-The objective of this work was to evaluate the effects of temperature (10, 20, 30, 20/10 and 30/10ºC) and period of storage on electrical conductivity (EC) in four seed lots of corn (Zea mays L.), as well as the mineral composition of the soaking solution. EC test determines indirectly the integrity of seed membrane systems, and is used for the assessment of seed vigor, because this test detects the seed deterioration process since its early phase. The research comprised determinations of water content, germination, accelerated aging (AA), cold (CT) and EC vigor tests, and determinations of Ca 2+ , Mg 2+ and K + release to the solution, after seed soaking of four corn seed lots. The evaluations were performed each four months during a period of 16 months. For statistical analysis, a completely randomized split plot design was used with eight replications. Except for seed lots stored at 10ºC, all vigor evaluations revealed a decline in vigor, but AA and CT showed more sensitiveness to declines of seed physiological quality than EC. Potassium was the main leached ion regardless of the storage temperature.

; JULIANA ALTAFIN GALLI 5 RESUMO -A pesquisa teve por objetivo avaliar a qualidade física, fisiológica e sanitária de sementes de milho durante as etapas de beneficiamento. Foram utilizadas 16 amostras de um lote de sementes do híbrido D766 safra 2001/2002 , classificado em sementes chatas médias curtas e redondas curtas, de peneiras 20 e 22. As amostras foram obtidas durante as fases do beneficiamento de recepção, pré-limpeza, pós-mesa de gravidade, pós-classificador e pós-ensaque. As sementes foram avaliadas quanto ao teor de água, germinação, primeira contagem da germinação, índice de velocidade de germinação, envelhecimento acelerado, teste de frio, condutividade elétrica, emergência das plântulas em campo, sanidade, através do teste de papel filtro e dano mecânico. Para análise estatística utilizou-se o delineamento inteiramente casualizado, com quatro repetições, e a comparação das médias foi feita usando-se o programa SAEG, teste de comparações múltiplas de Scott-Knott a 5% de probabilidade. Os resultados deste trabalho sugeriram que os danos mecânicos podem ocorrer em cada fase do processamento e são cumulativos e o beneficiamento de sementes de milho pode aprimorar a qualidade de sementes de um lote em termos de germinação, vigor e sanidade.Termos para indexação: Zea mays L., germinação, vigor, processamento, injúria mecânica. QUALITY EVALUATION OF CORN SEEDS DURING CONDITIONINGABSTRACT -The objective of this research was to evaluate the physical, physiological and sanitary quality of corn seeds during conditioning. Sixteen samples of a corn seed lot hybrid D766 produced in 2001/2002 was used, classified as medium short flat and short round, from the screens 20 and 22. The seed samples were obtained during the following conditioning steps: reception, pre-cleaning, post-gravity separator, post-grader and after bagging. The seeds were evaluated for the moisture content, standard germination, first germination count, speed of germination index, accelerated aging, cold test, electrical conductivity, seedling field emergence, health test through the filter paper and injury test. The experimental design used was completely randomized with 4 replications and the mean comparison was made through the Scott-Knott multiple path comparison test at 5% level of probability. According to the obtained results it was concluded that mechanical injury can occur at any stage of seed conditioning and is cumulative and the corn seed conditioning may improve the seed lot quality in for germination, vigor and health.

ELECTRICAL CONDUCTIVITY TEST OF SOYBEAN SEEDS STORED UNDER DIFFERENT TEMPERATURESThere are some results showing that the electrical conductivity test can be influenced by low temperature of seed storage, such as 10 o C. This work was carried out in order to study the effect of temperature and period of storage on electrical conductivity and chemical composition of the imbibing solution of soybean seeds. For that, seed water content, germination, vigor (accelerated aging, cold test and electrical conductivity), and chemical composition (K + , Ca 2+ and Mg 2+ ) of the imbibing solution were determined. Two soybean seed lots of cultivar FT-20 with high and low vigor were used. The evaluations were performed at every three months intervals, during 15 months. Both temperature and storage period influenced seed vigor, as well as the ions leakage. It can be concluded that the electrical conductivity test is not suitable to evaluate vigor of soybean seeds stored at low temperature, and potassium is the major ion leakage regardless of the storage temperature.

