanzânia. Termos para indexação: Avena... / The purpose of this study was to evaluate the effect of oats seeding density and Tanzania grass height cutting on yield, number of winter pasture plants, crude protein (CP) and in vitro dry matter digestibility (IVDMD) of grasses overseeded. Three oats seding density (60, 90 and 120 kg.ha-1 seed) and two Tanzania grass height cutting (10 and 30 cm) was evaluated. Oats seeding density there was no significant difference in yield and nutritive value of tropical or winter pasture. Oats yield was 313.04 and 232.94 kg MS.ha-1 and Tanzania grass yield was 366.06 e 214.51 kg MS.ha-1 in height cutting 10 and 30 cm, respectively. Oats CP 22.40% and 21.28% and Tanzania grass CP 17.23% e 15.85% was observed in height cutting 10 and 30 cm, respectively. Oats IVDMD 81.66% and 78.09% and Tanzania grass IVDMD 64.95% e 68.65% was observed in height cutting 10 and 30 cm, respectively. Seeding density more proper is 60 g.ha-1 because is less expensive that another and Tanzania grass height cutting 10 cm had better forage yield and nutritive value... (Complete abstract click electronic access below)

Dormant bermudagrass (Cynodon dactylon) fairways become matted down and thinned out from winter traffic. This appears to be more of a problem on the coarser textured, winter hardy, improved varieties (e.g., 'Midiron' and 'Vamont') typically used in the colder regions of the upper transition zone. Winter overseeding with cool-season species can improve dormant bermudagrass winter and spring quality. However, bermudagrass persistence can decline in golf course fairways overseeded with ryegrasses (Lolium sp.) for winter quality if ryegrasses persist due to cool spring temperatures, use of persistent ryegrass varieties, and management practices that favor ryegrasses over bermudagrass. Winter overseeding practices that facilitate a reliable transition from overseeded species to bermudagrass would enable transition zone golf courses to overseed bermudagrass fairways for winter-spring quality while allowing the bermudagrass turf to persist without excessive competition from cool-season overseeded species. Studies were conducted to determine the effects of perennial ryegrass (L. perenne) and annual ryegrass (L. multiflorum) seeding rates on winter-spring quality and subsequent transition to bermudagrass in two transition zone locations. Studies were also conducted to determine the potential influence trinexapac-ethyl (TE), a plant growth regulator used by many professional turfgrass managers to suppress foliar growth, has on encouraging overseeded species to transition to bermudagrass. These studies demonstrated that higher overseeding rates (448 and 896 kg ha-1) can provide greater winter-spring quality but do not enhance transition to bermudagrass over lower overseeding rates (224 kg ha-1). This was especially evident in cooler transition zone climate, where higher overseeding rates delayed transition to bermudagrass. Annual ryegrass transitioned to bermudagrass better than perennial ryegrass, but the overseeded winter-spring quality of annual ryegrass was unacceptable. Perennial ryegrass varieties differed in transition. Some perennial ryegrass varieties were too persistent to fully transition to bermudagrass even with the onset of summer temperatures. Intermediate ryegrasses (L. multiflorum x L. perenne) appeared to be promising alternatives to overseeding perennial ryegrass in areas of the transition zone where summer reliance on bermudagrass turf is strongly preferred. Trinexapac-ethyl, when applied to overseeded perennial ryegrasses, did not enhance overseeded ryegrass transition to bermudagrass. Spring TE applications to overseeded perennial ryegrasses were found to reduce or delay their transition to bermudagrass. / Master of Science

Benefits of establishing legumes into permanent pastures have been well studied. Successful establishment of legumes in pastures can be challenging, however, and more information is needed about different seeding methods and variables that affect legume establishment. A pasture and a small plot experiment were conducted in Blacksburg, Va from 2009 to 2011to gain better understanding of how seeding method and management variables affected red clover (Trifolium pratense L.) and white clover (Trifolium repens L.) establishment into permanent cool season grass pasture and sod. In the pasture experiment, seedling density was measured two months after sowing and grass, white clover, red clover, and weed biomass were periodically measured during the experiment. Broadcast seeding treatment had 93% more clover seedlings than drill treatment (P = 0.1087) two months after sowing. No difference (P > 0.10) for clover biomass was observed between sowing treatments in any year and clover establishment was considered successful (over 25% of pasture composition) in both treatments. In the drill treatment, clover seedling density was negatively affected by the residual grass biomass