Sementes de feijão-caupi (Vigna unguiculata L. (Walp), tratadas com extrato de folhas de nim (Azadirachta indica A. Juss.) avaliação da germinação e da incidência de fungos

This study aimed to evaluate the effect of aqueous extract of neem on germination and fungi incidence on seeds of three cultivars (Serrinha, BR 17 and Maranhão) of cowpea. Neem leaves were dryed, crushed and prepared dilutions of 0.5; 1.0; 2.0, 4.0 g dm -3and control. The fungi incidence was evaluated by the test filter paper and germination according to the Rules for Seeds Testing (Regras para Análise de Sementes). In the three cultivars analyzed, reduction in the incidence of Aspergillus sp and Fusarium sp was observed. In relation to the influence of extracts of neem leaves on seed germination, significant effect of extract in Maranhão cultivar was observed, where all concentrations differed from the control, and propovided a considerable increase in the percentage of normal seedlings. It was concluded that the leaf extract of neem was effective in controlling Aspergillus sp, Fusarium sp , Phoma sp and Macrophomina phaseolina at different concentrations in different cultivars and seed germination was stimulated for the Maranhão cultivar.

Superação de dormência e influência dos fatores ambientais na germinação de sementes de Spermacoce latifolia

Understanding basic information on weed biology contributes to the implementation of appropriate management and control strategies. Thus, this work was developed to evaluate the germination of Spermacoce latifolia Aubl. seeds, an important weed in reforestation areas. The seeds were subjected to dormancy break treatments, in which the mechanical scarification, chemical treatment (H2SO 4 and KNO 3), heat treatment, and control, were evaluated. Three more tests were done determinate the effects of temperature (10, 15, 20, 25, 30 and 35°C), light filters (absence of light and red, green, yellow, distant red, blue, orange and clear light) and water availability (0.0, -0.2, -0.4, -0.6, -0.8 and -1.0 MPa) on the seeds germination and vigor. The treatments were arranged in a completely randomized design with four replications, and the experimental plot was constituted by gerbox plastic boxes with 50 seeds. The mechanical scarification (sanding) provided the best dormancy break, indicating that Spermacoce latifolia seeds have tegument water impermeability. The seeds showed higher germination percentage under conditions of mild water stress (-0.2 MPa) and the optimal temperature was 25°C. The blue light reduced seed germination.

Germinação e vigor de sementes de crambe sob estresse hídrico

This study aimed to evaluate crambe seeds germination and vigor under water stress conditions induced by polyethylene glycol solutions. The seeds were germinated on substrate moistened with polyethylene glycol solutions, using the osmotic potentials of 0 (control), -0.2, -0.4, -0.6, -0.8, -1.0, -1.2 and -1.4 MPa. The seeds germination was evaluated by normal seedlings and root emission percentages. Vigor was evaluated by germination average time, relative frequency, velocity and synchronization index. It was observed that more negative osmotic potential caused significant reduction in crambe seed germination and vigor, and no normal seedlings was observed at potentials below -0.6 MPa.

Temperatura, escarificação mecânica e substrato na germinação de sementes das palmeiras juçara e açaí

The propagation of 'juçara' and 'açaí' is done by seeds, but there is a great desuniformity in the germination process. In this way, the objective of this study was to verify the effect of temperature, mechanical scarification and substrate on seed germination of both species. Two experiments were conducted in a completely randomized design, with four replications each consisting of 25 seeds. The first was conducted with 14 treatments in factorial scheme 7 x 2, seven temperatures (20, 25, 30, 35, 20-30 and 25-35 °C and natural condition), with and without mechanical scarification. The second was constituted of eight treatments in factorial scheme 4 x 2, four substrates (sand, vermiculite, coconut fiber and soil + manure), with and without mechanical scarification. Seeds of 'juçara' palm present the highest mean percentage and germination speed index in alternating temperatures of 20-30 and 25-35 °C and natural condition and in substrates sand, vermiculite and coconut fiber. Temperatures of 30, 35, 20-30 and 25-35 °C and natural condition in all substrates tested were the most favorable condition for 'açai' seeds. The scarification of the seeds was favorable to the germination process of 'juçara' whereas the seeds of açaí does not need to be scarified.

