Cassyo de Araújo Rufino

Synthesis of Chitosan Oligomers/Propolis/Silver Nanoparticles Composite Systems and Study of Their Activity against Diplodia seriata

The synthesis and characterization of composites of oligomeric chitosan with propolis extract which allow the incorporation of a third component (silver nanoparticles) are reported, together with their application in aqueous or hydroalcoholic solutions with a view to the formation of adhesive substances or nanofilms for the protection of vineyards against harmful xylophagous fungi. The antimicrobial properties of the association of the two biological products or those resulting from the incorporation of silver nanoparticles (NPs) are studied and discussed. The efficacy of the chitosan oligomers/propolis/silver NPs ternary system is assessed in vitro for Diplodia fungi. A preliminary study on the convenience of replacing propolis with gentisic acid is also presented.

Envelhecimento acelerado em sementes de azevém com e sem solução salina e saturada

The objective of the present study was to evaluate the methodology of the accelerated aging test to evaluate the physiological potential of s ryegrass seeds, as well as verify the possibility of the use of unsaturated and saturated solution of NaCl as an option for control of water uptake by seeds during the test without reducing its sensitivity. Four lots of ryegrass seeds were tested for germination, seedling emergence, speed emergence and accelerated aging (periods of 24, 48, 72 and 96h, with or without the use of saturated and saline solution of NaCl). The use of unsaturated and saturated solution of NaCl reduces water absorption by ryegrass seeds during the accelerated aging test, resulting in a rate of deterioration is less pronounced ,less drastic and more uniform results. Option 24h with unsaturated solution (SNS) was only able to stratify plots into two groups and should not be designated as promising. Thus, it should be used the 48h saturated NaCl solution (SSS), which stratified into three lots.

Performance of lowland rice seeds coated with dolomitic limestone and aluminum silicate

The objective of this study was to evaluate the performance of seeds of two cultivars of lowland rice (Oryza sativa L.), coated with dolomitic limestone and aluminum silicate. It was used a completely randomized experimental design, with the treatments arranged in a 4 X 2 factorial scheme [4 treatments: dolomitic limestone; dolomitic limestone + aluminum silicate; aluminum silicate, at the dosages of 50 g/100 kg of seeds; and control (without the products) X 2 cultivars: IRGA424 and IRGA 422 CL], totaling eight treatments with four replications each. The variables analyzed were: fresh and dry weights of aerial biomass; plant height; leaf area at 10, 20, and 30 days after emergence (DAE). The physiological quality of seeds was also assessed using tests of: seed emergence; first count of germination; emergence speed index; and field emergence. It was concluded that the coating of rice seeds with dolomitic limestone and aluminum silicate does not affect seed germination and field seedling emergence. Aluminum silicate used via seed coating on cultivar IRGA 424 promoted greater leaf area, after 20 DAE. The dolomitic limestone and the aluminum silicate used via seed coating generated plants with larger dry biomass, after 20 DAE, for the cultivar IRGA 422 CL.

Desempenho de sementes de soja sob deficiência hídrica: rendimento e qualidade fisiológica da geração F1

Seed vigor interferes significantly in tolerance to water deficit and seed yield. The objective of this study was to evaluate the influence of water stress on yield and physiological quality of seeds produced in the F1 generation. The study was conducted in a greenhouse using seeds of the cultivar M-SOY 8008RR, sown in pots with capacity of 15kg of soil A1 horizon of a Eutrophic Haplic Planosol Solodicin . The experimental design was completely randomized in a 2x2 factorial, with and without water deficit of 1st to 10th day after emergence and seed vigor level: high and low, totaling four treatments with five replicates. The variables analyzed were dry mass of shoots and leaf area at 10, 20, 30 and 40 days after emergence, yield and physiological quality through germination, first count, accelerated aging and weight of a thousand seeds of seeds in the F1 generation. The use of seed provides high force increases over 15% yield with respect to the use of low seed vigor. Water deficit from the 1st to the 10th day after emergence does not interfere in the yield and seed quality of the F1 generation, either for seeds of high and low vigor.

