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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Agronomic performance and beef cattle grazing preference among three prairie bromegrasses

Hubbard, Allen Stewart 15 December 2007 (has links)
Prairie bromegrass is a cool-season perennial bunchgrass with potential as a valuable forage crop in the southeastern USA. The objective of this study was to compare dry matter production, persistence, nutritive value, and beef cattle grazing preference of two experimental lines and a commercial species (cv. Matua) of prairie bromegrass. Plots were established in a randomized complete block design with four replications. When each plot accumulated at least 20 cm of growth, plots were grazed with Hereford x Angus steers at a stocking rate of 8400 kg/ha until the first plot was grazed down to 7 cm in height. Pre- and post-grazing quadrats were taken for DM and animal preference estimation and nutrient analyses. No differences in nutritive value or grazing preference were seen among species. Treatment interactions were observed for DM production and persistence. The results suggest that there are differences in growth traits among the bromegrass species observed.
52

Improved Hermetic Grain Storage System for Smallholder Farmers in Tanzania

Milindi, Paschal 29 December 2016 (has links)
No description available.
53

Growth, leaf gaseous exchange and nutritive value of selected summer forage legumes and their contributions to succeeding winter grass (Secale cereale) in District Agro-ecological zone of Limpopo Province

Lekgothoane, Philemon Lesetja January 2022 (has links)
Thesis (M.Sc. (Pasture Science)) -- University of Limpopo, 2022 / In South Africa, livestock production is a rapidly growing business in the agricultural sector contributing up to 46.9% of the gross domestic value. The shortage of adequate, good quality forage during the winter months is one of the biggest problems confronting livestock farmers in the Limpopo Province. This study was initiated in 2019 to evaluate the production potential and nutritive value of different summer annual forage legumes, namely sunnhemp (Crotalaria juncea), forage cowpea (Vigna unguiculata), lablab bean (Lablab purpureus), and pigeon pea (Cajanus cajans), and their impact on succeeding winter stooling ryegrass (Secale cereale), at the University of Limpopo experimental farm Syferkuil and a Cooperative farmers’ field at Ofcolaco. The study was evaluated in a randomized complete block design with four replications. Dry matter yield, crude protein, crude protein yield, leaf chlorophyll content, Normalized Difference Vegetative Index (NDVI), and leaf gaseous exchange parameters of forage crops were statistically analysed with Statistical Analysis System (SAS), Enterprise Version 9.4, using the least significant difference (LSD) method for mean comparison. Pigeon pea biomass accumulation was 57% lower than the average of the three other legumes at Syferkuil. Sunnhemp produced superior biomass (P<0.05) compared to the other three species, reaching a peak yield of 3142.4 kg.ha-1 and 8970.8 kg ha-1 at Syferkuil and Ofcolaco, respectively. Cowpea and lablab produced similar biomass at Syferkuil. The crude protein content of the forage species ranged from 22.91% to 26.82% at Syferkuil and 17.03% to 23.84% at Ofcolaco. Leaf chlorophyll content differed (P<0.001) among the forage legume species at both locations with cowpea producing the highest chlorophyll content at Syferkuil, whereas at Ofcolaco, pigeon pea constantly produced the highest chlorophyll compared to other species. Pigeon pea was the only species rated moderately healthy with Normalised Difference Vegetative Index (NDVI) readings at Syferkuil, unlike at Ofcolaco where all forage legumes were rated as very healthy. At Syferkuil, no root nodules were observed among all the forage legumes at all sampling dates but at Ofcolaco, nodules were produced at 44 DAE with cowpea producing the highest, 92.32% higher than the average of sunnhemp, lablab, and pigeon-pea. At this location pigeon pea did not nodulate. The transpiration rate at Syferkuil was significant (P<0.01) among the species starting with a low transpiration rate from 24 days after planting and reaching their peak at 66DAE. Overall, pigeon pea had the highest (P<0.05) mean transpiration rate compared to the other species. At Ofcolaco the forage legume treatment did not have any significant (P>0.05) influence on transpiration rate, stomatal conductance and sub-stomatal conductance. The transpiration rate of the species ranged from 0.1 mol m-2 s -1 to 5.15 mol m-2 s -1 across all sampling dates whereas stomatal conductance ranged from 0.06 to 5.59 mol m-2 s -1 at Syferkuil and 0.1 to 5.15 mol m-2 s -1 at Ofcolaco, across all sampling dates and species. At Syferkuil, the mean stomatal conductance values ranged from 129.75 mol m-2 s -1 to 374 mol m-2 s -1 across the sampling dates and species, whereas, at Ofcolaco, the means ranged from 185 mol m-2s -1 to 390.25 mol m-2s -1 . The succeeding stooling rye produced a similar biomass yield under every preceding forage legume. This can be concluded that all the four forage legumes did not have any effect on the biomass production of stooling rye. However, there appeared to be a tendency of higher biomass production in the grass species grown after pigeon pea and lablab compared to those following sunnhemp and cowpea. Further experiments are required to establish the full benefits of the forage legumes on succeeding forage grass crop. Based on the results from this study, it was concluded that sunnhemp can be considered as the first choice forage legume at both Syferkuil and Ofcolaco due to its consistently high biomass production, comparable nutrient profile, high crude protein content and high protein yield compared with the other legumes. Though sunnhemp was superior, the other forage summer legumes species studied also managed to produce enough biomass for grazing and had similar nutritive value which was above minimum recommendations. They can therefore be cultivated in the province to meet the constraint of the feed gap in the province. Additional studies at different locations, however, will help to understand the productivity of the species and also to establish the full benefits of the forage legumes on succeeding forage grass crops / National Research Foundation (NRF) and Department of Science and Innovation
54

