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Soybean (Glycine max L. Merr.) planting date and plant density are agronomic decisions made simultaneously at the beginning of the growing season that can be used to maximize yield and economic return. Research on these basic soybean agronomic decisions must be conducted to support the expansion of soybean production in northern growing regions of the Northern Great Plains (NGP). The objectives of this study were to evaluate the effects of planting dates based on soil temperature on soybean emergence, maturity, and yield for short and long season varieties in Manitoba, and to determine optimum soybean plant density for early to very late planting dates in northern growing regions of the NGP. In the first experiment, calendar date had a greater influence than soil temperature at planting on soybean yield. Soybean yield declined with later planting rather than increasing soil temperature at planting. The earliest planting dates resulted in the greatest soybean yields. In the second experiment, soybean yield-density relationships were responsive to planting date. Yield-density relationships formed early/mid (May 4 to 26) and late/very late (June 2 to 23) planting date groups for combined site years. Early/mid planting dates resulted in greater maximum yields. According to the yield-density model, true yield maximization did not occur for any planting dates and site years within the range of plant densities tested in this field study. Soybean economic optimum seed densities (EOSDs) were much lower than predicted plant densities that maximized yield. Soybean EOSDs were identified as 492,000 and 314,000 seeds ha-1 by marginal cost analysis for early/mid and late/very late planting, respectfully. These values were sensitive to changes in soybean grain price and seed cost. Thus, growers need to adjust EOSDs for changes in price and cost. A combined analysis of soybean yields from both experiments using similar target plant densities determined that a significant negative linear relationship existed between soybean yield and planting date. The greatest soybean yields resulted from early planting and declined by 16 kg ha-1 for each one-day delay in planting from Apr 27 to June 16. However, yield responses varied among site years. The overall recommendation from this study would be to plant soybeans during the month of May at a profit-maximizing seed density, accounting for fluctuating grain price and seed cost. / May 2017

Members of the family Chenopodiaceae are routinely used as colonizer plant species to rehabilitate waste and tailings materials on mine sites in the Eastern Goldfields of Western Australia. These are specifically selected for their salt and drought tolerance and also because they are representative of the surrounding natural vegetation. Where these have been sown, competition between several species has been observed. The resulting plant community structure is typically lower in species diversity than the initial seed mixture. This study aimed to determine whether competition was occurring between five of the species commonly used and some of the mechanisms that determine community structure on the rehabilitated areas of waste material. Atriplex bunburyana, Atriplex codonocarpa, Maireana brevifolia, Maireana georgei and Enchylaena tomentosa were selected for the study, which was conducted in three parts. Firstly, different plant densities and species combinations were studied in the field and in a pot trial to determine whether or not competition was occurring and to determine the resources that the plants were competing for. The results of the field trial revealed that competition was occurring, but that it formed only one component of the complex interactions between plant species, density and soil characteristics (i.e. pH and salinity). The pot trial complemented the outcome of the field trial. In addition, it showed that competition was occurring, but was even more pronounced. This was most likely due to the lack of nutrients and the limited availability of space in the pots. / In the second part of this study, the ability of each species to survive and grow when subjected to adverse environmental conditions, such as low moisture availability, high salinity and low light availability, was examined in relation to competition. All five species were treated with different water regimes and soil salinity. Salt played an important role, especially for the Atriplex spp. and M. brevifolia, in ensuring survival when moisture availability was low. The effect of shade on the Maireana species and E. tomentosa was also researched after field observations suggested that M georgei was adversely affected when growing within the canopy of A. bunburyana. The pot trial showed that growth of M. georgei was affected by progressively more shade, whereas E. tomentosa was facilitated by shade. Maireana brevifolia exhibited significant tolerance to low light intensity. In the last part of this three-part study, all five chenopods were screened for allelopathy. Allelopathy may play an important role in determining community structure in successive plant generations. All chenopod species produced allelopathic substances, which were isolated from their leaves. The inhibition of seed germination was found to be speciesspecific and occurred only at certain concentrations. The seed of the Atriplex spp. was not affected by M. georgei and E. tomentosa extracts.

