Maristela Pereira Carvalho-Zanão

Variabilidade espacial de atributos químicos em diferentes profundidades em um Latossolo em sistema de plantio direto

Spatial variability of chemical attributes at different depths in an Oxisol under no-till system The study of spatial variability of soil chemical attributes is an important step in precision agriculture. The objective of this study was to evaluate the spatial variability at two depths (0-10 and 10-20 cm) of the pH in water, base saturation, and levels of organic matter and micronutrients (B, Cu, Fe, Mn and Zn) in an Oxisol, medium texture, under no-tillage system for eight years. Soil sample collection was performed at regular intervals of 50 m in a regular grid of 121 points. Data were analyzed by descriptive statistics and geostatistics based on the adjustment of semivariograms. Higher levels of organic matter, Zn and Mn were recorded in the first 10 cm of soil. The greatest variability was found for B and the lowest for pH in water. Most of the data fit the model of Gaussian semivariogram. The values of range were different as a function of the sampling depth and greater at the depth 010 cm. If a geostatistical sampling scheme is used, the number of samples to be collected will be different for the two depths and among the evaluated attributes.

Yield and shelf life of chrysanthemum in response to the silicon application

O crisântemo de vaso e uma das principais flores produzidas em ambiente protegido. O silicio tem promovido melhorias tanto no aspecto quantitativo quanto no qualitativo quando fornecido a algumas especies ornamentais produzidas nestas condicoes. Assim, o objetivo desse trabalho foi avaliar a resposta a aplicacao de silicio de tres cultivares de crisântemo cultivadas em vaso. O experimento foi conduzido em casa de vegetacao da Universidade Federal de Vicosa. Os tratamentos foram dispostos em esquema fatorial 3x2 (tres cultivares de crisântemo: Coral Charm, White Reagan e Indianapolis e duas doses de silicio aplicadas no substrato: 0 e 800 mg kg-1) com seis repeticoes, em delineamento inteiramente casualizado. Foram avaliados o diâmetro dos botoes e das hastes florais; comprimento das hastes florais; altura da planta; producao de materia seca de raizes, folhas, caule, inflorescencias e parte aerea; numero total de inflorescencias; diâmetro da inflorescencia mais aberta; teor de Si nos tecidos foliares; ciclo e longevidade floral. A cultivar White Reagan produziu o maior numero de inflorescencias (29,17) por vaso e mostrou ser mais precoce (85,83 dias). Nao houve interacao negativa entre Si, Ca e K e nao foi constatado efeito do silicio na producao e na longevidade das inflorescencias de crisântemo. Houve aumento nos teores deste elemento nas folhas com a aplicacao do metasilicato de potassio.

Produção de rosas influenciada pela aplicação de doses de silício no substrato

The use of Si in the cultivation of pot-grown ornamental species in greenhouse has increased the output and quality of the final product. The objective of this study was to evaluate yield and nutrient uptake of two rose cultivars grown in pots under Si application to the substrate. The treatments, arranged in a 2 x 5 factorial design, consisted of two rose cultivars (Yellow Terrazza® and Red White Terrazza®) and five Si doses (0.0; 0.25; 0.50; 0.75 e 1.00 g kg-1), and evaluated in a randomized block design with four replications. The plant height, cycle, yield, diameter, floral longevity, concentration and amounts foliar Si, macro- and micronutrients were evaluated. Analysis of variance was performed adjusting regression equations for the effect of Si doses. Silicon applied to the substrate improved the output and quality of the roses grown in pots in greenhouse, although the plant response varied with the Si rates. To obtain 90 % of the maximum production of flowers dry matter the Si rates were of 0.43 and 0.22 g kg-1 for the Yellow Terrazza® and Red White Terrazza®, respectively. Negative effects of the element were however observed at rates of 0.86 and 0.55 g kg-1 Si and upwards for Yellow Terrazza® and Red White Terrazza®, respectively. The foliar Si contents increased according to the Si rate applied to the substrate.

Leaf anatomy and gas exchange of ornamental sunflower in response to silicon application

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. 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.

Produção de gladíolo submetido a ácido giberélico em ambiente protegido

1. Manuscript received in Jul./2016 and accepted for publication in Dec./2016 (http://dx.doi.org/10.1590/1983-40632016v4642418). 2. Universidade Estadual do Oeste do Paraná, Centro de Ciências Agrárias, Marechal Cândido Rondon, PR, Brazil. E-mails: maristelacarvalho@gmail.com, fvilla2003@libero.it, claudiotsutsumi@unioeste.br. 3. Universidade Estadual do Oeste do Paraná, Centro de Ciências Exatas e Tecnologias, Cascavel, PR, Brazil. E-mail: pe.nataliaa@gmail.com. Gladiolus is an important cut flower commercialized in Brazil, and the use of gibberellic acid (GA3) to cultivate it in a protected environment may promote the production of high quality flower spikes. This study aimed at evaluating the production of flower spikes and corms of gladiolus (‘White Friendship’ cultivar) submitted to high concentrations and application methods of gibberellic acid, in a protected environment. The experimental design was randomized blocks, in a 2 x 4 factorial arrangement, being two application methods (foliar spraying and corm soaking) and four concentrations (0 mg L-1, 250 mg L-1, 500 mg L-1 and 1,000 mg L-1) of gibberellic acid, with six replications and two plants per experimental unit. The following traits were evaluated: plant height, number of leaves per plant, marketable harvest point of flower spikes, number of florets per flower spike, flower panicle length, stem and floret diameter, corm perimeter, number of cormels per plant and production of corm fresh matter and leaf dry matter, flower spikes, corms and cormels. High concentrations of GA3 are not recommended for the production of flower spikes and corms of the gladiolus ‘White Friendship’ cultivar. The corm soaking application method anticipates the harvest of flower spikes and produces a higher number of cormels per plant. Regardless of the application method, the concentration of 550 mg L-1 of GA3 increases the cormel yield of the ‘White Friendship’ cultivar.

Adubação do arroz com silício e manganês em um Latossolo Vermelho

The objective of this research was to study the biomass production, plant architecture and Si and Mn uptake in rice plants cultivated in a Acrustox fertilized with silicon and manganese. The experiment was carried out in a greenhouse using a 2x5 factorial (0 and 1000mg dm-3 Si x 0, 4, 12, 16 and 20mg dm-3 Mn) with four replications, in a randomized block design. The application of Si to the soil resulted in a smaller leaf insertion angle, a greater Si content in the leaves and roots and biomass production. Moreover, Si caused the decrease content of Mn in leaves and its increase in roots. With the rising dose of Mn, there was an increase in the content of this element in soil, roots and leaves, regardless of the Si application and reduction in biomass production of rice in the larger doses only when the Si was not added to the soil.