Genetic analysis of earliness traits in chickpea (<i>Cicer arietinum</i> L.)

Kabeta, Yadeta Anbessa 31 July 2007
The latter part of the reproductive growth phase in chickpea (<i>Cicer arietinum</i> L.) often coincides with declining temperature and wet conditions in western Canada, in sharp contrast to many other growing environments. This exacerbates the indeterminate nature of the crop, leading to excessive canopy development, and subsequently resulting in delayed maturity. The objectives of this study were to: i) determine the genetic relationships of short internode, double podding and early flowering traits with earliness of crop maturity; ii) determine the genetic control of major earliness traits in chickpea; iii) assess the patterns of post-flowering dry matter accumulation and partitioning to reproductive parts as related to earliness. <p>The results showed that double podding significantly reduced the number of days taken to maturity, under the conditions where this trait was sufficiently expressed. The best double podding genotypes, i.e. those with 1535% of the podded nodes bearing double pods, were about one week earlier than their single podding counterparts and standard checks. A physiological study revealed that the double podding parental genotype 272-2 partitioned a relatively greater proportion (about 58%) of the total dry matter to pods compared to 4254% in the single podding genotypes. Double podding increased the total number of pods set, and thus the increased demand for assimilates may have precluded further production of stems and leaves, resulting in an earlier transition of reproductive growth to physiological maturity. Days to flowering was positively associated with days to maturity, and partial path analysis revealed that days to flowering contributed to days to maturity indirectly via days to first pod maturity. Days to flowering explained 32% of the variation in days to first pod maturity. However, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. <p>Genetic studies revealed that days to flowering was determined by two major genes plus polygenes in chickpea in the short-season temperate environment of western Canada. The two major genes control over 65% of the phenotypic variation. Also, the additive component of genetic variance was significant for days to first podding, days to first pod maturity, reproductive period, and days to maturity; which is desirable for development of superior inbred cultivars of chickpea. These key phenological traits are interrelated but could be manipulated separately in the breeding process. Additional gain in earliness of crop maturity may be achieved through combined selection for these traits.
55

Genetic analysis of earliness traits in chickpea (<i>Cicer arietinum</i> L.)