Salvia miltiorrhiza is a traditional Chinese herbal medicine widely used to prevent and treat cardiovascular and other diseases. With the increasing awareness and use of herbal medicines worldwide, there has been a rapid increase in the use of medicinal plants in the United States. Currently, the majority of medicinal plants used in the US are imported from foreign countries. However, increasing concerns over safety such as heavy metal and chemical contaminations pose significant challenges to US pharmaceutical and related industries in sourcing quality plant materials. It is critical for US industries to have access to high-quality medicinal plants, which provides an opportunity for US farmers to incorporate medicinal plants as an alternative crop. The purpose of this study is to evaluate and identify adaptive cultivars and develop best management practices for Salvia miltiorrhiza production in Mississippi. Salvia miltiorrhiza seeds from different sources were sown and grown in a greenhouse at Mississippi State University (MSU) in 2019, 2020, and 2021. Plants were transplanted into a container or field located at MSU North Farm to evaluate cultivar performance and production practices including different seed sources, fertilization (0, 2, 4, 6, or 8 g N per plant from NH4NO3), planting density (20×30, 20×45, 30×30, 30×45, 40×30, 40×45 cm), and timing of harvest (60, 120, 180 days after transplanting). The data were processed by ANOVA using the PROC GLM procedure. The three seed sources tested in this study (V1, V2, and V3) differed in germination rates, maximum root lengths, and maximum root diameters in both years (2019, 2020). V1 and V2 had higher germination rates than V3. In general, plants treated with 6 or 8 g N per plant and plants planted in 30×45 or 40×45 cm had better performance in shoot growth, root growth, and content of bioactive compounds, including tanshinone I, tanshinone IIA, cryptotanshinone, and salvianolic acid B. Shoot growth, root growth, and content of bioactive compounds increased with increasing days to harvest after transplanting.

O presente experimento teve por objetivos, avaliar a maneira como a planta de soja se adapta a diferentes arranjos espaciais (plasticidade) e identificar o arranjo espacial que melhor represente ou possibilite associar o manejo do cultivar MG/BR 46 (Conquista) com alta produtividade agrícola. O experimento foi conduzido em área experimental da Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP), no município de Piracicaba - SP, durante o ano agrícola de 2001/2002. Os tratamentos constaram de diferentes arranjos espaciais, variando-se e combinando-se 6 níveis do fator espaçamento entre linhas (0,20; 0,30; 0,40; 0,50; 0,60 e 0,70 m) e 5 níveis do fator densidade de plantas na linha visando as populações de 70.000; 140.000; 210.000; 280.000 e 350.000 plantas/ha, totalizando 30 tratamentos, delineados em blocos ao acaso com parcelas subdivididas e com três repetições. As características avaliadas foram: tempo de fechamento de entrelinhas; índice de área foliar; altura final de planta; altura de inserção da primeira vagem; número de ramificações; número de vagens por planta; número de grãos por planta; grau de acamamento; massa de 1000 sementes e produtividade agrícola. As principais conclusões são: a) o cultivar MG/BR 46 (Conquista), cultivado em linhas espaçadas entre si de 0,20 a 0,60 m, apresenta índice de área foliar máximo no estádio fenológico correspondente ao início da granação das vagens (R5); b) o número de vagens é o mais importante componente da produção por planta, por ser diretamente influenciado pelo arranjo populacional das plantas na área de produção; c) o cultivar MG/BR 46 (Conquista) apresenta ampla plasticidade, ajustando os seus componentes de produção aos diferentes arranjos espaciais, sem que ocorram significativas diferenças de produtividade; d) para cada combinação entre o espaçamento entre linhas e a densidade de plantas na linha existe uma população de plantas mais bem ajustada, que possibilita maior produtividade de grãos. / This research had as purposes to evaluate the soybean plant adaptations (plasticity) to different space arrangements and identify the best space arrangements for higher yields of cultivar MG/BR 46 (Conquista). The experiment was carried out at the experimental fields of Escola Superior de Agricultura "Luiz de Queiroz" (USP/ESALQ), São Paulo State University, in Piracicaba-SP, during the 2001/2002 growing season. The 30 treatments consisted of different space arrangements, combining 6 row spacing (0,20; 0,30; 0,40; 0,50; 0,60; 0,70 m) with 5 different population (70.000; 140.000; 210.000; 280.000; 350.000 plants/ha), in a complete randomized blocks design with subdivided plots and three replications. The evaluated characteristics were: time to achieve closed canopy; leaf area index; final plant height; height of the first pod; number of branches per plant; number of pods per plant; number of grains per plant; lodging; mass of 1,000 grains and yield. The main conclusions are: a) the cultivar MG/BR - 46 (Conquista) cultivated under 0,20 to 0,60 m row spacing shows a leaf area index maximum at the begging of seed-filling stage (R5); b) the number of pods is the best related component to yield per plant, being directly influenced by plant population; c) the cultivar MG/BR - 46 (Conquista) presents wide plasticity, adjusting its yield components to the different space arrangements, without significant yield changes; d) for each row spacing there is a better plant population to achieve higher yield.

Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-20Bitstream added on 2014-06-13T19:27:14Z : No. of bitstreams: 1 brachtvogel_el_me_botfca.pdf: 424866 bytes, checksum: 3ab3fe0b44645fcfe2ba5dd7b99a5f80 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / 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... / 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)

Made available in DSpace on 2014-06-11T19:22:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-01-29Bitstream added on 2014-06-13T19:07:36Z : No. of bitstreams: 1 souzaschlick_gd_me_botfca.pdf: 1162676 bytes, checksum: ea5596a01761141a74d3a02f1103f6ca (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / 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... / 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)

Resumo: 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. / Abstract: 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. / Orientador: Arthur Bernardes Cecílio Filho / Coorientador: José Carlos Barbosa / Banca: Leila Trevizan Braz / Banca: Paulo César Tavares de Melo / Banca: Rumy Goto / Banca: Joaquim Adelino de Azevedo Filho / Doutor

O presente experimento teve por objetivos, avaliar a maneira como a planta de soja se adapta a diferentes arranjos espaciais (plasticidade) e identificar o arranjo espacial que melhor represente ou possibilite associar o manejo do cultivar MG/BR 46 (Conquista) com alta produtividade agrícola. O experimento foi conduzido em área experimental da Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP), no município de Piracicaba - SP, durante o ano agrícola de 2001/2002. Os tratamentos constaram de diferentes arranjos espaciais, variando-se e combinando-se 6 níveis do fator espaçamento entre linhas (0,20; 0,30; 0,40; 0,50; 0,60 e 0,70 m) e 5 níveis do fator densidade de plantas na linha visando as populações de 70.000; 140.000; 210.000; 280.000 e 350.000 plantas/ha, totalizando 30 tratamentos, delineados em blocos ao acaso com parcelas subdivididas e com três repetições. As características avaliadas foram: tempo de fechamento de entrelinhas; índice de área foliar; altura final de planta; altura de inserção da primeira vagem; número de ramificações; número de vagens por planta; número de grãos por planta; grau de acamamento; massa de 1000 sementes e produtividade agrícola. As principais conclusões são: a) o cultivar MG/BR 46 (Conquista), cultivado em linhas espaçadas entre si de 0,20 a 0,60 m, apresenta índice de área foliar máximo no estádio fenológico correspondente ao início da granação das vagens (R5); b) o número de vagens é o mais importante componente da produção por planta, por ser diretamente influenciado pelo arranjo populacional das plantas na área de produção; c) o cultivar MG/BR 46 (Conquista) apresenta ampla plasticidade, ajustando os seus componentes de produção aos diferentes arranjos espaciais, sem que ocorram significativas diferenças de produtividade; d) para cada combinação entre o espaçamento entre linhas e a densidade de plantas na linha existe uma população de plantas mais bem ajustada, que possibilita maior produtividade de grãos. / This research had as purposes to evaluate the soybean plant adaptations (plasticity) to different space arrangements and identify the best space arrangements for higher yields of cultivar MG/BR 46 (Conquista). The experiment was carried out at the experimental fields of Escola Superior de Agricultura "Luiz de Queiroz" (USP/ESALQ), São Paulo State University, in Piracicaba-SP, during the 2001/2002 growing season. The 30 treatments consisted of different space arrangements, combining 6 row spacing (0,20; 0,30; 0,40; 0,50; 0,60; 0,70 m) with 5 different population (70.000; 140.000; 210.000; 280.000; 350.000 plants/ha), in a complete randomized blocks design with subdivided plots and three replications. The evaluated characteristics were: time to achieve closed canopy; leaf area index; final plant height; height of the first pod; number of branches per plant; number of pods per plant; number of grains per plant; lodging; mass of 1,000 grains and yield. The main conclusions are: a) the cultivar MG/BR – 46 (Conquista) cultivated under 0,20 to 0,60 m row spacing shows a leaf area index maximum at the begging of seed-filling stage (R5); b) the number of pods is the best related component to yield per plant, being directly influenced by plant population; c) the cultivar MG/BR – 46 (Conquista) presents wide plasticity, adjusting its yield components to the different space arrangements, without significant yield changes; d) for each row spacing there is a better plant population to achieve higher yield.