Germinação de sementes de algodoeiro provenientes de plantas submetidas a diferentes densidades larvais do curuquerê-do-algodoeiro

The cotton crop yield is directly associated with the efficient control of pests. This work evaluated the relationship of different densities of A. argillacea per plant at different cotton plant ages with seed germination of four cotton cultivars: IAC 25, Delta Opal, Fibermax 993, and Fibermax 966. A randomized block design was set up in 4x3 factorial with four replications. Densities of larvae per plant (0, 2, 4, and 6 larvae) was the major factor while plant ages (30, 60 and 90 days after emergency - DAE) the second level factor. Larvae were released on plants with 30, 60 and 90 DAE. The seeds were manually picked, for the evaluation of the germination in the laboratory using the seed viability through sand emergency method. The results showed that studied cotton cultivars differently to defoliate caused by A. argillacea larvae; the cotton development stage had more influence in the physiologic quality of the seeds than the defoliation; the germination is negatively affected when the defoliation took place at 60 DAE.

Caracterização morfométrica de sementes e plântulas e germinação de anadenanthera macrocarpa (benth.) brenan

Anadenanthera macrocarpa (Benth.) Brenan is a tree species belonging to the family Leguminosae-Mimosoideae which is popularly known as mimosa-black. It features characteristics of early successional, natural occurrence in Brazil and can form clusters almost homogeneous, with great potential in the recovery of degraded areas. This study was conducted at the Center for Agricultural Sciences, University Federal of Alagoas state, aiming at the physical and morphological characterization of seeds, describing the various stages of post-seminal development, and to evaluate various conditions of temperature and substrate to perform the test germination. The seeds were manually extracted, then homogenized, where two samples of 50 seeds were used to determine the initial moisture. Another sample, consisting of eight repetitions of 100 seeds was used to measure the biometry and the number of seeds per fruit. The morphological characterization and the seeds were immersed in distilled water to allow the cuts to the observed structure in microscopes. In the post-seminal study, it was observed the daily processes of seedling growth in rolled paper filter and constant temperature of 30 °C. To assess the germination behavior, the constant temperatures of 15 °C, 25 °C, 30 °C, 40 °C and 20-30 °C as well as the paper and the sand substrates were tested and it was evaluated the percentage, the rate of germination, the relative frequency distribution, and the tests conducted in a randomized design in factorial 5 x 2 (x substrate temperature) with four replicates of 25 seeds, and the averages compared by Duncan 5 % probability. The fruits of black angico show great variation in the seed number per fruit. The embryonic axis occupies part of the central region of the seed with axial and linear positions. The germination is epigeal and the seedlings are fanerocotylar. The temperature determines the 30 °C and the filter paper substrate provided higher average percentage and germination rate.

Expressão gênica no embrião e no endosperma micropilar de sementes de café (coffea arabica L.) durante a germinação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Temperatura e osmocondicionamento na germinação de sementes de Urochloa brizantha (STAPF) Webster cv. Basilisk

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da germinação de sementes de Tibouchina mutabilis (Vell.) Cogn. (Melastomataceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência da variação sazonal da temperatura e umidade do solo na germinação de sementes de espécies do cerrado: Xylopia aromatica (Lam.) Mart. (Annonaceae), Banisteriopsis variabilis B. Gates (malpighiaceae) e Vochysia tucanorum Mart. (Vochysiaceace)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização da mobilização das reservas das sementes do maracujá-amarelo (Passiflora edulis Sims f. flavicarpa O. Deg) durante a germinação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Germinação de sementes de Passiflora setacea DC: temperatura, luz e reguladores vegetais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Frugivoria por morcegos em floresta estacional semidecídua: dieta, riqueza de espécies e germinação de sementes após passagem pelo sistema digestivo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da predação por Acanthoscelides schrankiae(Coleoptera: Bruchidae) e de altas temperaturas na germinação de sementes de Mimosa bimucronata (DC.) Kuntze (Fabaceae: Mimosoideae)

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

Efeito da inoculação de fungos na atividade enzimática de solos e germinação de sementes de milho

Pós-graduação em Agronomia (Ciência do Solo) - FCAV