Kabeta, Yadeta Anbessa 31 July 2007 (has links)
The latter part of the reproductive growth phase in chickpea (<i>Cicer arietinum</i> L.) often coincides with declining temperature and wet conditions in western Canada, in sharp contrast to many other growing environments. This exacerbates the indeterminate nature of the crop, leading to excessive canopy development, and subsequently resulting in delayed maturity. The objectives of this study were to: i) determine the genetic relationships of short internode, double podding and early flowering traits with earliness of crop maturity; ii) determine the genetic control of major earliness traits in chickpea; iii) assess the patterns of post-flowering dry matter accumulation and partitioning to reproductive parts as related to earliness. <p>The results showed that double podding significantly reduced the number of days taken to maturity, under the conditions where this trait was sufficiently expressed. The best double podding genotypes, i.e. those with 1535% of the podded nodes bearing double pods, were about one week earlier than their single podding counterparts and standard checks. A physiological study revealed that the double podding parental genotype 272-2 partitioned a relatively greater proportion (about 58%) of the total dry matter to pods compared to 4254% in the single podding genotypes. Double podding increased the total number of pods set, and thus the increased demand for assimilates may have precluded further production of stems and leaves, resulting in an earlier transition of reproductive growth to physiological maturity. Days to flowering was positively associated with days to maturity, and partial path analysis revealed that days to flowering contributed to days to maturity indirectly via days to first pod maturity. Days to flowering explained 32% of the variation in days to first pod maturity. However, the short internode trait had an undesirable effect, in that all the short internode segregants were too late to mature. <p>Genetic studies revealed that days to flowering was determined by two major genes plus polygenes in chickpea in the short-season temperate environment of western Canada. The two major genes control over 65% of the phenotypic variation. Also, the additive component of genetic variance was significant for days to first podding, days to first pod maturity, reproductive period, and days to maturity; which is desirable for development of superior inbred cultivars of chickpea. These key phenological traits are interrelated but could be manipulated separately in the breeding process. Additional gain in earliness of crop maturity may be achieved through combined selection for these traits.
56

Inclusão de milho desintegrado com palha e sabugo em silagem de milheto forrageiro / Crumbled corn cob and inclusion with straw in millet of forage silage

Silva, Vanderli Luciano da 19 February 2016 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-18T12:29:37Z No. of bitstreams: 2 Dissertação - Vanderli Luciano da Silva - 2016.pdf: 2379182 bytes, checksum: 7f2d6cde360630b08c84abb051eeaf57 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-18T12:31:09Z (GMT) No. of bitstreams: 2 Dissertação - Vanderli Luciano da Silva - 2016.pdf: 2379182 bytes, checksum: 7f2d6cde360630b08c84abb051eeaf57 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-18T12:31:09Z (GMT). No. of bitstreams: 2 Dissertação - Vanderli Luciano da Silva - 2016.pdf: 2379182 bytes, checksum: 7f2d6cde360630b08c84abb051eeaf57 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-19 / This study aimed to evaluate the chemical composition and fermentation characteristics of silage millet farming ADR500 under the inclusion of different levels of corn disintegrated with straw and cob (CEC): 0%, 5%, 10% and 15%, after 78 days of vegetative growth and observe his capacity as moisture scavenger in silage. The experimental design was completely randomized with 4 treatments and 4 replications, totaling 16 experimental units. Data were