Francisco Guilhien Gomes Junior

Avaliação de danos mecânicos em sementes de soja por meio da análise de imagens.

The present study had the objective of developing a non-conventional method to determine mechanical damage in soybean seeds, and also to verify its relation to the physiological quality, using the image analysis technique. Unlike the traditional tests, this technique analyzes seeds without destroying them, and together with the germination test, it can be observed that the damage detected in the image analysis is really important because of its influence on the germination process. The research was carried out with three cultivars of soybean (FT-2, FT-10 and IAC-2), possessing different contents of lignin in the seed coat (different resistance performance for mechanical damage). The mechanical damage had been caused by means of the pendulum test in six different regions of the seeds. The image analysis identified external and internal mechanical damage in soybean seeds, and was also efficient in detecting weathering and stink-bug damage.

Avaliação da viabilidade de sementes de pinhão manso pelos testes de tetrazólio e de raios X

The Jatropha curcas L. presents a great potential for fuel, but there are few studies to assess seed quality of this species. Therefore, this research aimed to study the performance of the tetrazolium salt test procedures and to verify the efficiency of the X-ray test to evaluate the seed viability of this species. Seeds were hydrated between paper towel and immersed in water to reach 30 and 40% m.c.. Following, seed coat was removed manually and seeds were immersed in 0,075 and 0,5% tetrazolium solutions for 120 min., respectively, at 40oC. Best results of tetrazolium test comprised the hydration between paper, until the seeds reach 30% m.c. and coloration in contact with a solution of 0,5%. The Jatropha curcas L. seeds were also submitted to X-ray test, in intensity of the 25Kv for 60s. Results of tetrazolium and X-ray tests were compared to germination and it was shown that both are efficient to assess Jatropha curcas L. seeds viability.

Assessment of physiological potential of cucumber seeds using the software Seedling Vigor Imaging System® (SVIS®)

The software Seed Vigor Imaging System (SVIS®), has been successfully used to evaluate seed physiological potential by automated analyses of scanned seedlings. In this research, the efficiency of this system was compared to other tests accepted for assessing cucumber (Cucumis sativus L.) seed vigor of distinct seed lots of Supremo and Safira cultivars. Seeds were subjected to germination, traditional and saturated salt accelerated aging, seedling emergence, seedling length and SVIS analyses (determination of vigor indices and seedling growth uniformity, lengths of primary root, hypocotyl and whole seedlings). It was also determined whether the definition of seedling growth/uniformity ratios affects the sensitivity of the SVIS®. Results showed that analyses SVIS have provided consistent identification of seed lots performance, and have produced information comparable to those from recommended seed vigor tests, thus demonstrating a suitable sensitivity for a rapid and objective evaluation of physiological potential of cucumber seeds. Analyses of four-days-old cucumber seedlings using the SVIS® are more accurate and growth/uniformity does not affect the precision of results.

Avaliação do vigor de sementes de milho superdoce por meio da análise computadorizada de imagens de plântulas

The objective of this study was to verify the efficiency of an automated system for seedling evaluation (SVIS®) to assess supersweet corn seed vigor compared to information from accepted vigor tests. Five seed lots, each of the SWB 551 and SWB 585 hybrids, were subjected to germination, accelerated aging (traditional and saturated salt) and field seedling emergence tests. The Seed Vigor Imaging System (SVIS®) parameters comprised mean seedling growth, uniformity and a vigor index, computed in scanned images of three-day old seedlings from the germination test. The results for both hybrids provided by SVIS® were comparable to those from the traditional accelerated aging test, thus demonstrating an efficient vigor evaluation of supersweet corn seeds.

Spatial variability of soil fertility and its relationship with seed physiological potential in a soybean production area

The correlation of soil fertility x seed physiological potential is very important in the area of seed technology but results published with that theme are contradictory. For this reason, this study to evaluate the correlations between soil chemical properties and physiological potential of soybean seeds. On georeferenced points, both soil and seeds were sampled for analysis of soil fertility and seed physiological potential. Data were assessed by the following analyses: descriptive statistics; Pearsons linear correlation; and geostatistics. The adjusted parameters of the semivariograms were used to produce maps of spatial distribution for each variable. Organic matter content, Mn and Cu showed significant effects on seed germination. Most variables studied presented moderate to high spatial dependence. Germination and accelerated aging of seeds, and P, Ca, Mg, Mn, Cu and Zn showed a better fit to spherical semivariogram: organic matter, pH and K had a better fit to Gaussian model; and V% and Fe showed a better fit to the linear model. The values for range of spatial dependence varied from 89.9 m for P until 651.4 m for Fe. These values should be considered when new samples are collected for assessing soil fertility in this production area.

Utilização da análise computadorizada de plântulas na avaliação do potencial fisiológico de sementes de amendoim tratadas com fungicida e inseticida

