Academic literature on the topic 'Signalgrass'

Tropical signalgrass is one of the most serious weed problems in the St. Augustinegrass sod production in Florida, and its presence increases production costs and lowers turfgrass quality. The objectives of our research were to: (1) evaluate herbicides preemergence and postemergence for control of tropical signalgrass and (2) compare control of tropical signalgrass and other problem weeds (torpedograss, blanket crabgrass, and India crabgrass) with postemergence herbicides. In preemergence herbicide field trials, only benefin + oryzalin, imazapic, imazapic + 2,4-D, and oryzalin provided ≥75% tropical signalgrass control 8 wk after application (WAA). By 11 WAA, only benefin + oryzalin and imazapic + 2,4-D provided ≥75% tropical signalgrass control. In greenhouse experiments, eight herbicide treatments were applied postemergence to tropical signalgrass seedlings at the two-, four-, six-, and eight-leaf stages. Asulam and CGA 362622 provided ≥89% tropical signalgrass control at all application timings. Imazaquin controlled tropical signalgrass ≥98% when applied before the eight-leaf stage. However, in field trials with mature tropical signalgrass (>20 cm stolons), none of the 20 herbicide treatments applied postemergence provided acceptable control.

Broadleaf signalgrass control from preemergence (PRE) herbicides was usually lower in no-till than in tilled plots. Broadleaf signalgrass control was most nearly complete in tilled plots treated with metolachlor in 1995, a year that favored an herbicide with more soil persistence. Broadleaf signalgrass control was most nearly complete in tilled plots treated with acetochlor in 1996, a year in which rainfall to activate the herbicides did not occur until 9 d after planting. The 1996 data indicated that acetochlor was more stable on the soil surface under the drier conditions. There was no difference in broadleaf signalgrass control between the two acetochlor formulations. Alachlor, metolachlor, and dimethenamid controlled broadleaf signalgrass > 80% for about 4 wk, acetochlor provided control for about 4 wk under no-till conditions and about 8 wk in tilled plots, and pendimethalin provided about 2 wk broadleaf signalgrass control. Acetochlor provided consistent control regardless of the rainfall pattern after application.

Broadleaf signalgrass is sensitive to nicosulfuron and resistant to primisulfuron, but corn is resistant to both. Research was conducted to determine the effect of varying light level and air temperature on absorption, translocation, and metabolism of nicosulfuron and primisulfuron in broadleaf signalgrass and corn. Corn absorbed between 60 and 85% of the applied nicosulfuron and primisulfuron within 72 h after treatment (HAT), depending on environmental treatment. Absorption, translocation, and metabolism all tended to be more rapid at higher temperature and light intensity. Nicosulfuron and primisulfuron translocation out of the treated leaf was < 4.5% of herbicide absorbed through 72 HAT. Corn rapidly metabolized both herbicides in both environments. However, primisulfuron was metabolized more rapidly (high = 99%, low = 92%) than nicosulfuron (high = 95%, low = 78%). Broadleaf signalgrass absorbed 20% more nicosulfuron than primisulfuron through 72 HAT. Nicosulfuron translocation out of the treated leaf in broadleaf signalgrass was ≤ 15% absorbed through 72 HAT, while primisulfuron translocation was ≤ 4% during the same time period. Primisulfuron metabolism was more rapid than nicosulfuron in broadleaf signalgrass. During the first 4 HAT, broadleaf signalgrass metabolized > 20 times more primisulfuron than nicosulfuron. By 72 HAT, broadleaf signalgrass under conditions of high light and temperature had metabolized nearly 90% of the primisulfuron absorbed but ≤ 7% of the nicosulfuron absorbed was metabolized during the same time. These results suggest that differential activity of nicosulfuron and primisulfuron on broadleaf signalgrass may be based on differential rates of metabolism to nonphytotoxic compounds; uptake and translocation differences agree with the differential broadleaf signalgrass activity. Additionally, environment has the potential to affect rates of sulfonylurea absorption, translocation, and metabolism.

