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A produtividade de sementes juntamente com a qualidade deve ser a preocupação do dia a dia do produtor de sementes. Para o perfeito entendimento dos resultados da produtividade, considerando os efeitos dos fatores genéticos, ambientais e de manuseio da cultura (técnicas de cultivo), é necessária e importante a avaliação dos componentes da produtividade de sementes. Basicamente, os componentes são: número de plantas por unidade de área, número de infl orescências por planta, número de sementes por infl orescência e massa média da semente. As diferentes espécies ou grupos de espécies como gramíneas, fabáceas e outras apresentam particularidades morfológicas, fi siológicas e fenológicas nas plantas e em seus sistemas de cultivo, que resultam em componentes de produtividade distintos daquele básico, sendo necessário conhecê-los para avaliá-los adequadamente. Conhecido os componentes da produtividade de sementes, o passo seguinte é o reconhecimento do momento ou período em que ocorre a defi nição de cada componente para poder avaliar o seu modo de atuação ou para saber de qual fator sofre efeito. O momento ou período de defi nição do componente é associado à ocorrência de um evento ou fase morfológica, fi siológica ou fenológica da planta ou ao instante de realização do manuseio da cultura, exigindo conhecimentos sobre a espécie e o cultivo dela. [ABSTRACT FROM AUTHOR]

The pigeon pea (Cajanus cajan (L.) Millsp) is a shrubby leguminous plant cropped for green manure and forage; its protein-rich grains are used as animal and human food. The objective of the present experiment was to study the germination behavior during the storage of pigeon pea seeds of two cultivars (one with and the other without hard seeds). The newly harvested seeds were packed in paper bags and stored for six years in a laboratory with natural environment without control of air temperature and relative humidity. Soon after harvest and then yearly, seed moisture was evaluated and the seed germination was tested. Germination dates were submitted to statistical analysis, in a randomized complete design, considering as treatments the seven evaluation times during storage, with four replications. Analysis of variance was performed for each cultivar separately and then analyzed as series of similar experiments. Regression equations were calculated, choosing the ones with better fit and higher coefficient of determination. Seeds of both cultivars maintained germination above 70% during three years of storage, followed by decrease and presented nearly 10% in the sixth year. The presence of hard seeds caused differences in germination between cultivars during the storage period. [ABSTRACT FROM AUTHOR]

The present work had as its objective to study the traditional method of accelerated aging (with water), in black oats seeds with and without fungicid treatment, and the accelerated aging with saturated solution of salt (NaCl), by aiming to identify the exposition period and temperature that allow the classification of lots of black oats seeds in different vigour levels. The study was carried out by using five lots of black oats seeds. Tests were carried out to characterization of initial quality of the seed lots (tests of germination, seedlings emergency in the field, electrical conductivity, length of normal seedlings and mass of 1000 seeds) and the studies of accelerated aging consisted the traditional method (with water), with and without fungicid treatment, and accelerated aging with saturated solution of salt (NaCl) for periods of 24, 48, 72, 96 and 120 hours, conditioning at temperatures of 40, 43 and 45°C. The studies concluded that the test of accelerated aging is adequated to evaluate the vigor of black oats seeds using the test of traditional accelerated aging (with and without treated seeds) or with saturated solution of salt, both at 40°C during 24 hours. [ABSTRACT FROM AUTHOR]

The safflower (Carthamus tinctoriusL.) has an uneven flowering and fruiting, which can cause problems in seed production and harvesting in regions with hot and humid climates. However, little is known about the optimal safflower harvest time. Therefore, this study evaluated the optimumtiming for seed harvest of three safflower genotypes (2106, S-325, and 7329).The experiment was a randomized complete block design with six replications. The harvest started 16 days after flowering (DAF) and ended at 52 DAF. Ten harvests were made in total. Seed water content, seeds fresh and dry matter, seed germination, and first germination counts were evaluated.Genotypes 2106 and 7329 had germination rates of 79% and 91%, respectively, at 34 and 38 DAF, while genotype S-325 had 90% germination at 37 DAF. Harvesting at 52 DAF combined with a rainy season impaired the germination of safflower seeds. The harvest time most suitable for safflower occurred between 34 and 42DAF, when the seeds have the seed water content between 26% and 33%. [ABSTRACT FROM AUTHOR]

