Conselho Nacional de Desenvolvimento Científico e Tecnológico / The study was carried out to evaluate the changes in the physical and chemical properties of a sandy soil and the tree growth after afforestation of an Eucalyptus forest planted in different spacing. It was accomplished an experiment planted with Eucalyptus dunnii Maiden planted on native grassland. The spacings of cultivation were 3,50x3,50m; 3,50x1,75m; 1,75x1,75m and 1,75x0,87m. The soil studied was an Alfisol located in São Francisco de Assis city. The experimental design was a complete randomized block with four replicates. It was studied physical and chemical properties of the soil before and after 24 and 36 months of old. Soil samples were taken, for each experimental unit, in the layers soil 0,00-0,10m; 0,10-0,20m; 0,20-0,40m to determine physical properties and layers ,00-0,10m; 0,10-0,20m; 0,20-0,40m; 0,40-0,60m; 0,60-1,00m to chemical properties. The soil physical properties measured were: bulk density, total, macro and microporosity and wet aggregate size distribution. The soil chemical properties measured were: water pH, exchange Calcium, Magnesium and Potassium, available Phosphorus, and Total Nitrogen and Organic Carbon. The trees growth was evaluated to 12, 18, 24, 30, 36 and 42 months old, it was measured breast height diameter (DAP) and height of the plants, the survival percentage was determined and calculated the basal area for hectare. The results indicate to Eucalyptus cultivation changed soil structure by reduce the aggregation, the bulk density and the macroporosity. However it is not observed effect of the plant spacing on the physical properties to 24 and 36 months of Eucalyptus cultivation. In the chemical properties the Eucalyptus cultivation reduced pH, Ca and K contents of the surface layers and increase Ca content of the deep layers, increase contents Mg contents of the surface layers and reduced in the 0,60-1,00m layer; reduced contents of the N and C in the surface layers. It is not observed effect of the spacing planting in the survival percentage until 42 months old. It was higher DAP in the large plant space, while the height was higher in the narrower plant spacing, however this resulted can be changed because the forest is in full fledge. The basal area per hectare was higher in the narrower plant spacing because of there are more plants. / O estudo foi realizado com o objetivo de avaliar as alterações ocorridas nas propriedades físicas e químicas de um solo arenoso e o crescimento das árvores após a implantação de povoamentos de eucalipto em diferentes espaçamentos. O trabalho foi realizado a partir da instalação de um experimento implantado com Eucalyptus dunnii Maiden em campo nativo, nos espaçamentos 3,50X3,50m; 3,50X1,75m; 1,75X1,75m e 1,75X0,87m, em um Argissolo Vermelho Distrófico no município de São Francisco de Assis (RS). O experimento foi instalado em delineamento experimental blocos ao acaso, com quatro repetições. As avaliações das propriedades físicas e químicas do solo foram feitas antes do plantio e após 24 e 36 meses de cultivo do eucalipto, em que foram coletadas, em cada unidade experimental, amostras de solo nas camadas 0,00-0,10m; 0,10-0,20m e 0,20-0,40m para a avaliação das propriedades físicas e nas camadas 0,00-0,10m; 0,10-0,20m; 0,20-0,40m; 0,40-0,60m e 0,60-1,00m para as propriedades químicas. As propriedades físicas do solo avaliadas foram: a densidade do solo, a porosidade total, a macroporosidade, a microporosidade, a distribuição do tamanho dos agregados estáveis em água. As propriedades químicas determinadas foram: pH em água, Cálcio, Magnésio e Potássio trocáveis, Fósforo disponível, Nitrogênio e Carbono Orgânico totais. As avaliações de crescimento das árvores foram feitas aos 12, 18, 24, 30, 36 e 42 meses após o plantio, foram feitas medições do diâmetro a altura do peito (DAP) e altura das plantas, determinada a porcentagem de sobrevivência e calculada a área basal por hectare. Os resultados indicam que o cultivo de eucalipto interferiu na estrutura do solo através da redução na agregação, na densidade e na macroporosidade. No entanto não se verificou efeito do espaçamento de plantio nas propriedades físicas do solo aos 24 e 36 meses de cultivo do eucalipto. Quanto às propriedades químicas, o cultivo do eucalipto promoveu redução do pH; e dos teores de Ca e K nas camadas mais superficiais e aumentou o Ca nas camadas mais profundas; aumentou os teores de Mg na superfície do solo e reduziu na camada 0,60-1,00m; reduziu os teores de N e C nas camadas superficiais. Não se verificou efeito do espaçamento de plantio na porcentagem de sobrevivência das plantas até os 42 meses de idade. Em relação ao crescimento, observou-se maior DAP nos espaçamentos mais amplos, enquanto a altura foi maior nos espaçamentos mais densos, entretanto, essa relação pode ser alterada, pois a floresta apresenta-se em fase de pleno desenvolvimento. Em relação à área basal por hectare, os espaçamentos mais densos apresentam área basal mais elevada devido ao maior número de plantas.

Made available in DSpace on 2014-06-11T19:33:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-05-09Bitstream added on 2014-06-13T20:45:35Z : No. of bitstreams: 1 may_a_dr_jabo.pdf: 3234831 bytes, checksum: c3e3fa1e46ab316d1ec124f8d7e0d7ec (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho objetivou avaliar o desenvolvimento da planta e a produtividade de bulbos de dois híbridos de cebola quando submetidas a doses de nitrogênio e potássio em diferentes populações de plantas e a influência desses fatores na classificação do bulbo. O estudo foi conduzido no município de São José do Rio Pardo-SP. Avaliaram-se a altura da planta, número de folhas, diâmetro do pseudocaule, comprimento do pseudocaule, ciclo das plantas, massa do bulbo, massa seca da parte aérea, massa seca de bulbos, produtividade, classificação de bulbos, acúmulo e exportação de macronutrientes. O nitrogênio foi o fator que mais influenciou no crescimento da parte aérea e do bulbo das duas cultivares. O ciclo foi menor quanto maior a dose de nitrogênio aplicada e quanto maior a população de plantas. A massa do bulbo foi altamente influenciada pela população de plantas. O fator população de plantas e doses de potássio não influenciaram significativamente a produtividade, mas houve incrementos significativos na produção com a aplicação das doses de nitrogênio. / The objective of this paper was to study the effects of nitrogen and potassium fertilizer doses on plant growth, yield and bulb quality of two onion cultivars, growing in different plants population. The experiment was carried out in São José do Rio Pardo in São Paulo State, Brazil. Parameters studied were: plant height, leaf number, pseudostem diameter and length, growing season duration, bulb and aereal part dry matter, bulb mass, yield and bulb classification, nutrient accumulation and exportation. The cicle was less in the higher nitrogen dose and higher plant density. Higher nitrogen fertilizer doses increased bulb yield. Plant population and potash doses did not influence yield, but its was bigger with nitrogen application.

