Seed coating is a process in which a thin and uniform polymer layer is deposited on the surface of a seed. The objective of this study was to evaluate the vigor of barley seed coated with a commercial polymer and various combinations of calcium, silicon and fungicide. In addition to a control with only the polymer coating, a total of 17 seed coating treatments were used in a completely randomized factorial design (18 treatments × 4 replicates per treatment). Calcium and silicon were applied at concentrations of 0, 25 or 50 g kg -1 of seed, and 0 or 3.0 mL of fungicide was applied. The means were compared using a Duncan test (P≤0.05). The results showed that a coating of polymer, fungicide, calcium and silicon did not affect the physiological quality of the barley seed and that the use of these products can protect the seed against pathogens without affecting the rate of emergence of the barley seedlings while ensuring good seed appearance, adhesion, distribution and coloration.

The study aimed to evaluate the influence of physiological seed quality on the spatial distribution of plants in the field, as well as the effect on variability among soybean plants. Six lots of soybean cultivar CD 202, with three vigor levels (high, medium and low) and two lots on each level were used. Lots of high physiological quality showed germination of 96% and lots considered of medium vigor showed 82% of germination and vigor between 60% and 67%, whereas lots of low vigor showed 70% germination and vigor between 55% and 58%. The test was conducted in plots formed by seven 5 m long rows with spacing of 0.45 m. The sowing was performed by opening furrows by hand with the equidistant distribution of seeds using marked rulers, corrected by the germination of each seed lot. Lots of seeds of higher vigor provide greater uniformity in the distribution of plants in the field. The reduction in seed physiological quality provides increased variability among plants within populations, throughout the entire developmental period of soybean, also affecting the seed yield per plant.

The objective of this study was to evaluate the physiological and sanitary quality of seeds of rocket; the research was done at the Laboratory of Seed Analysis and greenhouse of the Department of Plant Science, Federal University of Pelotas (UFPel). Four lots of the cultivar "Antonella'' were tested for following features: initial and final moisture content, germination rate, first count of germination, accelerated aging with saline solution, dry matter contents, seedling shoot and root length, emergence speed index, emergence of seedlings in substrate, electrical conductivity and sanitary condition. A completely randomized design with four replications was used for all tests done and means were compared by Tukey test (P≤0.05). For all tests performed it was concluded that despite changes in the ranking of the best lots, there was agreement regarding the indication of the inferiority of the lot 3 in all tests and it was also observed that the incidence of fungi associated with seeds of rocket interfere with the physiological quality of the lots.

The practices and techniques used in irrigated rice to improve performance include optimal plant density and the best arrangement of the plants in an area. This study aims to evaluate the performance and plasticity in the yield and grain quality of three rice hybrids using different row spacing. The field experiments were conducted during the 2010/2011 season in rice crops in Capão do Leão, Viamão and Uruguaiana in the state of Rio Grande do Sul, Brazil. Three different sowing arrangements were evaluated, i.e., row spacing of 17 cm, 34 cm, and 17 cm alternated with 34 cm, which corresponded to densities of 40, 20 and 32 kg ha -1 , respectively. The experimental design used was randomized blocks with subdivided plots replicated three times considering each location as a replication. Yield and grain quality were evaluated. The grain yield and grain quality components of the rice hybrids were not affected by the planting arrangements. The performance of the hybrids demonstrates their plasticity to compensate for lower densities resulting from different distances between planting rows. Therefore, with respect to seeding rates and row spacing for these hybrids, the amount of seed sown per area can be reduced compared with current recommendations. This will result in a cost reduction that can make this technology more attractive and ensure it is widely used in commercial rice fields.

