Phosphorus priming influence on different quality of wheat cv. “Pardela” and “Gralha Azul” seeds

The seed priming allows the beginning of the metabolic processes necessary for the germination. Phosphorus is a macronutrient necessary for the growth and development of seedlings, since it participates in the structural components cell like the nucleic acid molecules. The objective was to evaluate the effect of priming and priming with phosphorus (P) on the physiological quality of wheat seeds with different levels of vigor. For the experiment, three lots of wheat seeds of Pardela cultivar, with different levels of vigor i.e. high, medium and low were used. The effect of priming with water and priming with different potential levels of phosphorus was evaluated: 0 (control), 0.10 %, 0.20 %, 0.30 %, 0.40 % and 0.50 % P. The first germination count, percentage of germination, abnormal seedlings, root and shoot length, and dry mass of the seedlings were determined. For the priming with water, the data were submitted to analysis of variance and the means compared by the Tukey test. In the study of the effect of the different concentrations of phosphorus, a variance and regression analysis was carried out, following the completely randomized design, in a factorial scheme 3x6. The Priming in water had significantly influenced all treatments, independently of the seeds vigor levels, increases in the percentage of normal seedlings obtained in the first count and also in the percentage of germination of the low and medium vigor lots, and the seedlings primed in water had significantly larger shoot length in the three different lots. Regarding the different concentrations of phosphorus, significant differences were observed only in the first count of the germination, which decreased with the increase of the phosphorus concentration and the length of the aerial part, which presented an inverse behavior, increasing with the highest levels of phosphorus. Significant interaction between the different vigor levels and phosphorus concentrations was observed only for the root length variable, where concave, linear and convex trends were observed for the high, low and medium vigor lots, respectively. Phosphorus solutions had the optimum role as priming source in promoting seed emergence and root development irrespective of quality seed

Germinação de sementes de milho com diferentes níveis de vigor em resposta à diferentes temperaturas

The objective of this study was to evaluate the performance of maize seeds with different levels of vigor at different germination temperature. To this was used six seed lots of hybrid corn Balu-580 with similar germination potential, but different level of vigor. After the initial characterization of the lots, the effects of temperature were determined by first counting and the germination test conducted on paper substrate germitest, at 16, 19, 22, 25, 28, 31, 34, 37 and 40 °C. The data obtained in the initial characterization of the lots were subjected to analysis of variance and means were compared by Tukey test (p < 0,05). In the study of the effect of adverse conditions of temperature on first counting and germination was carried out the analysis of variance following a completely randomized design, factorial scheme 6 X 9. Low temperatures slowed the germination of seeds, especially those of low vigor, and there was no germination at 16 ° C. Lots of smaller effect were also more susceptible to high temperatures, with higher percentages of abnormal seedlings and ungerminated seeds.O objetivo do trabalho foi avaliar o desempenho germinativo de sementes de milho, com diferentes níveis de vigor, sob diferentes temperaturas. Utilizaram-se seis lotes de sementes de milho híbrido Balu- 580 com potenciais germinativos próximos, porém com diferentes níveis de vigor (baixo, intermediário e alto), submetidos a germinação sob temperaturas de 16; 19; 22; 25; 28; 31; 34; 37 e 40ºC seguindo o delineamento inteiramente casualizado, em esquema fatorial 6 X 9, com quatro repetições. Foram avaliadas a porcentagem de plântulas normais na primeira contagem e de plântulas normais, anormais e sementes mortas no teste de germinação. Os dados obtidos foram submetidos à análise de variância, a comparação de médias pelo teste de Tukey (p < 0,05) e, estudo de regressão para efeito de temperaturas. Temperaturas baixas retardam a germinação das sementes, principalmente às de baixo vigor, não sendo observada germinação à 16ºC. Lotes de maior vigor possuem maior desempenho germinativo em todas as temperaturas, porém com destaque em temperaturas supra-ótimas

Germinação sob altas temperaturas para avaliação do potencial fisiológico de sementes de milho

O objetivo do trabalho foi avaliar e padronizar o teste de germinação sob altas temperaturas para avaliação do vigor de sementes de milho. Foram utilizados seis lotes de sementes de milho híbrido com diferentes níveis de vigor e potenciais germinativos semelhantes em três temperaturas (31, 34 e 37°C), em esquema fatorial 3x6, com quatro repetições. Além da caracterização da qualidade fisiológica pelos métodos padrão, foram determinados, sob altas temperaturas, a germinação, primeira contagem, comprimento e massa seca da raiz e parte aérea das plântulas. Os dados foram submetidos à análise de variância, comparação de médias pelo teste de Tukey e estudo de correlação linear simples a 5%, respectivamente. As temperaturas de 31, 34 e 37ºC mostraram-se eficientes para a avaliação do vigor de lotes de sementes de milho. A temperatura de 34ºC mostrou-se mais adequada para avaliação do potencial fisiológico de sementes de milho, com maiores valores de correlação com os testes laboratoriais e com a emergência e índice de velocidade de emergência de plântulas no campo

Teste de deterioração controlada na avaliação do vigor de sementes de milho

Objetivou-se com este trabalho estudar combinações de tempo e temperatura na adequação do teste de deterioração controlada para avaliação do vigor de sementes de milho com diferentes teores de água. Foram utilizados oito lotes de sementes de milho híbrido CO32, cuja qualidade inicial foi determinada pelos testes de: teor de água, massa de mil sementes, porcentagens de germinação e de plântulas normais na primeira contagem do teste de germinação, massa seca das porções aérea, radicular e total de plântulas, teste de frio, teste de envelhecimento acelerado, teste de condutividade elétrica, tetrazólio, emergência de plântulas no campo e velocidade de emergência de plântulas no campo. A umidade inicial dos lotes de sementes foi ajustada pelo método de imersão em água para 15, 20 e 25%. Para cada teor de água foram avaliadas nove combinações de períodos (16, 24 e 48 horas) e temperaturas de deterioração (42, 45 e 48 °C). Após a deterioração determinou-se o teor de água e a porcentagem de germinação das sementes. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey e análise de correlação aos 5% em esquema fatorial 9X8, sendo nove combinações de tempo e temperatura e oito lotes de sementes. As combinações 24 h-45 °C, 48 h-45 °C e 16 h-45 °C para sementes com teor de água ajustado para 15, 20 e 25%, respectivamente, são eficientes para avaliação do vigor de sementes de milho pelo teste de deterioração controlada.The objective of the present research was to study the combination of time and temperature on the suitability of the controlled deterioration test for evaluating the vigor of maize seed with different water contents. Eight seed lots of hybrid maize CO32 were used, whose initial quality was determined by the following tests: water content, thousand seed weight, electric conductivity, germination, first germination count, seedling total dry matter and of the aerial parts and roots, cold test, accelerated aging, tetrazolium, emergence and rate of emergence in the field. The initial moisture content of seed lots was adjusted by immersion in water to 15, 20 and 25%. Nine combinations of periods (16, 24 and 48 hours) and deterioration temperatures (42, 45 and 48 °C) were evaluated for each water content. After deterioration, the water content and percentage of germination were determined and the data submitted to ANOVA with means compared by the Tukey test and a correlation analysis to 5% in a factorial 9x8, with nine combinations of temperature and time and eight seed lots. The combinations 24-45 °C, 48-45 °C and 16-45 °C for seeds with water contents adjusted to 15, 20 and 25% respectively, are efficient for evaluating maize seed vigor using a controlled deterioration test

Mucilage extraction and substrates in the seedling development of yellow passion fruit plants

The object of this work was to evaluate different methods of mucilage extraction and substrates on passion fruit seedling emergence and development , in a mist chamber. Five methods of mucilage extraction were used: water, water + sand, water + virgin whitewash; blender with protected blades and fermentation in water, and three different types of substrates: rice hull, vermiculite and coconut fiber. The experiment had a completely randomized design with five replications in a factorial 5 x 3 scheme (5 extraction methods of seed mucilage and 3 substrates) being each parcel composed of 25 seeds. The parameters evaluated were: seedling emergence, speed of emergence index, leaf number, stem length, longest root length, weight of dry matter of roots and shoots. Water and fermentation in water are the best method for mucilage extraction and rice hull and coconut fiber are the best substrate for passionfruit seedling emergence and development