Made available in DSpace on 2015-03-26T13:53:24Z (GMT). No. of bitstreams: 1 texto completo .pdf: 3744163 bytes, checksum: c93df7883e2e8885bfb3350a4e639efc (MD5) Previous issue date: 2012-07-27 / The remaining forests of Minas Gerais harbor great wealth and diversity of native plant species, among these the genus Eremanthus sp., Popularly known as candeia stand out. This grows on shallow soils are not very fertile and yielding pure stands, called monodominant. Its occurrence is also recorded within forests after some disturbance with consequent gap formation, since this is heliophile. The candeia has a high economic potential. Its wood has high durability and can be used as fence posts and also in construction. It also has a substance known as α-bisabolol, essential oil, which has properties antiflogísticas, antibacterial, antifungal and dermatology. The study of the remaining monodominados candeia is needed, since its exploitation and commercialization of its products have been accomplished without the implementation of a management plan that efficiently prime for conservation of the species. This study aims to: classify land use in the northern municipality of Mariana (MG) with a focus on the areas covered by candeia (Eremanthus sp.); Evaluate the influence of environmental factors on the distribution of areas of natural occurrence of candeia in the northern municipality of Mariana (MG); analyze nutrient cycling in mounds on different substrates Quadrilatero Ferrifero in forest systems monodominant of a candeia. We used four images RapidEye's northern municipality of Mariana (MG), with radiometric and geometric corrections. The basemap contains the vector files extracted from highways and hydrography of letters planialtimétricas IBGE. We tested two algorithms for image classification, as follows: MaxVer and SVM employing the software interface of ArcGIS 10 and Envi 4.8. We tested 51 combinations of bands, involving compositions of image RapidEye multispectral bands, two and three principal components of the image (PCAc12 and PCAc123) and NDVI to assess what the best combination for differentiating areas under monodominance candeia of the other classes land use. For the inventory of forest areas under monodominance of a candeia sampled up to 6800 m² candeiais totaling seventeen parcels where the circumferences were measured at 1.30 m above the ground with all CAP stems> 15.7 cm. The total height of each stem was estimated with the aid of a calibrated rod. The parametric structure of the vegetation was analyzed in terms of the forecast variables: number of trees per hectare and basal area. The information in the inventory of the plots for the number of individuals and basal area coverage value, chemical and physical characteristics of the soil, were gathered into a single array analysis, and the data subjected to multivariate statistical techniques. In each of the seventeen areas of natural occurrence of a candeia, a composite sample was collected from surface soil samples and three of the outer wall of termite mounds in each of the areas, which were subjected to physical and chemical analysis routine. The physical and chemical properties of soils of the plots and mounds of each of the fragments were compared by applying the statistical test t. For each mound sampled was calculated relative increment (IC) of the physical and chemical attributes evaluated in relation to the surrounding soil. Regression equation was adjusted between the values observed in soil vs IC for the chemical and physical soil. Tests were performed Spearman correlation between the following physical and chemical properties: pH, P, OM, t e percentage clay soils to the fragments of a candeia and the ground of the external walls of the termites. And the values of Kappa conditional Kappa obtained from different classifiers and different combinations of bands were compared by applying the test statistic z (α = 95%). The ratings obtained from the Maxver algorithm are higher than those obtained from SVM. The information extracted from the thematic map possibly indicate that 29.76% of the study area, approximately 25,320.85 hectares, is covered by a candeia in monodominance. In plots inventoried's low diversity. In forest fragments studied, the lamp has high dominance, frequency and density. The study showed that candeiais are installed in soils with low nutrient content marked where the sum of base and base saturation are markedly lower. The variables, sum of bases, base saturation and number of individuals allowed to group the fragments evaluated in three groups. The figures show that the relative increase in clay soil with less than 15%, the capability of selecting the final particles is greater by termites. The outer walls of the nests differ environment of its surroundings by higher accumulation of organic matter and nutrients, and this accumulation more evident for Ca and Mg. Organic matter is primarily responsible for the relative increase of nutrients in mounds. / Os remanescentes florestais de Minas Gerais abrigam grande riqueza e diversidade de espécies vegetais nativas, dentre essas as espécies do gênero Eremanthus sp., conhecidas popularmente como candeia, se destacam. Esta se desenvolve sobre solos pouco férteis e rasos originando povoamentos puros, denominados de monodominantes. Sua ocorrência também é registrada dentro de florestas após alguma perturbação com consequente formação de clareiras, visto que essa é heliófila. A candeia apresenta alto potencial econômico. Sua madeira apresenta alta durabilidade e resistência podendo ser empregada como moirões e também na construção civil. Além disso, possui uma substância conhecida como α-bisabol, óleo essencial, que possui propriedades antiflogísticas, antibacterianas, antimicóticas e dermatológicas. O estudo dos remanescentes monodominados pela candeia se faz necessário, visto que sua exploração e a comercialização de seus produtos têm sido realizadas sem a implantação de um plano de manejo eficiente que prime pela conservação da espécie. O presente trabalho tem por objetivos: classificar o uso da terra na região norte do município de Mariana (MG) com enfoque para as áreas cobertas por candeia (Eremanthus sp.); avaliar a influência dos fatores ambientais sobre a distribuição das áreas de ocorrência natural de candeia na região norte do município de Mariana (MG); analisar a ciclagem de nutrientes em montículos sobre diferentes substratos do Quadrilátero Ferrífero, em sistemas florestais monodominantes de candeia. Utilizou-se quatro imagens Rapideye da região norte do município de Mariana (MG), com as devidas correções radiométricas e geométricas. A base cartográfica é composta pelos arquivos vetoriais de rodovias e hidrografia extraídos de cartas planialtimétricas do IBGE. Foram testados dois algoritmos de classificação de imagens, sendo eles: MaxVer e SVM, empregando a interface dos softwares ArcGis 10 e Envi 4.8. Foram testadas 51 combinações de bandas, envolvendo composições de bandas multiespectrais da imagem Rapideye, duas e três componentes principais da imagem (PCA2 e PCA3) e o NDVI, a fim de avaliar qual a melhor combinação para diferenciar as áreas sob monodominância de candeia das demais classes de uso do solo. Para a realização do inventário florestal de áreas sob monodominância de candeia, amostrou-se 6800 m² de candeiais, totalizando dezessete parcelas, onde foram medidas as circunferências a 1,30m do solo de todos os fustes com CAP > 15,7 cm. A altura total de cada fuste foi estimada com o auxílio de uma vara calibrada. A estrutura paramétrica da vegetação foi analisada em termos da estimativa das variáveis: número de árvores por hectare e área basal. As informações do inventário das parcelas do referente ao número de indivíduos, área basal e valor de cobertura, características químicas e físicas do solo, foram reunidas em uma única matriz de análise, sendo os dados submetidos a técnicas de estatística multivariada. Em cada uma das dezessete áreas de ocorrência natural de candeia, se coletou uma amostra composta de solo superficial e três amostras da parede externa de montículos de cupins em cada uma das áreas, que foram submetidos a análises físicas e químicas de rotina. Os atributos físicos e químicos dos solos das parcelas e dos montículos de cada um dos fragmentos foram comparados entre si aplicando o teste estatístico t. Para cada montículo amostrado foi calculado o incremento relativo (IC) dos atributos físicos e químicos avaliados em relação ao solo adjacente. Foi ajustada equação de regressão entre os valores observados no solo vs IC, para os atributos químicos e físicos do solo. Foram realizados testes de correlação de Spearman entre as seguintes propriedades físicas e químicas: pH, P, MO, t e porcentagem de argila para os solos dos fragmentos de candeia e o solo das paredes externas dos cupins. Os valores de Kappa e Kappa condicional obtidos a partir de diferentes classificadores e diferente combinações de bandas foram comparados entre si aplicando o teste estatístico z (α = 95%). As classificações obtidas a partir do algoritmo Maxver são superiores aos obtidos a partir do SVM. As informações extraídas do mapa temático permitem indicar que 29,76% da área de estudo, cerca de 25.320,85 ha, se encontra coberta por candeia em monodominância. Nas parcelas inventariadas há baixa diversidade. Nos fragmentos florestais estudados, a candeia apresentou alta dominância, frequência e densidade de indivíduos. O estudo demonstrou que os candeiais estão instalados nos solos com oligotrofismo marcante, onde a soma de base e a saturação de bases são notadamente baixas. As variáveis, soma de bases, saturação por bases e número de indivíduos, permitiram agrupar os fragmentos avaliados em três grupos. Os valores de incremento relativo mostram que em solos com teores de argila menores que 15%, a capacidade de seleção de partículas finais pelos térmitas é maior. As paredes externas dos cupinzeiros se diferenciam do ambiente de seu entorno pelo maior acúmulo de matéria orgânica e nutrientes, sendo este acúmulo mais evidente para Ca e Mg. A matéria orgânica é a principal responsável pelo incremento relativo de nutrientes nos montículos.

