Germinação e emergência de plântulas para três espécies de gramíneas invasoras de cultura do gênero Digitaria Heister ex Haller

Barbosa, José Marcos; Silva, Theóphilo Salem da; Andreani, Roberto; Pitelli, Robinson Antônio; Barbosa, Luiz Mauro

doi:10.1590/s0102-33061989000300024

Cited by 4 publications

(4 citation statements)

References 3 publications

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“…A análise de regressão revelou velocidade constante de emergência até 8 cm (IVE = 190), após os quais o decréscimo foi linear (IVE = 198 -10,42 P; R 2 = 0,96**), onde a cada centímetro em que se aumentava a profundidade de semeadura houve uma redução de 10,42 unidades no índice de velocidade máxima de emergência estimado (198). Barbosa et al (1991) verificaram que os níveis mais altos de porcentagem e índices de velocidade de emergência de plântulas do gênero Digitaria encontraram-se na superfí-cie e a 2 cm de profundidade. Verificaram ainda que, de uma maneira geral, os valores de porcentagens e os índices de velocidade de emergência diminuem estatísticamente à medida que se aumenta a profundidade de semeadura.…”

Section: Reb Toledo Et Alunclassified

Fatores que afetam a germinação e a emergência de Xanthium strumarim L.: dormência, qualidade da luz e profundidade de semeadura

1993

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RESUMOForam conduzidos três ensaios com o objetivo de estudar os efeitos de diferentes métodos de quebra de dormência das sementes, da qualidade da luz e da profundidade de semeadura na germinação e emergência do Xanthium strumarium L. (carrapichão). No primeiro ensaio, sob condições de câmara de crescimento, os tratamentos constaram de 5 métodos de quebra de dormência: mecânico (lixa), químico (H2SO4 conc. por 10 min.), pré-tratamento em água (imersão por 2 horas), físico (choque térmico: água à 80°C por 2 min.) e testemunha, que proporcionaram 100%, 93%, 93%, 87% e 80% de germinação, respectivamente, sem haver diferença estatística entre os mesmos. O pré-tratamento em água apresentou menor índice de velocidade de germinação (IVG) e os de mai s não di fer ir am significativamente entre si . No segundo ensaio, também sob condições de câmara de crescimento, os tratamentos de qualidade da luz constaram de 6 filtros de luz, que resultaram nas seguintes porcentagens de ger minaçã o: azu l -com ref let ivi dad e máx ima a 450 nm (13%), verde-500 nm (33%), vermelho-700 nm (13%), vermelho/distante-760 nm (7%), ausência de luz (26%) e transparente -sem absortividade na região de 380 a 760 nm (testemunha, 73%), indicando sensibilidade das sementes à qualidade de luz. No terceiro ensaio, sob condições de casade-vegetação, os tratamentos foram diferentes profundidades de semeadura (0 a 20 cm, em intervalos de 2 cm), sendo que o máximo de emergência ocorreu no intervalo de 0 a 8 cm, no qual foi observado 67 % de emergência do carrapichão, com maior índ ice de velocid ade emergência (IVE), sendo que após os 16 cm, praticamente não houve emergência.Palavras-chave: Carrapichão, fisiologia. ABSTRACT Factors affecti ng germinat ion and emergenc e of Xanthiu m strumar ium L.: Dormancy , light quality and sowing depthThree trials were carried out to study the effects of different methods to overcome dormancy, light quality and sowing depth on the germination and emergence of Xanthi um struma rium L. (co ckle bur ). In the first trial, under growth chamber conditions, the treatments consisted of 5 methods of seed scarification: mechanical (sand-paper), chemical (concentrated sulphuric acid for 10 min), sowing treatment (2 hours soaking in water ), physical (thermal shock: 2 min in water at 80°C) and the control, which resulted in germination percentages of 100%, 93%, 93%, 87% and 80%, respectively, without significant differences between the treatments; the sowing treatment caused lower germination speed (IVG). In the second trial, under identical conditions, the light quality treatment consisted of 6 light filters, resulting in the following germination percentages: blue -450 nm (13%), green -500 nm (33%), red -700 nm (13%), distant red -760 nm (7%), darkness (26%) and transparency -without absortion at 380 to 760 nm (control, 73%), indicating that this species can be considered a preferencial photoblastic. In the third trial, under greenhouse conditions,

