ABSTRACT 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.

RESUMO O açaizeiro solteiro vem sendo demandado devido às características funcionais dos frutos e, por isso, seu plantio tem sido incentivado. Todavia, não há informações acerca do sistema de produção da muda, bem como não estão definidos o ambiente adequado e nem a quantidade de adubo que possa compor o substrato, a fim de formar uma muda sadia e vigorosa. Objetivou-se avaliar o efeito de ambientes e doses de fertilizante de liberação lenta na produção de mudas de açaizeiro. Utilizou-se delineamento em blocos casualizados, com três repetições e dez plantas por parcela. Os tratamentos foram arranjados em esquema fatorial 4 x 5, sendo quatro ambientes (20 %, 30 %, 50 % e 75 % de sombra) e cinco doses de fertilizante de liberação lenta (0,0 kg m-3; 2,5 kg m-3; 5,0 kg m-3; 7,5 kg m-3; e 10,0 kg m-3 de substrato). Foram analisados a altura da muda; diâmetro do coleto; número de folhas; massa seca das folhas, do estipe, das raízes e total; e o índice de qualidade de mudas. Houve interação significativa entre os ambientes de sombra e as doses de adubo de liberação lenta para todas as variáveis analisadas. O ambiente com 75 % de sombra proporciona mudas de melhor qualidade. O fertilizante de liberação lenta pode ser utilizado para a produção de mudas de açaizeiro solteiro em ambientes com 50 % e 75 % de sombra, sendo as doses de 4,60 kg m-3 e 8 kg m-3, respectivamente, as mais indicadas.

ABSTRACT 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.