Soil management systems directly interfere in the soil–plant relationship. However, there are still few studies evaluating the influence of long-term management systems on the physiological quality of soybean seeds. Another little-known topic is the influence of pre-harvest desiccation on the physiological quality of soybean seeds, especially on seed longevity. Thus, the aim of this research was to evaluate the physiological quality of soybean seeds cultivated under conventional tillage and no-tillage systems with and without desiccant use. The experiment was carried out in design is a split plot in a randomized complete block design. The treatments consisted of soil management systems (conventional tillage and no-tillage), with and without pre-harvest desiccation. In the treatment with desiccation, the herbicide Paraquat was applied, when the plants were at the R7.3 phenological stage (most of the seeds had a yellowish coat, with a shiny surface and were already detached from the pod). Seed germination, vigor (first germination count, seedling dry mass, seedling length, time to reach 50% germination (T50), seedling emergence and emergence speed index) and longevity (P50) were evaluated. Seeds cultivated under conventional tillage showed greater vigor for most traits evaluated, with values of T50 and seedling length higher by 24.39% and 24.77%, respectively, compared to NT. In addition, non-desiccation increased the seedling length and dry mass, in 15.45% and 21.59%, respectively. The use of desiccant aiming at seed vigor is dependent on the soil management system. Soybean seed longevity was superior in the no-tillage system, but desiccant application reduced seed longevity. [ABSTRACT FROM AUTHOR]

The Soybean crop is extremely relevant to the Brazilian economy. Priming is a technique that allows improvement of seed quality, especially those of low vigor. Vigor is defined as the ability of the seed to perform adequately when exposed to different environmental conditions. High vigor seeds generate plants with higher emergency speed and superior yield components, favoring into a higher seed yield. The objective of this work was to evaluate the agronomic behavior of soybean plants under field conditions originated from primed seeds with different level of vigor. Yield components and soybean yield were also evaluated. Seed priming in seed with medium vigor positively influences the components (seedling emergence, first pod height, number pods/plant, number of seeds/plant, number of seeds/pod) and favored productivity of soybean cultivar 'M7211RR'. Different levels of vigor of soybean seeds cause differences in the number of pods/plant. [ABSTRACT FROM AUTHOR]

This research had the objective of standardizing the methodology for preconditioning of castor bean (Ricinus communis L.) seeds for the evaluation of their physiological potential by the tetrazolium test. The evaluated seed preconditioning methods were: seeds with coat between moist paper towel at 30, 35 and 40°C for 6, 8, 10, 12, 14, 16 and 18 hours; and seeds without coat between moist paper towel; and seeds with coat immersed in water, at 25, 30, 35 and 40°C for 1, 2, 3, 4, 5 and 6 hours. After preconditioning, the seed coat was removed, the seeds were cut lengthwise, and immersed in tetrazolium solution at a concentration of 0.2% for 120 minutes at 35°C. The seeds′ germination percentage, moisture content before and after preconditioning, and staining uniformity after the tetrazolium were evaluated. The statistical design was completely randomized, and the means comparisons were accomplished by the Tukey test at 0.05 level of probability. It was concluded that castor bean seeds should be preconditioned with coat between moist paper towel at 35°C for 12 hours, so that the results of the tetrazolium test will be similar to those obtained in the germination test. [ABSTRACT FROM AUTHOR]

