RESUMO

The carbonized rice husk (CRH) is an agro-industrial residue with great potential for use in mixtures with other substrates for the production of vegetable seedlings. Thus, the purpose of this study was to evaluate the effect of the addition of CRH to the commercial substrate for the production of greenhouse seedlings. The evaluated vegetables were lettuce, broccoli and mustard, cultivated in polystyrene foam (Styrofoam®) trays. Five treatments were evaluated: 100% of the commercial substrate (CS); 25% of CRH + 75% of CS; 50% of CRH + 50% of CS; 75% CRH + 25% CS; and 100% CRH, in a completely randomized design with twelve replicates. The substrates were evaluated for their physical and chemical characteristics. The morphometric evaluations were: number of leaves per plant, plant height, shoot fresh matter yield, root length, and shoot and root dry matter yield. The data were submitted to regression analysis, and the homogeneity of the variance between the experiments was confirmed by the Cochran test. With the addition of CRH to the substrate, there was an increase in total porosity and P content and a reduction in density, water holding capacity, cation exchange capacity, electrical conductivity, and N, K, S, Ca and Mg contents. The carbonized rice husk added to the commercial substrate is a viable alternative for the production of lettuce, broccoli and mustard seedlings. The quality of the vegetable seedlings was higher when there was a 25% CRH + 75% CS mixture.

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ABSTRACT The analysis of nematode communities allows inferring consequences of management practices on the soil food web. We studied the taxonomic structure of nematode communities in preserved areas of the Atlantic forest (native forest = NF) in Ponta Grossa, Paraná State, Brazil, and in three different agroecosystems in neighboring areas to assess the effect of agricultural land use on nematode assemblages. Agroecosystems were located in a red latosol cropped during 30 years under conventional tillage (CT), no-tillage (NT), and minimal tillage (MT). We collected ten composite soil samples in each area in the summer. Nematodes were extracted by Baermann funnel and fixed with formalin. Subsequently, individuals were classified into taxonomic groups and counted on a Peters slide to determine densities of each taxon. Plant-parasitic and free-living nematodes were classified at the genus level. Data were analyzed with the parameters abundance, Bray & Curtis, Shannon-Weaver, and Simpson indexes. We recorded 35 genera and abundance of nematodes in MT and NT areas was more similar. Higher richness was observed in NF in relation to cropped areas, especially under NT and CT. The PCA and clustering analyses from both nematode communities and soil chemical characteristics showed that MT and CT were more similar and NT was clustered near NF. The replacement of native vegetation by cropping systems caused a reduction of nematode diversity, demonstrating the influence of agricultural practices on nematode communities.

RESUMO

The analysis of nematode communities allows inferring consequences of management practices on the soil food web. We studied the taxonomic structure of nematode communities in preserved areas of the Atlantic forest (native forest = NF) in Ponta Grossa, Paraná State, Brazil, and in three different agroecosystems in neighboring areas to assess the effect of agricultural land use on nematode assemblages. Agroecosystems were located in a red latosol cropped during 30 years under conventional tillage (CT), no-tillage (NT), and minimal tillage (MT). We collected ten composite soil samples in each area in the summer. Nematodes were extracted by Baermann funnel and fixed with formalin. Subsequently, individuals were classified into taxonomic groups and counted on a Peters slide to determine densities of each taxon. Plant-parasitic and free-living nematodes were classified at the genus level. Data were analyzed with the parameters abundance, Bray & Curtis, Shannon-Weaver, and Simpson indexes. We recorded 35 genera and abundance of nematodes in MT and NT areas was more similar. Higher richness was observed in NF in relation to cropped areas, especially under NT and CT. The PCA and clustering analyses from both nematode communities and soil chemical characteristics showed that MT and CT were more similar and NT was clustered near NF. The replacement of native vegetation by cropping systems caused a reduction of nematode diversity, demonstrating the influence of agricultural practices on nematode communities.

Assuntos

RESUMO

The analysis of nematode communities allows inferring consequences of management practices on the soil food web. We studied the taxonomic structure of nematode communities in preserved areas of the Atlantic forest (native forest = NF) in Ponta Grossa, Paraná State, Brazil, and in three different agroecosystems in neighboring areas to assess the effect of agricultural land use on nematode assemblages. Agroecosystems were located in a red latosol cropped during 30 years under conventional tillage (CT), no-tillage (NT), and minimal tillage (MT). We collected ten composite soil samples in each area in the summer. Nematodes were extracted by Baermann funnel and fixed with formalin. Subsequently, individuals were classified into taxonomic groups and counted on a Peters slide to determine densities of each taxon. Plant-parasitic and free-living nematodes were classified at the genus level. Data were analyzed with the parameters abundance, Bray & Curtis, Shannon-Weaver, and Simpson indexes. We recorded 35 genera and abundance of nematodes in MT and NT areas was more similar. Higher richness was observed in NF in relation to cropped areas, especially under NT and CT. The PCA and clustering analyses from both nematode communities and soil chemical characteristics showed that MT and CT were more similar and NT was clustered near NF. The replacement of native vegetation by cropping systems caused a reduction of nematode diversity, demonstrating the influence of agricultural practices on nematode communities.(AU)

