Effect of foliar fertilization and soil conditioners on the rooting of a hybrid of Pinus tecunumanii vs. Pinus caribaea var. honduransis

Abstract

The techniques of seedling production via vegetative propagation are alternative forms of sexual reproduction (use of seeds), however, several factors impair their use in a comprehensive way, such as low rooting rates of some species. The objective of this study was to evaluate the effect of foliar fertilizers and substrate conditioners on rooting rates, growth and production of clonal minestacks of hybrids of Pinus tecunumanii vs. caribaea var. honduransis. The experiments were carried out in a forest nursery in the city of Paranapanema-SP, with a randomized block design, in a 4x2 factorial arrangement. Four foliar fertilizers were used: AF1 based on chitosan, AF3 based on humic acid, AF4 extract of Ascoplhyllum nodosum, and M2AF (mixture of AF1+AF3+AF4, 33.3% of each) and two substrate conditioners: C1 based on marine fish; C2 based on humic acids. The minestacks were evaluated in the greenhouse (rooting rate) and shade house (total height, dry and green mass of shoots and roots) phases. The foliar fertilizer AF4 provided higher rooting rates of the seedlings, together with the AF3 fertilizer combined with the C2 substrate conditioner and the AF1 fertilizer combined with the C2 substrate conditioner. In general, foliar fertilizer AF4 promoted higher rates of plant biomass production.