Germinative pretreatments to dormancy break in Guazuma ulmifolia Lam. seeds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

New species of Phrynohyas from Atlantic rain forest of southeastern Brazil (Anura, Hylidae)

A new species of hylid frog is described from south of the State of São Paulo, southeastern Brazil in Atlantic rain forest. The new species is a member of the genus Phrynohyas and is characterized by snout rounded in dorsal view and nearly truncate in lateral view, small adhesive disks, fingers slightly webbed, nasal bones widely separated, and frontoparietals without medial articulation.

Efeito da temperatura na germina̧ão de sementes de Sebastiania commersoniana (Baillon) Smith & Downs separadas pela colora̧ão do tegumento

Sebastiania commersoniana (Euphorbiaceae) is a tree species of riparian forests in Brazil. Seeds of this species released from mature fruits have heteromorphy in coat colour: dark (dark-brown to black), striated (dark with light-grey stria) and clear (light-grey to whitish). In this work two experiments were carried out in order to study the effect of temperature on seed germination in interaction with coat colour. Germination final percentage and speed index were evaluated. In the first experiment seeds of the three colours were submitted to constant (30°C) and alternating (20-35°C) temperatures. For all the seed colours, best results were obtained at alternating temperature. Physiological quality of striated seeds was greater than those clear seeds and dark seeds were intermediate. In the second experiment striated and clear seeds were submitted to three amplitudes of alternating temperature: 5°C (20-25°C and 25-30°C), 10°C (20-30°C and 25-35°C) and 15°C (20-35°C). Both germination percentage and speed were higher in striated seeds and for the two seed colours, best results were obtained at 20-30°C and 20-35°C. These temperatures are recommended for the germination test.

Physiological maturity of Cnidosculus quercifolius Pax & K. Hoffm. seeds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Germinação de sementes de pinho-cuiabano sob deficiência hídrica com diferentes agentes osmóticos

The species Schizolobium amazonicum (Huber ex Ducke) commonly known as pinho-cuiabano or paricá, is one of the trees in Amazonian area used for plantings in degraded areas, reforestations and agroforestry systems. The present work evaluated the germinative behaviour of seeds of Schizolobium amazonicum in relation to the hydric stress, defining their levels of tolerance to those limitations in the environment. The seeds were collected from 30 trees in Alta Floresta-MT and submitted the dormancy treatment by submersion into water at 100°C for 1 minute; followed by treatment with fungicide Ridomil and Cercobin 0,25% each, then being left to germinate in a BOD camera at 30°C under a photoperiod of 12 hours. For evaluating the effect of different water potentials in the germinative process, polyethylene glicol (PEG 6000) was used and the salts NaCI and CaCl 2 used to simulate saline stress. The seeds were put to soak in potentials of 0 (control); -0.1 ; -0.2; -0.3; -0.4 and -0.5MPa. For each treatment 5 repetitions of 20 seeds were used in gerbox, placed between filter paper moistened with 20 mL of PEG, NaCI and CaCl 2 solutions. The solutions were changed at intervals of 24 hours for maintenance of the potential. The evaluations of percentages and germination speed were carry out daily for 8 days, being considered germinated the seeds that presented a 2mm root extension or longer. The data were submitted to analysis of variance and averages compared by the Tukey test at 5% probability. It was concluded that osmotic potentials between -0.4 and -0.5MPa inhibited the germination of seeds of Schizolobium amazonicum completely. The osmotic stress caused by CaCl 2, and PEG injured the germination more than did the stress caused by NaCl.

Biometria e qualidade fisiológica de sementes de diferentes matrizes de Tabebuia chrysotricha (Mart. Ex A. DC.) Stand I.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Viabilidade de sementes de Piptadenia moniliformis Benth. Pelo teste de tetrazólio

Piptadenia moniliformis Benth. is a tree species which is important for beekeeping, as well as being recommended for soil restoration, reforestation, wood production for small civil construction projects, and cattle and sheep forage. Information on how to evaluate seed physiological quality is still scarce and in this was the study aimed to adapt the procedures of the tetrazolium test to assess the viability of P. moniliformis seeds. Four seed lots were scarified in sulphuric acid for 30 min, and soaked between paper towels at 25 °C for 24 hours. The seed coat was then removed and the naked seeds immersed in tetrazolium solutions with concentrations of 0.05, 0.075 and 0.1% for 2, 3, and 4 hours at 35 oC in the dark. Each treatment consisted of four replications of 25 seeds. The embryos were classified according to viability based on the staining patterns. The previous soaking of the seeds for 24 hours at 25 oC between paper towels, followed by the removal of the seed coat and staining of the naked seeds for 4 hours in a 0.075% tetrazolium solution at 35 oC was the most efficient method for evaluating the viability of P. moniliformis Benth seeds.