Made available in DSpace on 2016-12-08T16:44:44Z (GMT). No. of bitstreams: 1 PGPV10MA103.pdf: 641680 bytes, checksum: bdec82e807b366c5f670a27418b25bbe (MD5) Previous issue date: 2010-08-24 / During its evolution process from teosinte, maize was selected to produce a single ear in the main stem and to tolerate stresses caused by crowding. However, high yields of modern hybrids can only be achieved in a narrow range of plant population. This behavior reduces yield stability when plant density is above or below the ideal value. The main cause of maize low yield stability is linked to the plant small plasticity to compensate empty spaces. The identification of mechanisms that increase maize yield stability is important to mitigate damages to grain yield caused by low plant densities. With this objective, two field experiments were set in Lages, Santa Catarina, Brazil. The first experiment examined the response of grain yield and the contribution of tillers to variations in plant arrangement. Four plant densities were tested: 3.0, 5.0, 7.0 and 9.0 pl m-2. Each plant density was tested at three row spacing: 0.4, 0.7 and 1.0 m. The second trial evaluated whether the tillering and prolificacy are effective characteristics to stabilize maize grain yield in different plant densities. Four plant densities were used: 2.5, 5.0, 7.5 and 10 pl m-2. Three hybrids were tested at each plant density: P30F53 (tillering), AG9020 (prolific) and AS1570 (low tillering and poor prolificacy). In the first experiment, tiller contribution to grain yield differed between growing seasons. In 2007/2008, there was no water restriction to crop development and grain yield was not affected by plant arrangement. At this year, tiller grain yield contributed with more than 40% of total productivity at the density of 3.0 pl m-2. Whit the increase in plant population, tiller contribution to grain yield decreased. It reached only 3.3% when maize was sown with 9 pl m-2. In 2008/2009, there was water deficit during maize flowering and grain filling. Such weather pattern decreased tiller contribution to grain yield at the lower densities and enhanced maize yield response to the increment in plant population. In the second trial, grain yield of the three hybrids increased in a quadratic way when plant population increased from 2.5 to 10 pl m-2. Grain yield of the three hybrids did not differ when they were grown at 2.5 pl m-2. Therefore, the higher tillering hability of P30F53 and the greater capacity of AG 9020 to produce more than one ear per plant did not benefit these hybrids, when compared to AS1570, when maize was grown with smaller plant population than recommended / No seu processo de melhoramento a partir do teosinto, o milho foi selecionado para produção de uma única espiga no colmo principal e para tolerância a estresses ocasionados pelo adensamento. Contudo, altas produtividades de híbridos modernos só podem ser alcançadas numa estreita faixa de densidade de plantas. Isto reduz a estabilidade produtiva quando a densidade de plantas está abaixo ou acima da ideal. A principal causa da baixa estabilidade produtiva está ligada a pouca plasticidade da planta de milho para compensar espaços vazios. A identificação de características que incrementem a estabilidade produtiva do milho é importante para minimizar os prejuízos ao rendimento de grãos ocasionados por baixas densidades de plantas. Com este objetivo, foram conduzidos dois experimentos a campo, em Lages, Santa Catarina. O primeiro ensaio analisou a resposta do rendimento de grãos e a contribuição dos perfilhos a variações no arranjo de plantas do híbrido P30F53. Foram testadas quatro densidades: 3,0, 5,0, 7,0 e 9,0 pl m-2 e três espaçamentos entre linhas: 0,4, 0,7 e 1,0 m. O segundo ensaio avaliou se o perfilhamento e a prolificidade são características eficientes para estabilizar o rendimento de grãos de milho em diferentes densidades de plantas. Foram avaliadas as densidades de 2,5, 5,0, 7,5 e 10 pl m-2 e os híbridos P30F53 (perfilhador), AG9020 (prolífico) e AS1570 (baixo perfilhamento e prolificidade). No primeiro experimento, a contribuição dos perfilhos ao rendimento de grãos variou entre os anos agrícolas. Em 2007/2008 não houve restrição hídrica ao desenvolvimento da cultura e o rendimento de grãos não foi afetado por variações no arranjo de plantas. Neste ano, o rendimento de grãos dos perfilhos contribuiu com mais de 40% da produtividade total na densidade de 3,0 pl m-2. A medida que a densidade aumentou, houve decréscimo na contribuição dos perfilhos ao rendimento que foi de apenas 3,3% quando se utilizou 9,0 pl m-2. Em 2008/2009 houve deficiência hídrica nas fases de florescimento e enchimento de grãos. Isto diminuiu a contribuição dos perfilhos ao rendimento de grãos nas densidades de 3,0 e 5,0 pl m-2 e aumentou a resposta da produtividade ao incremento na densidade. No segundo experimento, o rendimento de grãos dos três híbridos aumentou de forma quadrática com o incremento na densidade de plantas. Não houve diferenças significativas na produtividade dos híbridos na densidade de 2,5 pl m-2. Isto demonstrou que a maior capacidade de perfilhamento do P30F53 e de emissão da segunda espiga do AG 9020 não trouxeram vantagens produtivas a estes híbridos, em relação ao AS1570, quando se trabalhou com estandes menores que o 5 pl m-2

Orientador: Silvio José Bicudo / Banca: Claudio Cavariani / Banca: Augusto Dias kanthack / Resumo: A otimização da exploração dos recursos do ambiente é necessária para a maximização do rendimento do milho. Dentre os fatores que interferem na resposta ao ambiente está o arranjo de plantas, compreendido pelo arranjo espacial e área ocupada pela planta de milho, interagindo diretamente sobre a competição intraespecífica por fatores do meio. Desta forma, a hipótese desse trabalho é de que o arranjo espacial eqüidistante entre plantas de milho diminua os efeitos da competição intraespecífica principalmente em altas densidades, com conseqüente aumento da produtividade. Portanto, o objetivo deste trabalho é comparar as formas de distribuição espacial de plantas eqüidistante e o espaçamento de 0,80 metro na entrelinha, preconizado como o convencionalmente utilizado, em populações de 30000, 45000, 60000, 75000, 90000, 105000 plantas ha-1. O ensaio foi conduzido em área de Nitossolo Vermelho distroférrico, de textura argilosa situada na Fazenda Experimental Lageado, da Faculdade de Ciências Agronômicas da UNESP/Campus de Botucatu, na safra 2007/2008. O delineamento experimental foi o de blocos casualizados, em esquema fatorial 2 X 6 (quatro repetições), em parcelas de 4,5 x 10 metros. Foram avaliados altura das plantas, altura de inserção de espiga, relação entre altura da espiga e altura da planta e diâmetro do colmo em pleno florescimento; índice de área foliar no florescimento e na maturidade fisiológica, índice de persistência e senescência foliar, produção de massa de matéria seca por planta e por área no florescimento e na maturidade fisiológica, índice de remobilização, índice de colheita, comprimento de espiga, diâmetros de espiga e do sabugo, comprimento do grão, número de fileiras, massa de mil grãos, massa de grãos por espiga, índice de espiga, estimativa do número de espigas e grãos por hectare, população de plantas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The maximization of environmental resources exploration is necessary to maximize maize grain yield. Among the factors that interfere in response to the environment is the plant arrangement, understood by spatial arrangement and occupied area by the maize plant, interacting on the intraspecific competition by factors of the environment. Thus, the hypothesis of this work is that the equidistant plant spacing between maize plants can reduce the effects of intraspecific competition mainly at high densities, aiming improvement of maize grain yield. The objective of this essay was to compare the equidistant plant spacing and 0.80 