submitted to analysis of variance, means were compared by 5% Tukey test and regression analysis for the inclusion levels. dry matter content (DM) determined in silage differ (P <0.05) as a function of the MDPS inclusion levels, ranging from 26.53% to 38.69% control treatment and for treatment with higher level inclusion. For values of organic matter found a significant difference only from the IV treatment with 15% inclusion of CEC (P <0.05) compared to other treatments. Regarding crude protein (CP) observed a linear increase (P <0.05) due to the increase of CEC levels, ranging between 9.46% and 14.92%. NDF and the FDA determined in silages ranged from 58.50% to 66.25% and 31.25% for FDA to 38.50 for the FDA so there significant differences between treatments. For certain ether extract in silages millet forage with inclusion of MDPS ranged from 3.13 to 3.95%. The content of mineral matter (MM) showed a significant difference (P <0.05) according to the MDPS inclusion levels, ranging from 5.26 to 7.55%. The inclusion of MDPS reduced (P <0.05) losses gases and effluents in all the treatments, ranging from 6.10 to 3.48 for gas losses and 9.05 to 17.28 for losses effluent and contributed significantly in the dry matter recovery process (MS). The buffer power values (PT), pH and ammonia-N were influenced (P <0.05) by the inclusion of different levels of ground ear corn silage. The levels of acetic, propionic, butyric and lactic, so influenced by the addition of ground ear corn silage. The soluble carbohydrate values have an increasing depending on the MDPS inclusion levels, proving to be efficient in their use to improve the fermentation profile of silages. / Objetivou-se avaliar a composição químico-bromatológica e as características fermentativas da silagem de milheto forrageiro, cultivar ADR500 sob a inclusão de diferentes níveis de milho desintegrado com palha e sabugo (MDPS): 0%, 5%, 10% e 15%, aos 78 dias de crescimento vegetativo e observar sua capacidade como sequestrante de umidade na silagem. O delineamento experimental utilizado foi inteiramente casualizado com 4 tratamentos e 4 repetições, totalizando 16 unidades experimentais. Os dados foram submetidos à análise de variância, as médias comparadas pelo teste de Tukey a 5% e análise de regressão para os níveis de inclusão. Os teores de matéria seca (MS) determinados na silagem diferiram (P<0,05) em função dos níveis de inclusão do MDPS, com variação de 26,53% para o tratamento controle e 38,69% para o tratamento com maior nível de inclusão. Para os valores de matéria orgânica encontrados houve diferença significativa apenas do tratamento IV com 15% de inclusão de MDPS (P<0,05) comparando aos demais tratamentos. Em relação à proteína bruta (PB) observou-se aumento linear (P<0,05) em função da elevação dos níveis de MDPS, variando entre 9,46% e 14,92%. Os teores de FDN e FDA determinados nas silagens variaram entre 58,50% até 66,25% para FDA e 31,25% até 38,50 para o FDA havendo assim diferenças significativas entre os tratamentos. Para o extrato etéreo determinado nas silagens de milheto forrageiro com inclusão de MDPS variaram entre 3,13 a 3,95%. O conteúdo de matéria mineral (MM) apresentou diferença significativa (P<0,05) em função dos níveis de inclusão de MDPS, com variação de 5,26 a 7,55%. A inclusão de MDPS reduziu (P<0,05) as perdas por gases e efluentes em todos os tratamentos avaliados, variando de 6,10 a 3,48 para as perdas por gases e 9,05 a 17,28 para as perdas por efluentes, e contribuiu significativamente no processo de recuperação da matéria seca (MS). Os valores de poder tampão (PT), pH e N-amoniacal foram influenciados (P<0,05) pela inclusão dos diferentes níveis de MDPS à silagem. Os teores dos ácidos acético, propiônico, butírico e lático, forma influenciados pela adição de MDPS na silagem. Os valores de carboidratos solúveis tiveram um aumento crescente em função dos níveis de inclusão do MDPS, demonstrando ser eficiente em seu uso para melhorar o perfil fermentativo da silagem.
57