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RESUMO

The objective of this work was to evaluate the effects of various Si sources currently used in studies of Si doses in nutrient solutions on dry matter yield and the accumulation of nutrients and Si in rice plants. Treatments of rice plants with three sources of Si (monossilicic acid, sodium metasilicate, potassium metasilicate) and a treatment without Si were allocated in a randomized block design with ten replications. After 39 days in the nutrient solution, the following traits were evaluated: leaf area, leaf specific mass, dry matter yield of roots and shoots, and levels of K, Na, and Si in leaves and roots. Si increased leaf area, leaf specific mass, and dry matter yield of shoots and roots regardless of the Si source. Levels of Si in leaves and roots were significantly higher in relation to the control treatment but no significant difference among Si sources was identified. It was also observed that K and Na were adequately balanced across the treatments. Thus, a cheaper and easier to obtain Si source, such as sodium metasilicate and potassium metasilicate, may be chosen to carry out studies of Si additions to nutrient solutions.

O objetivo deste trabalho foi avaliar fontes de Si utilizadas atualmente nos estudos com Si em solução nutritiva, na produção de massa seca e acúmulo de nutrientes e Si em plantas de arroz. Foram avaliadas fontes de Si (ácido monossilícico, metassilicato de sódio, metassilicato de potássio) e um tratamento sem aplicação desse elemento, em delineamento em blocos casualizados, com dez repetições, utilizando a cultura do arroz. Após 39 dias em solução nutritiva com os tratamentos foram avaliadas a área foliar, massa foliar específica, produção de matéria seca das raízes e da parte aérea, teores de K, Na e Si nas folhas e nas raízes. O Si aumentou a área foliar, a massa foliar específica e produção de massa seca da parte aérea e raízes, independentemente da fonte utilizada. Os teores de Si nas folhas e nas raízes foram significativamente maiores em relação à testemunha e não houve diferença entre as fontes utilizadas. Observou-se também que o balanceamento de K e Na entre os tratamentos foi adequado. Desse modo, pode-se escolher uma fonte de menor custo e mais fácil obtenção como o metassilicato de sódio e o metassilicato de potássio para a execução de trabalhos que avaliem a adição de Si à solução nutritiva.

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RESUMO

Anatomical modifications of leaves and other organs associated with mineral nutrition have been observed in many plants. However, little is known about the quantitative effects of Si and Mn on the anatomy of plant leaves, especially in rice. This study aimed to quantify the tissue thickness of rice leaves and the density of silica bodies in rice leaves grown in a nutrient solution supplemented with Si and Mn and evaluate the possible effects of Si on Mn toxicity. Treatments were arranged in a 2×3 factorial scheme = six combinations of treatments, two doses of Si (0 and 2 mmol L-1), and three doses of Mn (0.5, 2.5, and 10 µmol L-1) in randomized complete block design with four replications. After 39 days in the nutrient solution with the respective treatments, anatomical and micromorphometric measures of the leaf blade were carried out to determine the thickness and area of leaf tissues. The data were submitted to analysis of variance (ANOVA) and Tukeys multiple comparisons test of means. The abaxial and adaxial epidermal thickness, as well as the density of silica bodies increased with the addition of Si to the nutrient solution. This study demonstrated that Si reduced the number of vascular bundles and Mn reduced the thickness of the chlorenchyma with increasing doses. Manganese doses of up to 10 µmol L-1 do not inhibit the uptake and deposition of silicon in rice leaf tissues. Higher Si concentration in the solution caused anatomical changes in the leaf, which was associated with a possible alleviation of Mn toxicity due to the higher concentration of Si in plants since this effect was observed mainly when Si was present in the nutrient solution.(AU)

Modificações anatômicas foliares e de outros órgãos, relacionadas à nutrição mineral, têm sido observadas em muitos vegetais. No entanto, sabe-se pouco sobre os efeitos quantitativos do Si e do Mn na anatomia foliar das plantas, especialmente o arroz. Com este estudo foi quantificado a espessura dos tecidos e a densidade de corpos silicosos de folhas de arroz cultivado em solução nutritiva com doses de Si e Mn e avaliar a possível ação do Si como atenuante à toxidez de Mn. Os tratamentos foram dispostos em um esquema fatorial 2×3 = seis combinações de tratamentos, sendo duas doses de Si (0 e 2 mmol L-1) e três doses de Mn (0,5; 2,5 e 10 µmol L-1), em delineamento de blocos completos casualizados, com quatro repetições. Após 39 dias em solução nutritiva com os respectivos tratamentos, foi realizado o estudo anatômico micromorfométrico do limbo das folhas e determinadas as espessuras e áreas dos tecidos foliares. Os dados foram submetidos à análise de variância (ANOVA) e o teste de comparações múltiplas para as médias pelo teste de Tukey. As espessuras da epiderme das faces abaxial e adaxial das folhas de arroz aumentaram com a adição de Si à solução nutritiva bem como a densidade de corpos silicosos. Verificou-se que o Si reduziu a quantidade de feixes vasculares e o Mn reduziu a espessura do parênquima clorofiliano com o aumento da sua dose na solução nutritiva. Doses de Mn de até 10 µmol L-1 não inibem a absorção e deposição de silício em tecidos foliares de arroz. O aumento da concentração de Si na solução causou alterações anatômicas dos órgãos foliares do arroz, o que foi associado a uma possível atenuação da toxidez de Mn devido à maior concentração de Si nas plantas, uma vez que esse efeito foi observado, principalmente, quando o Si estava presente na solução nutritiva.(AU)