m row width, in populations of 30000, 45000, 60000, 75000, 90000, 105000 plants ha-1. The essay was located in a clay red alfisol area, in the Experimental Lageado Farm of the Agronomic Science College, UNESP-Botucatu-SP, in 2007/2008 growing season. The experimental design was a randomized block in four replications, in 4.5 x 10 m plots. It was evaluated plant and ear height, the relationship between ear and plant height and stem diameter at the flowering; leaf area index at the flowering and physiological maturity, leaf persistence and leaf senescence index, dry matter production per plant and per area at physiological maturity, steam remobilization index, harvest index, ear length, ear and cob diameter, grain length, number of grain rows, a thousand grains weight, grain weight per ear, ear index, ear and grain number per hectare, final plant population, percentage of stalk lodged plants, grain yield, as well the correlations between source and sink characteristics with yield. All parameters evaluated were affected by plant densities, except the mobilization and harvesting index. The spatial arrangements affected the relationship between ear and plant... (Complete abstract click electronic access below) / Mestre

Orientador: Rogério Peres Soratto / Banca: Napoleão Esberard de Macedo Beltrão / Banca: Lilian Sichmann Heiffig del Aguila / Resumo: Com o lançamento de novas cultivares de mamona de porte baixo e frutos indeiscentes, adequados para o cultivo em grandes áreas e colheita mecanizada, fez-se necessário estabelecer quais os melhores espaçamentos e populações de plantas, para que cada um desses materiais possa atingir a máxima produtividade. Nesse sentido, objetivou-se com o presente trabalho avaliar a influência do espaçamento entre fileiras e da população de plantas no crescimento e produtividade de cultivares de mamona de porte baixo na safra de verão (novembro) e em safrinha (março). Para tanto, foram realizados quatro experimentos, com dois cultivares (FCA-PB e IAC 2028), em duas épocas de cultivo (safra de verão e safrinha), conduzidos durante os anos agrícolas 2007/08 e 2008/09. O delineamento experimental utilizado em todos os experimentos foi o de blocos casualizados, em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram constituídas por quatro espaçamentos entre fileiras (0,45, 0,60, 0,75 e 0,90 m) e as subparcelas por quatro populações iniciais de plantas (25.000, 40.000, 55.000 e 70.000 plantas ha-1). O trabalho de pesquisa foi conduzido em condições de campo, na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas - UNESP, campus de Botucatu, SP. Na safra de verão foi possível observar que: para a cultivar FCA-PB, o aumento da população de plantas, independente do espaçamento entre fileiras, diminuiu a população final de plantas, a matéria seca da parte aérea, o número de racemos por planta e de frutos por racemo; o aumento da população de plantas nos espaçamentos de 0,60 e 0,75 m entre fileiras aumentou a altura de inserção do primeiro racemo; a maior produtividade de grãos e de óleo da mamoneira FCA-PB foi obtida com população inicial entre 55.000 e 70.000 plantas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The release of new dwarf castor bean cultivars and indehiscent fruit is suitable for growth in large scale with and mechanized harvest, therefore there is a need to establish which row spacing and plant population is the best for each of these materials can achieve the maximum yield. In this sense, the objective of this study was to evaluate the influence of the row spacing and plant population in the growth and yield of dwarf castor bean cultivars in the summer (November) and out-of-season (March) cropping. Therefore, four experiments were performed, i.e., two cultivars (FCA-PB e IAC 2028) in two cropping seasons (summer and out-of-season), conducted during 2007/08 and 2008/09 agricultural years. The experiment was arranged in a randomized block design with split-plot and four replications. Plots comprised four row spacings (0.45, 0.60, 0.75, and 0.90 m), and subplots comprised four initial plant populations (25,000, 40,000, 55,000, and 70,000 plants per hectare). In summer cropping season was observed: in the FCA-PB cultivar, plant population increasing, regardless of row spacing, decreased final plant population, aboveground dry matter, stem diameter, racemes per plant and fruits per raceme; the plant population increasing, at 0.60 and 0.75 m row spacings, increased the height of the first raceme insertion; the highest grain and oil yields were obtained with a population among 55,000 and 70,000 plants per hectare and 0.45 or 0.60 m row spacings. In the IAC 2028 cultivar, the plant population increasing, decreased final plant population, aboveground dry matter, stem diameter, number of racemes per plant, number of fruits per raceme, mass of 100 grains... (Complete abstract click electronic access below) / Mestre

Although Brazil is the fourth watermelon (Citrullus lanatus) producing country in ranking position, its greatest challenge is the low yield average obtained (22.5 t ha-1). Such yield, places Brazil in the 38th position in the world rank, reflecting the amount of effort still needed to increase Brazilian yield efficiency. Thus, greater knowledge about the agronomic traits of new cultivars is relevant to obtain more yield efficiency. The constant search for yield increase demands for the optimization of crop practices associated to plant density, as a function of new cultivars, planting regions and market characteristics. Spacing variation can change plant development and its response to production factors. Presently, both for watermelon fruit thinning management and plant density, the recommendations are based on old varieties in greenhouses or in agreement with empirical observations of growers and technicians. Therefore, this study evaluated the effects of plant density and fruit thinning, in different plant positions, on watermelon yield and fruit quality, under dripping irrigation, in two experimental watermelon hybrids. The experiments were done at Bayer Vegetable Seeds Experimental Farm, in Uberlândia-MG, in two seasons, from April to July (Autumn-Winter) and from August to November (Winter-Spring), consisting of two watermelon experimental hybrids (X and Y); two fruit thinning management systems (A basal, or B distal), and four plant densities (3000, 4000, 5000 e 6000 plants ha-1). Fruit average weight, fruit density, brix, flesh firmness, flesh color, hollow heart and yield were evaluated. Average fruit weight was inversely proportional to the plant density up 5000 plants ha-1. Fruit size increases again, between 5000 and 6000 plants ha-1, probably due to better use of fertilizers. Therefore, greater yield was obtained with plant density of 6000 plants ha-1, with a commercial fruit size better accepted in the market (above 10 kg). Better performance was observed in all characteristics within management A (basal), season 2 (August-November), while some characteristics showed better performance in the season 1 (April-July) under the management B (distal). Thus, basal fruit thinning becomes relevant only if there is no adequate water supply and temperature for watermelon crop. Greater yield potential was observed in hybrid X, as well as greater qualitative traits potential, especially when weather conditions were more adequate for its development. Under less favorable weather conditions (season 1) hybrid X was more responsive to basal fruit thinning (management A) considering the trait average of fruit weight, with an increase of 2.5 kg per fruit and, consequently, more responsive to yield with an increase of 11.4 t ha-1. / Apesar de o Brasil ocupar a quarta posição mundial no ranking dos países que mais produzem melancia (Citrullus lanatus), o maior desafio reside na baixa produtividade média alcançada (22,5 t ha-1). Com esta produtividade, o Brasil ocupa a 38o colocação no ranking mundial, o