O planejamento de colheita na cultura da cana-de-açúcar busca otimizar o retorno econômico, baseado no conceito de que a cana tem uma época, durante o ano, onde ocorre máxima concentração de sacarose nos colmos. Realizaram-se neste trabalho estudos enfocando as influências dos fatores edafo-climáticos sobre o rendimento e açúcares totais recuperáveis. Foram testadas as hipóteses de que há interação entre as épocas de plantio e corte, bem como a hipótese de que há interação do tratamento muda inteira e picada com cada época de plantio. Utilizaram-se dados de pesquisa conduzida, no Campo de experimentação da COPERSUCAR - Piracicaba/SP, num solo Latossol Vermelho Eutrófico. O delineamento utilizado foi blocos ao acaso, com parcelas subdivididas em faixas e sub-subparcelas dentro das faixas. Os tratamentos foram épocas de plantio (Novembro, Janeiro, Março, Maio), as faixas foram épocas de corte (Maio, julho, Setembro, Novembro), e os sub-subtratamentos foram mudas picada e inteira. Mediram-se as variáveis: toneladas de colmos (TCH) e toneladas de açúcar por hectare (TAH), e açúcar total recuperável (ATR). A soqueira foi avaliada da mesma forma que o 1º corte, aos (12) meses de idade. Foram instalados três experimentos, cada um com uma variedade, SP 70-1143, NA 56-79 e SP 71-1406. Os experimentos foram instalados e repetidos em três anos-safra, 1983/84, 1984/85 e 1985/86, com colheitas nas safras dos anos de 1985 até 1988, obtendo-se assim, rendimentos de estágios iguais em anos diferentes e estágios diferentes no mesmo ano. Concluiu-se que as épocas de plantio afetaram TCH, ATR e TAH do 1º corte; épocas de plantio interagiram com os tipos de mudas na cana planta; épocas de corte afetaram TCH, ATR e TAH nas canas planta e soqueiras; ATR sempre evoluiu do início para o final da safra, com os picos nos meses de setembro e novembro; plantios tardios atrasam a maturação; os valores de TAH acompanham as curvas de ATR sendo influenciados por TCH. Para a variedade SP 70-1143 no primeiro corte o clima influenciou os resultados de épocas de plantio e de tipos de mudas; os menores valores de TCH foram obtidos nas épocas de plantio Maio com mudas de cana picada e nas demais épocas de plantio não houve diferenças, indicando que se podem plantar mudas de cana inteiras em qualquer época; nos dois cortes estudados, os maiores valores de ATR foram obtidos na colheita de Setembro e os menores valores foram obtidos na época de plantio de Maio indicando que o pico de maturação ocorre no mês de setembro. Para a variedade NA 56-79 os valores de TCH das mudas picadas e inteiras não mostraram diferenças indicando que se pode plantar cana inteira; os maiores valores de ATR e TAH foram obtidos a partir das colheitas de Julho. Para a variedade SP 71-1406, no primeiro corte, houve superioridade para mudas picadas sendo o melhor manejo, os menores valores de TCH foram obtidos no plantio de Maio e o maior valor de ATR foi obtido na colheita de Novembro; nos dois cortes os valores de TAH e de ATR indicaram que a colheita deve ser feita partir de setembro. / Harvest planning in sugarcane attempts to optimize the crop's economic return based on the concept that sugarcane presents, along the cropping season, a period during which the maximum concentration of sucrose occurs in the stalks. This work consisted of studies that focused on the influences of edaphic-climatic factors on yield and total recoverable sugars. The hypothesis was tested that an interaction exists between the planting and harvesting seasons, as well as the hypothesis that an interaction exists between the whole-stalk and the bud seedling treatments with each planting season. Data from a research conducted at COPERSUCAR’s Experimental Field - Piracicaba/SP, in a Red Eutrophic Latosol, were used. A random blocks design with strip split-plots was used, where sub-subplots were allocated within strips. Treatments were planting seasons (November, January, March, May), with harvesting seasons represented by strips (May, July, September, November), while sub-subtreatments consisted of bud and whole-stalk seedlings. The variables measured were: tons of sugarcane stalks (TSS) and tons of sugar per hectare (TSH), and total recoverable sugar (TRS). The ratoon (second cut) was evaluated in the same manner