at sowing (P = 0.0196). In the broadcast treatment, a quadratic relationship between clover seedling density and residual grass biomass at sowing was found (P = 0.0516). Clover seedling density in April 2009 determined the amount of clover biomass in August 2009 (P = 0.0008) and the 2010 clover biomass mean (P = 0.0249). Further exploration of the influence fertilization with P and K, grass biomass at sowing, and defoliation frequency on clover establishment were studied in a split-split plot study. Fertilization with P and K was assigned to whole plots that were split in half and assigned a high or low grass biomass at sowing treatment, the subplots were split in and designated either a high or low cutting frequency. Prior to cutting, samples from each plot were sorted to grass, white clover, red clover, and weed. Plots with a low grass biomass at sowing (232 seedlings m-2) had a higher seedling density (P < 0.0001) compared with plots with a high grass biomass at sowing plots (111 seedlings m-2). Greater biomass of white and red clover depended both on having a low grass biomass at sowing and a high frequency of defoliation (P = 0.0026 and P < 0.0001, respectively). Red clover yield was also determined by interactions between fertilization and a high frequency of defoliation (P < 0.0001), as well as between fertilization and low grass biomass at sowing (P = 0.0026). Dry conditions resulted in low clover yields (6% of total herbage mass) with red clover producing four times the herbage mass of white clover. These data show that creating a favorable environment for seedlings to germinate and establish was more important than seeding method. / Master of Science

Resumo: O objetivo deste trabalho foi avaliar o efeito da densidade de semeadura de aveia e altura de corte do capim-Tanzânia sobre a produção, emergência de plantas, proteína bruta (PB) e digestibilidade in vitro da matéria seca (DIVMS) das espécies em sobressemeadura. Foram avaliados três taxas de semeadura de aveia (60, 90 e 120 kg.ha-1 de sementes puras viáveis) e duas alturas de corte do capim-Tanzânia (10 e 30 cm). A taxa de semeadura não teve efeito sobre a produção ou valor nutritivo tanto da espécie tropical como de clima temperado. A produção de aveia foi de 313,04 e 232,94 kg MS.ha-1 e de capim-Tanzânia de 366,06 e 214,51 kg MS.ha-1, para as alturas de 10 e 30 cm, respectivamente. Foram observados teores de PB na aveia de 22,40% e 21,28% e no capim-Tanzânia de 17,23% e 15,85%, para alturas de 10 e 30 cm, respectivamente. Os teores de DIVMS obtidos para aveia foram de 81,66% e 78,09% e para capim-Tanzânia foram de 64,95% e 68,65% pra as alturas de 10 e 30 cm, respectivamente. A densidade de semeadura mais adequada foi a de 60 kg.ha-1, por ser a menos onerosa e a altura de corte de 10 cm do capim-Tanzânia no momento da sobressemeadura proporcionou melhor produção de forragem e valor nutritivo das pastagens de aveia e de capim-Tanzânia. Termos para indexação: Avena... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The purpose of this study was to evaluate the effect of oats seeding density and Tanzania grass height cutting on yield, number of winter pasture plants, crude protein (CP) and in vitro dry matter digestibility (IVDMD) of grasses overseeded. Three oats seding density (60, 90 and 120 kg.ha-1 seed) and two Tanzania grass height cutting (10 and 30 cm) was evaluated. Oats seeding density there was no significant difference in yield and nutritive value of tropical or winter pasture. Oats yield was 313.04 and 232.94 kg MS.ha-1 and Tanzania grass yield was 366.06 e 214.51 kg MS.ha-1 in height cutting 10 and 30 cm, respectively. Oats CP 22.40% and 21.28% and Tanzania grass CP 17.23% e 15.85% was observed in height cutting 10 and 30 cm, respectively. Oats IVDMD 81.66% and 78.09% and Tanzania grass IVDMD 64.95% e 68.65% was observed in height cutting 10 and 30 cm, respectively. Seeding density more proper is 60 g.ha-1 because is less expensive that another and Tanzania grass height cutting 10 cm had better forage yield and nutritive value... (Complete abstract click electronic access below) / Orientador: Josivaldo Prudêncio Gomes de Morais / Coorientador: Patrícia Perondi Anchão de Oliveira / Banca: Jozivaldo Prudêncio Gomes de Morais / Banca: Ciniro Costa / Banca: Mauro Dall Seco de Oliveira / Mestre