que reflete o quanto de esforços ainda precisa ser feito para aumentar a eficiência produtiva. Desta forma, o conhecimento aprofundado das características agronômicas das novas cultivares é muito relevante. A busca incessante pelo aumento de produtividade faz com que, em razão de novas variedades, novas regiões de plantio e de características de mercado, haja uma otimização de práticas culturais associada à adequação da densidade populacional. Variações no espaçamento podem alterar o desenvolvimento da planta e a resposta aos fatores de produção. Atualmente, tanto para o manejo do desbaste de frutos, quanto para a densidade populacional da melancieira, as recomendações são baseadas em variedades antigas sob cultivo protegido ou de acordo com observações empíricas de produtores e técnicos. Em razão do exposto, objetiva-se avaliar os efeitos da densidade de plantas e dos desbastes de frutos, em diferentes posições na planta, sobre a produtividade e qualidade da melancia, no sistema de gotejo, em dois híbridos experimentais de melancia. Os experimentos foram realizados na fazenda experimental da empresa Bayer Vegetable Seeds, no município de Uberlândia-MG. Estes foram conduzidos em duas épocas, entre Abril e Julho (Outono-Inverno) e entre Agosto e Novembro (Inverno-Primavera). O experimento constituiu-se de dois híbridos experimentais de melancia (X e Y); dois manejos de posição de frutos (manejos A-basal e B-distal) e de quatro densidades de plantas (3000, 4000, 5000 e 6000 plantas.ha-1). Peso médio de frutos, densidade de fruto, brix, firmeza de polpa, cor de polpa, presença de cavidade interna e produtividade foram avaliadas. O peso médio de fruto foi inversamente proporcional à densidade de plantas até 5000 plantas.ha-1. Entre 5000 e 6000 plantas.ha-1, o tamanho de fruto volta a aumentar, provavelmente, devido ao maior aproveitamento de fertilizantes. Portanto, maior produtividade foi obtida na densidade de 6000 plantas/ha com tamanho comercial de fruto mais aceitável no mercado (acima de 10 kg). Dentro do manejo A (basal), na época 2 (Agosto-Novembro) observou-se valores superiores para todas as características. Já no manejo B(distal), algumas características responderam melhor na época 1 (Abril-Julho). Portanto, o desbaste de frutos dos nós basais só é relevante se não houver água e temperatura adequadas para a cultura da melancia. Maior potencial produtivo foi observado no híbrido X, como também, maior potencial qualitativo, especialmente quando as condições de clima foram mais adequadas ao seu desenvolvimento. Em condições de clima não muito favoráveis (época 1), o híbrido X foi mais responsivo ao desbaste dos primeiros frutos (manejo A-basal) para a característica peso médio de fruto com um incremento de 2,5 kg por fruto e, consequentemente, mais responsivo à produtividade com um incremento de 11,4 t.ha-1. / Mestre em Agronomia

Made available in DSpace on 2014-06-11T19:30:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-28Bitstream added on 2014-06-13T19:00:26Z : No. of bitstreams: 1 aguiar_eb_dr_botfca.pdf: 799841 bytes, checksum: 76febcd3057aea23b05ef3cdca2c3afa (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A poda da parte aérea da mandioca é prática comum nos cultivos comerciais destinados à industrialização. Vem sendo praticada principalmente por possibilitar o controle das plantas infestantes com herbicidas no segundo ciclo vegetativo. Seus efeitos no desenvolvimento das plantas e na produtividade de raízes de mandioca ainda não são claros e resultados controversos são encontrados na literatura. Com o objetivo de estudar os efeitos da poda foram realizados seis experimentos, em dois ambientes: Botucatu, experimentos 1, 3 e 5 e em São Manuel, experimentos 2, 4 e 6. Os experimentos 1 e 2 tiveram como causas de variação cinco variedades de mandioca cultivadas com e sem poda. Os experimentos 3 e 4 avaliaram nove épocas de poda frente a uma testemunha conduzida sem poda. Os experimentos 5 e 6 tiveram como causas de variação quatro densidades de plantio avaliadas com e sem poda. Concluiu-se que: a poda altera a produtividade de matéria seca de raízes de maneira distinta considerando a variedade e o ambiente; a poda anterior ao período de repouso fisiológico ou após o início do segundo ciclo vegetativo reduz a produtividade de matéria seca de raízes; em altas densidades de plantio, a poda reduz de maneira significativa a produtividade de matéria seca de raízes. Desse modo, a poda da parte aérea da mandioca não deve ser recomendada de maneira genérica, devendo considerar entre outros, os fatores avaliados no presente estudo / Cassava pruning is common in commercial crops destined for industrialization, a practice mainly aimed at enabling weed control with herbicides in the second growth cycle. Its effects on plant development and cassava yields remain unclear and controversial results are reported in the literature. With the objective of studying the effects of pruning, six experiments were conducted in two environments: in Botucatu, experiments 1, 3 and 5, and in São Manuel, experiments 2, 4 and 6. In experiments 1 and 2, the established variables were five varieties of cassava cultivated with and without pruning. Experiments 3 and 4 evaluated nine pruning dates compared with control cultivated without pruning. The established variables in experiments 5 and 6 were four planting densities, evaluated with and without pruning. It can be concluded that: cassava pruning causes distinct alterations in the productivity of dry root matter, depending on the variety and culture environment; pruning before or after the period of physiological rest or after the onset of the second growth cycle reduces the productivity of dry root matter; and pruning in high planting densities significantly reduces the productivity of dry root matter. Thus, cassava pruning cannot be recommended as a general practice, as currently occurs, and the factors evaluated in this study should be taken into consideration

Hintergrund und Zielstellung Im Zuge des Waldumbaus wird die Rotbuche (Fagus sylvatica L.) über Voranbau in Fichtenreinbestände eingebracht. Deren Bewirtschaftung zielt meist auf die Erzeugung von Wertholz ab. In diesem Zusammenhang dient der Fichtenschirm als Instrument der Steuerung der Ressourcenversorgung und damit der Qualifizierung der Buchen („edle Halbschattform“). Die in der Vergangenheit zumeist niederdurchforstungsartige Behandlung bedingt jedoch, dass viele Fichtenbestände hinsichtlich ihrer Stabilität keine geeigneten Ausgangsbedingungen für eine langfristige Schirmstellung bieten. Die Schadbilder infolge immer häufiger auftretender Windwurfereignisse verdeutlichen dies eindrucksvoll und belegen unmissverständlich, dass diesbezüglich Handlungsbedarf besteht. Die vorliegende Untersuchung ging daher den Folgen eines unplanmäßigen, sturmbedingten Schirmverlusts für Wachstum und Qualität vorangebauter Rotbuchen nach. In diesem Zusammenhang wurden auch der Einfluss von Pflanzendichte und Entwicklungsstadium des Voranbaus geprüft. Material und Methoden In den beiden Modellregionen „Thüringer Wald und Hügelland“ sowie „Sächsisches Erzgebirge und Vorland“ wurden Qualitätserhebungen (vgl. BÖRNER ET AL. 2003) auf insgesamt 29 Buchenvoranbauflächen durchgeführt. Auf 17 dieser Flächen wurde der Fichtenschirm im Januar 2007 durch den Orkan KYRILL meist vollständig geworfen. Seitdem entwickelten sich die Rotbuchen ohne Schirmschutz. Alle weiteren Voranbauten stehen nach wie vor unter Fichtenschirm und dienen als Referenz für Wachstum und Qualität. Jedem Voranbau wurde das auf den Freistellungszeitpunkt bezogene Entwicklungsstadium (vor oder nach Dickungsschluss) zugewiesen. Zur repräsentativen und objektiven Festlegung der Aufnahmeeinheiten in den Flächen wurde ein rasterbasiertes Probekreisverfahren gewählt. Das quadratische Gitternetz mit einer Weite von 20 m wurde mittels GPS im Gelände eingemessen. Die Rasterschnittpunkte bildeten zugleich die Zentren der 19,95 m² großen Probekreise (Plotradius: 2,52 m). Die Datenaufnahme erfolgte auf insgesamt 204 repräsentativen Plots. In jedem Probekreis wurde die Pflanzenzahl erhoben und auf Hektarwerte hochgerechnet. Für die Referenzflächen erfolgte hier weiterhin eine Ansprache des Überschirmungsgrads. Einbezogen wurden nur Plots mit locker-lichtem Fichtenschirm. Die Datenerhebung wurde an den maximal sechs höchsten Buchen eines jeden Probekreises vorgenommen und konzentrierte sich damit auf die (vor-)herrschenden und somit vitalsten Bestandesglieder. Daraus resultierte ein Stichprobenumfang von 895 Einzelbäumen. Die Datenaufnahme fand nach Abschluss der Vegetationsperiode 2012 statt, sodass seit der Freistellung sechs Jahre vergangen waren. Mathematisch-statistische Auswertung Aufgrund der räumlich geschachtelten Versuchsanlage kamen bevorzugt gemischte Modelle zur Anwendung. In Abhängigkeit vom Skalenniveau der Response-Variable und dem vorliegenden Verteilungstyp wurden lineare gemischte Modelle (LMM) oder aber generalisierte lineare gemischte Modelle (GLMM) eingesetzt. Multinomialdaten mit einer festen Rangordnung der Response-Kategorien wurden mit einem erweiterten logistischen Regressionsmodell, der Proportional Odds Logistic Regression (POLR), analysiert. Zur Umsetzung aller beschriebenen Methoden wurde die Statistiksoftware R (Version 3.0.1) genutzt. Ergebnisse • Wachstum und Zuwachsreaktion: Sechs Jahre nach dem Sturmereignis besteht kein signifikanter Höhenunterschied zwischen den Buchen auf Sturmflächen und unter Schirm. Allerdings stiegen die Haupttrieblängen ab dem zweiten Jahr der Freistellung an, sodass der Wachstumsgang der freigestellten Individuen signifikant von dem der überschirmten Bäume abweicht. Hohe Stammzahldichten im Voranbau fördern das Höhenwachstum. Das Durchmesserwachstum profitiert im Vergleich dazu deutlich stärker von der Freistellung, wie die signifikant größeren Wurzelhalsdurchmesser der freigestellten Buchen belegen. Entsprechend intensiv fiel auch die Reaktion des Radialzuwachses aus, die ohne Verzögerung bereits im Jahr der Freistellung einsetzte. Der stärkste Grünast zeigt einen im Vergleich zum Stamm synchronen Wachstumsgang, wenn auch auf niedrigerem Niveau. Unabhängig von der Überschirmung dämpfen hohe Bestandesdichten das Durchmesserwachstum. Gemessen am H/D-Verhältnis weisen die Buchen unter Schirm sowie bei hoher Pflanzendichte einen schlankeren Wuchs auf. Zwischen den beiden Entwicklungsstadien, das heißt vor oder nach Dickungsschluss, bestand kein Unterschied. • Astigkeit und Astreinigung: Sechs Jahre nach dem Schirmverlust sind an den freigestellten Buchen signifikant größere Astdurchmesser bei zugleich steileren Astwinkeln zu erkennen. Mit zunehmender Pflanzenzahl im Voranbau werden die Buchen feinastiger, während der Astwinkel unbeeinflusst bleibt. ASIX und Grünastdichte sinken nur auf der Freifläche merklich, erreichen dadurch aber ab Pflanzenzahlen von 8.500 St./ha bzw. 6.000 St/ha niedrigere Werte als Buchen unter Schirm. Zwischen den beiden Entwicklungsstadien sind hinsichtlich der Wirkung des Schirmverlusts keine Unterschiede zu verzeichnen. Totastanzahl und grünastfreie Schaftlänge hingegen werden durch die Freistellung nicht beeinflusst. Auf der Freifläche wurden jedoch stärkere Totäste gefunden. Mit zunehmender Pflanzenzahl im Voranbau steigen Anzahl und Durchmesser der Totäste sowie die grünastfreie Schaftlänge signifikant. Am deutlichsten tritt dieses Phänomen bei Voranbauten nach Dickungsschluss zutage. • Schaft- und Kronenmorphologie sowie Häufigkeit von Z-Baum-Anwärtern: Sechs Jahre nach dem Schirmverlust sind an freigestellten Buchen signifikant häufiger Steiläste und vor allem Zwiesel erkennbar. Im Stadium vor Dickungsschluss treten auf Freiflächen doppelt bis dreifach so häufig Tiefzwiesel auf wie unter Fichtenschirm. Mit zunehmender Pflanzenzahl im Voranbau sinkt die Zwieselanzahl moderat, der Anteil tief gezwieselter Buchen sogar rapide. Dadurch kommen im Stadium nach Dickungsschluss ab 9.000 Buchen pro Hektar unabhängig von der Überschirmung kaum noch Tiefzwiesel vor. Die gutachterliche Qualitätsansprache bestätigt, dass durchschnittlich etwa 60–70 % aller Buchen auf den KYRILL-Flächen den Zwieseltypen zuzurechnen sind, während unter Fichtenschirm mit ca. 90 % die (sehr) guten Formen dominieren. Mit zunehmender Bestandesdichte steigt der Anteil der besseren Qualitäten tendenziell, jedoch nicht signifikant. Die gutachterliche Qualitätsansprache zeigt eine sehr hohe Übereinstimmung mit der anhand von ASIX, Astwinkel und Zwieselzahl einer Buche modellierten Qualitätsklasse. Unter Fichtenschirm ist die Dichte der Z-Baum-Anwärter grundsätzlich sechsmal so hoch wie in freigestellten Voranbauten. Diese steigt aber unabhängig vom Schirm mit der Pflanzendichte des Voranbaus signifikant an. Schlussfolgerung und Handlungsempfehlungen Der Fichtenschirm hat eine herausragende Bedeutung für die Qualitätsdifferenzierung von Buchenvoranbauten. Eine locker-lichte Überschirmung stellt den geeigneten Kompromiss zwischen vitalem Wachstum und Qualitätsentwicklung der Buchen dar. Ungeachtet aller weiteren Faktoren bewirkt ein plötzlicher, unplanmäßiger Schirmverlust gravierende Qualitäts-einbußen der an den Halbschatten adaptierten Buchen. Sehr gute Qualitäten, das heißt wipfelschäftige Buchen mit gering dimensionierten, horizontal ausgerichteten Ästen und zügiger Astreinigung, sind nur durch die Kombination aus langfristig stabiler Überschirmung und Pflanzendichten im Voranbau ab 6.000–8.000 St./ha zu erreichen. Eine Kompensation des Freistellungseffekts ist durch hohe Pflanzenzahlen im Voranbau nur in sehr begrenztem Umfang möglich. Ein hoher Seitendruck kann den fehlenden Schirmdruck demnach nicht ersetzen. Selbst bei höchster Bestandesdichte waren die Formen auf den Freiflächen weitaus schlechter als unter Schirm. Dies gilt unabhängig vom Entwicklungsstadium der Voranbauten. Der Bestandesschluss bewahrt also offenbar nicht vor freistellungsbedingten Qualitätsverlusten. Allerdings gewährleisten Pflanzendichten ab 8.000–9.000 St./ha, dass die Tiefzwieselbildung in geschlossenen Buchendickungen auch bei einer abrupten Freistellung weitgehend unterbleibt und eine hinreichende Anzahl von Z-Baum-Anwärtern zur Verfügung steht. Ist es erst einmal zu einem Schirmverlust über einem Buchenvoranbau gekommen, bestehen kaum Möglichkeiten, aktiv zugunsten der Buchenqualität tätig zu werden. Die einzige Chance besteht im gezielten Erhalt bestehender Z-Baum-Anwärter und deren konsequenter Pflege. Für zukünftige Waldumbaumaßnahmen wird deshalb ein standort- und risikodifferenziertes Vorgehen beim Buchenvoranbau empfohlen. Dieses sollte sich an erster Stelle an der Stabilitätssituation des Fichtenschirms orientieren. Ausschließlich bei gegebener Stabilität ist das Produktionsziel Buchenwertholz als realistisch einzustufen, sodass kostenintensive Voranbauten mit den oben genannten Pflanzendichten angelegt werden sollten (Funktionsumbau). Bei einer offensichtlich (sehr) hohen Prädisposition der Fichtenschirme gegenüber Sturm und Borkenkäferbefall ist stattdessen ein extensiver Voranbau mit reduzierter Pflanzenzahl vorzuziehen. Dieser zielt im Sinn eines Nachhaltsumbaus primär auf eine Stabilisierung der Waldökosysteme ab und trägt zur Erhöhung der Flexibilität der zukünftigen Waldbewirtschaftung bei (WAGNER 2007, 2008). / Backround and Objectives In the course of forest conversion European beech (Fagus sylvatica L.) is introduced in spruce monocultures by advanced planting. Management of beech stands aims mostly on production the of high quality timber. In this context, the shelterwood of spruce officiates as an instrument for controlling resource availability and thus to qualify advanced planted beech. But because of low-thinning treatment in past, most spruce stands do not provide suitable conditions for long-term shelterwood with regard to their missing stability. The situation of forest damage due to periodic