Effect of Fusarium graminearum and infection index on germination and vigor of maize seeds. Fitopatologia Brasileira 30: 470-474. 2005. ABSTRACTPathogens in maize (Zea mays) seeds cause serious problems, such as the loss of their capacity to germinative. The objectives of this study were to identify the optimal period for infection of maize seeds on agar colonized by Fusarium graminearum, when incubated for 4, 8, 16 and 32 h, and to evaluate the effect of the fungus on the germination and vigor of seeds with different infection levels. After the respective incubation periods, the seeds were removed from the culture medium and submitted to the blotter test for 3 min with and without superficial disinfection with 1% solution of sodium hypochlorite. Once the optimal period for seed incubation was identified, seeds from the same sample were again placed on the colonized agar for infection. Germination and vigor tests (accelerated aging and cold test) were performed with a mixture of healthy seeds (placed on PDA medium) and inoculated seeds, resulting in seeds with 0, 20, 40, 60, 80 and 100% rates of infection. The results showed that a period of 32 h was long enough to obtain seeds infected by the pathogen. There were no significant effects of fungal infection on seed germination at any of the infection levels, probably due to the high vigor of the maize seed lot tested. Regarding vigor tests, infection levels differed significantly from the control (0% infection), but there were no significant differences among the infection levels.Additional keywords: Zea mays, seed pathology. RESUMO Efeito de Fusarium graminearum e índice de infecção na germinação e vigor de sementes de milhoPatógenos em sementes de milho (Zea mays) causam sérios problemas, como a perda de sua capacidade germinativa. O objetivo do trabalho foi determinar qual o melhor tempo para infecção das sementes de milho com Fusarium graminearum, para posterior avaliação dos danos causados pelo fungo na germinação e vigor das mesmas. As sementes foram colocadas sobre meio de BDA contendo o patógeno e incubadas por 4, 8, 16 e 32 h. Após os respectivos períodos de incubação, estas foram submetidas ao teste de sanidade (papel de filtro), com duas variações, sem e com assepsia superficial, usando hipoclorito de sódio a 1% de cloro ativo, por 3 min. Determinado o melhor tempo para infecção, outras sementes foram infetadas com o patógeno, para realização dos testes de germinação e vigor (envelhecimento acelerado e teste de frio) com uma mistura de sementes sadias (colocadas sobre o meio BDA) e sementes inoculadas, resultando em 0, 20, 40, 60, 80 e 100% de sementes infetadas com o fungo em estudo. Os resultados obtidos mostraram que o período de incubação de 32 h foi suficiente para se obter sementes infetadas. Com relação à germinação, não houve diferenças significativas entre os diferentes níveis de infecção, provavelmente devido ao alto vigor das sementes de milho testadas. Quanto aos testes de vigor, os níveis de infecção diferiram significativamente da testemun...

The objectives of this research were to elaborate a water imbibition curve to determine the best period to regulate broccoli seed water content and to improve the controlled deterioration test for this species. Three commercial inbreed seeds were used, two seed lots of Piracicaba precoce, two seed lots of Florida and four seed lots of Ramoso. These seeds were submitted to water content determination, germination test, first count germination, seedling length, seedling emergence test, seed index emergence and controlled deterioration (18, 20, 21, 23 e 24% water content, at 45ºC and 24h period). The water imbibition curve was determined at about 84 hours. The experiment was conducted in a randomized complete block design and the means were compared by the Tukey test (5% probability). The water imbibition curves permitted estimation of 15, 20, 22, 32 and 48 hour periods needed to increase the water content to values 18, 20, 21, 23 and 24%, respectively. The controlled deterioration test gave good results and in all water contents evaluated it was efficient in detecting vigor differences among broccoli seed lots as well as the emergence speed index and seedling emergence.