The electrical conductivity test is still an excellent tool to evaluate the effect of seeds of various forest and agricultural species and recent studies have been conducted aiming at verifying its application in forest seeds. The objective of this study was to establish a specific methodology to test the electrical conductivity of forest seeds of Zeyheria tuberculosis. Four lots of seeds were used, which were submitted to the germination test, evaluating the percentage of germination, germination speed index and dry mass of seedlings. For the electrical conductivity test, five replicates of 20 seeds installed in three volumes of deionized water (75, 100 and 125 mL) were used and eight periods for seed imbibitions (2, 4, 6, 12, 18, 24, 48 and 72 hour) at 25 ºC were allowed. The statistical design used was completely random; the comparison of means was performed by Tukey test at 5 % probability. Lot II showed higher germination percentage and speed. The electrical conductivity test allows discrimination of the same batch by the germination test under laboratory conditions. It was possible to separate the seed lot presenting better physiological quality (lot II) from among the other lots. It was recommended the use of 75 or 125 mL of deionized water at a temperature of 25 ºC to perform the electrical conductivity test.

La prueba de la conductividad eléctrica de las semillas es una excelente herramienta para evaluar el vigor de semillas de diversas especies forestales y agrícolas. Recientemente la prueba ha sido aplicada en semillas forestales. El objetivo del presente trabajo fue adaptar dicha metodología para realizar la prueba de conductividad eléctrica y estudiar el volumen de agua y el periodo de imbibición para evaluar la calidad fisiológica de lotes semillas forestales de Zeyheria tuberculosa. Cuatro lotes de semillas (árboles madre) fueron sometidos a la prueba de germinación para evaluar el porcentaje de germinación, el índice de velocidad de germinación y materia seca de plántulas. Para la prueba de conductividad eléctrica fueron utilizados cinco repeticiones de 20 semillas cada una, instaladas en tres volúmenes de agua desionizada (75, 100 y 125 mL), con ocho periodos de imbibición (2, 4, 6, 12, 18, 24, 48 y 72 horas) a 25 ºC. El diseño estadístico empleado fue completamente al azar y la prueba usada fue Tukey al 5 % de propabilidad. El lote II presentó mayor porcentaje y velocidad de germinación. La prueba de la conductividad eléctrica y de germinación juzgaron igual a los lotes de semillas. Se recomienda el uso de 75 o 125 mL de agua desionizada, a la temperatura de 25 ºC, para la realización de la prueba de la conductividad eléctrica.

The objective of this study was to analyze the germination of seeds of Albizia hassleri under different temperatures. A completely random design arranged as a split plot for temperatures regimes, with 11 seed lots and four replications of 15 seeds was used. The plot was represented by the various lots and the sub plots for different temperatures. The means were compared by Scott-Knott test at 5% probability. The temperatures used were: a) constant: 20, 25 and 30° C, and b) alternating: 20-30 and 25-35° C. For all 11 seed lots the mean germination was 90%, speed germination index (IVG) was 5.059, fresh matter of seedlings (MMF) was 0.0628 g and dry matter (MMS) 0.0499 g. The variation coefficient (CV) between plots ranged from 8.48% for germination to 51.71% for dry matter of seedlings and sub plot of 6.77% to 60.45% for germination and MMS. These high values of CV, tested for MMS and MMF, indicate low repeatability of results within each treatment. In general, the IVG obtained at temperatures of 20 and 25° C was lower than those in temperatures of 30, 20-30 and 25-35° C. The best temperature for IVG was the alternating 25-35° C and constant 30° C. The germination test can be conducted at 30, 20-30 and 25-35° C for 19 days.

El objetivo de este estudio fue analizar el comportamiento germinativo de semillas de Albizia hasslerii bajo diferentes temperaturas. El diseño estadístico utilizado fue completamente al azar en parcelas subdivididas para temperaturas, con 11 árboles madres llamados lotes y cuatro repeticiones de 15 semillas. La parcela fue representada por los diferentes lotes y las subparcelas por las diferentes temperaturas. La comparación de las medias fue realizada por la prueba de Scott-Knott al 5% de probabilidad. Las temperaturas utilizadas fueron: a) constantes: 20, 25 y 30° C; y b) alternadas: 20-30 y 25-35° C. Para el conjunto de los 11 lotes se obtuvo germinación media de 90%, índice de velocidad de germinación (IVG) de 5,059, masa de materia fresca (MMF) de 0,0628 g plántula-1 y seca (MMS) de 0,0499 g plántula-1. Los coeficientes de variación (CV) entre parcelas variaron de 8,48% para germinación a 51,71% para masa seca de plántula y subparcela de 6,77% para germinación a 60,45% para MMS. Estos altos valores de C V, verificados para MMF y MMS indican baja repetibilidad de los resultados dentro de cada tratamiento. En general, los índices de velocidad de germinación (IVG) obtenidos en las temperaturas de 20 y 25° C fueron inferiores a los obtenidos en las temperaturas de 30, 20-30 y 25-35° C. La mejor temperatura para IVG fue la alternada de 25-35° C y la constante de 30° C. El ensayo de germinación puede ser realizado a 30, 20-30 y 25-35° C, por 19 días.