The influence of seed coating on the vigor and early seedling growth of barley

El recubrimiento de semillas consiste en la deposicion de una capa delgada y uniforme de un polimero sobre la superficie de la semilla. El objetivo de este estudio fue evaluar el vigor de las semillas de cebada, revestido con calcio y silicio, polimero comercial y fungicida. Los tratamientos consistieron de dos concentraciones de calcio y silicio para el revestimiento de las semillas, con niveles de 0, 25 y 50 g kg-1 semilla. Se utilizo 3,0 mL de fungicida y un total de 17 tratamientos y un control, sin ningun tratamiento. El diseno experimental fue completamente al azar en un esquema factorial (18×4) y los resultados fueron analizados a traves de la comparacion de medias, utilizando la prueba de Duncan (P≤0,05). Los resultados mostraron que las semillas de cebada recubiertas con fungicida, calcio y silicio, no se vieron afectadas en su calidad fisiologica y, posiblemente, el uso de estos productos protege la semilla contra patogenos, sin afectar su velocidad de aparicion, y proporcionan semillas con buena apariencia, adherencia, distribucion y coloracion.

Desempenho de sementes de arroz tratadas com zinco, boro e molibdênio

The objective of this study was to assess physiological quality of seeds and the initial growth of lowland rice seedlings, cv. PUITA INTA-CL, treated with a product based on Zinc, Boron and Molybdenum. The following dosages of product were used: 0 (control), 50, 100, 150 and 200 mL.100 kg-1 seed. A completely randomized experimental design was used, with 10 treatments and four replications. Physiological quality of seeds was assessed by following tests: germination; first count of germination; and length and dry phytomass of seedlings. The initial growth was assessed at 7, 14, 21, 35, and 42 days after emergence (DAE) through plant height, leaf area and dry phytomass of aerial parts and roots. It was concluded that the treatment of rice seeds with the product containing Zinc, Boron and Molybdenum up to the dosage tested of 200 mL.100 kg-1 seed does not influence germination, first count of germination, and the dry phytomass of aerial parts and roots; however, negatively influences seedling length. In addition, it also promotes greater plant height, higher leaf area, higher production of dry phytomass of seedlings, and increase on the growth rate, until 42 DAE.

Performance of Soybean Seedlings Upon Nutrient Application by Seed Coating

The aim of this study was to evaluate the effect of different seed coatings consisting of various combinations of three nutrients (calcium, magnesium and silicon) on two soybean cultivars (BRS 243 RR and CD 233 RR). Dolomitic limestone and aluminum silicate were chosen as the nutrient sources. Leaf area, plant height, shoots dry matter, crop growth rate, relative growth rate and net assimilation rate were the studied variables, evincing that the seed coating that comprised calcium, magnesium and silicon led to better performance in terms of growth rates 30 days after emergence. Significant differences in the response to the seed coatings were also observed between the two studied soybean genotypes.

Crescimento de plântulas de aveia branca submetidas ao estresse salino

The cultivation of white oat in succession to irrigated rice is considered a viable alternative, mainly because of their added value and for their restorative characteristics of the soil, though their productive potential can be reduced considerably because of the soil salinization, being very important to determine salt concentration tolerated by different white oat cultivars.The objective is to evaluate, oat cultivars recommended for the state of Rio Grande do Sul under different salt concentrations in seed germination and early growth. The experimental design was completely randomized factorial 2X5, with four replications, (cultivars Barbarasul and Chiarasul, salt concentration and levels 0, 25, 50, 75 and 100 mM NaCl per liter of water). The physiological seed quality was evaluated in the laboratory by germination, first count of germination, length of shoot and root dry weight of shoot and root. Based on the results we can conclude that: germination and seedling growth of oat cultivars and Barbarasul Chiarasul are 1 Eng°s Agros, Discente de Doutorado em Ciência e Tecnologia de Sementes, Universidade Federal de Pelotas UFPEL, Pelotas, RS. E-mail: beldar_brunes@msn.com; danielfonseca30@yahoo.com.br; lizandro_cicilianotavares@yahoo.com.br 2 Licenciado em Ciências Agrícolas, Discente de Doutorado em Ciência e Tecnologia de Sementes, UFPEL, Pelotas, RS. E-mail: cassyo.araujo@yahoo.com.br 3 Enga Agra, Profa Dra do Programa em Pós-Graduação em Ciência e Tecnologia de Sementes, UFPEL, Pelotas/RS. E-mail: lilianmtunes@yahoo.com.br 4 Prof. Dr. do Programa em Pós-Graduação em Ciência e Tecnologia de Sementes, UFPEL, Pelotas, RS. E-mail: francisco.villela@ ufpel.edu.br * Autor para correspondência