The objective of this research was to study the tetrazolium solution concentration and staining period for the evaluation of the physiological quality of castor bean seeds (Ricinus communis L.) by the tetrazolium test, standardizing the nomenclature of the observed colors in seeds after staining. The treatments of tetrazolium solution concentration and staining period were: 0.075% and 0.1% for 120, 180 and 240 minutes, 0.2% for 60, 120 and 180 minutes, 0.5% for 60, 90 and 120 minutes and 1.0% for 30, 60 and 90 minutes. The results were compared to the germination test. The seed color after the tetrazolium test in each treatment was evaluated by comparing with the Munsell book of color, and the percentage of seeds observed in each color was established. A randomized complete block design was used and the means were compared by the Tukey test at the 0.05 level of probability. To evaluate physiological quality by the tetrazolium test, castor bean seeds should be placed in tetrazolium solution at the concentration 0.2% for 120 minutes, at 35°C, for staining development, and in this treatment, the viable seeds after the staining in tetrazolium solution showed predominantly the colors pink and dark pink in their essential structures. Thus these colors can be considered as the characteristics colors for the tetrazolium test in castor bean seeds. [ABSTRACT FROM AUTHOR]

The tetrazolium test is a quick and accurate method for estimating seed viability and vigor. This research had the objective of standardizing the preparation methods for castor bean seeds (Ricinus communis L.) to evaluate the physiological potential by the tetrazolium test. The evaluated seed preparation methods were: longitudinal cut through the middle of the seed coat, endosperm and embryo; longitudinal and diagonal cut without reaching the embryo; seed coat removal; seed coat removal with longitudinal cut through the middle of the endosperm and embryo; and seed coat removal with longitudinal cut parallel to the cotyledons through the middle of the endosperm and embryo. Before carrying out the preparation methods, the seeds were preconditioned between moist paper towels for 18 hours at 30°C, and after preparation, the seeds were immersed in tetrazolium solution at 0.5% concentration and then placed in a dark chamber at 35°C for the staining development. The staining uniformity was evaluated after each preparation method by comparing the methods. It was concluded that the best seed preparation method was coat removal with a lengthwise longitudinal cut, through the middle of the endosperm and embryo. [ABSTRACT FROM AUTHOR]

The scarcity of information on the maturation physiology of the peanut seed (Arachis hypogaea L.; Virgínia group) makes harvesting high quality seeds a challenge for the seed industry. During two consecutive crop seasons, we studied the acquisition of physiological quality of peanut seeds during maturation in tropical conditions. We bring new insights about the period of late maturation of seeds and the influence of the maternal environment on physiological quality. We monitored water content, dry weight, ability of germination, desiccation tolerance, vigor and longevity. In addition, we monitored temperature and precipitation throughout plant growth. We demonstrate that the physiological quality of peanut seeds is acquired during development, with a maximum between 57 and 76 days after flowering in the late stage of maturation. This final period represents about 25% of the development, considered the best time to harvest peanut seeds with the highest quality. Our findings also support the idea that the adequate proportion of rainfall and thermal sum in the maternal environment are factors that favor the acquisition of peanut seed longevity. [ABSTRACT FROM AUTHOR]

Millet is a species of the grass family used in cattle pastures, for hay, for silage, and in soil cover in notillage systems. However, studies on seed production and post-harvest techniques for this species have not been sufficiently developed, considering the demand for and potential of this crop. The objective of this study was to monitor the physiological quality of millet seeds stored in porous packaging. Millet seeds were stored under four ambient conditions (natural laboratory environment, dry chamber, refrigerator, and freezer). Physiological quality was evaluated by germination and vigor tests before and during storage each year, up to six years for the dry chamber and natural laboratory environment, and up to 12 years for the refrigerator and freezer. Analysis of variance was conducted on the data, which were in 4 × 6 and 2 × 12 (environment and storage period) factorial arrangements. The means of the environments were compared by the Tukey test (p = 0.05) and the storage periods by regression analysis. The germination capacity of millet seeds is best conserved in a refrigerator and freezer, and they remain viable for up to twelve years of storage under these conditions. [ABSTRACT FROM AUTHOR]