Assuntos

RESUMO

Anatomical modifications of leaves and other organs associated with mineral nutrition have been observed in many plants. However, little is known about the quantitative effects of Si and Mn on the anatomy of plant leaves, especially in rice. This study aimed to quantify the tissue thickness of rice leaves and the density of silica bodies in rice leaves grown in a nutrient solution supplemented with Si and Mn and evaluate the possible effects of Si on Mn toxicity. Treatments were arranged in a 2×3 factorial scheme = six combinations of treatments, two doses of Si (0 and 2 mmol L-1), and three doses of Mn (0.5, 2.5, and 10 µmol L-1) in randomized complete block design with four replications. After 39 days in the nutrient solution with the respective treatments, anatomical and micromorphometric measures of the leaf blade were carried out to determine the thickness and area of leaf tissues. The data were submitted to analysis of variance (ANOVA) and Tukeys multiple comparisons test of means. The abaxial and adaxial epidermal thickness, as well as the density of silica bodies increased with the addition of Si to the nutrient solution. This study demonstrated that Si reduced the number of vascular bundles and Mn reduced the thickness of the chlorenchyma with increasing doses. Manganese doses of up to 10 µmol L-1 do not inhibit the uptake and deposition of silicon in rice leaf tissues. Higher Si concentration in the solution caused anatomical changes in the leaf, which was associated with a possible alleviation of Mn toxicity due to the higher concentration of Si in plants since this effect was observed mainly when Si was present in the nutrient solution.

Modificações anatômicas foliares e de outros órgãos, relacionadas à nutrição mineral, têm sido observadas em muitos vegetais. No entanto, sabe-se pouco sobre os efeitos quantitativos do Si e do Mn na anatomia foliar das plantas, especialmente o arroz. Com este estudo foi quantificado a espessura dos tecidos e a densidade de corpos silicosos de folhas de arroz cultivado em solução nutritiva com doses de Si e Mn e avaliar a possível ação do Si como atenuante à toxidez de Mn. Os tratamentos foram dispostos em um esquema fatorial 2×3 = seis combinações de tratamentos, sendo duas doses de Si (0 e 2 mmol L-1) e três doses de Mn (0,5; 2,5 e 10 µmol L-1), em delineamento de blocos completos casualizados, com quatro repetições. Após 39 dias em solução nutritiva com os respectivos tratamentos, foi realizado o estudo anatômico micromorfométrico do limbo das folhas e determinadas as espessuras e áreas dos tecidos foliares. Os dados foram submetidos à análise de variância (ANOVA) e o teste de comparações múltiplas para as médias pelo teste de Tukey. As espessuras da epiderme das faces abaxial e adaxial das folhas de arroz aumentaram com a adição de Si à solução nutritiva bem como a densidade de corpos silicosos. Verificou-se que o Si reduziu a quantidade de feixes vasculares e o Mn reduziu a espessura do parênquima clorofiliano com o aumento da sua dose na solução nutritiva. Doses de Mn de até 10 µmol L-1 não inibem a absorção e deposição de silício em tecidos foliares de arroz. O aumento da concentração de Si na solução causou alterações anatômicas dos órgãos foliares do arroz, o que foi associado a uma possível atenuação da toxidez de Mn devido à maior concentração de Si nas plantas, uma vez que esse efeito foi observado, principalmente, quando o Si estava presente na solução nutritiva.

Assuntos

RESUMO

Soil mesofauna consists of small invertebrates that live in the soil or litter and are sensitive to climatic conditions, management systems, plant cover and physical or chemical soil attributes. These organisms are active in the cycling of nutrients, since they fragment the organic matter hereby accelerating microbial decomposition. The aim of this study was to evaluate the invertebrate community in no-tillage, conventional tillage, minimum tillage and secondary forest in regeneration to determine the relationship of mesofauna to litter, soil attributes, management and seasonality. Therefore, ten soil samples in each system and eight litter samples in no-tillage and the forest were taken over four seasons. These samples remained in Berlese extractors for seven days for quantification and identification of mesofauna. For each fauna sample, soil samples were collected for chemical analysis. Next, diversity indices and richness were calculated and multivariate analyses were used to establish relationships between the mesofauna, soil attributes and management. In the soil, mites were more abundant in the agricultural systems than in the forest, but the springtails, sensitive to low moisture and high temperature, were more abundant in the forest. Diversity and richness were higher in soil from the forest than under other systems. In no-tillage, there was a lower density of soil mesofauna, however, under this system, many invertebrates live in litter, since litter is the main food resource for them. In forest litter, we found lower invertebrate density and higher diversity than in no-tillage. Carbon, basic cations, pH, Al and V% were the attributes that best explained fauna variability in the systems.(AU)

RESUMO

Soil mesofauna consists of small invertebrates that live in the soil or litter and are sensitive to climatic conditions, management systems, plant cover and physical or chemical soil attributes. These organisms are active in the cycling of nutrients, since they fragment the organic matter hereby accelerating microbial decomposition. The aim of this study was to evaluate the invertebrate community in no-tillage, conventional tillage, minimum tillage and secondary forest in regeneration to determine the relationship of mesofauna to litter, soil attributes, management and seasonality. Therefore, ten soil samples in each system and eight litter samples in no-tillage and the forest were taken over four seasons. These samples remained in Berlese extractors for seven days for quantification and identification of mesofauna. For each fauna sample, soil samples were collected for chemical analysis. Next, diversity indices and richness were calculated and multivariate analyses were used to establish relationships between the mesofauna, soil attributes and management. In the soil, mites were more abundant in the agricultural systems than in the forest, but the springtails, sensitive to low moisture and high temperature, were more abundant in the forest. Diversity and richness were higher in soil from the forest than under other systems. In no-tillage, there was a lower density of soil mesofauna, however, under this system, many invertebrates live in litter, since litter is the main food resource for them. In forest litter, we found lower invertebrate density and higher diversity than in no-tillage. Carbon, basic cations, pH, Al and V% were the attributes that best explained fauna variability in the systems.