Efeito do fornecimento de silagens de milho com alta ou baixa digestibilidade da fibra sobre o ganho de peso e consumo de novilhas em crescimento / Effect of feeding growing heifers with corn silages with high or low fiber digestibility on intake, body gain

Marques, Bárbara Santos 25 January 2013 (has links)
Objetivou-se avaliar o efeito da digestibilidade da fibra do milho sobre o consumo, ganho de peso e composição da carcaça de novilhas Nelore em crescimento, de modo a validar este índice como indicador da qualidade nutricional de híbridos de milho em programas de melhoramento genético e de seleção de híbridos para silagem. Foram plantados quatro híbridos de milho com diferente digestibilidade da fibra, IAC 8390, 30F90Y, 30S40Y e DKB 390Y, sendo a digestibilidade da FDN da dieta determinada após incubação de 30 horas. Os milhos foram colhidos aos 62, 82 e 104 dias crescimento, para determinar principalmente a digestibilidade da folha e do colmo dos híbridos, para determinar quais híbridos fariam parte da dieta experimental. Foram utilizadas quarenta e oito novilhas da raça Nelore com aproximadamente 250 kg, confinadas por 63 dias, em delineamento de bloco casualizados, em grupo de 3 novilhas por baia, de acordo com o peso vivo inicial. A cada 21 dias, os animais eram pesados, sendo a avaliação da carcaça feita no início do período A dieta experimental foi constituída de quatro rações, com relação volumoso/concentrado de 20:80 e 40:60, com volumoso de duas silagens de milho, 30F90Y, de alta digestibilidade da FDN e, 30S40Y, de baixa digestibilidade da FDN. Foi analisado o tamanho de partícula de amostras da dieta e das sobras/baia pela peneira Penn State Forage Particle. Houve diferença na digestibilidade da FDN dos híbridos na fração colmo, entre os dias de coleta, sendo que a digestibilidade in vitro da matéria seca (DIVMS) reduziu após o período de florescimento dos híbridos e houve uma variação entre os híbridos, em cada coleta. A digestibilidade in vitro da fibra em detergente neutro (DIVFDN), também reduziu com a maturidade da planta, porém houve uma diferença entre os híbridos apenas na coleta aos 82 dias de crescimento. O híbrido 30F90Y foi superior aos demais ao analisar a DIVMS e DIVFDN. Houve diferença entre o tamanho de partículas da dieta oferecida e o tamanho de partícula que restou na sobras, sendo que houve efeito de seleção apenas para a dieta com 40% de concetrado. Houve interação milho*dieta tanto para consumo de matéria seca (CMS) quanto para consumo da fibra em detergente neutro (CFDN), sendo que o híbrido 30F90Y, de maior digestibilidade, teve consumo maior, inclusive na dieta com 20% de concentrado. Para desempenho, foi observado efeito da dieta no ganho médio diário (GMD), sendo maior o ganho de peso (GP) na dieta com a silagem do híbrido 30F90Y Já a conversão alimentar e a composição de carcaça não tiveram efeito de dieta, híbrido de milho ou interação dieta*milho. A utilização de híbridos com melhor digestibilidade da fibra, é uma indicador de híbr do destinado a nutrição animal, pois alterou o consumo, o ganho de peso, porém não alterou a conversão alimentar e composição de carcaça. / The objective of this study was to evaluate the effect of fiber digestibility on intake, weight gain and carcass of growing Nellore heifers, aiming to validate this rate as an indicator of nutritional quality on corn hybrids in programs of genetical improvement and selection of hybrids for silage. Four corn hybrids on different fiber digestibility were raised, IAC 8390, 30F90Y, 30S40Y and DKB 390Y, being the FDN digestibility determined on the diet after a 30-hour-incubation period. The harvest was at the 62, 82 and 104 growing days to mainly determine the leaf and stem digestibility in hybrids to identify which ones would be part of the experimental diet. Forty-eight Nellore heifers of approximately 250 kg BW were housed for 63 days, in randomized blocks, in groups of three heifers per pen, according to its initial body weight. Each 21 days the animals were weighed and the carcass evaluation was done in the beginning of the period. The experimental diet was composed of four rations at 20:80 and 40:60 of roughage/concentrate respectively, in which the corn silage was used the 30F90Y, the one with high digestibility in FDN, and the 30S40Y, of low digestibility in FDN. The particle size of samples collected from the diets and ortis of each pens were analyzed by the Penn State Forage Particle sieve. There was difference in the FDN digestibility for hybrids in the stem fraction among the collection days, being the dry matter digestibility in vitro (DIVMS) reduced after the hybrid blossom and there was a variancy among the hybrids, in each collection. The digestibility in vitro of fiber detergente neuter (DIVFDN), was also reduced according to tha plant maturity, however there was a difference among the hybrids only in the collection at the 82 day of growth. The hybrid 30F90Y was superior to the other when analyzed the DIVMS and DIVFDN. There was difference between the particle size on the diets and the particle size on the ortis, with a selection affect only for the diet at 40% concentrate. There was interaction on the corn*diet for the dry matter intake (CMS) and for the fiber detergent neuter intake (CFDN), beingt the hybrid 30F90Y of higher digestibility, intake, and also on the diet with 20% concentrate. For performance was observed the diet effect on the average in daily weight gain (GMD), in which the highest weight gain (GP) was obtained on the silage of the hybrid 30F90Y. The feed conversion and carcass had no diet effect, neither corn hybrid nor interaction diet*corn. The hybrids with higher fiber digestibility is an indicator for its usage in animal nutrition once they altered the intake and the weight gain, although it hasn\'t altered the feed conversion and the carcas.
58

Fósforo e potássio associados a enxofre, boro e zinco na adubação de manutenção de capim-marandu