The seed physiological maturity knowledgment is critical determine its maximum production and physiological quality. The objective of this study was to determine the ideal time to harvest by evaluating seeds physiological maturity. Seventeen weekly harvests of fruits and seeds from matrices located in the Brazilian city of Botucatu, SP, were performed from May to September 2001. Fruits size and weight, seed water content and dry matter, and germination and emission of primary root were evaluated. Seeds showed maximum dimension in the thirteenth week of collection, while the highest fruit weight was obtained in the twelfth week of collection. Water content decreased over time. Seeds dry matter showed its highest value in the sixteenth week harvest, while germination percentage showed its highest value between the fourteenth and fifteenth week harvest. The percentage of primary root emission was observed with maximum value in the tenth week harvest. Based on the results, it is concluded that the best Anadenanthera colubrina harvest season occurs between the fourteenth and fifteenth weeks. [ABSTRACT FROM AUTHOR]

Phosphorus is a limiting nutrient in common bean grain yield and may influence the chemical composition of seeds. The aim was to assess the effects of phosphorus fertilization and planting dates ('water' and 'dry') in the seeds chemical composition of two dry bean cultivars. A field experiment was carried out in Botucatu (SP) in a randomized block design with five replications. Two dry bean cultivars 'Carioca Precoce' e 'IAC Carioca Tybatã' were evaluated in growing 'water' and 'drought' in six levels of P2O5 (0, 30, 60, 90, 120 and 150kg ha-1) applying superphosphate at planting row. It was assessed seed samples to determine the levels of N, P, K, Ca, Mg, S, Cu, Mn, Fe, Zn, total and reducing sugar and protein. The phosphorus in the soil alters the seeds chemical composition, increasing contents of P and decreasing Ca and Cu contents. The K and Fe contents showed minimum point at a level of 69.9 and 66kg ha-1 of P2O5, respectively. It was observed that occurred increase in contents of N, P, and protein of seeds in the growing season 'drought'. The cultivar 'Carioca Precoce' showed higher N content and protein of seeds than 'IAC Carioca Tybatã'. There is interaction between cultivar and growing season for the content of S, Mn, Fe, Ca, Mg, Cu, total and reducing sugars. [ABSTRACT FROM AUTHOR]

O teste de lixiviação de íons de potássio, cálcio e magnésio é baseado na integridade das membranas celulares das sementes, sendo considerado um procedimento rápido para a avaliação do vigor em sementes de várias espécies. Porém, para sementes de milho doce não se têm informações necessárias para a validação deste procedimento. Com isso, o trabalho teve como objetivo obter informações que permitam o aperfeiçoamento dos testes de lixiviação de potássio, cálcio e magnésio para a avaliação do vigor em sementes de milho doce. Foram utilizados 14 lotes de sementes de milho doce de duas cultivares, BR-401 e BR-402. O delineamento utilizado foi inteiramente casualizado com três repetições. A qualidade fisiológica das sementes foi avaliada por meio dos testes de germinação, condutividade elétrica, emergência a campo, lixiviação de potássio, de cálcio e de magnésio. Os testes de lixiviação de potássio e magnésio foram eficientes na avaliação do vigor em sementes de milho doce. A condutividade elétrica apresentou correlação negativa com a emergência de plântulas e positiva com a lixiviação de íons de potássio e magnésio. [ABSTRACT FROM AUTHOR]

The objective of the present research was to study the combination of time and temperature on the suitability of the controlled deterioration test for evaluating the vigor of maize seed with different water contents. Eight seed lots of hybrid maize CO32 were used, whose initial quality was determined by the following tests: water content, thousand seed weight, electric conductivity, germination, first germination count, seedling total dry matter and of the aerial parts and roots, cold test, accelerated aging, tetrazolium, emergence and rate of emergence in the field. The initial moisture content of seed lots was adjusted by immersion in water to 15, 20 and 25%. Nine combinations of periods (16, 24 and 48 hours) and deterioration temperatures (42, 45 and 48 °C) were evaluated for each water content. After deterioration, the water content and percentage of germination were determined and the data submitted to ANOVA with means compared by the Tukey test and a correlation analysis to 5% in a factorial 9x8, with nine combinations of temperature and time and eight seed lots. The combinations 24-45 °C, 48-45 °C and 16-45 °C for seeds with water contents adjusted to 15, 20 and 25% respectively, are efficient for evaluating maize seed vigor using a controlled deterioration test. [ABSTRACT FROM AUTHOR]