as the 1st cut, when sugarcane was 12 months old. Three experiments were installed, each consisting of one variety: SP 70-1143, NA 56-79, and SP 71-1406. The experiments were installed and replicated in three cropping years: 1983/84, 1984/85, and 1985/86, with harvests in the cropping seasons from 1985 through 1988; therefore, yields for the same stage in different years, and yields for different stages in the same year were obtained. It was concluded that planting seasons affected TSS, TRS, and TSH in the 1st cut; planting seasons interacted with seedling types in one-year-old sugarcane; harvesting seasons affected TSS, TRS, and TSH in one-year-old and ratoon sugarcane; TRS always progressed from the beginning to the end of the cropping season, with peaks in the months of September and November; late plantings delayed maturation; TSH values followed the TRS curves, and were influenced by TSS. In the first cut of variety SP 70-1143, climate influenced the planting season and seedling type results; the smallest TSS values were obtained in the May planting seasons with bud seedlings, while no differences were observed in the other planting seasons, indicating that whole-stalk seedlings can be planted in any season; in both cuts under study, the highest TRS values were obtained for the September harvesting, and the smallest values were obtained for the May planting season, indicating that peak maturity occurs in the month of September. In variety NA 56-79, the TSS values for bud and whole-stalk seedlings did not show differences, indicating that whole-stalk cane can be planted; the highest TRS and TSH values were obtained from harvests made in July. In the first cut of variety SP 71-1406, the best management consisted of bud seedlings, which were superior; the smallest TSS values were obtained for the May planting and the highest TRS value was obtained for the November harvesting; in both cuts, the TSH and TRS values indicated that harvesting should be done beginning in September.

O planejamento de colheita na cultura da cana-de-açúcar busca otimizar o retorno econômico, baseado no conceito de que a cana tem uma época, durante o ano, onde ocorre máxima concentração de sacarose nos colmos. Realizaram-se neste trabalho estudos enfocando as influências dos fatores edafo-climáticos sobre o rendimento e açúcares totais recuperáveis. Foram testadas as hipóteses de que há interação entre as épocas de plantio e corte, bem como a hipótese de que há interação do tratamento muda inteira e picada com cada época de plantio. Utilizaram-se dados de pesquisa conduzida, no Campo de experimentação da COPERSUCAR – Piracicaba/SP, num solo Latossol Vermelho Eutrófico. O delineamento utilizado foi blocos ao acaso, com parcelas subdivididas em faixas e sub-subparcelas dentro das faixas. Os tratamentos foram épocas de plantio (Novembro, Janeiro, Março, Maio), as faixas foram épocas de corte (Maio, julho, Setembro, Novembro), e os sub-subtratamentos foram mudas picada e inteira. Mediram-se as variáveis: toneladas de colmos (TCH) e toneladas de açúcar por hectare (TAH), e açúcar total recuperável (ATR). A soqueira foi avaliada da mesma forma que o 1º corte, aos (12) meses de idade. Foram instalados três experimentos, cada um com uma variedade, SP 70-1143, NA 56-79 e SP 71-1406. Os experimentos foram instalados e repetidos em três anos-safra, 1983/84, 1984/85 e 1985/86, com colheitas nas safras dos anos de 1985 até 1988, obtendo-se assim, rendimentos de estágios iguais em anos diferentes e estágios diferentes no mesmo ano. Concluiu-se que as épocas de plantio afetaram TCH, ATR e TAH do 1º corte; épocas de plantio interagiram com os tipos de mudas na cana planta; épocas de corte afetaram TCH, ATR e TAH nas canas planta e soqueiras; ATR sempre evoluiu do início para o final da safra, com os picos nos meses de setembro e novembro; plantios tardios atrasam a maturação; os valores de TAH acompanham as curvas de ATR sendo influenciados por TCH. Para a variedade SP 70-1143 no primeiro corte o clima influenciou os resultados de épocas de plantio e de tipos de mudas; os menores valores de TCH foram obtidos nas épocas de plantio Maio com mudas de cana picada e nas demais épocas de plantio não houve diferenças, indicando que se podem plantar mudas de cana inteiras