Teste de tetrazólio em sementes de Copaifera langsdorffii E schizolobium parahyba

This research aimed to standardize the tetrazolium test for evaluation of viability of Copaifera langsdorffii Desf. and Schizolobium parahyba Vell. Blake seeds. It evaluated the following methodologies: seeds scarificated mechanically and soaked up by 24 and 48 hours, with posterior seed coat removal and immersed in tetrazolium solution at 0.075; 0.10 and 0.20% for 2, 3 and 4 hours, 35 °C, the dark one. The evaluated methodologies that had been efficient in the attainment of satisfactory coloration, allowing the differentiation of tissues, and in the evaluation of the physiological quality of the seeds when compared with the germination test, had been: for the species Copaifera langsdorffii, seeds scarificated and soaked up by 24 hours, 35 °C, with posterior seed coat removal, submitted to the tetrazolium solution 0.20% for 4 hours, 35 °C, in the dark one, and for the species guapuruvu, seeds scarificated and soaked up by 48 hours, 35 °C, with posterior seed coat removal, submitted to the tetrazolium solution 0.10% for 4 hours, 35 °C, in the dark one.

Doses e épocas de aplicação de nitrogênio em cobertura na qualidade fisiológica de sementes de milho doce

The amount and timing of nitrogen application can favor seed quality, such as increasing protein content, which is an important constituent for embryo development. The objective of this study was to evaluate the physiological quality of sweet corn seeds collected from plants cultivated with different dosages and timings of nitrogen top-dressing applications. Seeds of the BR 400 variety (Super Sweet) were used obtained from plants submitted to dosages of 0, 40, 80 and 120kg ha -1 of N in two top-dressing applications (vegetative and reproductive stages). The weight of 100 grains, germination, first count of germination test, dry weight of normal seedlings from the germination test, seedling growth, cold test, accelerated aging, tetrazolium vigor and electric conductivity and emergency speed rate were determined. Data was submitted to an analysis of variance using the F-test at the 5% level and second degree regression analysis. The dosage and time of application of nitrogen top-dressing did not affect seed weight or the germination of sweet corn seeds. An increase of the N top-dressing dosage, applied in the vegetative stage reduced the length of the aerial part, the root and the whole seedling.

Nitrogen and potassium concentrations in the nutrients solution for melon plants growing in coconut fiber without drainage

With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The Bonus no. 2 was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L-1) and four K concentrations (4, 6, 8, and 10 mmol L-1). The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO3 and of K, and the electrical conductivity (CE) of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L-1) and K (10 mmol L-1) resulted in higher masses for the first (968 g) and the second (951 g) fruits and crop yield (4,425 gm-2). © 2013 Luiz Augusto Gratieri et al.

Sugarcane vinasse: Environmental implications of its use

The inadequate and indiscriminate disposal of sugarcane vinasse in soils and water bodies has received much attention since decades ago, due to environmental problems associated to this practice. Vinasse is the final by-product of the biomass distillation, mainly for the production of ethanol, from sugar crops (beet and sugarcane), starch crops (corn, wheat, rice, and cassava), or cellulosic material (harvesting crop residues, sugarcane bagasse, and wood). Because of the large quantities of vinasse produced, alternative treatments and uses have been developed, such as recycling of vinasse in fermentation, fertirrigation, concentration by evaporation, and yeast and energy production. This review was aimed at examining the available data on the subject as a contribution to update the information on sugarcane vinasse, from its characteristics and chemical composition to alternatives uses in Brazil: fertirrigation, concentration by evaporation, energy production; the effects on soil physical, chemical and biological properties; its influence on seed germination, its use as biostimulant and environmental contaminant. The low pH, electric conductivity, and chemical elements present in sugarcane vinasse may cause changes in the chemical and physical-chemical properties of soils, rivers, and lakes with frequent discharges over a long period of time, and also have adverse effects on agricultural soils and biota in general. Thus, new studies and green methods need to be developed aiming at sugarcane vinasse recycling and disposal. © 2013 Elsevier Ltd. All rights reserved.

Estágios de colheita e repouso pós-colheita dos frutos na qualidade de sementes de mamoneira

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Uso de biossólidos como substrato para produção de mudas de pinus e eucalipto

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Divergência genética entre árvores matrizes de Guazuma ulmifolia Lam

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Frugivoria e germinação de sementes após passagem pelo sistema digestivo de masupiais em floresta estacional semidecidual

Pós-graduação em Ciências Biológicas (Botânica) - IBB