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Section: Reb Toledo Et Alunclassified

Fatores que afetam a germinação e a emergência de Xanthium strumarim L.: dormência, qualidade da luz e profundidade de semeadura

1993

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“…Likewise, Barbosa et al (1989) have verified that the highest values of seedling emergence of the genus Digitaria were found on the surface and 2 cm deep. For species Similar results with other grasses were obtained by Pereira et al (2012), which have verified a reduction of 40.2% in the germination of Urochloa decumbens and of 23.7% in the germination of Urochloa ruziziensis in -0.2 MPa.…”

Section: Germination (%)mentioning

confidence: 73%

Effects of Environmental Factors on Seed Germination and Emergence of Glyphosate Resistant and Susceptible Sourgrass

2017

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-Sourgrass is one of the most problematic weeds of Brazil. It is an aggressive species in the allocation of resources from the environment and reported to be glyphosate resistant in several states of the country. This work has aimed to verify environmental effects on seed germination and seedling emergence of sourgrass. Laboratory and field trials were conducted to determine the effects of temperature, light, photoperiod, water availability and depth of burial in germination and emergence of seeds. The maximum germination was greater than 80% for seed originated from resistant plants between 15 and 30 o C. For the susceptible ones, the maximum germination occurred only at 30 o C. Germination occurred for both biotypes independent of the presence of light. The best photoperiod for germination of both biotypes was between 8 and 14 hours. Seeds originated from resistant plants showed higher germination levels at low temperatures in the presence of light and in less water availability. There was no germination from -0,8 MPa for both biotypes. The emergence for both biotypes was low, indicating that seed burial could be used in the management of the species. Seeds from resistant plants showed higher and larger germination in temperatures, water content and depth of burial ranges than from originated from susceptible plants.Keywords: Digitaria insularis, water availability, photoperiod, seeds, temperature. RESUMO -O capim-amargoso é uma das espécies mais problemáticas da agricultura brasileira. É uma espécie agressiva na alocação de recursos do meio

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“…Similar results of seed propagation system are found in the literature. According to Barbosa et al (1991), seed depth in the soil also affects plant emergence; however, the highest percentages and speeds of seedling emergence for Digitaria spp. were found in the soil surface, at 2 cm depth.…”

Section: Resultsmentioning

confidence: 99%

Growth and Development of Sourgrass Plants from Vegetative Parts of Clumps

et al. 2019

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Sourgrass (Digitaria insularis) is a perennial plant with high infestation potential, has fast and aggressive development, and reproduces by seeds and rhizomes. D. insularis infestations have increased in agricultural areas without cover crops established between the main crop seasons. The control of this species has become one of the most expensive in these areas in Brazil. The present work evaluated the growth and development of D. insularis plants from different vegetative parts of clumps. Two greenhouse experiments were conducted in a completely randomized design, with four replications. A 5 × 4 factorial arrangement was used, with factor A corresponding to the different propagation methods, and factor B corresponding to the biotypes used (experiment 1) and the different planting depths evaluated (experiment 2). The parameters evaluated in all experiments were: rate of tiller emergence, number of tillers, flowering time, number of inflorescences, and shoot dry weight. Fragments of different parts of the sourgrass clumps, planted at up to 7 cm depth, can generate a new plant. The management of perennial plants of sourgrass by using plows, harrows, or cultivators favors the dispersal of this species.

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Germinação e emergência de plântulas para três espécies de gramíneas invasoras de cultura do gênero Digitaria Heister ex Haller

Cited by 4 publications

References 3 publications

Fatores que afetam a germinação e a emergência de Xanthium strumarim L.: dormência, qualidade da luz e profundidade de semeadura

Fatores que afetam a germinação e a emergência de Xanthium strumarim L.: dormência, qualidade da luz e profundidade de semeadura

Effects of Environmental Factors on Seed Germination and Emergence of Glyphosate Resistant and Susceptible Sourgrass

Growth and Development of Sourgrass Plants from Vegetative Parts of Clumps

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