No abstract

This study aimed to evaluate the effect of insecticide thiamethoxam as a bioactivators on cucumber seed physiological quality and seedling performance. The treatments used were: T 1 = no product; T 2 = 0.2 L of product per 100 kg of seeds; T 3 = 0.3 L product per 100 kg of seeds; T 4 = 0.4 L of product per 100 kg seeds; T 5 = 0.5 L of product per 100 kg of seeds; T 6 = 0.6 L of product per 100 kg of seeds. The variables evaluated were: seed germination, first count of germination, seedling root length, accelerated aging, cold test and seedling emergence. The experimental design was completely randomized with three replicates for each treatment and data were analyzed by regression. Doses of thiamethoxam from 0.3 to 0.4 L (per 100 kg of seed) provide positive effects on cucumber seed physiological quality and seedling performance, as was shown in germination and vigor tests results.Key words: Cucumis sativus L., insecticide, physiological quality, vegetable seeds, vigor tests Uso de tiametoxam como bioativador na qualidade fisiológicade sementes e desempenho de plântulas de pepino RESUMONesse trabalho o objetivo foi avaliar o efeito do inseticida tiametoxam como biativador na qualidade fisiológica de semente e no desempenho de plântula de pepino. Os tratamentos utilizados foram: T 1 = sem produto; T 2 = 0,2 L do produto por 100 kg de sementes; T 3 = 0,3 L do produto por 100 kg de sementes; T 4 = 0,4 L do produto por 100 kg de sementes; T 5 = 0,5 L do produto por 100 kg de sementes e T 6 = 0,6 L do produto por 100 kg de sementes. As variáveis avaliadas foram germinação, primeira contagem de germinação, comprimento de raiz, envelhecimento acelerado, teste de frio e emergência de plântulas. O delineamento experimental foi inteiramente casualizado com três repetições para cada tratamento. Os dados foram submetidos à análise por regressão polinomial. Doses de 0,3 a 0,4 L de tiametoxam (por 100 kg de sementes) proporcionam efeitos positivos na qualidade fisiológica das sementes e no desempenho de plântulas de pepino, como se pode observar nos resultados do teste de germinação e de vigor. Palavras-chave:Cucumis sativus L., inseticida, qualidade fisiológica, sementes de hortaliças, testes de vigor

The objective of this study was to evaluate the physiological changes of pumpkin seeds during the maturation process. Thereby, the study was conducted in the municipality of Juazeiro, at the experimental area of the State University of Bahia. Seeds of the cultivar 'Maranhão' were harvested from fruits at regular intervals, every 10 days, from 15 to 60 days after anthesis (DAA). The experimental design was completely randomized with six treatments (15, 25, 30, 40, 50 and 60 DAA) and four repetitions. For each period, the fruits were assessed visually and average weights were determined, and the seeds extracted from fruits were evaluated for the following tests: moisture content, dry matter of the seeds, germination, electrical conductivity, field emergence, emergence speed index. The seeds reached physiological maturity at 50 days after anthesis, although the best time to begin harvesting fruit of this cultivar is between 50 to 60 DAA. At this time the seeds moisture content is low enough to allow the harvest.

Accelerated aging of onion seeds (Allium cepa L.) submitted to saturated salt solution Envejecimiento acelerado de semillas de cebolla (Allium cepa L.) sometidas a soluciones salinas saturadas ABSTRACTThe objective of the present study was to evaluate the methodology of the accelerated aging test to evaluate the physiological potential of onion seeds, as well as verify the possibility of using unsaturated and saturated solutions of sodium chloride (NaCl) as an option for water uptake control in seeds during the test without reducing sensitivity. Five lots of onion seeds were tested for germination, seedling emergence, emergence speed and accelerated aging (periods of 24, 48, 72, or 96 hours, with or without the use of a saturated saline solution of NaCl). The use of unsaturated and saturated solutions of NaCl reduced water absorption by onion seeds during the accelerated aging test, resulting in a less pronounced rate of deterioration, and less drastic and more uniform results. The 48 hour treatment with unsaturated and saturated NaCl solutions is an option for use because it promotes a better classification of the onion seed lots at different vigor levels. LILIAN MADRUGA DE TUNES RESUMENEl objetivo del presente estudio fue evaluar la metodología del test de envejecimiento acelerado para evaluar el potencial fisiológico de las semillas de cebolla, también verificar la posibilidad de usar soluciones de cloruro de sodio (NaCl) saturadas e insaturadas como una opción para controlar la absorción de agua de las semillas durante el test sin reducir su sensibilidad. En cinco lotes de semillas de cebolla sometidos a tratamientos de envejecimiento acelerado (periodos de 24, 48, 72 o 96 horas, con o sin el uso de soluciones saturadas de NaCl) se evaluó la germinación, emergencia de plántulas y la velocidad de emergencia. El uso de soluciones saturadas e insaturadas de NaCl redujo la absorción de agua por las semillas de cebolla durante el test de envejecimiento acelerado, dando como resultado una tasa de deterioro menos pronunciada y resultados menos drásticos y más uniformes. El tratamiento de 48 horas con soluciones insaturadas y saturadas de NaCl es una opción para usar, ya que promueve una mejor clasificación de los lotes de semillas de cebolla en diferentes niveles de vigor.