RESUMO

Spatial variability of chemical attributes in soils tends to increase under the no-tillage system. However, data regarding this variability under this system for a long time are scarce. This study aimed to evaluate the spatial variability of phosphorus (P), organic matter (OM), pH, aluminum (Al), calcium (Ca), magnesium (Mg), potassium (K), base saturation (V%), sulfur (SO42-), and micronutrients: boron (B), iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) in soil with conventional tillage and no-tillage treatments for more than three decades in order to optimize fertilization and maintain soil conservation. Samples of Rhodic Hapludox were collected at 0.00­0.20 m depth. Sampling points were spaced 5 m apart, totaling 100 points. All sampling points were georeferenced according to the tillage system. Samples were analyzed chemically. Semivariograms and kriging were used in descriptive statistics and geostatistics analyses of the results. Only micronutrients and P presented distinct spatial variability between the treatments. Most of the analyzed chemical attributes presented spatial dependency in both tillage systems, which may help determine the best form of sampling and indicate adequate fertilization. According to semivariogram range values of OM, Mg, and K, the same sampling strategy may be adopted for analysis in both tillage systems, yet for Al, Ca, and pH the strategy should be specific

A variabilidade espacial dos atributos químicos tende a aumentar em solos sob sistema plantio direto. No entanto faltam informações sobre essa variabilidade em solos submetidos a esse sistema por longo período.Este estudo objetivou avaliar a variabilidade espacial do fósforo (P), matéria orgânica (MO), pH, alumínio (Al), cálcio (Ca), magnésio (Mg), potássio (K), saturação por bases (V%), enxofre (SO42-) e dos micronutrientes boro (B), ferro (Fe), cobre (Cu), manganês (Mn) e zinco (Zn) em plantio direto e plantio convencional adotados há mais de três décadas, como forma de otimizar a aplicação de fertilizantes e preservar a adoção do manejo conservacionista. Amostras de Latossolo Vermelho distrófico coletadas na profundidade de 0,00 - 0,20 m, e 5 m de distância entre os 100 pontos amostrados e georreferenciados por manejo, foramanalisadas quimicamente e os resultados submetidos à estatística descritiva e à geoestatística, através do estudo de semivariogramas e krigagem. Apenas os micronutrientes e o P apresentaram variabilidade espacial distinta entre os manejos. A maioria dos atributos químicos estudados apresentou dependência espacial em ambos os sistemas de manejo, o que pode determinar a melhor forma de amostragem e indicar a adubação adequada. De acordo com os alcances atribuídos aos semivariogramas, para MO, Mg e K pode-se adotar a mesma estratégia de amostragem para análise em ambos sistemas de manejo e para Al, Ca e pH deve ser específica

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RESUMO

Leakage of transformer dielectric fluids is a concern because it may pose a risk of environmental contamination. In this study, the deleterious effects of vegetable and mineral dielectric fluids in water bodies were investigated using biodegradability and acute toxicity tests with Danio rerio and Artemia salina. Regarding biodegradability, all four tested vegetable oils (soy, canola, sunflower and crambe) were considered as easily biodegradable, presenting degradation rates significantly higher than the Lubrax-type mineral fluid. Acute toxicity tests were performed in two separate experiments without solution renewal. In the first experiment, the organisms were exposed in direct contact to different concentrations of vegetable (soy) and mineral (Lubrax) oils. Total soy-type vegetable oil has a higher toxic effect than Lubrax-type mineral oil. In the second experiment, the organisms were exposed to increasing percentages of the water-soluble fraction (WSF) of both types of tested oils. The LC50 values for the water-soluble fraction of the Lubrax-type mineral oil were about 5 and 8% for the Danio rerio and Artemia salina bioindicators, respectively, whereas the vegetable oil did not present toxic effect, regardless of its WSF. These results have shown that a strict selection of dielectric fluids and monitoring the leakage from power transformers is a serious duty of environmental protection agencies.

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ABSTRACT: Growth retardants, such as paclobutrazol, reduce plant height, and thus enable commercialization of larger ornamental plants in pots. The aim of this research was to evaluate the size, yield and flower quality of two rose cultivars as a function of various paclobutrazol applications to growing substrate. Treatments consisted of two cultivars (Yellow Terrazza® and Shiny Terrazza®) planted in plastic pots and five paclobutrazol doses (0, 0.5, 1.0, 1.5, and 2.0mg pot-1). The experiment was carried out in a greenhouse. Experimental design was randomized blocks with four replications. The following traits were evaluated: plant height; stem diameter, number of flowers and leaves of floral stem; length of flower bud; floral cycle, leaf area; flower diameter and floral longevity; chlorophyll content in leaves; and yield. Paclobutrazol improved the quality and esthetics of flowers of both cultivars. It also reduced leaf dry matter production, plant height, flower height and diameter and increased chlorophyll content and flower longevity. Paclobutrazol effectively reduced plant height, producing a harmonious relationship between the plant and the pot, without phytotoxicity. Therefore, we suggested applying 2.0mgpot-1 of paclobutrazol to the substrate of Yellow Terrazza® and Shiny Terrazza® rose cultivars.