windthrow events illustrate this impressively and show need for action. Therefore, the present study analyzed the consequences of an unplanned, storm-related loss of canopy for growth and quality of advanced planted beech. In this context, the influence of stand density and developmental stage of advanced regeneration will be examined as well. Material and Methods In two model regions "Thuringian Forest” (middle of Germany) and "Saxon Oremountains” (East of Germany) quality investigations (cf. BÖRNER ET AL. 2003) were carried out on a total of 29 advanced planted beech stands. In 17 of these stands the spruce canopy was mostly completely thrown by hurricane KYRILL in January of 2007. Thus, the beech trees have grown without shelter since then. The other advanced regeneration stands are still under spruce canopy and serve as a reference for growth and quality. A developmental stage (before or after thicket-stage) was designated to each advanced planting site in reference to the time of overhead canopy release. For representative and objective definition of experimental plots a grid-based plotdesign was used. The square grid with distance of 20 m was calibrated by GPS in the field. The grid inter-sections built the centers of 19.95 m² circular sample areas (plot radius 2.52 m). Data was collected on a total of 204 representative plots. On each plot, the number of beech plants was collected and extrapolated to hectare values. In addition, the canopy closure was also estimated for reference plots within the sample plots. For data collection only plots with moderate canopy closure were included (maximum area of canopy gaps: one crown projection). Data collection was carried out at maximum of six highest trees per plot. Thus it is concentrated on (pre-) dominant and therefore most vital individuals. This resulted in a sample size of 895 trees. The data collection was started after growing season in 2012, six years after canopy release. Mathematical and statistical analysis Due to spatially nested plot design Mixed Models have been applied preferably. Depending on scale level of the response variable and given distribution type, Linear Mixed Models (LMM) or Generalized Linear Mixed Models (GLMM) were used. Multinomial data with fixed order of response categories was analyzed with an extended logistic regression model, the Proportional Odds Logistic Regression (POLR). These calculations were implemented by statistical software R (version 3.0.1). Results • Growth and reaction of annual increment: Six years after the storm event there is no significant difference in height between beech trees on storm areas and such under shelterwood. However the annual increment of terminal shoot rose from the second year after release, so the trend of increment deviates significantly from beech trees under shelterwood. High stand density in advanced planting promotes height growth. Diameter growth benefits significantly more from release compared to height growth. So released beech trees showed significantly larger root collar diameters. Reaction of radial increment, which began immediately after release, was appropriately intensive. The thickest living branch shows synchronous trend of increment, but on a lower level. Regardless of canopy cover high stand densities delimitate diameter growth. The H/D-ratio demonstrated that beech trees under shelterwood and in high density stands showed more slender forms. There was no difference between the two developmental stages. • Branchiness and natural pruning: Six years after the loss of spruce canopy significantly greater branch diameters in combination with steeper branch angles were found on released beech trees. With increasing stand density in advanced planting the beeches showed finer branches while branch angles remain unaffected. ASIX and the density of living branches decreases appreciably for released trees only, so reached lower values than trees under shelterwood by stand densities off 8.500 pcs/ha and 6.000 pcs/ha, respectively. There was no difference of release effect between the developmental stages. Number of dead branches and bole-length without living branches however, were not affected by loss of canopy. However more dead branches were found on beeches in the opening. With increasing stand density in advanced planting, the number and diameter of dead branches and bole-length without living branches increased significantly. This was most distinct for beech stands that reached thicket-stage before release. • Stem- and crown shape, number of crop tree candidates: Six years after canopy-loss, released beeches showed significantly more steep branches and especially forks. Released stands before thicket-stage showed two to three times as likely deep-forks in relation to stands under spruce canopy. With increasing stand density in advanced planting the number of forks per trees decreased moderately, the proportion of deep-forks even rapidly. In consequence, regardless of the canopy cover, deep-forks only occurred marginally in beech stands after thicket-stage with at least 9.000 pcs./ha. The expert quality estimation confirms that on average about 60–70 % of beeches on KYRILL sites belong to a “fork type”, while under spruce shelterwood (very) good shapes dominate with about 90 %. With increasing stand density, the proportion of good shapes tends to increase, however not significantly. The estimated quality class showed a very high correlation with the modeled one, based on ASIX, branch angle and fork number per beech. The density of crop tree candidates under spruce canopy is basically six times as high as in released stands. However, regardless of shelterwood it increases significantly with stand density. Conclusion and silvicultural implication: Spruce canopy is of outstanding importance for quality and differentiation of advance planted beech. A moderate shelterwood is the appropriate compromise between vital growth and good quality development. Regardless of any other factors, a sudden and unplanned loss of canopy effects a loss of quality of shade adapted beech trees. Very good qualities, that means straight to top trees with fine, horizontally oriented branches and timely self-pruning, can only be achieved by combining of long-term shelterwood and stand densities in advanced planting of at least 6.000–8.000 pcs./ha. Compensation of the release effect through high stand density in advanced planting is only possible to a very limited extent. High intraspecific competition cannot replace the lack of shelterwood. Beech shapes were far worse than under shelterwood, even at the highest stand density. This applies regardless of the developmental stage of a beech stand. So closing of advanced planted beech stand (thicket-stage) does not prevent release related quality losses. However, plant densities from 8.000–9.000 pcs./ha ensure that deep fork formation in closed beech thickets is largely suppressed and a sufficient number of crop tree candidates is available, even after abrupt release. Once an abrupt loss of canopy above advanced planted beech has occurred, there are hardly any opportunities to actively engage in favor of beech quality. The only chance is maintenance of existing crop tree candidates and their consistent care. Therefore, for future forest conversion with beech, a site- and risk-differentiated approach is recommended for advanced planting. This should be based firstly on the stability of shelterwood. Only with high stand stability, the target of high-grade beech-timber is realistic, so costly beech plantings with high stand density mentioned above should be applied. For spruce stand with an obvious (very) high risk towards bark beetles and / or storms, an extensive advanced planting with reduced stand density is preferable. In terms of “Sustainability-conversion” this aims primarily on stabilizing forest ecosystems and increasing flexibility for future forest management (WAGNER 2007, 2008).

