Victor Augusto Forti

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.

Avaliação de danos por umidade, em sementes de soja, utilizando a técnica da análise de imagens

RESUMO - Entre os problemas envolvidos na producao de sementes de soja destacam-se os danos por umidade, queresultam em perdas de germinacao e de vigor. A tecnica de analise de imagens, por meio do teste de raios X, e ummetodo de precisao que possibilita examinar , com detalhes, a regiao danificada ou alterada, sua localizacao e extensao.Por ser um metodo nao destrutivo, as sementes em analise podem ser submetidas a testes fisiologicos e, desta forma,e possivel estabelecer as relacoes de causa e efeito. O presente trabalho teve como objetivo avaliar a eficiencia datecnica de analise de imagens, por meio do teste de raios X, na identificacao dos danos por umidade em sementes desoja, comparativamente ao teste de tetrazolio. Sementes de diferentes lotes de um mesmo cultivar (BRS 184) foramsubmetidas ao teste de raios X e, posteriormente, destinadas ao teste de primeira contagem de germinacao, de forma arelacionar os danos com os possiveis prejuizos proporcionados as sementes. Paralelamente, foi realizado o teste detetrazolio visando comparacao com o teste de raios X. Para a analise interpretativa do teste de raios X, foram consideradasa severidade e a localizacao dos danos, juntamente com as fotografias digitais das plântulas ou sementes mortasresultantes do teste de primeira contagem de germinacao. Com os resultados obtidos, pode-se afirmar que a analise deimagens mostrou-se eficiente na deteccao dos danos por umidade em sementes de soja.Termos para indexacao : Teste de raios X, qualidade de sementes, Glycine max ( L.) Merrill.IMAGE ANAL YSIS TECHNIQUE T O EVALUA TE WEA THERING DAMAGE IN SOYBEAN SEEDSABSTRACT - Image analysis is a very promising technique to determine damage in seeds, which can result in germinationand vigor losses. This precise method examines seeds individually using enlarged images in which damaged areas, aswell their exact location and extension, can be found and examined in detail. Since this is a non-destructive method,analyzed seeds can be submitted to physiological tests to establish the relationship between damage and quality loss.The goal of this research was to study the efficiency of the image analysis technique, by the X-ray test, to identifyweathering damage in soybean seeds, compared with the tetrazolium test. Seeds of different lots of soybean, cultivarBRS 184, were submitted to the X-ray test and, consecutively , used for the first count of the germination test, in orderto determine the possible relationship between cause and ef fect. Simultaneously , the X-ray test was compared with thetetrazolium test. For the interpretation of X-ray test, the severity and location of weathering damage was considered.The results showed that image analysis, by the X-ray test, was efficient in detecting weathering damage in soybeanseeds.Index terms: X ray , seed quality , Glycine max ( L.) Merrill

Use of X-ray to evaluate damage caused by weevils in cowpea seeds

No Brasil, o feijao-caupi [Vigna unguiculata (L.) Walp], tem destaque na Regiao Nordeste, sendo uma cultura tipica da agricultura familiar. A importância dos danos causados por pragas de armazenamento em sementes da referida especie, em relacao a sua qualidade, tem sido evidenciada em varios trabalhos. Atraves de imagens de raios X e possivel visualizar as estruturas internas da semente, identificando possiveis alteracoes e danificacoes. Dessa forma, esse trabalho teve o objetivo de identificar os danos causados por caruncho (Callosobruchus maculatus) e sua relacao com a qualidade fisiologica das sementes de feijao-caupi, por intermedio da analise de raios X. Foram utilizadas tres cultivares (IPA-206, BRS-Pajeu e BRS-Potengi) e duas linhagens (L 281.005 e L ESP 10). As amostras foram submetidas ao teste de raios X e ao teste de germinacao, a fim de determinar a relacao de causa e efeito entre os danos provocados pelo caruncho e a germinacao das sementes. Nas avaliacoes das imagens de raios X foi considerada a severidade e a localizacao dos danos na semente. Para os danos classificados como severos, localizados no eixo embrionario e, ou nos cotiledones, as sementes originaram plântulas anormais ou as sementes estavam mortas. Portanto, o teste de raios X e eficiente para a avaliacao de danos causados por caruncho em sementes de feijao-caupi, permitindo relacionar os eventuais danos com os prejuizos causados a germinacao.

Teste de raios X para avaliação do potencial fisiológico de sementes de ipê-roxo

The use of seeds with a high physiological potential is essential to guarantee proper field establishment and seedling development. Several techniques have been used to evaluate seed quality including the X-ray test. The objective of this study was to evaluate the physiological potential of Tabebuia heptaphylla seeds with X-ray and germination tests after grading by color and size. Seeds were classified using the Munsell color chart and screens, in light-yellow larger, light-yellow smaller, dark-yellow larger, dark-yellow smaller, mixture of light-yellow larger, light-yellow smaller and dark-yellow larger and control. Seeds from different fractions were then submitted to X-ray and germination tests. The experimental design was completely randomized with six treatments and five replicationsand mean values were compared by the Scott-Knott test (< 5%). Results showed that the X - ray test effectively evaluates the internal morphology of Tabebuia heptaphylla seeds and its relationship with physiological potential. Seed color and size affect the physiological potential of Tabebuia heptaphyla seeds.

Temperatura inicial de germinação no desempenho de plântulas e mudas de tomate

Seedling production is an important step for the tomato production and can be influenced by the initial temperature of germination. The aim of this study was to evaluate the effect of this factor in the tomato germination and seedling growth. It was used four seed lots which were tested for germination, accelerated aging and electrical conductivity to evaluate the physiological potential. After lots characterization, seeds were exposed to initial germination temperatures (20-30, 30, 33 and 35°C) and were analyzed by the SVIS® software. The seedling performance was evaluated using the emergence speed index and percentage, height and dry weight of shoots and roots. In general, the higher temperatures decreased the seedlings development. However, 28 days after sowing, the seedlings growth was similar among temperatures.

Efeitos de potenciais hídricos do substrato e teores de água das sementes na germinação de feijão

Many environments factor can affect the germination, among them, the water availability and the seeds moisture content are important. The objective of the present investigation was to verify the influence of water availability of the substratum and moisture content of several cultivars of beans seeds in their germination and to verify the possible effects of imbibitions damage. The treatments were constituted with bean seeds of seven cultivars: IAC-Tuna, IAC-Ybate, IAC-Apua, IAC-Tybata, IAC-Votuporanga, IAC-Carioca and Carioca with moisture content of 9, 11 and 13% and submitted the water availability of the substratum of -0,04, -0,1, -0,2 and -0,4 MPa. The germinations percentage of each cultivar was evaluated for each condition. Therefore, the conclusion was that when the water availability decrease, with the increase of the hydro deficiency, the germination is reduced to any moisture content condition in the seeds for the seven cultivars. As for the seeds moisture content, it was not checked the influence in the germination. The imbibitions damage was not observed in the conditions which the seeds had been submitted.