Field experiments were conducted in 1984 and 1985 at Stuttgart, AR, to investigate the interspecific and intraspecific interference of broadleaf signalgrass densities of 0, 10, 50, 100, and 150 plants/m2with rice. In 1984, significant reductions in rice leaf area index (LAI) occurred 6 weeks after emergence with all broadleaf signalgrass densities. The first reduction in LAI occurred 8 weeks after emergence at the density of 150 plants/m2in 1985. Densities of 50 plants/m2or greater reduced rice dry weight 6 weeks after emergence in 1984, and the highest density of 150 plants/m2reduced rice dry weight 12 weeks after emergence in 1985. Height of rice was reduced by densities of 100 and 150 plants/m2. Linear regression equations indicated that each broadleaf signalgrass plant/m2reduced rough rice yield 18 kg/ha both years. Growth of broadleaf signalgrass was reduced by interspecific and intraspecific interference. The dry weight of broadleaf signalgrass increased at a decreasing rate at plant densities of 100 to 150/m2when grown alone in 1984 and 1985, when a quadratic equation best described the response. Regression equations indicated interspecific interference from rice reduced broadleaf signalgrass dry weight an average of 48 and 81% in 1984 and 1985, respectively. The height of broadleaf signalgrass was greater when grown with rice than when grown alone.

Field experiments were conducted during 1996 and 1998 to determine the effect of atrazine, bentazon, atrazine + bentazon, the amine salt of 2,4-D, and bromoxynil on broadleaf signalgrass and barnyardgrass control when applied in mixture with sethoxydim. Herbicide combinations were applied with crop oil concentrate, crop oil concentrate + ammonium sulfate, or BCH 815. Bentazon and atrazine + bentazon reduced broadleaf signalgrass and barnyardgrass control by sethoxydim. Bromoxynil reduced barnyardgrass control but had no affect on broadleaf signalgrass control. Including ammonium sulfate with crop oil concentrate or substituting BCH 815 for crop oil concentrate increased barnyardgrass and broadleaf signalgrass control by sethoxydim when applied with bentazon. Ammonium sulfate and BCH 815 increased barnyardgrass control when sethoxydim was applied with bromoxynil but did not affect control when sethoxydim was applied with atrazine + bentazon. Atrazine and the ammonium salt of 2,4-D did not reduce barnyardgrass and broadleaf signalgrass control by sethoxydim regardless of adjuvant.

The objective of this work was to evaluate the initial growth and the physiological characteristics of eucalypt submitted to different managements of signalgrass. The experiment was conducted in a protected environment, using a randomized blocks design with five repetitions. The treatments were arranged in a (5 x 2) + 1 factorial design, and the first factor corresponded to the types of weed management (no control; chemical control keeping the signalgrass shoot on the soil; chemical control with removal of the signalgrass shoot; mechanical control keeping the signalgrass shoot on the soil, and mechanical control with removal of the signalgrass shoot); the second factor corresponded to the two weeds species (U. brizantha and U. decumbens) and a control relative to the eucalypt in monoculture. The eucalypt growth was not affected by the presence of the Urochloa species until 50 days after treatments (DAT). However, the coexistence of these species with eucalypt for 107 DAT reduced the collar diameter, total dry matter, and the leaf area, but did not alter the characteristics related to photosynthesis and transpiration. The control method adopted, with removal or maintenance of the signalgrass shoot, regardless of species, did not change the initial eucalypt growth. It can be concluded that the coexistence of eucalypt with Urochloa decumbens or Urochloa brizantha for 105 days reduces the eucalypt growth. However, the use of chemical or mechanical control, with or without removal of signalgrass residue, were effective methods to prevent interference of these weeds.

Abstract Silvopasture systems (SPS) area management option to enhance delivery of ecosystem services and diversification of income. This study evaluated productive responses of signalgrass (UrochloadecumbensStapf.) in monoculture or in SPS in the sub-humid tropical region of Brazil during six months of the rainy season. The experimental design was randomized complete block with three replications. Treatments were signalgrass + Mimosa caesalpiniifolia Benth. (SPS-Mimosa); signalgrass + Gliricidia sepium (Jacq.) (SPS-Gliricidia); and signalgrass monoculture. Cattle were managed under continuous stocking with variable stocking rate. Response variables included herbage mass (HM), herbage accumulation (HA), stocking rate (SR), average daily gain (ADG), and gain per area (GPA). Herbage mass (HM) was greater (P &lt; 0.0001) on signal grass monoculture (2045 kg DM/ha) than in SPS (1370 kg DM/ha, average for both SPS). Herbage accumulation rate was similar for signalgrass in monoculture and SPS-Gliricidia (avg. 61 kg DM ha-1 d-1), and both were greater than SPS-Mimosa (37 kg DM ha-1 d-1). Average daily gain was greater(P &lt; 0.0001) for SPS-Gliricidia (1.1 kg head-1 d-1), followed by signalgrass in monoculture (0.9 kg head-1 d-1), and SPS-Mimosa (0.3 kg head-1 d-1). Stocking rate ranged from 0.6 animal units (1AU = 450-kg animal) per ha in April to 2.2 AUha-1 in June. Stocking rate and animal performance per area were similar for signalgrass in monoculture and SPS-Gliricidia, and both greater than SPS-Mimosa. Gliricidia enhanced animal performance and provided ecosystem services. Mimosa, however, reduced animal performance likely due to the competition with signalgrass. Mimosa trees, however, are an important source of income (timber used for fence posts) and that might overcome the losses in animal performance.

