The effect of gibberellic acid (GA3) and different substrates on the growth of Laelia tenebrosa was evaluated. In vitro germinated plants were transplanted to trays, acclimatized, and after nine months used in two experiments: (a) effect of different substrates: coconut powder, Pinus sp. bark, coconut powder + Pinus sp. bark, coconut powder + Pinus sp. bark + charcoal and coconut powder + Pinus sp. bark + charcoal + crushed walnut shells, with five plants/pot and seven repetitions; (b) effect of pulverization with GA3 (0, 25, 50, 100 and 200 mg L-1) with four plants/pot and seven repetitions. After 360 days, the following variables were evaluated: survival rate, shoot height, number of leaves and buds, length and width of leaves and root length. Significant differences were found for number of buds, length of leaves and roots, with the best results for the plants grown in coconut powder + Pinus sp. bark and coconut powder + Pinus sp. bark + charcoal + walnut shells. Significant differences were found with pulverization with GA3 for all variables except for leaf width and the best results were obtained with 25, 50 and 200 mg L-1.

Se evaluó el efecto del ácido giberélico (GA3) y de diferentes sustratos en el crecimiento de plantas de Laelia tenebrosa oriundas de la germinación in vitro, trasplantadas para bandejas colectivas, aclimatadas y tras nueve meses utilizadas en dos experimentos: a) evaluación del efecto de la pulverización con GA3 (0, 25, 50, 100 e 200 mgL-1) con cuatro plantas/florero y siete repeticiones; b) evaluación del efecto de los sustratos: polvo de coco, cáscara de Pinus sp., polvo de coco + cáscara de Pinus sp., polvo de coco + cáscara de Pinus sp. + carbón y polvo de coco + cáscara de Pinus sp. + carbón + cáscara de nueces, con cinco plantas/ florero y siete repeticiones. Tras 360 días se evaluó: supervivencia, altura de la parte aérea, número de hojas y brotes, largura y anchura de las hojas y largura de la raíz. Diferencias significativas fueron observadas para todas las variables excepto anchura de las hojas con pulverización con GA3 y mejores resultados con 25, 50 y 200 mgL-1. Diferencias significativas fueron observadas para número de brotes, largura de las hojas y mayor raíz, con mejores resultados cuando las plantas fueron cultivadas con polvo de coco + cáscara de Pinus sp. y polvo de coco + cáscara de Pinus sp.+ carbón + cáscara de nueces.

The objective of this study was to evaluate the effect of extracts obtained from leaves of Jatropha curcas L. on germination and initial growth of wheat. The aqueous and alcohol (ethanol and methanol) extracts of dried leaves were prepared in the concentration of 50 mg/mL. From the crude extract were made dilutions and obtained different concentrations. Some of the aqueous extracts tested were autoclaved. Over seven days, the germination characteristics and growth of wheat seedlings were evaluated with the different treatments. There was no effect of aqueous extracts on percentage of seed germination, however the methanolic and ethanolic extracts 5% affected the germination of a cultivar in study. There was a decrease in the germination speed index when the seeds were incubated with crude aqueous extract and methanol extract. The extracts affected the growth of seedlings and the most phytotoxic was the ethanol extract 5%. The autoclaved extracts promoted a reduction in all parameters evaluated. The results presented here show the extracts of dried leaves of jatropha promoted allelopathic effects on wheat.

El objetivo de la investigación fue evaluar el efecto de los extractos obtenidos a partir de hojas de Jatropha curcas L. sobre la germinación y el crecimiento inicial del trigo. Las acuosas y alcohol (etanol y metanol) extractos de hojas secas se prepararon de la concentración de 50 mg/ml. A partir del extracto crudo se hicieron diluciones, obteniendo diferentes concentraciones. Algunos de los extractos acuosos ensayados se trataron en autoclave. Durante siete días, las características de germinación y crecimiento de plántulas de trigo fueron evaluados con los diferentes tratamientos. No hubo efecto de extractos acuosos en el porcentaje de germinación de las semillas; sin embargo, los extractos metanólicos y etanólicos 5% afectaba la germinación de un cultivar en estudio. Hubo una disminución en el índice de velocidad de germinación cuando las semillas se incubaron con extracto crudo acuoso y extracto de metanol. Los extractos afectaron el crecimiento de las plántulas y el más fitotóxico era el extracto en etanol 5%. Los extractos autoclave promovieron una reducción en todos los parámetros evaluados. Los resultados aquí presentados muestran los extractos de hojas secas de Jatropha que promueven efectos alelopáticos sobre el trigo.

