Tamanho e secagem de sementes de palmeira Jussara sobre a germinação e o vigor

With the objective to determine the influence of the dehydration and of the size and/or weight on germination percentage and the vigor of jussara palm seeds (Euterpe edulis Mart.), 10 individuals' ripe fruits, picked in the Experimental Station of Ubatuba (IAC) they were classified by size in 5 sieves of circular sieve: 26/64" (10,31mm), 28/64" (11,11mm), 30/64" (11,90mm), 32/64" (12,69mm) and 34/64" (13,49mm). It was determined, the medium weight of the classified seeds. The quality of the seeds was evaluated through the following parameters: water content of the seeds; germination and vigor (first germination counting). It was evaluated the drying speed of different seed sizes for 48 hours, in dry chamber. The sizes of 28/64", 30/64" and 32/64" represented 98,7% of the total weight of the harvested seeds and showed similar drying speed, percentage of germination and vigor. With the increase of the drying period, the smaller seeds (28/64") had their germination less affected them the intermediate (30/64") and bigger sized seeds (32/64").

Germination and early growth of soybean, dry bean and turnip grown under Digitaria horizontalis straw

The study aimed to evaluate the possible inhibitory effects of different concentrations of crabgrass (Digitaria horizontalis Willd.) dry mass incorporated to the soil over the germination and early growth of soybean (Glycine max (L.) Merril.), dry bean (Phaseolus vulgaris L.), and turnip (Raphanus raphanistrum L.). The experimental design adopted was completely random, with four replications where, each one was consisted of a 2.5 L capacity pot. Dry mass of crabgrass at equivalent amounts of 0, 2.5, 5.0 and 10 t ha(-1) were incorporated into the soil. Crops seedling emergence was checked daily, and germination, speed germination index, mean germination time, relative frequency and synchronization index of germination were computed at the final of 10 days. The height and dry mass of plants were evaluated at 35 days after sowing. The incorporation to the soil of D. horizontalis dry mass caused significant reduction of the height and dry weight of soybean, dry bean and turnip, but were not observed consistent influence over the germination of these species.

Seed priming improves endosperm weakening, germination, and subsequent seedling development of Solanum lycocarpum St. Hil.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desidratação de sementes de quatro lotes de pupunheira: efeitos sobre a germinação e o vigor

Com o objetivo de verificar o efeito da desidratação sobre a germinação e o vigor de sementes de pupunheira inerme (Bactris gasipaes Kunth), quatro lotes de sementes, colhidos nas localidades de Yurimaguas, Peru; Camamu e Piraí do Norte, BA e Pindorama, SP, foram submetidos à secagem em câmara seca a partir das testemunhas não desidratadas, retirando-se amostras a cada 24 horas. O efeito da desidratação sobre a qualidade das sementes foi avaliado por meio de teste de germinação (184 dias da semeadura, em vermiculita, 20-30ºC), primeira contagem de germinação (36 dias), velocidade de germinação e teor de água das sementes. Comprovou-se que sementes dessa espécie são sensíveis à desidratação, com germinação inicial alta (59 a 84%) quando não desidratadas (47 a 38% de umidade inicial). Teores de água abaixo da faixa de 28 a 23% reduziram significativamente a germinação e o vigor. Todas as sementes com teores de umidade abaixo de 15% (lotes 2 e 4) e 13% (lotes 1 e 3) morreram.

Digital monitoring of mycelium growth kinetics and vigor of shiitake (Lentinula edodes (Berk.) Pegler) on agar medium

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

Influência do tamanho na germinação e no vigor de sementes de milheto (Pennisetum americanum (L.) Leeke)

