Armazenamento de sementes de camu-camu (Myrciaria dubia) com diferentes graus de umidade e temperaturas

O objetivo do presente trabalho foi avaliar a qualidade fisiológica das sementes de camu-camu (Myrciaria dubia (H.B.K.) McVaugh), com diferentes graus de umidade (46 e 40%), submetidas a diferentes condições (temperatura ambiente - média de 26,5°C, câmara a 20°C e câmara a 10°C) e períodos de armazenamento (30, 60, 90, 120 e 150 dias). Após cada período, foram retiradas amostras dos tratamentos para as avaliações do grau de umidade e da qualidade fisiológica das sementes. A redução do grau de umidade afetou negativamente a viabilidade e o vigor das sementes, e a temperatura de 10°C não foi favorável ao armazenamento das sementes. Assim, as sementes de camu-camu devem ser armazenadas com grau de umidade elevado (próximo a 46%) e, preferencialmente, sob temperatura de 20°C, para manter a viabilidade e o vigor por maior período de tempo.<br>The objective of the present study was to evaluate the physiological potential of camu-camu (Myrciaria dubia (H.B.K.) McVaugh) seeds with different moisture contents (46 and 40%) under different storage conditions (laboratory environment - mean 26,5°C, cold storage at 20°C and 10°C) and periods (30, 60, 90, 120 and 150 days of storage). After each storage period, samples of the treatments were removed to evaluate moisture content and physiological quality of seeds. The reduction of moisture content negatively affected the viability and vigor of seeds and the temperature of 10ºC was unfavorable for the storage of seeds. Camu-camu seeds should be stored with high moisture content (close of 46%) and, preferentially, at a temperature of 20°C to maintain viability and vigor for larger period of time

Preparação das subamostras, temperatura e período de secagem na determinação do grau de umidade de sementes de camu-camu (Myrciaria dubia (H.B.K.) McVaugh)

Wheat and soybean seed sector is one important branche of Rio Grande do Sul State agribusiness, Brazil. However, there are few studies towards market analysis and, when present, they don,t consider the seed company peculiarities. To fullfill this lacune, one study was accomplished with the objective of elaborate a diagnostic of the seed sector, centering the analysis on how seed companies act. This study used secondary data, in wich inputs and outputs of the seeds companies were analyzed. The institutional relationship of these companies and genetic breeding programs was treated as inputs. Their performance in scale, management, new varieties and destiny of their sales, among other, were considered outputs. Multivariate techniques of analysis were used. To identify groups by performance on the outputs, clusters analysis was accomplished for correspondence analysis with the inputs. The study showed that seed companies with small and very small production scale, up to 460 and 955 tons for wheat and soybean, respectively, are majority in the Rio Grande do Sul State. Those companies without institutional relationship and genetic breeding programs, presented also the worst performance in scale, innovation and segmentation

Dominó das hortaliças: desenvolvimento de jogo didático para horta escolar

http://dx.doi.org/10.5902/231817967239Esse artigo analisa o jogo como um recurso que pode promover a aprendizagem significativa no ambiente escolar, com objetivo de apresentar os procedimentos de desenvolvimento de jogo de dominó de hortaliças para ser aplicado em hortas escolares. O trabalho abrangeu as seguintes etapas: criação, determinação das regras e confecção do dominó das hortaliças folhosas e das hortaliças-fruto. O dominó das hortaliças, ao ser jogado, despertou interesse e prendeu a atenção das crianças. As regras sugeridas funcionaram adequadamente. O material confeccionado proporcionou leveza, simplicidade, praticidade e beleza às peças. O jogo está pronto para ser disponibilizado às crianças participantes de hortas escolares

Germinação de sementes de Psidium friedrichsthalianum (O. Berg) Nied. em função da temperatura e do armazenamento

Psidium friedrichsthalianum is a species whose fruit can be used to make juices, jellies/jams and sweets, and its seedlings serve as rootstocks with resistance to Meloidogyne spp. The aim of this study was to evaluate the performance of seeds of this species at different germination temperatures, and to verify the effects of different moisture levels on their storage in two experiments. In the first, six germination temperatures (15, 20, 25, 30, 35, and 40 ºC) were evaluated, and in the second, seeds with different moisture levels (15.4, 9.8, 9.0, 8.4, and 8.2%) were stored in sealed containers at 20 °C for 0, 1, 3, 6, 9, and 12 months. Seed germination was favored by temperatures of 20 ºC and 25 ºC, reaching 93% and 87%, respectively, along with the highest germination speed indexes (2.582% day1 and 2.568% day-1) and shortest germination times (37.9 and 36.9 days). Temperatures of 30 °C and 35 °C maintained the seeds quiescent, while 40 °C was lethal. In storage, the seeds tolerated desiccation to 8.2% moisture content and could be stored in sealed containers at 20 ºC for 12 months, with germination higher than 70%. © 2018, Associacao Brasileira de Tecnologia de Sementes. All rights reserved

Emergência de plântulas de tucumã (Astrocaryum aculeatum) em função do pré-tratamento das sementes e da condição de semeadura