Abstract Silvopasture systems (SPS) area management option to enhance delivery of ecosystem services and diversification of income. This study evaluated productive responses of signalgrass (Urochloadecumbens Stapf.) in monoculture or in SPS in the sub-humid tropical region of Brazil during six months of the rainy season. The experimental design was randomized complete block with three replications. Treatments were signalgrass + Mimosa caesalpiniifolia Benth. (SPS-Mimosa); signalgrass + Gliricidia sepium (Jacq.) (SPS-Gliricidia); and signalgrass monoculture. Cattle were managed under continuous stocking with variable stocking rate. Response variables included herbage mass (HM), herbage accumulation (HA), stocking rate (SR), average daily gain (ADG), and gain per area (GPA). Herbage mass (HM) was greater (P &lt; 0.0001) on signal grass monoculture (2045 kg DM/ha) than in SPS (1370 kg DM/ha, average for both SPS). Herbage accumulation rate was similar for signalgrass in monoculture and SPS-Gliricidia (avg. 61 kg DM ha-1 d-1), and both were greater than SPS-Mimosa (37 kg DM ha-1 d-1). Average daily gain was greater(P &lt; 0.0001) for SPS-Gliricidia (1.1 kg head-1 d-1), followed by signalgrass in monoculture (0.9 kg head-1 d-1), and SPS-Mimosa (0.3 kg head-1 d-1). Stocking rate ranged from 0.6 animal units (1AU = 450-kg animal) per ha in April to 2.2 AUha-1 in June. Stocking rate and animal performance per area were similar for signalgrass in monoculture and SPS-Gliricidia, and both greater than SPS-Mimosa. Gliricidia enhanced animal performance and provided ecosystem services. Mimosa, however, reduced animal performance likely due to the competition with signalgrass. Mimosa trees, however, are an important source of income (timber used for fence posts) and that might overcome the losses in animal performance.

Abstract Field studies were conducted to evaluate broadleaf signalgrass and southern crabgrass control and effect on peanut yield of clethodim alone and sequential applications with six broadleaf herbicides. When rated 9 wk after treatment (WAT), broadleaf signalgrass control with clethodim followed by (fb) acifluorfen, imazapic, or 2,4-DB 24 hr later did not differ from clethodim alone. When acifluorfen, acifluorfen plus bentazon, imazethapyr, imazapic, and lactofen were applied in a tank-mix with clethodim, broadleaf signalgrass control was less than 65%. Clethodim alone or clethodim plus 2,4-DB controlled 86 and 73% broadleaf signalgrass, respectively. When acifluorfen, acifluorfen plus bentazon, or imazethapyr was fb clethodim, signalgrass control was less than 72%. Southern crabgrass control was reduced in 2 of 3 yr from clethodim alone when acifluorfen was tank-mixed with clethodim. When other broadleaf herbicides were tank-mixed with clethodim, reduced crabgrass control was noted in only 1 of 3 yr. Where no POST herbicides were used, peanut yield was &lt; 1600 kg/ha, while all plots which received a POST herbicide yielded over 2200 kg/ha.

A 3-yr study was initiated in 1982 to determine the effects of herbicides and crop rotations on large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA] and broadleaf signalgrass [Brachiaria platyphylla(Griseb.) Nash # BRAPP] population dynamics. Regardless of the crop rotation sequence, broadleaf signalgrass immediately became the predominant weed where standard herbicide programs were used. Large crabgrass became the predominant species after two growing seasons if no herbicides were applied. Domination by large crabgrass appeared to be due to greater seed production. The domination by broadleaf signalgrass in plots treated with herbicides was attributed to its tolerance to the primary grass herbicide alachlor [2-chloro-N-(2,6-diethylphenyl)-N-methoxymethyl)acetamide]. Broadleaf signalgrass emergence from soil treated with 2.2 kg ai/ha was not statistically different from that in untreated soil, while large crabgrass and fall panicum [Panicum dichotomiflorum(L.) Michx. # PANDI] emergence was significantly reduced at the same rate.

Orientador: Edivaldo Domingues Velini
Resumo: A espécie Urochloa decumbens é uma das plantas mais importantes e frequentes em áreas com culturas perenes e em áreas não-agrícolas. Os efeitos secundários que ocorrem nas plantas pela aplicação de baixas doses de glyphosate ainda são pouco compreendidos. Desse modo, a hipótese dessa pesquisa foi de que as baixas doses de glyphosate podem suprimir o crescimento, reduzir a competição e permitir a sua utilização para manutenção da cobertura vegetal. Assim, o objetivo do trabalho foi avaliar os efeitos de doses subletais de glyphosate no crescimento, consumo de água, metabolismo e absorção de nutrientes em plantas de U. decumbens. Foram realizados três experimentos em casa de vegetação, seguindo delineamento em blocos casualizados, com três doses de glyphosate (0; 22,5 e 45 g e.a. ha-1) e cinco repetições. As unidades experimentais utilizadas nos experimentos foram constituídas por duas estruturas plásticas acopladas, sendo a superior preenchida com 500 g de substrato comercial e semeada com U. decumbens, e a inferior com 650 mL de água. Aos 15 dias após a semeadura (DAS) realizou-se o desbaste, mantendo 20 plantas por unidade e aos 16 DAS a aplicação dos tratamentos utilizando pulverizador estacionário. Na primeira avaliação, de consumo de água, os três experimentos corresponderam aos períodos de avaliação em dias após aplicação (DAA), sendo feitas medições do volume de água remanescente na estrutura inferior a cada 48 horas, com reposição do volume inicial de 0-15 DAA; 0-30 DA... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The species Urochloa decumbens is one of the most important and frequent plants in perennial and non-agricultural areas. The secondary effects that occur on plants by the application of low doses of glyphosate, are still poorly understood. Thus, the hypothesis of this research was that low doses of glyphosate may suppress growth, reduce competition and allow the use for maintenance of vegetation cover. Therefore, the objective of this study was to evaluate the effects of sublethal doses of glyphosate on the growth, water consumption, metabolism and nutrient absorption on U. decumbens plants. Three greenhouse experiments were carried out, following a randomized block design with three doses of glyphosate (0, 22.5 and 45 g a.e. ha-1) and five replications. The experimental units used in the experiments consisted of two coupled plastic structures, the upper one filled with 500 g of commercial substrate and sowed with U. decumbens, and the lower with 650 mL of water. At 15 days after sowing (DAS) plants were thinned, maintaining 20 plants per unit and at 16 DAS the application of treatments using a stationary sprayer. In the first evaluation, of water consumption, the three experiments corresponded to the evaluation periods in days after application (DAA), with measurements of the remaining water volume in the lower structure every 48 hours, with initial volume replacement from 0-15 DAA; 0-30 DAA and regrowth of plants (16-30 DAA). At the end of each experiment, the tillers were ... (Complete abstract click electronic access below)
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O capim-braquiária (Brachiaria decumbens Stapf. cv. Basilisk) tem grande importância para sistemas de produção pecuários no Brasil, notadamente em regiões com baixa fertilidade natural do solo. O objetivo do presente trabalho foi estudar efeitos de duas intensidades (5 e 10 cm de altura pós-pastejo) e duas frequências de desfolhação (descanso até 95 e 100% de interceptação luminosa, IL, para início do pastejo) como definidores da estrutura do dossel, da morfogênese e do valor nutritivo da B.decumbens cv. Basilisk sob lotação intermitente. O estudo foi conduzido em Brotas - SP. O período experimental foi de Jan 2007 a Ago 2008, compreendendo sete épocas (Verão/2007, Outono/2007, Inverno/2007, Final de primavera/2007, Verão/2008, Outono/2008 e Inverno/2008) para as variáveis: produção de forragem, composição morfológica, índice de área foliar (IAF), altura de dossel, IL e valor nutritivo de folhas. Para características morfogênicas, densidade e demografia de perfilhos, o período foi de Ago 2007 a Ago 2008 e para valor nutritivo da forragem de Jan 2008 a Ago 2008. Os tratamentos foram quatro combinações possíveis entre as duas intensidades e frequências de desfolhação, em arranjo fatorial, com quatro repetições num delineamento inteiramente casualizado.O manejo com 100% IL resultou em produção total de 17,1 Mg MS ha-1, enquanto que para 95% IL a produção foi de 14,2 Mg MS ha-1. Pastos sob a estratégia 100% IL resultaram em maior produção de colmos e material morto, e maior IAF-pré pastejo. A intensidade de 10 cm promoveu maior produção de forragem e colmos (16,6 e 4,4 Mg MS ha-1), e maior IL e IAF no pós-pastejo. As maiores taxas de aparecimento de folhas (TAPF) e menores taxas de senescência foliar (TSF), alongamento (TALC) e acúmulo de colmo (TAFCM), na primavera de 2007 até outono de 2008 foram obtidas para 95% IL.As maiores taxas de acúmulo de folhas (TAFLM)no final da primavera ocorreram em pastos submetidos a 95% de IL e no verão e outono para o tratamento 10/95 (24,3, 26,8 e 23,3 kg MS ha-1 dia-1). De forma geral, o tratamento 10/95 resultou em altas taxas de aparecimento e de sobrevivência de perfilhos basais nas épocas com maior disponibilidade nos fatores de crescimento, épocas em que também foram encontrados os maiores teoresem proteína bruta (PB) de folhas para 95% IL, enquanto adigestibilidade in vitro da matéria orgânica (DIVMO)de folhas foi maior para a intensidade de 10 cm. As menores DIVMOs da forragem foram encontradas nos pastos que receberam a combinação 5/100, indicando que períodos longos de descanso e intensidades altasde pastejo resultam na produção de forragem de baixo valor nutritivo. A altura de dossel no pré-pastejo para o manejo com 95% IL ficou próximo a 16 cm e para 100% IL em 22 cm. A desfolhação do capim-braquiária deve ser realizada até10 cm uma vez que isto resulta em rebrotações rápidas e, quando associado à frequência de 95% IL, permite que animais em pastejo tenham acesso a forragem com maior participação de folhas e menor de material morto e colmo.
Signalgrass (Brachiaria decumbens Stapf. cv. Basilisk) is an important forage resource in Brazilian livestock systems, mainly where soil natural fertility is low. The objective in this study was to investigate the effects of two intensities (5 and 10 cm stubble) and two frequencies of defoliation (rest periods determined by 95 or 100% light interception LI by the canopy) as determinants of sward structure, morphogenesis, and forage nutritive value of B.decumbens cv. Basilisk under intermittent grazing. The work was carried out in Brotas, SP. The experimental period was from Jan 2007 through Aug 2008, divided in seven seasons (Summer/2007, Autumn/2007, Winter/2007, Late Spring/2007, Summer/2008, Autumn/2008 and Winter/2008) for the response variables: forage production, plant-part composition, leaf area index (LAI), sward height, LI, and leaf nutritive value. For the morphogenetic characteristics, tiller density, and tiller demography, the experimental period was from Aug 2007 through Aug 2008. For forage nutritive value, it was from Jan 2008 through Aug 2008. Treatments included all possible combinations among two grazing frequencies and two intensities, in a factorial arrangement of a completely randomized design. The 100% LI management resulted in total yield of 17.1 Mg DM ha-1, whereas for the 95% LI treatments total production was 14.2 Mg DM ha-1. Pastures under the 100% LI strategy produced more stem and dead material, as well as higher pregraze LAI. The 10-cm stubble resulted in higher forage and stem yield (16.6 and 4.4 Mg DM ha-1, respectively), as well as higher postgraze LI and LAI.The highest leaf appearance rates and lowest rates of leaf senescence, leaf elongation, and stem accumulation from Spring 2007 through Autumn 2008 were recorded for 95%LI. The highest rates of leaf accumulation in late spring were found in pastures under 95% LI, and in the summer and autumn for the 10/95 treatment (24.3, 26.8 and 23.3 kg DM ha-1 d-1, respectively). In general, the 10/95 treatment resulted in high rates of basal tiller appearance and survival, when the environmental conditions were favorable, which was also when crude protein concentration in leaves was highest under 95% LI, whereas in vitroorganic matter digestibility (IVOMD) of leaves was higher for the 10 cm stubble. The lowest IVOMDs were found in pastures receiving the 5/100 treatment combination, indicating that long rest periods combined with high grazing intensities result in forage of low nutritive value. Pregraze sward height for the 95%-LI managements was around 16 cm and for the 100%-LI, around 22 cm. Defoliation of signalgrass should not be lower than 10 cm height, since this results in rapid regrowth and, when associated with the 95%-LI frequency, allows animals to harvest forage with high proportion of leaves and low proportion of stem and dead material.

A deficiência de nitrogênio tem sido apontada como uma das principais causas da degradação de pastagens, mas o suprimento de enxofre também é relevante nessa situação. Objetivou-se avaliar os efeitos das combinações entre doses de nitrogênio e de enxofre em características produtivas, fisiológicas e nutricionais da planta e nos atributos químicos do solo, na implantação do capim-Marandu (Brachiaria brizantha cv. Marandu) em Neossolo Quartzarenico proveniente de área de capim-Braquiária (Brachiaria decumbens) em degradação, com baixo teor de matéria orgânica. O experimento foi conduzido em casa-de-vegetação, em Piracicaba, Estado de São Paulo, no período de dezembro de 2004 a abril de 2005. Utilizou-se esquema fatorial 52 fracionado, com 13 combinações para as doses de nitrogênio e enxofre, em mg dm-3: 0-0; 0-20; 0-40; 100-10; 100-30; 200-0; 200-20; 200-40; 300-10; 300-30; 400-0; 400- 20 e 400-40, as quais foram distribuídas em delineamento estatístico de blocos ao acaso, com quatro repetições. Foram realizados três cortes nas plantas e a cada corte era coletada uma amostra de solo de cada unidade experimental. Após o terceiro corte as raízes foram separadas do solo e tiveram o comprimento e a superfície avaliados. Os resultados demonstraram que o fornecimento de nitrogênio foi fundamental para o crescimento inicial e adequado estabelecimento do capim-Marandu. Quando o nitrogênio foi fornecido em altas doses foi necessário cuidar do fornecimento de enxofre para a maximização da produção do capim- Marandu, bem como para o valor SPAD, a concentração de nitrogênio e de enxofre nas lâminas de folhas recém-expandidas e parte aérea e para a relação N:S na parte aérea. O valor SPAD refletiu diretamente a concentração de nitrogênio nas lâminas de folhas recém-expandidas do capim. O nitrogênio foi determinante para a maximização da massa seca de raízes, do comprimento do sistema radicular, da relação nitrogênio e enxofre no sistema radicular do capim- Marandu e dos teores de nitrato e amônio no solo suportando o capim-Marandu. A aplicação de enxofre proporcionou aumento da concentração de enxofre na parte aérea e no sistema radicular do capim, e dos teores de sulfato e enxofre total no solo com a presença do capim. A relação adequada entre as doses de nitrogênio e de enxofre para a maximização das características produtivas do capim-Marandu esteve no intervalo entre doses de 8:1 a 11:1.
Nitrogen deficiency has been mentioned as one of the main reasons for pasture degradation, but sulphur supply also is considerable in such cases. The objective was to evaluate the effects of combinations between nitrogen and sulphur rates in productive, physiological and nutritional plant characteristics and in some soil parameters at the establishment of Marandu grass in Typic Quartzipsamment with low organic matter concentration taken from a degrading Signal grass pasture. The experiment was carried out in a greenhouse, at Piracicaba, Satate of São Paulo, Brazil, from December 2004 to April 2005. A fractionated 52 factorial was used, with 13 combinations for the nitrogen and sulfur rates, in mg dm-3: 0-0; 0-20; 0-40; 100-10; 100-30; 200- 0; 200-20; 200-40; 300-10; 300-30; 400-0; 400-20 e 400-40, which were set in a randomized block design, with four replications. Plants were harvested three times, and at each harvest a soil sample was taken from each experimental unit. Following the third harvest, roots were separated from the soil and their length and surface were measured. The results showed that nitrogen supply was essential for the initial growth and adequate establishment of Marandu grass. When nitrogen was supplied at high rates, it was necessary a special care with sulphur supply to maximize dry matter yield, SPAD value, nitrogen and sulphur concentrations in the newly expanded leaves and plant tops and N:S ratio in plant tops. SPAD value was directly related to nitrogen concentration in the newly expanded leaves. Nitrogen was also decisive for maximizing roots dry weight and length, N:S ratio in the roots, and nitrate and ammonium in the soil with the grass. Sulphur application resulted in increase in the sulphur concentration in the grass tops and roots, and in the sulphate and total sulphur in the soil supporting the grass. Adequate ratio between nitrogen and sulphur rates to maximize the productive characteristics of Marandu grass was in the range of 8:1 a 11:1.