RESUMO: A aplicação de retardantes de crescimento, como o paclobutrazol, reduz a altura das plantas e tem possibilitado a comercialização de algumas espécies ornamentais de maior porte em vasos. Objetivou-se com este estudo avaliar porte, produção e qualidade da flor de duas cultivares de roseira cultivadas em vaso em função da aplicação de doses de paclobutrazol no substrato. Os tratamentos foram dispostos em esquema fatorial 2x5, com duas cultivares de roseira (Yellow Terrazza® e Shiny Terrazza®) e cinco doses de paclobutrazol (0; 0,5; 1,0; 1,5 e 2,0 mg vaso-1). O experimento foi conduzido em vasos plásticos sob ambiente protegido, em delineamento de blocos ao acaso com quatro repetições. Foram avaliados a altura das plantas; diâmetro, número de flores e folhas da haste floral; comprimento do botão floral; ciclo, área foliar; diâmetro floral e longevidade floral; teor de clorofila nas folhas e produção. A aplicação de paclobutrazol no substrato proporcionou melhoria na qualidade floral e estética de ambas cultivares de roseira. Também reduziu a produção de matéria seca foliar, altura da planta e diâmetro floral e aumentou o teor de clorofila e a longevidade floral. O paclobutrazol foi eficiente em reduzir a altura, conferindo uma relação harmoniosa entre a planta e o vaso, sem causar sintomas de toxidez e alterações morfológicas. Sugere-se a aplicação no substrato de 2mg vaso-1 de paclobutrazol para as cultivares de roseira Yellow Terrazza® e Shiny Terrazza® produzidas em vasos.

RESUMO

Growth retardants, such as paclobutrazol, reduce plant height, and thus enable commercialization of larger ornamental plants in pots. The aim of this research was to evaluate the size, yield and flower quality of two rose cultivars as a function of various paclobutrazol applications to growing substrate. Treatments consisted of two cultivars (Yellow Terrazza® and Shiny Terrazza®) planted in plastic pots and five paclobutrazol doses (0, 0.5, 1.0, 1.5, and 2.0mg pot-1). The experiment was carried out in a greenhouse. Experimental design was randomized blocks with four replications. The following traits were evaluated: plant height; stem diameter, number of flowers and leaves of floral stem; length of flower bud; floral cycle, leaf area; flower diameter and floral longevity; chlorophyll content in leaves; and yield. Paclobutrazol improved the quality and esthetics of flowers of both cultivars. It also reduced leaf dry matter production, plant height, flower height and diameter and increased chlorophyll content and flower longevity. Paclobutrazol effectively reduced plant height, producing a harmonious relationship between the plant and the pot, without phytotoxicity. Therefore, we suggested applying 2.0mgpot-1 of paclobutrazol to the substrate of Yellow Terrazza® and Shiny Terrazza® rose cultivars.(AU)

A aplicação de retardantes de crescimento, como o paclobutrazol, reduz a altura das plantas e tem possibilitado a comercialização de algumas espécies ornamentais de maior porte em vasos. Objetivou-se com este estudo avaliar porte, produção e qualidade da flor de duas cultivares de roseira cultivadas em vaso em função da aplicação de doses de paclobutrazol no substrato. Os tratamentos foram dispostos em esquema fatorial 2x5, com duas cultivares de roseira (Yellow Terrazza® e Shiny Terrazza®) e cinco doses de paclobutrazol (0; 0,5; 1,0; 1,5 e 2,0 mg vaso-1). O experimento foi conduzido em vasos plásticos sob ambiente protegido, em delineamento de blocos ao acaso com quatro repetições. Foram avaliados a altura das plantas; diâmetro, número de flores e folhas da haste floral; comprimento do botão floral; ciclo, área foliar; diâmetro floral e longevidade floral; teor de clorofila nas folhas e produção. A aplicação de paclobutrazol no substrato proporcionou melhoria na qualidade floral e estética de ambas cultivares de roseira. Também reduziu a produção de matéria seca foliar, altura da planta e diâmetro floral e aumentou o teor de clorofila e a longevidade floral. O paclobutrazol foi eficiente em reduzir a altura, conferindo uma relação harmoniosa entre a planta e o vaso, sem causar sintomas de toxidez e alterações morfológicas. Sugere-se a aplicação no substrato de 2mg vaso-1 de paclobutrazol para as cultivares de roseira Yellow Terrazza® e Shiny Terrazza® produzidas em vasos.(AU)