This research evaluates the effects of different conditions of seed soaking, associated with different substrates and shade levels on the emergence of tucuma (Astrocaryum aculeatum) seedlings. The experimental design was entirely randomized with three replicates and 25 seeds. The treatments form a factorial of 2 conditions of seed soaking (shade and full sun) x 3 sowing substrates (sand, sawdust and sand + sawdust) x 3 levels of shade (30%, 50% and 70%), The seeds were sown in plastic boxes containing the substrate and covered with transparent polyethylene film, forming mini greenhouses. The emergence and emergence velocity index (EVI) showed interaction between the factors "soaking condition" and "sowing substrate". Seeds soaked in the shade (26-27 degrees C) and sown in sawdust showed 73% emergence and an EVI of 0.710, values significantly higher than those (58% and 0.578) obtained for seeds soaked in full sun (26-42 degrees C). The 30% and 50% shade levels gave the same percentage of emergence (68%) which was higher than the 44% emergency obtained with 70% shade. Environments with a higher temperature range (13-14 degrees C) and higher average temperatures (38-39 degrees C) promoted the process of seed germination. Thus, the best emergence of tucuma seedlings was achieved with seeds pre-soaked in the shade, sown in sawdust, under transparent polyethylene film and kept at 30% or 50% shade

Qualidade fisiológica e tamanho de sementes de cenoura

A maturação de sementes de cenoura ocorre escalonadamente nas umbelas de diferentes ordens e, sendo a colheita realizada em uma única etapa, pode ocorrer desuniformidade de tamanho, dentro de um mesmo lote de sementes. Desta forma, este trabalho foi realizado visando determinar o efeito do tamanho da semente na sua qualidade fisiológica. Quatro lotes de sementes comerciais de cenoura cv. Brasília, provenientes da região de Bagé-RS, foram separados em três frações: grande (retenção em peneira de perfuração redonda 2 mm); média (retenção em peneira de perfuração redonda 1,5 mm) e a mistura entre grande e média (em porções iguais). Foram conduzidos os seguintes testes: germinação, tetrazólio, condutividade elétrica, envelhecimento acelerado e emergência de plântulas em casa de vegetação. Não houve diferenças significativas quanto aos diferentes tamanhos de sementes em todos os testes realizados, com exceção do teste de emergência de plântulas em casa de vegetação com avaliação aos 14 dias após a semeadura. Porém, este teste não mostrou consistência na separação das frações em diferentes níveis de qualidade, para os diferentes lotes.Maturation of carrot seeds occurs in a sequence based on the different orders of the umbel. Since harvest is carried out only at one stage, nonuniform seed sizes within the same seed lot may occur. The effect of seed size on physiological quality was determined. Four lots of commercial carrot seeds (cv. Brasília) were separated in three fractions: large (retention at 2 mm diameter); medium (retention at 1.5 mm diameter) and a mixture of large and medium seeds (1:1 proportion). These fractions were tested for germination, tetrazolium reduction, electrical conductivity, accelerated aging and seedling emergence. Only seedling emergence, evaluated after 14 days, showed statistical difference. However this test did, not show consistency for the separation of the fractions into different quality levels, for different lots

Conservation of seeds of Coffea arábica L.: interference of moisture content and temperature

O presente trabalho foi realizado com o objetivo de verificar as influências do grau de umidade e da temperatura de armazenamento na manutenção da qualidade de sementes de Coffea arábica. Desse modo, sementes com 51, 41, 34, 23, 16 e 10% H20, mantidas sob temperaturas de 30°C, 20°C e 10°C por diferentes períodos de armazenamento, foram submetidas a avaliações periódicas do grau de umidade, da germinação, do vigor e da sanidade. Foi constatado que as reduções do grau de umidade e da temperatura são favoráveis à manutenção da qualidade fisiológica das sementes. As umidades próximas de 23% beneficiam o estabelecimento de Penicillium sp. e de Aspergillus sp. nas sementes.The aim of this work was to verify the influences of the moisture content and storage temperature in quality-keeping of Cojfea arabica seeds. Thus, 51, 41, 34, 23, 16 and 10% H20 seeds kept at temperatures 30°C, 20°C and 10°C for diferente storage periods were submitted to periodic evaluations of moisture content, germination, vigour and sanity. Decreases in moisture content and temperature were verified to be favorable to the maintenance of the physiological quality of the seeds. Moisture nearing 23% benefits the establishment of Penicillium sp. and Aspergillus sp. in seeds

Conservation of Myrciaria dubia (H.B.K.) McVaugh seeds.

As sementes de Myrciaria dubia apresentam curta longevidade e demandam a ampliação do conhecimento sobre fatores interferentes na sua conservação. Diante disso, o presente trabalho objetivou verificar as influências do grau de umidade e da temperatura do ambiente na manutenção da qualidade dessas sementes. Para tanto, sementes com 48, 43, 40, 34, 30, 24, 18 e 14% de água, acondicionadas em sacos de polietileno, foram armazenadas sob temperaturas controladas de 10ºC, 20ºC e 30ºC, durante 280 dias, e submetidas, periodicamente, a avaliações do grau de umidade, da germinação, do vigor e da sanidade. Foi constatado que as sementes têm a conservação favorecida pela associação do grau de umidade de 43% com a temperatura de armazenamento de 10°C; sob essa condição, a incidência de Fusarium sp. não prejudica o desempenho fisiológico das sementes.Seeds of Myrciaria dubia have a short lifespan and increased knowledge of the factors that interfere with their conservation is required. The aim of this study was to verify influences of moisture content and storage temperature on the maintenance of seed quality. Seeds with 48, 43, 40, 34, 30, 24, 18 and 14% water were kept in polyethylene bags at 10ºC, 20ºC and 30ºC for 280 days, and submitted to periodic evaluations of moisture content, germination, vigour and sanity. Seed conservation was favored by the 43% water and 10°C storage temperature association. In this condition, the incidence of Fusarium sp. does not hamper the seed physiological performance