em qualquer época; nos dois cortes estudados, os maiores valores de ATR foram obtidos na colheita de Setembro e os menores valores foram obtidos na época de plantio de Maio indicando que o pico de maturação ocorre no mês de setembro. Para a variedade NA 56-79 os valores de TCH das mudas picadas e inteiras não mostraram diferenças indicando que se pode plantar cana inteira; os maiores valores de ATR e TAH foram obtidos a partir das colheitas de Julho. Para a variedade SP 71-1406, no primeiro corte, houve superioridade para mudas picadas sendo o melhor manejo, os menores valores de TCH foram obtidos no plantio de Maio e o maior valor de ATR foi obtido na colheita de Novembro; nos dois cortes os valores de TAH e de ATR indicaram que a colheita deve ser feita partir de setembro. / Harvest planning in sugarcane attempts to optimize the crop's economic return based on the concept that sugarcane presents, along the cropping season, a period during which the maximum concentration of sucrose occurs in the stalks. This work consisted of studies that focused on the influences of edaphic-climatic factors on yield and total recoverable sugars. The hypothesis was tested that an interaction exists between the planting and harvesting seasons, as well as the hypothesis that an interaction exists between the whole-stalk and the bud seedling treatments with each planting season. Data from a research conducted at COPERSUCAR’s Experimental Field – Piracicaba/SP, in a Red Eutrophic Latosol, were used. A random blocks design with strip split-plots was used, where sub-subplots were allocated within strips. Treatments were planting seasons (November, January, March, May), with harvesting seasons represented by strips (May, July, September, November), while sub-subtreatments consisted of bud and whole-stalk seedlings. The variables measured were: tons of sugarcane stalks (TSS) and tons of sugar per hectare (TSH), and total recoverable sugar (TRS). The ratoon (second cut) was evaluated in the same manner as the 1st cut, when sugarcane was 12 months old. Three experiments were installed, each consisting of one variety: SP 70-1143, NA 56-79, and SP 71-1406. The experiments were installed and replicated in three cropping years: 1983/84, 1984/85, and 1985/86, with harvests in the cropping seasons from 1985 through 1988; therefore, yields for the same stage in different years, and yields for different stages in the same year were obtained. It was concluded that planting seasons affected TSS, TRS, and TSH in the 1st cut; planting seasons interacted with seedling types in one-year-old sugarcane; harvesting seasons affected TSS, TRS, and TSH in one-year-old and ratoon sugarcane; TRS always progressed from the beginning to the end of the cropping season, with peaks in the months of September and November; late plantings delayed maturation; TSH values followed the TRS curves, and were influenced by TSS. In the first cut of variety SP 70-1143, climate influenced the planting season and seedling type results; the smallest TSS values were obtained in the May planting seasons with bud seedlings, while no differences were observed in the other planting seasons, indicating that whole-stalk seedlings can be planted in any season; in both cuts under study, the highest TRS values were obtained for the September harvesting, and the smallest values were obtained for the May planting season, indicating that peak maturity occurs in the month of September. In variety NA 56-79, the TSS values for bud and whole-stalk seedlings did not show differences, indicating that whole-stalk cane can be planted; the highest TRS and TSH values were obtained from harvests made in July. In the first cut of variety SP 71-1406, the best management consisted of bud seedlings, which were superior; the smallest TSS values were obtained for the May planting and the highest TRS value was obtained for the November harvesting; in both cuts, the TSH and TRS values indicated that harvesting should be done beginning in September.