Realizou-se um experimento objetivando avaliar a influência de diferentes substratos no desenvolvimento inicial de seis porta-enxertos cítricos. Adotou-se o delineamento experimental inteiramente casualizado em esquema fatorial 6 x 4, avaliando os porta-enxertos: limões Cravo e Volkameriano Catania 2, tangerinas Cleópatra e Sunki, trifoliata Davis A e citrumelo Swingle; e os substratos: Plantmax® (Eucatex, Brasil); dois Tropstratos® (Vida verde substratos, Brasil), sendo um com e outro sem vermiculita; e o Golden Mix®, granulado de textura fina à base de fibra de coco (Amafibra). Empregaram-se quatro repetições e 15 tubetes por parcela. Avaliou-se a porcentagem de germinação, altura das plantas e, conforme os porta-enxertos atingiam 20 cm de altura, determinaram-se a área foliar e a massa seca do sistema radicular e da parte aérea das plantas. O primeiro porta-enxerto a atingir altura para a repicagem foi o Trifoliata, embora tenha apresentado os menores valores de massa seca da planta. Os substratos induziram diferenças somente na altura dos porta-enxertos: o Plantmax e o Tropstrato com vermiculita induziram os melhores resultados. Os porta-enxertos Trifoliata, Cleópatra e Swingle apresentaram maior porcentagem de emergência de plântulas.

This work aimed to evaluate the influence of different substrates on the initial growth of citrus rootstocks. The experimental design was the completely random in a 6 x 4 factorial arrangement by using the rootstocks Rangpur lime, Catania 2 Volkamer lemon, Cleopatra and Sunki mandarins, Davis A trifoliate, Swingle citrumelo and the substrates Plantmax® (Eucatex, Brazil), Tropstrato® (Vida Verde, Brazil) with Vermiculite or not, and the Golden Mix® [a granulated compound made of Coconut Fiber with fine texture (Amafibra, Brazil)], with 4 replications and 15 pots per experimental unit. The plant growth was measured every 15 days. In addition, as the rootstocks reached 20 cm in height, leaf area and dry weight of the aerial part and root system were measured, as well. The percentage of germination was also evaluated. The rootstock that first achieved the size of transfer was the trifoliate, although it has showed the lowest results as compared to all other traits. The substrates induced differences only in rootstocks height, to which Plantmax and Tropstrato with vermiculite induced de best growth. Trifoliate, Cleópatra and Swingle showed greater percentage of seedlings that emerged. Index terms: