Euterpe precatoria Mart. has been demanded due to the functional characteristics of its fruits and, therefore, its planting has been encouraged. However, there is a lack of information about the seedling production system of this palm tree. Neither a favorable environment nor the amount of fertilizer in the substrate have been defined for the production of healthy and vigorous seedlings. This study aimed to evaluate the effect of environments and doses of a slow-release fertilizer on the production of E. precatoria seedlings. The experiment was conducted in a randomized block design, with three replications and ten plants per plot. The treatments were arranged in a 4 x 5 factorial scheme, with four environments (under shading levels of 20 %, 30 %, 50 % and 75 %) and five doses of a slow-release fertilizer (0.0 kg m-3, 2.5 kg m-3, 5.0 kg m-3, 7.5 kg m-3 and 10.0 kg m-3 of substrate). The seedling height; root collar diameter; number of leaves; leaf, shoot, root and total dry mass; and the Dickson quality index were analyzed. There were significant interactions between the shaded environments and slow-release fertilizer doses for all the analyzed variables. The 75 %-shaded environment yielded better quality seedlings. The slow-release fertilizer can be used to produce E. precatoria seedlings in environments under shading levels of 50 % and 75 %, being the 4.60 kg m-3 and 8 kg m-3 doses, respectively, the most recommended ones.

The objective of this work was to evaluate the initial growth of assai seedlings (Euterpe oleraceae) in response to shading and slow release fertilizer. The experiment was conducted at Embrapa Acre in a randomized block design using a 4 × 5 factorial scheme with three replicates and 10 plants per plot. The treatments consisted of four shade environments (20%, 30%, 50% and 75%) and five levels of slow release fertilizer (0.0, 2.5, 5.0, 7.5 and 10.0 kg m-3). The following characteristics were evaluated: plant height, number of leaves, stem diameter, leaf dry mass, stem dry mass, root dry mass, total dry mass, and seedlings quality index. The growth of assai seedlings was influenced by shade environment conditions and slow release fertilizer. Shade environment with 30% or 50% and a dose of 8 kg m-3 resulted in better quality seedlings.

Brazil is the world's largest sweet orange producer, but production in the state of Acre is small and does not meet the local demand, despite having climatic conditions that are adequate for its cultivation. The objective of this study was to evaluate the behavior of the 'Pera' orange using different rootstocks under the edaphoclimatic conditions of Rio Branco, Acre, Brazil. We grafted the scion of the 'Pera' orange onto nine citrus rootstocks: 'Cleopatra' mandarin, TSKFL x CTTR-013, LVK x LCR-038, TSKC x CTQT 1439-004, LVK x LVA-009, 'Indio'citrandarin, 'Santa Cruz Rangpur' lime, TSKFL x CTC-25-002, and TSKC x CTSW-038. The experiment was organized in a random block design with three replicates and two plants per parcel. The following characteristics were evaluated: compatibility between scion and rootstocks, tolerance to drought, production and fruit quality. There was an effect of the rootstocks on the behavior of the 'Pera' variety. The 'Santa Cruz Rangpur' lime, 'Indio' citrandarin, and the hybrid LVK x LCR-038 rootstocks presented the best performance of the 'Pera' orange. Therefore, they constitute an alternative to the 'Rangpur' lime and may be incorporated into the current 'Pera' orange production system of the region.

Soil pollution by heavy metals is mainly caused by poor management of tailings generated by mining during exploration and processing of metals. Given the concern about the soil environment, this study aimed to evaluate the tolerance and effectiveness of isolates of rhizobium strains native to soils of Mn2+-mining areas in association with Mimosa caesalpiniaefolia (Benth.) cultivated under increasing concentrations of Mn2+. Isolates of rhizobium strains, obtained from Mn-mining area, were authenticated and morphologically characterized. Effect of Mn2+ on the growth and nodulation of M. caesalpiniaefolia was subsequently evaluated. We obtained 14 isolates which were similar, differing only in the form of colonies. Mn2+ did not inhibit the symbiotic process between isolates and plant species. The isolates from mining area showed higher efficiency than native strains. All isolates are Mn2+-tolerant, and those from mining area can increase the tolerance of M. caesalpiniaefolia to excess Mn2+ in the soil.

Na região norte, principalmente, no Acre, Amazonas e Pará são produzidos diversos resíduos provenientes do processamento de frutas nativas que, na maioria dos locais de beneficiamento, são descartados sem nenhum aproveitamento. Portanto, buscar alternativas de aproveitamento, sobretudo, como substrato para produção de mudas é de grande valia para a sustentabilidade do sistema produtivo. Objetivou-se, neste trabalho, avaliar o crescimento de mudas de maracujazeiro em substrato alternativo com adubo de liberação controlada. O experimento foi conduzido na casa de vegetação da Embrapa Acre. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 5x2, sendo 5 formulações de substrato e 2 doses de adubo (com e sem), com 4 repetições. Os tratamentos foram constituídos da casca de cupuaçu triturada e substrato comercial, puros (100%), e misturados nas proporções 25%, 50% e 75% v/v. Ambos, com e sem o adubo de liberação controlada. Foram avaliadas as variáveis respostas: Porcentagem de germinação, índice de velocidade de emergência, altura de planta, diâmetro do caule, número de folha, massas secas; da parte área, das raízes, total, e relação raiz/parte aérea. Nos tratamentos contendo a mistura dos substratos, bem como, no substrato comercial puro, houve influência significativa (p<0,05) para todas as variáveis analisadas, as quais foram destacadas com a presença do adubo de liberação controlada. O substrato alternativo formado a partir da mistura da casca de cupuaçu triturada com o MECPLANT Florestal nas proporções 25%, 50% e 75%, acrescido do fertilizante de liberação controlada, proporciona elevado crescimento das mudas de maracujazeiro, quando comparado sem a adição do fertilizante.

O objetivo deste trabalho foi avaliar o desempenho agronômico de bananeira, cultivar D'angola, consorciada com açaizeiro solteiro em diferentes arranjos. O experimento foi conduzido em blocos casualizados completos com quatro repetições e seis plantas por parcela. Os tratamentos foram: T1 - bananeira (3 x 3 m); T2 - bananeira (3 x 2 m) com açaizeiro solteiro (3 x 4 m); T3 - bananeira (3 x 3 m) com açaizeiro solteiro (3 x 4 m); T4 - bananeira (4 x 2 x 2 m) com açaizeiro solteiro (6 x 3 m), e; T5 - bananeira (4 x 2 x 2 m) com açaizeiro solteiro (4 x 2 x 3 m). Foram avaliadas as características de crescimento e desenvolvimento, produção e qualidade físico-químicas dos frutos. As médias foram comparadas pelo teste de Tukey a 5% de probabilidade. As características de crescimento e desenvolvimento, produção e qualidade físico-químicas não sofreram interferência do consórcio com açaizeiro solteiro, com exceção para o perímetro do pseudocaule, produtividade e quantidade de folhas ativas na colheita. As maiores produtividades foram obtidas em plantios mais adensados, independentemente do sistema de cultivo.

There are many residues that can be used for agriculture, especially as a substrate. However, it is often necessary to fertilize the growing media so that the seedlings can be produced with quality. The objective of this study was to evaluate the use of alternative and commercial substrates associated with different controlled-release fertilizer levels in producing yellow passion fruit seedlings. The experiment was conducted at the Embrapa Acre seedling nursery, with 50% luminosity. We used a randomized block experimental design in a 5 x 3 factorial scheme with 15 treatments, 4 replicates, and 10 plants per plot. The treatments consisted of five controlled-release fertilizer levels (0 kg m-3, 3 kg m-3, 6 kg m-3, 9 kg m-3, and 12 kg m-3) combined with lumps of acerola fruits (LAF), Brazil nut peel (BNP), and commercial (CS) substrates. The evaluated variables were seed height, stem diameter, number of leaves, shoot dry mass (SDM), root dry mass (RDM), total dry mass (TDM), and seedling quality index (SQI). Use of the alternative lumps of acerola fruit (LAF) substrate associated with the 10 kg m-³ level of controlled-release fertilizer promoted the best results. BNP has potential for use as a substrate for passion fruit seedlings, however adjustments are necessary to achieve an adequate composition.

Tolerância e eficiência de rizóbios nativos de área de mineração de manganês no desenvolvimento de Vigna unguiculata L. (Walp.) Tolerance and efficiency of native rhizobia from the manganese mining area in the development of Vigna unguiculata L. (Walp.