Vieira, Maycon Amim January 2019 (has links)
Orientador: Reges Heinrichs / Resumo: Os principais problemas das pastagens brasileiras são a deficiência de fósforo, acidez alta, pouca utilização de fertilizantes, além de pouca adubação de manutenção. Com o objetivo de avaliar fósforo e potássio associados a enxofre, boro e zinco na adubação de manutenção de pastagem de Urochloa brizantha cultivar Marandu, foi conduzido um experimento em Argissolo Vermelho Amarelo distrófico, na área experimental da Faculdade de Ciências Agrárias e Tecnológicas, UNESP, Campus de Dracena. O delineamento experimental foi em bloco casualizados, com quatro repetições. Em todos os tratamentos foram aplicados 120 kg ha-1 de N, na forma de nitrato de amônio, a qual foi dividida em quatro doses iguais, na semeadura e após os três cortes subsequentes. Os tratamentos foram os seguintes: T1) Controle - sem adubação, exceto N; T2) PK via fosfato monoamônio (MAP) e cloreto de potássio (KCl); T3) PKS via superfosfato simples (SS) e KCl; T4) PKS via S15 e KCl; T5) PKSB via S15 e KB; T6) PKSZn via SZ e KCl; T7) PKSBZn via SZ e KB; T8) PKSBZn via SZ, KB e Oxisulfato Zn. Nos tratamentos com PK foi aplicada a dose de 80 kg ha-1 de P2O5 e 50 kg ha-1 de K2O, respectivamente. As doses de enxofre, boro e zinco foram proporcionais a concentração na formulação de cada fertilizante, exceto o tratamento oito no qual foi acrescido o oxisulfato de Zn para fornecer o dobro do micronutriente em relação ao tratamento sete. MAP: (11%N, 52%P2O5); KCl: (60%K2O); SS (21%P2O5, 12%S); S15: (13% N, 33%P2O5, 15%S); ... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
59

Sistemas de manejo do solo e da cobertura vegetal na cultura da soja (Glycine max (L.) Merrill) semeada com dois mecanismos sulcadores /

Grego, Célia Regina 1972- January 2002 (has links)
Orientador: Sérgio Hugo Benez / Banca: Maria Helena Morais / Banca: Luiz Malcolm Mano De Mello / Banca: Rubens Siqueira / Banca: Suedemio de Lima Silva / Resumo: A adoção dos sistemas de manejo conservacionistas requer adaptações do solo e das culturas utilizadas, em função das variações edafoclimáticas encontradas nas regiões agrícolas, para que o processo se torne produtivo e viável. Diante deste contexto, foi desenvolvido o presente trabalho, no Município de Botucatu, SP, em Terra Roxa Estruturada ((NITOSSOLOS VERMELHOS - NV, EMBRAPA, 1999), durante o período de agosto de 1999 a maio de 2001. O objetivo foi avaliar a cultura da soja nos sistemas de manejo do solo: preparo convencional (uma gradagem pesada seguida de duas gradagens niveladoras); escarificação seguida de gradagem niveladora; escarificação; sistema de plantio direto com três épocas de dessecação da cobertura vegetal (30 e 10 dias antes da semeadura da soja e após a semeadura) empregando dois tipos de mecanismos sulcadores, disco duplo e haste sulcadora), para abertura do sulco de deposição de fertilizantes na semeadora-adubadora de plantio direto, em todos os sistemas de manejo do solo. Avaliou-se a densidade do solo, resistência do solo à penetração, cobertura vegetal, infestação de planta daninha, sulco de semeadura, emergência, nutrição, sistema radicular e produtividade da soja. O delineamento experimental foi em blocos ao acaso com parcelas subdivididas em faixas, sendo seis tratamentos primários constituídos pelos preparos e dois secundários constituídos por mecanismos sulcadores, com quatro repetições. A deficiência hídrica, no inverno e na primavera, impediu a formação de cobertura vegetal por triticale (X triticossecale Wittmack) e milheto (Penisetum americanum (L.) Leeke), por isso, a vegetação espontânea foi utilizada como alternativa de cobertura vegetal...(Resumo completo, clicar acesso eletrônico abaixo). / Abstract: The adoption of the conservation management systems requires the soil adaptation and the crop utilized as a function of the edafoclimatic variations found in agricultural areas, so that the process becomes productive and viable. In the light of this, the present work was developed in Botucatu of State São Paulo, Brazil, from August 1999 to May 2001 in Ultisol. The aim was to appraise the soybean crop in the soil management systems: conventional tillage (one harrow plowing followed by two harrow leveling); chiseling followed by harrow leveling; chiseling, no-tillage system with three seasons of weed blanket dessication (30 and 10 days before soybean seeding and after the seeding). Two kinds of furrow openers mechanisms, double disc and chisel opener were combined for the furrow for fertilizer application in no-tillage seeders / planters, in all soil management system. The soil physical properties density and strength, crop blanket, weeds, seeding furrow, emergence, nutrition, root systems and soybean grain yield were evaluated. The experiment was made randomized block with subdivided plots in strips, with six primary treatments, two secondary and with four repetitions. During the winter and spring, the hydro deficiency did not allow the covering formation for por triticale (X triticossecale Wittmack) and milhet (Penisetum americanum (L.) Leeke), so using the spontaneous vegetation was the choice...(Complete abstract, click electronicaccess below). / Doutor
60