Assuntos

RESUMO

ABSTRACT: Growth retardants, such as paclobutrazol, reduce plant height, and thus enable commercialization of larger ornamental plants in pots. The aim of this research was to evaluate the size, yield and flower quality of two rose cultivars as a function of various paclobutrazol applications to growing substrate. Treatments consisted of two cultivars (Yellow Terrazza® and Shiny Terrazza®) planted in plastic pots and five paclobutrazol doses (0, 0.5, 1.0, 1.5, and 2.0mg pot-1). The experiment was carried out in a greenhouse. Experimental design was randomized blocks with four replications. The following traits were evaluated: plant height; stem diameter, number of flowers and leaves of floral stem; length of flower bud; floral cycle, leaf area; flower diameter and floral longevity; chlorophyll content in leaves; and yield. Paclobutrazol improved the quality and esthetics of flowers of both cultivars. It also reduced leaf dry matter production, plant height, flower height and diameter and increased chlorophyll content and flower longevity. Paclobutrazol effectively reduced plant height, producing a harmonious relationship between the plant and the pot, without phytotoxicity. Therefore, we suggested applying 2.0mgpot-1 of paclobutrazol to the substrate of Yellow Terrazza® and Shiny Terrazza® rose cultivars.

RESUMO: A aplicação de retardantes de crescimento, como o paclobutrazol, reduz a altura das plantas e tem possibilitado a comercialização de algumas espécies ornamentais de maior porte em vasos. Objetivou-se com este estudo avaliar porte, produção e qualidade da flor de duas cultivares de roseira cultivadas em vaso em função da aplicação de doses de paclobutrazol no substrato. Os tratamentos foram dispostos em esquema fatorial 2x5, com duas cultivares de roseira (Yellow Terrazza® e Shiny Terrazza®) e cinco doses de paclobutrazol (0; 0,5; 1,0; 1,5 e 2,0 mg vaso-1). O experimento foi conduzido em vasos plásticos sob ambiente protegido, em delineamento de blocos ao acaso com quatro repetições. Foram avaliados a altura das plantas; diâmetro, número de flores e folhas da haste floral; comprimento do botão floral; ciclo, área foliar; diâmetro floral e longevidade floral; teor de clorofila nas folhas e produção. A aplicação de paclobutrazol no substrato proporcionou melhoria na qualidade floral e estética de ambas cultivares de roseira. Também reduziu a produção de matéria seca foliar, altura da planta e diâmetro floral e aumentou o teor de clorofila e a longevidade floral. O paclobutrazol foi eficiente em reduzir a altura, conferindo uma relação harmoniosa entre a planta e o vaso, sem causar sintomas de toxidez e alterações morfológicas. Sugere-se a aplicação no substrato de 2mg vaso-1 de paclobutrazol para as cultivares de roseira Yellow Terrazza® e Shiny Terrazza® produzidas em vasos.

RESUMO

The aim of this work was to evaluate morphological and anatomical alterations in leaves of Yellow Terrazza® and Red White Terrazza® pot roses sprayed with paclobutrazol (0, 40, 60, 80 mg L-1) and daminozide (0, 2000, 4000, 6000, 8000 mg L-1). The experiments were conducted under greenhouse conditions using a factorial treatment design (cultivars x growth retardant doses) with five replications and experimental units arranged in randomized blocks. Cv. Yellow Terrazza ® presented higher plants, greater floral diameter and leaf area than cv. Red White Terrazza ®. Plant height, leaf area, and flower diameter decreased linearly with paclobutrazol and daminozide doses. In addition, paclobutrazol and daminozide applications changed leaf tissue proportions by increasing the thickness of leaf blade, mesophyll, palisade parenchyma, and spongy parenchyma but did not influence the thickness of leaf epidermis.(AU)

Objetivou-se com esse trabalho avaliar características fitotécnicas e alterações anatômicas quantitativas nas folhas de duas cultivares de roseira (Yellow Terrazza® e Red White Terrazza®), cultivadas em vaso em função da pulverização foliar de doses de paclobutrazol (0, 40, 60, 80 mg L-1) em um experimento e doses de daminozide (0, 2000, 4000, 6000, 8000 mg L-1) em outro. Os experimentos foram conduzidos em ambiente protegido e os tratamentos dispostos em esquema fatorial (cultivares x doses dos retardantes), em delineamento de blocos casualizados com cinco repetições. A cultivar Yellow Terrazza® apresentou plantas com maior altura, diâmetro floral e área foliar que a Red White Terrazza®. O aumento da dose dos retardantes nas duas cultivares reduziu altura e área foliar, promoveu mudanças na proporção dos tecidos, aumentou a espessura da lâmina foliar, mesofilo e dos parênquimas paliçádico e lacunoso. Os retardantes não influenciaram a espessura das epidermes das cultivares. O tecido parenquimático das cultivares apresenta plasticidade com aplicação dos retardantes.(AU)

Assuntos

RESUMO

The aim of this work was to evaluate morphological and anatomical alterations in leaves of Yellow Terrazza® and Red White Terrazza® pot roses sprayed with paclobutrazol (0, 40, 60, 80 mg L-1) and daminozide (0, 2000, 4000, 6000, 8000 mg L-1). The experiments were conducted under greenhouse conditions using a factorial treatment design (cultivars x growth retardant doses) with five replications and experimental units arranged in randomized blocks. Cv. Yellow Terrazza ® presented higher plants, greater floral diameter and leaf area than cv. Red White Terrazza ®. Plant height, leaf area, and flower diameter decreased linearly with paclobutrazol and daminozide doses. In addition, paclobutrazol and daminozide applications changed leaf tissue proportions by increasing the thickness of leaf blade, mesophyll, palisade parenchyma, and spongy parenchyma but did not influence the thickness of leaf epidermis.