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objectives of this dissertation were to determine the phyllochron, the final leaf number on the main stem and the duration of developmental stages to characterize leaf growth during the developmental cycle and to determine the tuber yield of tenadvanced potato clones of the Potato Breeding and Genetics Program of the Universidade Federal de Santa Maria (UFSM) and two potato cultivars grown in spring and fall conditions in Santa Maria, Depression Central Region of the Rio Grande do Sul State. Two field experiments were conducted during Spring 2010 and Fall 2011 at the experimental field of the, Santa Maria, RS. The advanced potato clones were: SMINIA 00017-6, SMINIA 793101-3, SMINIA 02106-11, SJSM 00211-3, SJSM 03478-37, SJSM 01212-2, SJSM 01274-4, SJSM 04503-9, SJSM 02349 - 1 and SJSM 02317-3. The two potato cultivars were Asterix and Macaca. The planting density was 3.79 hills m-2. The experiment was a complete randomized block design with seven replications. After emergence, four plants in each plot were marked and on these plants the number of leaves on the main stem were counted twice a week and on one of these plants the length of the leaves was measured once a week to determine the green leaf area index. Tuber initiation was determined by collecting four plants of each clone at the border rows. The phyllochron was calculated by the inverse of the slope of the linear regression between leaf number and accumulated thermal time. Power-like nonlinear models were used to relate leaf length and leaf area. For determining tuber yield all the hills were used. The phyllochron varied from 17.0°C to 21.5°C day leaf the in Spring and from 14.8°C to 22.1° C in the Fall. There are differences of the duration of vegetative and tuberization phases and the final leaf number among clones, cultivars and growing seasons. The evolution of leaf area index throughout the developmental cycle was different in the advanced clones and in the cultivars during the two growing seasons. The of advanced clones showed high tuber yield in both Spring and Fall growing seasons. / Os objetivos nesta dissertação foram determinar o filocrono, o número final de folhas na haste principal e a duração das fases de desenvolvimento, caracterizar o crescimento foliar durante o ciclo de desenvolvimento e determinar a produtividade de tubérculos de dez clones avançados do Programa de Genética e Melhoramento de Batata da Universidade Federal de Santa Maria (UFSM) e de duas cultivares de batata em cultivo de primavera e outono em Santa Maria, região da Depressão Central do Rio Grande do Sul (RS). Dois experimentos de campo foram conduzidos durante a primavera de 2010 e o outono de 2011, na área experimental do Departamento de Fitotecnia da UFSM, Santa Maria, RS. Foram utilizados os clones avançados SMINIA 00017-6, SMINIA 793101-3, SMINIA 02106-11, SJSM 00211-3, SJSM 03478-37, SJSM 01212-2, SJSM 01274-4, SJSM 04503-9, SJSM 02349-1 e SJSM 02317-3 selecionadas pelo Programa de Genética e Melhoramento de Batata da UFSM e as cultivares Asterix e Macaca. A densidade de plantio foi de 3,79 covas m-2. O delineamento experimental utilizado foi o de blocos ao acaso com sete repetições. Após a emergência, quatro plantas em cada parcela foram identificadas com anel colorido e nestas foram contadas, duas vezes por semana, o número de folhas na haste principal e, em uma destas plantas, semanalmente foi medido o comprimento das folhas para determinação do índice de área foliar verde. A data do início da tuberização foi determinada coletando-se a cada dois dias quatro plantas de cada clone nas linhas da bordadura. O filocrono foi calculado pelo inverso do coeficiente angular da regressão linear entre o número de folhas e a soma térmica acumulada. Obtiveram-se modelos não lineares do tipo potência para relacionar o comprimento das folhas com o índice de área foliar. Para determinação da produtividade foram utilizadas todas as covas da parcela. O filocrono variou de 17,0°C a 21,5°C dia folha-1, no cultivo de primavera, e de 14,8°C a 22,1°C dia folha-1, no cultivo de outono. Houve diferença na duração das fases vegetativa e de tuberização e do número final de folhas entre os clones avançados, as cultivares e as épocas de cultivo. A evolução do índice de área foliar foi diferente ao longo do ciclo de desenvolvimento nos clones avançados e nas cultivares nas duas épocas de cultivo. No cultivo de primavera e no cultivo de outono os clones avançados apresentaram elevada produtividade de tubérculos de batata.