A demanda de alimentos para 2050 está prevista ser o dobro da atual. A produção de alimentos no Brasil tem significativa relevância para a segurança alimentar mundial, sendo a pecuária de suma importância devido à grande demanda mundial de carne e leite provenientes do Brasil. Assim, surge a necessidade de estudos que visem aumentar a produção sem expandir área de plantio, sendo a irrigação uma das formas de intensificar a produtividade de sistemas agrícolas. Para um manejo da irrigação adequado é necessário o conhecimento da evapotranspiração da cultura (ETc), e estudos de técnicas que façam essa estimativa com precisão, de forma prática e acessível, são de grande valia para uma agricultura irrigada sustentável. Uma dessas técnicas é a reflectometria no domínio da frequência (FDR), que se destaca por sua praticidade e capacidade de medir a umidade do solo em camadas distintas. Por ser um equipamento portátil, sua utilização pode resultar em menos custo para estimativas de coeficientes de cultura, substituindo a lisimetria (método padrão). Portanto, o objetivo deste trabalho foi verificar a possibilidade da utilização de uma sonda (FDR) como instrumento auxiliar na estimativa de consumo hídrico e de coeficientes de cultura (Kc) do capim Marandu, em cultivo solteiro (primavera/verão) e consorciado com aveia preta + azevém ou centeio + azevém no período de outono/inverno. Como objetivos secundários, buscou-se: (i) estimar o consumo hídrico e os coeficientes de cultura dos dosséis forrageiros estudados com a sonda FDR devidamente calibrada ao solo local; (ii) comparar o consumo de água e os valores de Kc obtidos por meio da sonda FDR e por lisimetria de pesagem; (iii) verificar se a técnica capacitiva é capaz de identificar a atividade de absorção de água do sistema radicular das forrageiras estudadas; e (iv) analisar parâmetros produtivos do capim Marandu solteiro e consorciado, e estimar a produtividade de água da cultura. O experimento foi realizado na Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ/USP), em Piracicaba-SP. O período experimental foi de 21/09/2017 a 24/09/2018, com ciclos de corte de duração variada, baseados na fenologia das culturas. Os resultados obtidos revelaram que a técnica de capacitância com sonda FDR mostrou-se apropriada para a estimativa de ETc e Kc de dosséis forrageiros em cultivo solteiro e consorciado, com valores próximos ao método padrão (lisimetria de pesagem). O uso da sonda capacitiva também foi eficaz na identificação da atividade de absorção de água pelas raízes, por meio do monitoramento da umidade do solo. A sobressemeadura com culturas de inverno foi uma opção resiliente para o período de estacionalidade, durante o qual aumentou o potencial produtivo do dossel forrageiro. O consórcio Marandu + aveia preta + azevém apresentou maior produtividade que Marandu + centeio + azevém. / The demand for food by 2050 is expected to be the double of the current year. The food production in Brazil has significant relevance for the world food security, and pasture crops are very important due to the great world demand for meat and milk come from Brazil. Thus, there is a need for studies that aim to increase forage production without expanding tillage area, and irrigation is one way to increase the productivity of agricultural systems. Adequate irrigation management requires knowledge of crop evapotranspiration (ETc), and studies of techniques to accurately estimate it, in a practical and accessible way, having a great value for a sustainable irrigated agriculture. One of these techniques is frequency domain reflectometry (FDR), which stands out for being practical and able to measure soil moisture in different layers. Because it is a portable equipment, its use can result in lower costs for estimating crop coefficients, replacing lysimetry (standard method). Therefore, this work aimed at verifying the possibility to use a FDR probe as a tool for estimating the crop water consumption and crop coefficients (Kc) of \'Marandu\' palisade grass, single cropped (spring / summer) and intercropped with black oat + ryegrass and with rye + ryegrass during the fall / winter period. As secondary objectives, we sought to: (i) estimate the crop water consumption and crop coefficients of the forage canopies with the FDR probe properly calibrated to the local soil; (ii) compare the crop water consumption and Kc values estimated by the FDR probe and those ones determined by weighing lysimetry; (iii) verify if the capacitive technique is able to identify the water absorption activity of the root system; (iv) to analyze productive parameters of single and intercropped \'Marandu\' palisade grass, and to estimate the water productivity of the forage canopies. The experiment was carried out at an experimental area of \"Luiz de Queiroz\" College of Agriculture (ESALQ / USP), at Piracicaba-SP. The experimental period was from 09/21/2017 to 09/24/2018, with grow-and-cut cycles whose duration based on the phenology of the crops. The results revealed that FDR capacitance technique was adequate for ETc and Kc estimates of both, single cropped and intercropped forage canopies, with values near to the standard method (weighing lysimetry). The use of the capacitive probe was also effective in identifying the water absorption activity of the root system, through the monitoring of soil moisture. Overseeding with winter forage crops was a resilient option for the seasonality period, increasing the productive potential of the forage canopy. Intercropped \'Marandu\' + black oat + rye consortium presented higher forage yield than \'Marandu\' + rye + ryegrass consortium.