Objetivou-se com esse trabalho avaliar características fitotécnicas e alterações anatômicas quantitativas nas folhas de duas cultivares de roseira (Yellow Terrazza® e Red White Terrazza®), cultivadas em vaso em função da pulverização foliar de doses de paclobutrazol (0, 40, 60, 80 mg L-1) em um experimento e doses de daminozide (0, 2000, 4000, 6000, 8000 mg L-1) em outro. Os experimentos foram conduzidos em ambiente protegido e os tratamentos dispostos em esquema fatorial (cultivares x doses dos retardantes), em delineamento de blocos casualizados com cinco repetições. A cultivar Yellow Terrazza® apresentou plantas com maior altura, diâmetro floral e área foliar que a Red White Terrazza®. O aumento da dose dos retardantes nas duas cultivares reduziu altura e área foliar, promoveu mudanças na proporção dos tecidos, aumentou a espessura da lâmina foliar, mesofilo e dos parênquimas paliçádico e lacunoso. Os retardantes não influenciaram a espessura das epidermes das cultivares. O tecido parenquimático das cultivares apresenta plasticidade com aplicação dos retardantes.

Assuntos

RESUMO

Silicon applied to substrate for greenhouse cultivation of ornamental pot plants can improve the yield and quality of the ornamental product; however, the possible anatomical and physiological changes caused by Si have to be assessed. Therefore, the objective of this study was to evaluate gas exchange rates and leaf anatomy of ornamental sunflower 'Sunbright' grown on a substrate amended with Si. The experiment was conducted in a greenhouse, and the treatments consisted of sunflower plants cultivated in pots containing 600 g substrate fertilized with Si at rates of 0, 0.25, 0.50, 0.75, and 1.00 g kg-1. The treatments were arranged in randomized complete block design and four replications. Samples from the middle region of leaf blades in the sixth pair from the apex were collected and analyzed morphometrically. Epidermal trichomes were analyzed using diaphanization and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The following traits were determined: leaf blade thickness, palisade and spongy parenchyma thickness, mesophyll thickness, and abaxial and adaxial epidermis thickness. Net photosynthesis, stomatal conductance and transpiration rates were determined in the fifth leaf at the beginning of the flowering stage by an infrared gas analyzer. The data were subjected to ANOVA and regression analyses. The results indicate that the ornamental sunflower 'Sunbright' accumulates Si in leaf trichomes, and that leaf thickness is not affected by Si application to the substrate; however, transpiration rates decrease while net photosynthesis rate and stomatal conductance increase in response to Si application.

A utilização de silício no cultivo de algumas plantas ornamentais em vasos e em casa de vegetação tem proporcionado aumento na produção e qualidade do produto final. No entanto, possíveis alterações fisiológicas e anatômicas causadas por este elemento precisam ser avaliadas. Objetivou-se com este estudo avaliar trocas gasosas e anatomia foliar de girassol ornamental cv. Sunbright em resposta à aplicação de doses de Si no substrato. O experimento foi conduzido em casa de vegetação e os tratamentos consistiram em cinco doses de Si: 0; 0,25; 0,50; 0,75 e 1,00 g kg-1, em DBC, com quatro repetições. Para o estudo anatômico, amostras da região mediana do limbo do sexto par de folhas a partir do ápice foram coletadas e análises morfométricas realizadas. Tricomas da epiderme foram analisados usando-se as técnicas de diafanização e microscopia eletrônica de varredura acoplada a raios-X. Determinou-se a espessura da lâmina foliar, dos parênquimas paliçádico e lacunoso, do mesofilo e das faces abaxial e adaxial da epiderme. A taxa fotossintética líquida, condutância estomática e taxa de transpiração foram determinadas com o auxílio de um analisador de gás no infravermelho. Os dados foram submetidos à ANOVA e análise de regressão. O girassol ornamental cv. Sunbright acumula Si nos tricomas foliares. A espessura dos tecidos foliares do girassol não foi influenciada pela aplicação do Si ao substrato. Entretanto, houve redução da taxa de transpiração e aumento da taxa de fotossíntese líquida e da condutância estomática em resposta às doses de Si.

Assuntos

RESUMO

The production and quality of roses are influenced by fertilization management. The aim of this experiment was to evaluate the effects of doses of iron (Fe) in the production of potted rose bushes ( Rosa hybrida ). Treatments were based on five doses of Fe (0, 1, 3, 5 and 15mg kg-1) applied on the substrate, in a randomized block design with four replications. Seedlings presented two pairs of leaves and were individually transplanted into plastic pots (0.8dm3) containing commercial substrate. Each experimental plot consisted of a vase with a plant with two flower stalks. The following parameters were evaluated: number of leaves and flowers per flower stalk; dry matter production of roots, leaves and flowers; plant height and diameter and floral longevity. In addition, foliar levels of total chlorophyll and Fe were determined. Fertilization with Fe increases the production and quality of flowers of the rosebush cv. "Shiny Terrazza" (r). Dose of Fe to be added to the substrate used in this study for maximum economic efficiency for this cultivar is 3.6mg kg-1. (AU)