Influence of nitrogen, phosphorus and potassium foliar feed on stooling rye (Secale cereale)

Lebepe, Francis Mashala January 2018 (has links)
Thesis (MSc. (Agriculture Pasture Science)) -- University of Limpopo, 2018 / This study was conducted at the University of Limpopo’s Experimental Farm (Syferkuil), in the Limpopo Province, South Africa. The objective was to determine the effect of foliar fertilizers on the dry matter production over a period of two growing seasons. The experiment was laid out in a 3 x 3 factorial arrangement, fitted in a randomized complete block design (RCBD), with 4 replications. The experiment was planted on 28th March 2014 for season 1 (2014) and 31st March 2015 for season 2 (2015). Three sources of fertilizer (Nitrospray Plus, Potaspray and a combination of the two) were applied to stooling rye at three different fertilizer application rates (0 kg or ℓ/ha, 2.5 kg or ℓ/ha and 5.0 kg or ℓ/ha). The Nitrospray Plus and Potaspray fertilizers were applied on the 09th May, 02nd July, 27th August and 30th October 2014 for Season 1 (2014). During the Season 2 (2015), they were applied on 11th May, 04th July, 29th August and 02nd November 2015. The application was done using a knapsack sprayer. Above-ground biomass was harvested four times during each season when the plants reached a height of 25–30 cm. During 2014, harvesting was done on the 27th May, 24th July, 12th September and the 17th November 2014. During 2015, harvesting was done on the 29th May, 26th July, 14th September and the 19th November 2015. The dry matter production was determined by harvesting 1 m2 quadrates at 3 cm height. After weighing fresh material, it was oven–dried at 55oC until a constant mass was reached. Samples were then weighed again and the DM production (kg/ha) was calculated. Results were compared, using analysis of variance and the Fisher’s LSD test at P≤ 0.05 within each season. Based on the Least Significance Difference test, treatments were grouped in different production classes. During both seasons, fertilizer application rates had a significant (P≤0.001) influence on dry matter production. In 2014, the highest total dry matter production obtained was 5323 kg/ha in the high potassium fertilizer treatment and the lowest total dry matter was 4049 kg/ha in the control or zero application treatment. xiii In 2015, the highest total dry matter production obtained was 5595 kg/ha in the high potassium fertilizer treatment and the lowest 3678 kg/ha in the control treatment. Potassium fertilizers produced significantly (P≤0.001) higher than nitrogen fertilizers in both seasons. The main conclusions from this study were that high foliar fertilizer application rates (5.0 kg/ha) led to high, low foliar application rates (2.5 kg/ha) to lower and no fertilizer to low dry matter production. High levels of potassium produced the best, followed by combinations of intermediate potassium and nitrogen, and high nitrogen application rates. Yields of above 5000 kg/ha were obtained under high potassium rates. Lower rates led to total productions of more than 4000 kg/ha, while no foliar application produced between 3700 and 4000 kg/ha. It was also concluded that stooling rye is a suitable winter fodder crop for the Pietersburg Plateau Bushveld, but that the application of fertilizers is necessary for increased dry matter production. Both and Nitrospray and Potaspray Plus, as individual foliar fertilizers or in combination, can be applied to increase the dry matter production of stooling rye. However, it is essential to investigate the adaptability of stooling rye in other areas of the Limpopo bushveld, to determine its suitability as a fodder crop in other areas in the province. Keywords: Dry matter production, cutting dates, foliar fertilizers, Nitrospray Plus, Potaspray.

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