As sementes de amendoim sao consideradas de dificil producao, pois apresentam frequentemente indices insatisfatorios de germinacao e de vigor devido a muitos fatores, dentre eles, problemas associados a ocorrencia de fungos e a alta sensibilidade as injurias mecânicas. Assim, o tratamento das sementes com fungicida, juntamente com inseticidas, visando o controle de pragas iniciais na cultura, e recomendavel. Na avaliacao do potencial fisiologico de sementes de amendoim, alem dos metodos rotineiramente utilizados, a analise computadorizada de plântulas tem grande potencial, pois e metodo rapido, preciso e sem erros de interpretacao humana. O presente trabalho teve como objetivo avaliar a qualidade fisiologica de sementes de amendoim tratadas com fungicida ou inseticida, bem como a associacao de ambos, utilizando-se a tecnica de analise computadorizada de plântulas. Sementes do cultivar IAC 886 nao tratadas e tratadas com o fungicida Maxim XL (Fludioxonil + Metalaxyl), com o inseticida Cruiser 350 FS (Tiametoxam) e com a mistura de ambos os produtos foram submetidas aos periodos de armazenamento de 0, 15, 30, 45, 60, 90 e 180 dias (20 °C, 50% UR do ar). Apos cada periodo de armazenamento, as sementes foram submetidas a avaliacao do grau de umidade, germinacao, envelhecimento acelerado, emergencia de plântulas em campo, condutividade eletrica e sanidade, alem da analise computadorizada de plântulas. Concluiu-se que a analise computadorizada de plântulas apresenta eficiencia equivalente aos testes de envelhecimento acelerado e de emergencia de plântulas em campo na identificacao de diferencas entre tratamentos com ausencia ou presenca de fungicida e de fungicida associado a inseticida nas sementes de amendoim.

Computerized imaging analysis of seedlings for assessment of physiological potential of wheat seeds

Nowadays, image analysis is one of the most modern tools in evaluating physiological potential of seeds. This study aimed at verifying the efficiency of the seedling imaging analysis to assess physiological potential of wheat seeds. The seeds of wheat, cultivars IAC 370 and IAC 380, each of which represented by five different lots, were stored during four months under natural environmental conditions of temperature (T) and relative humidity (RH), in municipality of Piracicaba, Stated of Sao Paulo, Brazil. For this, bimonthly assessments were performed to quantify moisture content and physiological potential of seeds by means of tests of: germination, first count, accelerated aging, electrical conductivity, seedling emergence, and computerized analysis of seedlings, using the Seed Vigor Imaging System (SVIS ® ). It has been concluded that the computerized analyses of seedling through growth indexes and vigor, using the SVIS®, is efficient to assess physiological potential of wheat seeds.

Using Tomato Analyzer software to determine embryo size in x-rayed seeds.

A primary interest of image analysis of X-rayed seeds is to identify whether the extent of fill in the embryo cavity is associated with to seed physiological quality. The objective of this research was to verify the accuracy of the freely available Tomato Analyzer (TA) software developed at The Ohio State University to determine the ratio of embryo size over total seed area. Seeds of pumpkin, watermelon, cucumber and cotton were X-rayed and analyzed by the software which defines seed and embryo boundaries and automatically generates numerical values to quantify that ratio. Results showed that the TA has the sensitivity to evaluate the extent of embryo growth within the cucurbits and cotton seeds and is a promising alternative for this assessment in other seed species.

X-Ray analysis to assess mechanical damage in sweet corn seeds 1

The X-ray test is a precise, fast and non-destructive method to detect mechanical damage in seeds. In the present study, the efficiency of X-ray analysis in identifying the extent of mechanical damage in sweet corn seeds and its relationship with germination and vigor was evaluated. Hybrid SWB 551 (sh2) seeds with round (R) and flat (F) shapes were classified as large (L), medium (M1, M2 and M3) and small (S), using sieves with round and oblong screens. After artificial exposure to different levels of damage (0, 1, 3, 5 and 7 impacts), seeds were X-rayed (15 kV, 5 min) and submitted to germination (25 °C/5 days) and cold (10 °C/7 days) tests. Digital images of normal and abnormal seedlings and ungerminated seeds from germination and cold tests were jointly analyzed with the seed X-ray images. Results showed that damage affecting the embryonic axis resulted in abnormal seedlings or dead seeds in the germination and cold tests. The X-ray analysis is efficient for identifying mechanical damage in sweet corn seeds, allowing damage severity to be associated with losses in germination and vigor.

Proteína e qualidade de sementes de feijão (Phaseolus vulgaris L.) em função da adubação nitrogenada em plantio direto

Nitrogen limitation in the common bean (Phaseolus vulgaris L. ) produces reduced productivity and seeds with low protein content and physiological quality. We assessed the effects of nitrogen fertilizer side dressing on the protein content and physiological quality of the seeds of P. vulgaris L. cultivars (cv.) IPR Juriti and Perola grown in plots (soil type = Dystrophic Red Latosol) using a no-tillage system under a thick mulch of millet residues at the Experimental Station of UNESP - Ilha Solteira campus, located in Selviria, MS (Koppen climate type = Aw) during autumn (March/June) and winter (June/September) 2005. For each cultivar, a randomized block experimental design was used with four replicates and factorially arranged treatments equivalent to 0, 30, 60, 90 and 120 kg.ha-1 added nitrogen (as urea, containing 45% of N) applied as a side dressing during the V4-3 and V4-6 phenological stage corresponding to the 3rd and 6th completely opened trifoliolate leaf on the main stem. Supplementation with up to 120 kg.ha-1 nitrogen promoted a greater increase in crude protein at V4-3 (unsupplemented = 17.6% and 16.3%; 120 kg.ha-1 N = 24.1% and 22.3% for cv. IPR Juriti and Perola, respectively) than at V4-6 (unsupplemented = 19.2% and 18.3%; 120 kg.ha-1 N = 21.3% and 20.3% for cv. IPR Juriti and Perola, respectively). About 90% of the crude protein from cv. IPR Juriti was composed of soluble protein compared to 72% for the cv. Perola. Albumins and globulins represented about 80% of the soluble protein and prolamins were lower at 0.6%. In conclusion, nitrogen fertilization up to 120 kg.ha-1 applied as a side dressing at the V4-3 phenological stage in no-tillage under a thick mulch of millet promoted a greater increase of crude protein in common bean seeds than at the V4-6 stage. The highest accumulation of soluble protein occurred at 90 kg.ha-1 applied nitrogen without having a significant influence on the physiological quality of the seeds.