A produção e qualidade das rosas são influenciadas pelo manejo da adubação. Objetivou-se com este experimento, avaliar os efeitos de doses de ferro (Fe) na produção de roseiras ( Rosa hybrida ) cultivadas em vasos. Os tratamentos foram constituídos de cinco doses de Fe (0, 1, 3, 5 e 15mg kg-1) aplicadas no substrato, em delineamento de blocos casualizados, com quatro repetições. As mudas apresentavam dois pares de folhas e foram individualmente transplantadas para vasos plásticos (0,8dm3) contendo substrato comercial. Cada parcela experimental foi constituída por um vaso com uma planta com duas hastes florais. Foram avaliados a quantidade de folhas e flores por haste floral; produção de matéria seca de raízes, folhas e flores; altura das plantas e diâmetro e, longevidade floral. Além disso, foram determinados os teores foliares de clorofila total e Fe. A adubação com Fe aumenta a produção e a qualidade das flores da roseira cv. "Shiny Terrazza" (r). A dose de Fe a ser adicionada ao substrato para obtenção da máxima eficiência econômica para essa cultivar é 3,6mg kg-1. (AU)

Assuntos

RESUMO

The production and quality of roses are influenced by fertilization management. The aim of this experiment was to evaluate the effects of doses of iron (Fe) in the production of potted rose bushes ( Rosa hybrida ). Treatments were based on five doses of Fe (0, 1, 3, 5 and 15mg kg-1) applied on the substrate, in a randomized block design with four replications. Seedlings presented two pairs of leaves and were individually transplanted into plastic pots (0.8dm3) containing commercial substrate. Each experimental plot consisted of a vase with a plant with two flower stalks. The following parameters were evaluated: number of leaves and flowers per flower stalk; dry matter production of roots, leaves and flowers; plant height and diameter and floral longevity. In addition, foliar levels of total chlorophyll and Fe were determined. Fertilization with Fe increases the production and quality of flowers of the rosebush cv. "Shiny Terrazza" (r). Dose of Fe to be added to the substrate used in this study for maximum economic efficiency for this cultivar is 3.6mg kg-1.

A produção e qualidade das rosas são influenciadas pelo manejo da adubação. Objetivou-se com este experimento, avaliar os efeitos de doses de ferro (Fe) na produção de roseiras ( Rosa hybrida ) cultivadas em vasos. Os tratamentos foram constituídos de cinco doses de Fe (0, 1, 3, 5 e 15mg kg-1) aplicadas no substrato, em delineamento de blocos casualizados, com quatro repetições. As mudas apresentavam dois pares de folhas e foram individualmente transplantadas para vasos plásticos (0,8dm3) contendo substrato comercial. Cada parcela experimental foi constituída por um vaso com uma planta com duas hastes florais. Foram avaliados a quantidade de folhas e flores por haste floral; produção de matéria seca de raízes, folhas e flores; altura das plantas e diâmetro e, longevidade floral. Além disso, foram determinados os teores foliares de clorofila total e Fe. A adubação com Fe aumenta a produção e a qualidade das flores da roseira cv. "Shiny Terrazza" (r). A dose de Fe a ser adicionada ao substrato para obtenção da máxima eficiência econômica para essa cultivar é 3,6mg kg-1.

Assuntos

RESUMO

ABSTRACT: The production and quality of roses are influenced by fertilization management. The aim of this experiment was to evaluate the effects of doses of iron (Fe) in the production of potted rose bushes ( Rosa hybrida ). Treatments were based on five doses of Fe (0, 1, 3, 5 and 15mg kg-1) applied on the substrate, in a randomized block design with four replications. Seedlings presented two pairs of leaves and were individually transplanted into plastic pots (0.8dm3) containing commercial substrate. Each experimental plot consisted of a vase with a plant with two flower stalks. The following parameters were evaluated: number of leaves and flowers per flower stalk; dry matter production of roots, leaves and flowers; plant height and diameter and floral longevity. In addition, foliar levels of total chlorophyll and Fe were determined. Fertilization with Fe increases the production and quality of flowers of the rosebush cv. 'Shiny Terrazza' (r). Dose of Fe to be added to the substrate used in this study for maximum economic efficiency for this cultivar is 3.6mg kg-1.

RESUMO: A produção e qualidade das rosas são influenciadas pelo manejo da adubação. Objetivou-se com este experimento, avaliar os efeitos de doses de ferro (Fe) na produção de roseiras ( Rosa hybrida ) cultivadas em vasos. Os tratamentos foram constituídos de cinco doses de Fe (0, 1, 3, 5 e 15mg kg-1) aplicadas no substrato, em delineamento de blocos casualizados, com quatro repetições. As mudas apresentavam dois pares de folhas e foram individualmente transplantadas para vasos plásticos (0,8dm3) contendo substrato comercial. Cada parcela experimental foi constituída por um vaso com uma planta com duas hastes florais. Foram avaliados a quantidade de folhas e flores por haste floral; produção de matéria seca de raízes, folhas e flores; altura das plantas e diâmetro e, longevidade floral. Além disso, foram determinados os teores foliares de clorofila total e Fe. A adubação com Fe aumenta a produção e a qualidade das flores da roseira cv. 'Shiny Terrazza' (r). A dose de Fe a ser adicionada ao substrato para obtenção da máxima eficiência econômica para essa cultivar é 3,6mg kg-1.