Im nordostdeutschen Land ist die Zunahme des Ertrages und die Verbesserung der Qualität des Maises eine Folge von Licht, Temperatur und der Länge der Vegetationsperiode. Eine gute Belichtung durch blattreichere Sorten und Standort angepasste Bestandesdichte ist wichtige Voraussetzung für die gute Ertragsleistung des Silomaises. Am Standort Berge (nordostdeutsches Tiefland) sind in den Jahren 1997 und 1998 vier Landessortenversuche (Brandenburg) und zwei Parzellenversuche mit verschiedenen Silomaissorten und Bestandsdichten in die Untersuchungen zum Ertragsniveau, zur Futterqualität und zum Einfluss des Faktors Licht auf die Ertragsbildung bei Silomais einbezogen worden. Es handelte sich im Landessortenversuch um Untersuchungen in den Silomaissortimenten der Reifegruppe "früh" mit 28 Sorten und der Reifegruppe "mittelfrüh" mit 33 Sorten. In ergänzenden Parzellenversuchen ging es um detaillierte Untersuchungen zur Lichtinterzeption und des Blattflächenindexes in Abhängigkeit vom Wuchstyp der Maissorten sowie von der Bestandsdichte. Am Beginn der Untersuchungen standen die Sortenunterschiede bei den Merkmalen Gesamtertrag, Futterqualität (wie Trockensubstanzgehalt, Energiedichte und Stärkegehalt) und Lichtinterzeption im Mittelpunkt. Darauf aufbauend konzentrierten sich die Untersuchungen auf den Einfluss von Sorte und Bestandsdichte auf die vor allem auf den Ertragsparameter Trockenmassebildung in unterschiedlichen Wuchsabschnitten der Maispflanze, Kolbenanteil am Trockenmasseertrag, die Blattflächen, den Blattflächenindex, die Lebensdauer der Blätter und die Lichtaufnahme [wie die Lichtinterzeption, den Lichtextinktionskoeffizienten und die Lichtnutzungseffizienz]. Dazu wurden im Jahre 1998 zwei Parzellenversuche mit je zwei Sorten der Reifegruppen "früh" (Arsenal und Agadir) und "mittelfrüh" (Banguy und Attribut) angelegt. In den zweifaktoriellen Parzellenversuchen wurden bei der Messung der Lichtinterzeption zwei Messgeräte (PhAR-Sensor und LAI-2000) verwendet. Für die Messung des Blattflächenindexes wurde ebenfalls das Messgerät LAI-2000 verwendet. Der Blattflächenindex wurde mit den Ergebnissen aus der manuellen Messung der einzelnen Blätter verglichen. Die Sorten Arsenal und Banguy zeichneten sich durch die höhere Lichtnutzungseffizienz, den größeren Blattflächenindex und die größere Lichtinterzeption aus, was als Grund für den höheren Ertrag angesehen werden kann. Im Jahre 1998 führte die höhere Bestandesdichte von 10 Pflanzen pro qm im Vergleich zu 8 Pflanzen pro qm unter den herrschenden Standortverhältnissen zu keiner Ertragsüberlegenheit und es kam zu schlechteren Qualitätseigenschaften der vier Sorten. Der Unterschied zwischen den Werten des Blattflächenindexes der beiden Messmethoden bei Erreichen des maximalen Blattflächenindexes war kleiner als 14 %. / The higher yield and the better quality of maize depend on light, temperature, water and length of vegetation period in north eastern Germany. A good light interception of maize accompanied with higher leaf area index and plant density adjusted to region is essential for the better maize yield. In 1997 and 1998 four field trials for assessing varieties for the conditions of the federal state Brandenburg (variety trials) and two field experiments with four silage maize varieties and different plant densities in 1998 were carried out at Berge (plain of the north eastern Germany). The yield and the fodder quality of the maize crop (with special emphasis of the light conditions) as well as the effect of light conditions on yield forming out processes were examined. The variety trials included 28 maize varieties of maturity group "early" and 33 maize hybrids of maturity group "middle early". The aim of the two field experiments was to explain the light interception and the leaf area index in dependence of canopy structure and plant density. At the beginning of the variety trials we focused on the differences between the hybrids for maize yield, fodder quality (such as dry matter content, energy concentration and content of starch) and light interception. Closely related experiments were concentrated on the influence of variety and plant density on the yield (dry matter yield within different plant height, cobs weight ratio), development of leaf (leaf area index, leaf area and leaf age) and light absorption (such as light interception, light extinction coefficient and light use efficiency). At these field experiments, to which two hybrids Arsenal and Agadir (maturity group "early") and two hybrids Banguy and Attribut ("middle early") were analysed. In the two-factorial field experiments two devices (ceptometer and LAI-2000) were used to measure the light interception. The leaf area index we obtained from measurement with the LAI-2000 were valued by the leaf area index of individual leafs measured by hand. The hybrids Arsenal and Banguy were characterised by their higher light use efficiency, large leaf area index and higher light interception. These properties seem to be responsible for the higher maize yield. The higher Plant density of 10 plant per sqm for the four varieties compared to 8 plant per sqm resulted in no increase of yield and worse qualities in 1998. The difference between the maximum value of leaf area index of both methods was smaller than 14 %.