Este trabalho teve por objetivo verificar o uso do teste de condutividade elétrica para avaliar a qualidade fisiológica de sementes de Albizia hassleri (Chod) Burkart. provenientes de diferentes matrizes. O teste de condutividade elétrica foi realizado a 25 ºC, com cinco repetições de 20 sementes embebidas em 75 mL de água destilada por 2, 4, 6, 12, 24, 48, 72, 96 e 120 h. O teste de germinação foi conduzido a 25 ºC com cinco repetições de 20 sementes por 19 dias. Os dados foram submetidos à análise de variância e as médias de matrizes, comparadas pelo teste de Scott-Knott a 5% de probabilidade. Adicionalmente, procedeuse ao estudo de correlações entre os resultados de condutividade elétrica com os do teste de germinação e ao ajuste de regressões entre os valores de sementes com protrusão de radícula e de plântulas normais em função dos valores de condutividade elétrica, em cada período de embebição das sementes. Verificou-se grande variabilidade entre as matrizes, tanto no teste de germinação quanto no de condutividade elétrica. Os resultados de condutividade elétrica apontaram baixas estimativas de correlações com os obtidos no teste de germinação. As equações de regressão apresentaram baixos valores de coeficiente de determinação, denotando-se a grande variabilidade dos resultados. Pode-se concluir que o teste de condutividade elétrica não foi adequado para discriminação da qualidade fisiológica de sementes de A. hasslerii provenientes de diferentes árvores-matriz.

The objective of this research was to study the electrical conductivity test to evaluate the physiological quality of Albizia hassleri (Chod) Burkart. seeds. Sixteen mother tree plants were used and the conductivity test was performed at 25 ºC with the use of 75 mL of distilled water in periods of 2, 4, 6, 12, 24, 48, 72, 96 and 120 hours, with five replications of 20 seeds. The germination test was carried out at 25 ºC, and the final count was made on the 19th day. A completely randomized experimental design was used and the data were submitted to the variance analysis and the Scott-Knott test at 5% of probability to compare the mother tree means. Besides, correlations were performed between the electrical conductivity results and the germination percentage and normal seedlings and also the regression between both variables. A high variability was verified among the mother trees, both in the germination and in the electrical conductivity test. The results showed low correlation between the germination percentage and electrical conductivity. The regression between the electrical conductivity and germination presented a low determination coefficient. These data demonstrated that the electrical conductivity test was not adequate to discriminate the physiological seed quality of A. hasslerii obtained from different mother trees.

The objective of this research was to evaluate the growth of Tabebuia heptaphylla seedlings in distinct substrates with different amounts of urban waste compost and the relation between this growth and irrigation. A completely randomized experimental design was used, with a factorial arrangement of 15 substrates and 2 irrigation levels. The substrates were composed by the combination of different materials: urban waste, tanned cattle manure, vermiculite, soil and the commercial form Plantmax®. For the study of the seedlings development, the following characteristics were evaluated: plant height, stem diameter at soil level, number of leaves, above ground dry matter, root system dry matter, relation between plant height and stem base diameter, Dickson quality index and relation between plant height and above ground dry matter. Evaluations of plant height, stem diameter at soil level and number of leaves were made at 75, 90, 105, 120, 135 and 150 days after sowing. According to the results, it was concluded that urban waste compost does not increase plant development. Significant differences in relation to the irrigation levels were found, with better results for the 150% irrigation level compared to 100% evapotranspiration.

El estudio tuvo como objetivo evaluar el comportamiento de plántulas de Tabebuia heptaphylla producidas en sustratos con incorporación de diferentes cantidades de residuos urbanos y con dos regímenes de riego. El diseño estadístico utilizado consistió en bloques aleatorizados con 30 tratamientos en un esquema factorial de 15 x 2 (15 sustratos y dos niveles de irrigación), con dos repeticiones. Los sustratos fueron constituidos de diferentes combinaciones de: compuesto de residuo urbano, estiércol curtido, vermiculita más suelo, y sustrato comercial Plantmax®. Para el análisis de crecimiento de las plántulas se consideró: altura de la parte aérea, diámetro de la base del tallo de la planta, número de hojas, materia seca de la parte aérea y sistema radicular, relación altura de la parte aérea/diámetro de la base del tallo, índice de calidad de Dickson y relación altura de la parte aérea/materia seca de la parte aérea. Las características evaluadas fueron medidas a los 75, 90, 105, 120, 135 y 150 días después de la siembra. Se concluye que el compuesto de residuo urbano no favoreció el crecimiento de las plantas. El crecimiento de las plantas fue superior con el nivel de irrigación de 150% de la evapotranspiración con respecto al de 100%.