Chemical composition of substrates on the rooting vigor of Caryocar brasiliense air layering

Abstract

The definition of vegetative propagation protocols is important for the production of Caryocar brasiliense Cambess plants, for the formation of commercial orchards. Therefore, the objective of this study was to evaluate the substrate’s chemical characteristics influence on Caryocar brasiliense air layering. For this, a randomized block experiment with five substrates was carried out in eight plants. The following substrates were evaluated: Bioplant® commercial substrate; coconut fiber; a mixture of Bioplant® and coconut fiber in (1:1; 1:3; 3:1) proportions. After 150 days, the air layers were cut and evaluations of survival, callusing and rooting percentages, root length, dry and fresh root matter, rooting vigor and lignification were carried out. In laboratory, chemical and physical characterizations of the substrates were undertaken. The results showed that the rooting percentage varied from 40% to 77%. Rooting of Caryocar brasiliense air layers is optimized when phosphorus, calcium, magnesium and CEC in the substrate are above 3.0 mg dm-3, 7.0 cmolc dm-3, 3.5 cmolc dm-3 and 17 cmolc dm-3, respectively. Sodium and sodium saturation of the substrate must be below 1.4 cmolc dm-3 and 6%, respectively. Strong, positive and significant correlations were observed between rooting and P, Ca, Mg and CEC.