The forest product industry is keenly interested in extending the normal planting season, as well as in the comparative field performance of standard nursery bare-root seedlings and containerized rooted cuttings. The effect of seasonal planting dates on survival, above and belowground biomass allocation, water relations, gas exchange attributes and foliar carbon isotope composition (δ13C) of two stock types of slash pine (Pinus elliottii Engelm.) were examined. Slash pine bare-root seedlings (BRS) and containerized rooted cuttings (CRC) were hand planted in September, November, January, March and April in three consecutive planting seasons (2000-2001, 2001-2002 and 2002-2003) on three sites with silt loam topsoils in southwestern Louisiana. First-year mean survival of CRC across all planting dates and sites was consistently high at 96 to 98%, whereas BRS survival was significantly (P < 0.0001) lower at 59 to 81% and highly variable among study sites and dates through three planting seasons. Generally, there was a negative relationship between soil moisture at the time of planting and first-year survival of BRS planted September through March in 2001-2002 and 2002-2003 planting seasons, whereas the opposite was observed only for BRS planted in April 2002 and 2003. Survival of CRC was affected very little by the variation in soil moisture. Containerized rooted cuttings had higher early above and belowground biomass, and height and diameter than did BRS. However, three years after planting the size differences between stock types disappeared or became negligible. Early size differences among trees planted September through March also decreased after three years, although September trees were tallest. Growth of the April-planted trees was poor compared to trees planted in other months. Late-planted April trees had higher δ13C values, and higher water-use efficiency in the first growing season compared to earlier planted trees. Differences in δ13C values among the planting dates disappeared in the second growing season. Net photosynthesis rates did not differ considerably between stock types or among planting dates in the second and third growing seasons. This study indicates that it is possible to extend the planting season to as early as September and as late as March by using CRC.

The forest product industry is keenly interested in extending the normal planting season, as well as in the comparative field performance of standard nursery bare-root seedlings and containerized rooted cuttings. The effect of seasonal planting dates on survival, above and belowground biomass allocation, water relations, gas exchange attributes and foliar carbon isotope composition (&#948;13C) of two stock types of slash pine (Pinus elliottii Engelm.) were examined. Slash pine bare-root seedlings (BRS) and containerized rooted cuttings (CRC) were hand planted in September, November, January, March and April in three consecutive planting seasons (2000-2001, 2001-2002 and 2002-2003) on three sites with silt loam topsoils in southwestern Louisiana. First-year mean survival of CRC across all planting dates and sites was consistently high at 96 to 98%, whereas BRS survival was significantly (P < 0.0001) lower at 59 to 81% and highly variable among study sites and dates through three planting seasons. Generally, there was a negative relationship between soil moisture at the time of planting and first-year survival of BRS planted September through March in 2001-2002 and 2002-2003 planting seasons, whereas the opposite was observed only for BRS planted in April 2002 and 2003. Survival of CRC was affected very little by the variation in soil moisture. Containerized rooted cuttings had higher early above and belowground biomass, and height and diameter than did BRS. However, three years after planting the size differences between stock types disappeared or became negligible. Early size differences among trees planted September through March also decreased after three years, although September trees were tallest. Growth of the April-planted trees was poor compared to trees planted in other months. Late-planted April trees had higher &#948;13C values, and higher water-use efficiency in the first growing season compared to earlier planted trees. Differences in &#948;13C values among the planting dates disappeared in the second growing season. Net photosynthesis rates did not differ considerably between stock types or among planting dates in the second and third growing seasons. This study indicates that it is possible to extend the planting season to as early as September and as late as March by using CRC.

