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Camu-camu is an Amazonian species with fruits that have high a concentration of ascorbic acid, a feature of interest to the food and pharmacological industries. However, for cultivation, studies are needed on seedling production and the use of alternative substrates. The objective of the present study was to develop camu-camu seedlings using different alternative substrates. For seedlings formation, seeds were removed from fruits collected from plants on the Urubu River in Boa Vista-RR, Brazil. A completely randomized experimental design was used, with ten substrates, five replications and five plants per replication. The treatments consisted of: [T1 -Soil; T2 -standard substrate: 3 parts sand soil + 1, T3 -commercial substrate: organoamazon ® , T4 -standard substrate +75 % manure (E), T5 -standard substrate +50 % E; T6 -standard substrate + 25 % E, T7 -standard substrate +75 % rice hulls (C), T8 -standard substrate + 50% C; standard substrate T9 = 25% + C; T10 standard substrate +25% E + 25 % C]. The following characteristics were evaluated: plant height (cm), diameter (mm), shoot and root dry matter (g), root length (cm) and number of leaves. The substrate consisting of standard soil and sand at the ratio 3:1 gave favorable results for all the characteristics. Substrates with increasing proportions of rice hulls and manure did not improve the camu-camu tree seedling development.RESUMO: O camu-camu é uma espécie amazônica com frutas que apresentam elevado teor de ácido ascórbico, característica que desperta interesse do setor industrial de alimentos e farmacológico. Para ser cultivado, há necessidade de estudos sobre formação de mudas e substratos a serem utilizados. Foi avaliado o desenvolvimento de mudas de camu-camu em diferentes substratos alternativos. Para a formação das mudas, as sementes foram retiradas de frutas coletadas de plantas localizadas às margens do Rio Urubu, Boa Vista-RR. O delineamento foi inteiramente casualizado, com dez substratos, cinco repetições e cinco plantas por unidade experimental. Os tratamentos consistiram de: número de folhas. De acordo com os resultados obtidos, concluiu-se que o substrato padrão composto por solo e areia, na proporção 3:1, foi o que proporcionou resultados favoráveis em todas as características avaliadas. Substratos com proporções crescentes de casca de arroz carbonizada e esterco bovino não proporcionaram bom desenvolvimento de mudas do camucamuzeiro.

O cupuaçu pode ser propagado por via sexuada ou assexuada, sendo a via seminífera o processo mais utilizado. Dessa forma, ambientes apropriados para a produção de mudas propiciam melhores condições para o crescimento inicial em campo, colaborando para o aumento da homogeneidade, sanidade e redução da mortalidade de plantas no momento do plantio. Assim, fatores como luz e tipo de substrato são importantes para a germinação de sementes e emergência inicial de plantas. Nesse contexto, objetivou-se com o presente trabalho avaliar o efeito de diferentes substratos, bem como a influência do sombreamento na emergência e no crescimento inicial de plântulas de cupuaçu. O experimento foi conduzido na Embrapa Roraima, utilizando-se delineamento inteiramente casualizado, em esquema fatorial 3 x 7, constituídos de diferentes ambientes (canteiro sem cobertura, canteiro com cobertura tipo sombrite de 50% de luminosidade e canteiro com cobertura plástica transparente de 100 micras), combinados com diferentes substratos (areia, solo, vivatto®, serragem, areia+solo, areia+solo+vivatto® e areia+solo+serragem). Após a semeadura, avaliou-se a porcentagem de emergência e o índice de velocidade de emergência no intervalo de cinco dias, quando, ao final dos 50 dias, avaliou-se o comprimento da parte aérea, o número de folhas, a área foliar, o comprimento do sistema radicular, o diâmetro do caule, a massa seca da parte aérea e do sistema radicular. Observou-se que maior porcentagem de emergência, IVE e desenvolvimento inicial de plântulas de cupuaçuzeiro são obtidos ao se utilizar substrato constituído por areia+solo+serragem. O ambiente com sombreamento de 50% de luminosidade proporciona maior porcentagem de emergência, IVE, diâmetro do colo e massa seca do sistema radicular.

The açaí palm (Euterpe oleracea Mart.) is a tree native to the Amazonia. In some states in the region, growth of the planted area has been observed, but the difficulty in obtaining substrates which are viable for the production of seedlings is high. It was intended in a first step to evaluate the effect of seed size and substrates upon germination and in the second step, to evaluate the initial growth of seedlings of E. oleracea on different substrates. The experimental design was a completely randomized design in 2 x 2 factorial scheme with four replications at 100 seeds. Germination percentage, percentage of abnormal seedlings, shoot and root length and dry weight of the seedlings were evaluated after 70 days. In the second step, completely randomized design in 9 x 6 factorial scheme with five replications with four seedlings/ plot was utilized. At 60, 90 , 120 , 150 , 180 and 210 days after transplanting, shoot height and diameter of the stem of the plant were assessed, number of leaves were determinate at 90, 120 , 150, 180 and 210 dat and at 210 dat, determinations of dry weight of the shoot and root system were conducted. These samples were put in an oven with forced air circulation at 60 ºC for 72 hours. Açaí seeds considered large present greater germination percent as compared with small seeds and the substrate sand provides greater percentage of seed germination. The substrates composed of 75% (soil+sand) + 25% manure and with 75% (soil+sand) + 25% carbonized rice husk present better development of açai seedlings.

The caçari (Myrciaria dubia) is a native fruit tree from Amazon with high concentrations of vitamin C. This study aimed to adjust a culture medium that meets the nutritional needs for the in vitro development of caçari, evaluating the effect of different concentrations and nutritive culture media, antioxidant, and levels of agar and pH. Three experiments were carried out in a completely randomized design: 1-woody plant medium (WPM), Murashige and Skoog (MS) and Juan, Antonio, Diva and Silvia medium (JADS) nutritive media with 25, 50, 75 and 100% concentrations; 2-pH (3.7, 4.7, 5.7 and 6.7) and agar concentrations (0, 3.5, 7.0 and 10.5 g.L-1); 3-Antioxidants [(ascorbic acid (AA), citric acid (CA), polyvinylpyrrolidone (PVP)] and concentrations (0, 100, 200, 300 mg.L-1) on the control of phenolic oxidation of stem segments. After collection, the explants were disinfested in a laminar flow chamber, dipping in 70% ethanol for 3 min and 1.5% sodium hypochlorite for 12 min, followed by three washes in distilled and autoclaved water. After disinfestation, the explants were inoculated in 15 × 125 mm test tubes containing 30 mL culture medium, according to each experiment and their respective treatments. After 90 days, the number and length of sprouts (cm) and the oxidation were evaluated. The best results were obtained using the WPM medium at a concentration of 100% with 7 g.L-1 agar, and pH adjusted to 5.7. The use of antioxidants in the tested conditions did not contribute to decrease in oxidation in explants, indicating that there is no need of adding them into the culture medium.