Daniele Cardoso Pedroso

Envelhecimento acelerado em sementes de azevém com e sem solução salina e saturada

The objective of the present study was to evaluate the methodology of the accelerated aging test to evaluate the physiological potential of s ryegrass seeds, as well as verify the possibility of the use of unsaturated and saturated solution of NaCl as an option for control of water uptake by seeds during the test without reducing its sensitivity. Four lots of ryegrass seeds were tested for germination, seedling emergence, speed emergence and accelerated aging (periods of 24, 48, 72 and 96h, with or without the use of saturated and saline solution of NaCl). The use of unsaturated and saturated solution of NaCl reduces water absorption by ryegrass seeds during the accelerated aging test, resulting in a rate of deterioration is less pronounced ,less drastic and more uniform results. Option 24h with unsaturated solution (SNS) was only able to stratify plots into two groups and should not be designated as promising. Thus, it should be used the 48h saturated NaCl solution (SSS), which stratified into three lots.

Superação de dormência na qualidade de sementes e mudas: influência na produção de Senna multijuga (L. C. Rich.) Irwin & Barneby

The objective of this work was to determine the physiological and sanitary quality of Senna multijuga seeds related to the methods of dormancy overcoming and the influence on the seedlings quality. The seeds had been submitted to the following methods :immersion in water fervent, the seeds had been immersed in water, at 100°C, until cooling for 24 hours; acid escarification, where the seeds had been immersed in sulfuric acid (H 2 SO 4 ) 90%, for 10 and 20 minutes, and control (without treatment). The tests of sanity, germination and tetrazolium had been carried through, and were evaluated the quality of the seedlings. For the germination of the evaluation an factorial project was used (4 X 2), with four methods of dormancy X two light periods, for substrate paper and vermiculite. The acid scarification consisted in the method most efficient for the dormancy of Senna multijuga seeds. Penicillium sp. and Aspergillus sp. they had for its increased incidence when the seed coast was damaged by the acid scarification for 20 minutes. The control of Fusarium spp. increases gradual with the increase of the time of sulfuric acid exposition.

Critical levels of organic acids on seed germination and seedling growth of wheat

The objective of this study was to determine the responses of the wheat cultivars CD 108 and CD 111 for tolerance to organic acids. The effects of five concentrations of the three main acids formed in the soil were studied: acetic acid (0, 4, 8, 12 and 16 mM), propionic acid (0, 4, 8, 12 and 16 mM) and butyric acid (0, 2, 4, 8 and 12 mM). Tests included germination, shoot length, root length and dry weight of shoot and root. The variable root length is the most responsive variable for all the acids tested and the critical level of toxicity of acetic, propionic and butyric acids, which reduced root length by at least 50% was 9.0, 8.5 and 4.0 mM respectively. It was concluded that the presence of acetic, propionic and butyric acids in the germination substratum of wheat seeds of the cultivars CD 111 and CD 108 reduced seedling development, mainly by reducing the length of the radicles.

Tratamento de sementes de trigo com zinco: armazenabilidade, componentes do rendimento e teor do elemento nas sementes

The objective of this study was to evaluate the effects of seed treatment with zinc in zinc content and storability in seed as well as the components of yield of crops whose seeds were coated with doses 0, 1, 2, 3 and 4mL zinc sulfate (ZnSO4 kg-1) more fungicide, polymer and water, then were stored for six months in the environment without control of temperature and relative humidity. Before sowing the seeds were evaluated by germination test, and yield components were evaluated: number of spikelets per plant, number of grains per spikelet and grain weight per plant. After storage for six months assessed the zinc content in the seeds. The zinc coating shall not affect the viability of wheat seeds stored for six months, and further increases in the number of grains per spikelet and grain weight per plant. The zinc content in the seeds increased linearly with increasing doses of ZnSO4 via seed coating.

Detecção e influência de Fusarium spp. na qualidade fisiológica de sementes de pepino

Este trabalho teve por objetivo isolar, identificar e selecionar isolado(s) de Fusarium spp. em sementes de pepino e verificar a sua influencia na qualidade fisiologica. Foram utilizados tres sublotes e os tratamentos consistiram em: testemunha absoluta; BDA + manitol - 0,8Mpa; BDA; BDA + manitol - 0,8Mpa + fungo; e BDA + fungo. A qualidade fisiologica foi avaliada atraves de testes em laboratorio e casa de vegetacao. Cinco isolados de Fusarium verticillioides foram identificados e a sua transmissao atraves das sementes para plantas nao foi possivel afirmar. A tecnica da restricao hidrica foi eficiente para proporcionar infeccao das sementes, sabendo que e o fungo influencia negativamente na qualidade fisiologica das sementes de pepino da cultivar Caipira.

Inoculation methods of Alternaria alternata and A. dauci in parsley seeds and their influence on the physiological quality

The objective of the study was to evaluate the effect of the association of Alternaria alternata and A. dauci on the physiologic quality of parsley seeds inoculated by two methods: conidia suspension and water restriction. For the inoculation with suspension, a solution containing 105 conidia of A. alternata, A. dauci and both species (A. alternata + A. dauci), was prepared in which the seeds remained for 30 minutes. For inoculation by water restriction, a PDA medium was prepared, supplemented with 33.1 g/L of manitol, in which the A. alternata, A. dauci and A. alternata + A. dauci colonies grew. The seeds remain on the plates for 48 hours. After the inoculation, the quality of the seeds was evaluated by testing in the laboratory and greenhouse. The parsley seeds had their physiological quality damaged by association with A. alternata and A. dauci under laboratory conditions, especially in relation to germination, first count germination, abnormal seedlings, percentage of dead seeds and the cold test.

quALIDADE fISIOLÓGIcA E SANITáRIA DE SEMENTES DE Zinnia elegans Jacq. cOLHIDAS EM DIfERENTES ÉPOcAS 1

RESUMO - O objetivo do trabalho foi o de avaliar a influencia de diferentes epocas de colheita na qualidade fisiologica e sanitaria de sementes de zinia. As sementes zinia foram originadas de plantas semeadas em outubro de 2004, na area experimental do Departamento de Fitotecnia (UFSM). Os capitulos foram coletados manualmente e de acordo com a sua aparencia em sete epocas: 17 de janeiro, 10 de fevereiro, 15 de marco (coleta A), 23 de marco (coleta B), 12 de abril, 10 de maio (coleta A) e 29 de maio (coleta B) do ano de 2005. Aqueles provenientes de coletas em janeiro, fevereiro e maio (A) apresentavam-se verdolengos, os demais tinham aparencia seca. A qualidade fisiologica das sementes foi avaliada pelos testes de germinacao, primeira contagem, classificacao do vigor de plântulas, comprimento e massa fresca de plântulas, emergencia e comprimento de plantas em campo. Foi determinado ainda o grau de umidade das sementes. A qualidade sanitaria, pelo teste do papel filtro, foi avaliada aos sete dias. A epoca de colheita dos capitulos, de acordo com sua aparencia, influencia na qualidade fisiologica e sanitaria de sementes de Zinnia elegans Jacq. Sementes colhidas de capitulos em estadio seco, com menor grau de umidade, foram as que apresentaram melhor qualidade fisiologica. Alem disso, a ocorrencia de patogenos variou conforme a epoca de colheita, sendo que sementes provenientes da colheita de fevereiro apresentaram maior porcentagem de incidencia de Fusarium spp.