The sagebrush steppe is a particularly sensitive ecosystem that is easily disturbed by fires, oil and gas extraction, woody-plant encroachment, and overgrazing. The natural regeneration of native species following a disturbance within this system is typically slow and sporadic, which allows invasive grasses to occupy the landscape. Attempts to assist the recovery of these landscapes through direct seeding is commonly met with poor success rates, particularly in lower elevation, drier sites. Novel seed enhancement technologies and planting techniques that mitigate limiting factors impairing restoration efforts may improve the likelihood of restoring these degraded areas. For chapter 1, we evaluated a solid-matrix priming technique, where bluebunch wheatgrass (Pseudoroegneria spicata) and Lewis flax (Linum lewisii) were primed and then the priming matrix and seed were pelleted together. We evaluated primed seed that had been incorporated into pellets at two field sites against seed that was pelleted but been left unprimed, and untreated seed (control). These three seed treatments were planted in the spring (mid-march) in shallow (2-cm) and deep (15-cm) furrows, in a complete factorial design. We found that primed seeds generally produced higher plant densities than control seed at the beginning of the growing season; however, its influence diminished towards the end of the growing season. We also found that deep furrows increased plant density throughout the growing season and even into the following year. The combination of priming and deep furrows outperformed control seed in shallow furrows in all measured metrics. For chapter 2, we evaluated a seed conglomeration technique for improving Wyoming big sagebrush (Artemisia tridentata ssp. Wyomingensis) emergence and survival under fall and winter plantings. The trial was implemented at five sites across Utah and Nevada in a randomized complete block-split-split plot design, with site, and planting season, comprising the split-plot factors. Each site and season combination was seeded with conglomerated and control seed. We found that in most cases, a fall seeding of Wyoming big sagebrush was either the same or more successful compared to planting on the snow in the winter, which is the current suggested practice. Our results also demonstrated that seed conglomeration produced higher plant densities compared to control seed throughout the growing season. The higher density of plants produced from conglomerates combined with the improved seed delivery provided by the conglomeration technique was estimated to offset the cost in producing conglomerates and reduce overall restoration costs by 41%.

Made available in DSpace on 2014-08-20T14:38:50Z (GMT). No. of bitstreams: 1 Tese_Darcy_Bitencourt_Junior.pdf: 1269475 bytes, checksum: 4f393387d019287bb637c875eb063821 (MD5) Previous issue date: 2010-06-29 / The first experiment was carried out from May 29, 2006 to June 4, 2008. The objective was to evaluate the yield and agronomic characteristics of corn AS32 for ensiling as affected by early and late planting and the effect of grazing with dairy cows (starting when forage availability was at least 1,500 kg/ha of DM and finishing when residual plant height ranged from 7-10 cm) or mechanical harvesting (no grazing) on winter pasture, grown before corn, in straw in direct planting in an integrated crop-animal system. Experimental design consisted of split-split randomized complete blocks, with three replications. Data were submitted to analysis of variance (factorial 2x2x2 Years x Season x Cutting regimes). Harvesting criterium for corn plants evaluation and ensiling was made at the stage farinaceous hard grain. The second experiment was carried out from May 29, 2006 to June 4, 2008. The objective was to evaluate: (a) silage quality and (b) fermentative parameters, of corn AS32 for ensiling as affected by early and late planting on winter pasture desiccated straw, in direct planting in an integrated crop-animal system. Corn crops were sown in Oct 30, 2006; Nov 16, 2007 and Jan 16, 