O presente trabalho teve como objetivo avaliar a qualidade pós-colheita de frutos de cubiu (Solanum sessiliflorum) durante o amadurecimento após o tratamento com Etefon. Frutos das variedades Santa Luzia e Thais no estádio verde-maduro foram coletados, lavados e pulverizados até o completo molhamento com 1000 mg L-1 de Etefon e o controle com água. A cada três dias, durante 12 dias foram realizadas análises da firmeza do pericarpo, pH, teor de sólidos solúveis totais, acidez total titulável (ATT), umidade e cinzas. Foi avaliada a liberação de C0(2) e etileno diariamente durante 12 dias, conjuntamente com a perda de matéria fresca e evolução da cor, a cada três dias, sempre no mesmo grupo de frutos. Foi empregado o delineamento experimental inteiramente casualizado. Os dados foram submetidos à análise de variância e análise de regressão. Ocorreu perda de firmeza do pericarpo dos frutos com o tempo de armazenamento pós-colheita, com diminuição do pH, aumento da ATT e perda da matéria fresca. A aplicação de Etefon promoveu poucas mudanças na qualidade interna dos frutos, porém foi eficiente no desverdecimento da casca, o que pode ser verificado pelos menores valores do ângulo de cor e maiores da cromaticidade e luminosidade. O comportamento da respiração e produção de etileno aponta para um modelo de amadurecimento não climatérico.

The objective of the present work was to evaluate postharvest quality of cubiu (Solanum sessiliflorum) fruits during ripening after Ethephon treatment. Fruits from the varieties Santa Luzia and Thais were harvested at green-mature stage, washed and sprayed until run off with Ethephon (0 e 1000 mg L-1). At every three days, during 12 days, the following analyses were performed: pericarp firmness, pH, total soluble solid content, total titratable acidity (ATT), water content and ashes. CO2 and ethylene production were evaluated daily for 12 days, together with the loss of fresh matter and color evolution, at every three days, always the same fruit group. The experiment was arranged in a complete randomized design. Data were examined by analysis of variance and regression analysis. There was loss of pericarp firmness with time of postharvest storage, with decrease in pH, increase in ATT and loss of fresh matter. Ethephon promoted small changes in the internal quality of fruits, whereas it was efficient to induce degreening of fruit peel, which can be verified by the lower color angles and higher chromaticity and brightness. Respiration rates and ethylene production of the fruit suggest that cubiu has non-climateric behavior.

Objetivou-se, no presente trabalho, avaliar o efeito do 2,4-D e do BAP na formação de protocormos a partir de regiões meristemáticas da raiz e segmentos foliares de Miltonia flavescens Lindl., bem como testar o efeito de concentrações de sacarose e níveis de pH no crescimento in vitro dos protocormos. Ápices radiculares e segmentos de folhas de plantas germinadas in vitro foram inoculados em meio de cultura MS/2 suplementado com 2,4-D e BAP onde permaneceram por 210 dias no escuro, sendo transferidos para a luz e inoculados em meio de cultura isento de reguladores, avaliando-se a porcentagem de explantes com protocormos e o número médio de protocormos regenerados por explante. A associação de 3 mg L-1 de 2,4-D e 1 ou 3 mg L-1 de BAP proporcionou os melhores resultados quanto à formação de protocormos. Esses foram cultivados em meio de cultura MS/2 onde testou-se o efeito da sacarose (0, 15, 30, 45 e 60 g L-1) e do pH (5.0, 5.8 e 6.6) sobre o seu crescimento. As concentrações de 15 e 30 g L-1 de sacarose independentes do pH, mostraram-se mais eficientes para o cultivo in vitro da espécie proporcionando a formação de um maior número e comprimento de raízes, altura de parte aérea e peso da matéria fresca. O pH só apresentou-se significativo quando em combinação com 15 g L-1 de sacarose para as variáveis comprimento da maior raiz e peso da matéria fresca.

The aim of the present work was to evaluate the effect of 2,4-D and BAP on the protocorm formation from meristematic areas of the root and leaf segments of Miltonia flavescens Lindl., as well as to test the effect of sucrose concentrations and pH levels on the in vitro growth of protocorms. Root apexes and leaf segments of in vitro-germinated plants were cultured on MS/2 culture medium supplemented with 2,4-D and BAP and kept in the dark for 210 days. Explants were then transferred to light and cultured on culture medium lacking growth regulators. Percentage of explants with protocorms and average number of protocorms regenerated per explant were evaluated. The combination of 3 mg L-1 2,4-D and 1 or 3 mg L-1 BAP provided the best results for protocorm formation. Protocorms were cultured on MS/2 culture medium to test the effect of sucrose (0, 15, 30, 45, and 60 g L-1) and pH (5.0, 5.8, and 6.6) on their growth. The concentrations of 15 and 30 g L-1 sucrose, independently of the pH, were more efficient for the in vitro culture of this species, promoting an increase in the number and length of the roots, plant height, and fresh weight. The pH was significant only in combination with 15 g L-1 sucrose for the variables length of the largest root and fresh weight.