In a program of seed quality assurance, the evaluation of seed vigor is fundamental and necessary to the global production process outcome. The objective of this experiment was to verify the efficiency of different vigor tests for evaluation of sweet corn seeds quality towards lots differentiation and prevision of seedling emergence and storage capacity of those. Ten lots of DO-04 shrunken-2 (sh2) hybrid sweet corn seeds were submitted to the following evaluations: germination, first counting of germination test, earliness of primary root emission (32, 48, 56 and 72 hours), cold test, electrical conductivity test (50 seeds into 75ml of water, at 25°C for 4, 6, 8 and 24 hours), accelerated aging test (42°C) in distilled water (100% RH), potassium chloride saturated solution (87% RH) and sodium chloride saturated solution (76% RH). Four exposition periods (24, 48, 72 and 96 hours) were evaluated and also seed water content, field seedlings emergence and germination after seeds storage (10°C and 40%RH) during sixteen months. The electrical conductivity test (for 6, 8 and 24 hours) was the unique test efficient to distinguish vigor of sweet corn (sh2) seeds lots, but it did not present correlation with field seedlings emergence or storage capacity. [ABSTRACT FROM AUTHOR]

Soybean productivity under the no till system (NTS) can be influenced by the preceding type of plant cover and surface liming. However, the effects of this technique on yield components and the seed physiological quality have been little studied, especially in ("safrinha") off-season soybean under NTS. Therefore, this study aimed to evaluate some agronomic traits, yield components, productivity, and physiological quality of soybean grown during the off-season ("safrinha"), as a function of different cover plants, with or without surface liming, under NTS. The experiment was conducted during the 1999/00 cropping season on the Lageado Experimental Farm, FCA/UNESP/Botucatu-SP, Brazil. The experimental design was organized as randomized blocks in split-plots, with 4 replications. The 6m × 10m plots consisted of broomcorn (Sorghum bicolor), millet (Pennisetum americanum), fall panicum (Panicum dichotomiflorum), spontaneous vegetation, and no vegetation. At 53 days after emergence the cover plants were desiccated and lodged, and a surface application of 3.1 t.ha-1 lime was made in half of the plots, in order to increase V% to 70. Soybean (cv. IAC-19) was sown two weeks later, during the off-season ("safrinha"). Determinations were made for the final stand, first pod height, plant height, total number of pods and blank pods per plant, total number of seeds per pod, 100-seed weight and yield. As to seed physiological quality, determinations were made for germination, artificial aging, germination at 18°C, plantlet D.M., and electric conductivity. During NTS implementation, plant cover type and surface liming did not affect the agronomic traits studied, yield components, seed productivity, and physiological quality of soybean seeds grown in the off-season ("safrinha") system, except for electric conductivity. [ABSTRACT FROM AUTHOR]

Hydration speed in soybean seeds can be affected by seed coat permeability due to thickness and composition variations. The objective of the present research was to evaluate the relation between the hydration speed and seed coat thickness and lignin content in soybean of different cultivars and locations of production. Soybean seeds of four cultivars and four production locations, with their moisture content, weight of 100 seeds, mechanical damage, germination and electrical conductivity previously determined, were evaluated by their hydration speed and seed coat characteristics, that consisted of lignin content and the palisade layer, hypodermic layer, lacunary parenchyma and total thickness. A randomized complete design was used and the means were compared by the Tukey test (P≤0.05) and by the simple linear correlation test (r). The hydration speed was evaluated as a factorial arrangement 4 x 8 (cultivar x time of hydration) for each production location and equations were fitted. It was concluded that the hydration speed in soybean seeds was affected by cultivar and production location and that it is correlated significantly to the lacunary parenchyma thickness. [ABSTRACT FROM AUTHOR]