2007; Feb 06, 2008. Mechanical harvest was made at 15cm residual heights of plants, at the stage of farinaceous hard grain, and finely chopped to 1.5 cm particles size, and ensiled in experimental silos (3.5 kg). The experimental design consisted of completely randomized blocks, with three replications and subplots consisting of planting times (early and late). Data were submitted to analysis of variance, in factorial 2x2 scheme (years x times of plantings) and means compared by Tukey Test (P<0.05). Dry matter yield of normal planting date of corn was higher than for the alternative planting date; grazing, had no effect on dry matter yield . Corn cultivar AS32 recommended haversting stadium (farinaceous hard grain) presented variations in dry matter content of silage according to the year of cropping. Plant components proportions of green matter are different from the standard recommended for high quality corn silage. Fermentative and nutritional parameters showed adequate and acceptable values within the recommended patterns, either for early planting time as for late planting for AS32 hybrid grain corn-silage purpose. Cell wall components (NDF and ADF) showed acceptable values, although ADF remained slightly above of the ideal limit desired for both early and late ensiling of AS32 corn hybrid. / O experimento-1 foi conduzido de 2006 a 2008 na Escola Agrotécnica Federal de Rio do Sul EAFRS Rio do Sul, SC. Foram avaliadas a produtividade e as características agronômicas do milho AS32 para silagem em função da época de semeadura (safra e safrinha) e do pastejo com vacas leiteiras ou corte mecânico em pastagens de inverno. Foi levada em consideração a disponibilidade (1.500 de MS/ha) para entrada dos animais ou o corte e altura residual de 7-10 cm na saída, num sistema de integração lavoura-pecuária em plantio direto na palhada. O delineamento experimental foi de blocos completos ao acaso, com parcelas divididas com três repetições. Os dados foram analisados pelo teste F de análise de variância num esquema fatorial (2x2x2 Anos x Época x Regime de desfolha). O ponto de corte para avaliação das plantas de milho e confecção da silagem foi feito no estádio de grão farináceo duro. O experimento-2 foi conduzido na Escola Agrotécnica Federal de Rio do Sul, SC. Foram avaliadas a qualidade e características nutricionais da silagem do milho AS32 na safra e safrinha num sistema de integração lavoura pecuária (ILP), nos anos agrícolas de 2006/07 e 2007/08. As variáveis respostas foram: (a) parâmetros qualitativos (PB e DIVMS), (b) componentes da parede celular (FDN e FDA) e (c) parâmetros fermentativos da silagem (MS, pH e N-NH3). As lavouras da safra foram estabelecidas com plantio direto em 30/10/06 - 16/11/07 e da safrinha 16/01/07 06/02/08, sobre palhada dessecada de pastagem de inverno (safra), além de espécies espontâneas de verão (safrinha). O corte foi realizado a 15cm do solo, no estádio de grão farináceo duro, ficando as partículas com 1,5cm. Os silos experimentais de Polietileno (capacidade de 3,5kg) foram confeccionados adotando os procedimentos para silos comerciais. O delineamento experimental foi de blocos completos ao acaso com três repetições, com duas parcelas (safra e safrinha). Os tratamentos consistiram de: duas épocas de plantio e dois anos de cultivo. A análise de variância consistiu num fatorial 2x2 (anos x épocas), com Tukey (P<0,05). Resultados: A produção de matéria seca do milho safra foi superior ao da safrinha, não havendo diferença quanto à utilização ou não de pastejo no inverno anterior ao cultivo do milho. A cultivar AS32 no momento indicado para colheita (grão farináceo duro), apresentou variação nos teores de MS da silagem, em função do ano de cultivo. Os parâmetros fermentativos e nutricionais apresentaram valores adequados, dentro dos padrões recomendados, tanto para silagem da safra, como da safrinha. Os componentes da parede celular FDN e FDA apresentaram valores aceitáveis, embora o FDA tenha ficado pouco acima do limite ideal em relação aos padrões desejados, para ambas as épocas de ensilagem.