O milheto é uma gramínea anual de sementes pequenas, com grande diversidade de tamanho, e com dificuldade, às vezes, do estabelecimento da população adequada de plantas. Este experimento objetivou verificar a influência do tamanho da semente de milheto sobre sua germinação e vigor. Foram utilizados quatro lotes de sementes (I, II, III e IV), classificados em quatro tamanhos, através de peneiras de malha quadrada, sendo: peneira 1 ≥ 2,00mm, peneira 2: 1,68 a 2,00mm, peneira 3: 1,41 a 1,68mm, peneira 4: 0,71 a 1,41mm e mais uma porção do lote original (testemunha), que constituíram os tamanhos. Foram realizados os testes de: peso de 1000 sementes, germinação inicial e após seis meses de armazenamento (TGI e TGII, respectivamente) e vigor (primeira contagem do teste de germinação e condutividade elétrica das sementes). Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições por tratamento. As sementes de peneira 4 apresentaram menores pesos de 1000 sementes para todos os lotes, menores valores de germinação para o TGI, em todos os lotes, e para o TGII nos lotes II e IV. Para o vigor (primeira contagem do teste de germinação) observou-se menor valor para peneira 4, nos lotes I, II e IV; enquanto para a condutividade, a peneira 4 apresentou maior valor para todos os lotes, indicando pior qualidade fisiológica dessas sementes. Concluiu-se que a germinação e o vigor das sementes de milheto são influenciados pelo seu tamanho; sementes maiores são de melhor qualidade do que as menores.

Silicon leaf application and physiological quality of white oat and wheat seeds

Plant nutrition can positively influence quality of seeds by improving plant tolerance to adverse climate. In this context, silicon is currently considered a micronutrient and it is beneficial to plant growth, especially Poaceaes such as white oat and wheat, thereby improving physiological quality of seeds. This study had the objective of evaluating the effects of silicon leaf application on plant tillering, silicon levels and physiological quality of white oat and wheat seeds besides establishing correlations between them. Two experiments were carried out in winter with white oat and wheat. The experimental design was the completely randomized block with eight replications. Treatments consisted of foliar application of silicon (0.8% of soluble silicon, as stabilized orthosilicic acid) and a control (with no application). Silicon levels in leaves were determined at flowering whereas the number of plants and panicles/spikes per area was counted right before harvest. Seed quality was evaluated right after harvest through mass, germination and vigor tests. Data was submitted to variance analysis and means were compared by the Tukey test at a probability level of 5%. Person's linear correlation test was performed among silicon level in plants, tillering and seed quality data. Silicon leaf application increases root and total length of white oat seedlings as an effect of higher Si level in leaves. Silicon leaf application increases mass of wheat seeds without affecting germination or vigor.

Influence of light quality on germination and initial growth of canephori seedlings Peltophorum dubium (Sprenge) Taub.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seed germination and removal of Michelia champaca L. (Magnoliaceae) in eucalypt stands: the influence of the aril

Testou-se o efeito do arilo na germinação de M. champaca em condições controladas, bem como na sua remoção, em ambiente natural. Os ensaios de germinação foram mantidos a 25 ± 2 °C, sob luz branca constante. Os experimentos de remoção foram levados a cabo em três talhões velhos (idades de 39 a 62 anos) e três novos (15 anos de idade) de eucalipto mantidos no Horto Florestal Navarro de Andrade, em Rio Claro, SP. Os resultados indicaram que o arilo inibe a germinação, sendo as sementes fotoblásticas positivas. Observou-se que a remoção de sementes foi maior em talhões velhos do que em novos, provavelmente devido à maior densidade de roedores nos talhões velhos. Nos talhões novos, verificou-se que formigas removiam mais sementes ariladas. Esses insetos são importantes agentes na remoção do arilo de sementes derrubadas por pássaros, promovendo, assim, aumento na germinação e evitando a possível predação das sementes por roedores.

Seed biometry and the effect of pre germinative treatments, temperature, and light on seed germination and subsequent growth of three Stryphnodendron species

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of some phenolic compounds on soybean seed germination and on seed-borne fungi

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

Seed germination and seedling emergence of the invasive exotic species, Clausena excavata

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

Dimorphic cypsela germination and plant growth in Synedrella nodiflora (L.) Gaertn. (Asteraceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Maturation of Eugenia pyriformis seeds under different hydric and thermal conditions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study of seed-germination and etiolation of seedlings in Emilia-sonchifolia (l) dc and Emilia-fosgerbii nicolson (Asteraceae)

The germination of seeds of Emilia sonchifolia (2n) and E. fosgerbii (4n) was analysed and our results indicate that the former present light insensitive seeds and the latter germinated only under continuous white light. The germination of seeds under shade light presented no differences between both species, However under continuous white light, which maintain 70% of Pfr, the velocity of germination was greater in Emilia sonchifolia when compared to Emilia fosbergii, indicating that the threshold of 4n seeds were greater than 2n seeds. The analysis of the fluence response curves for etiolating process indicated that the process presented no differences between both species. The same was observed for the effect of the shade light in the etiolating process.