Estratificação das sementes, ácido giberélico e temperatura na obtenção de porta-enxertos de caquizeiros

Abstract

The persimmon is propagated by grafting, using rootstock obtained from seeds. Due to low germination, the aim of this study was to increase the production of rootstock of the Dyospyros kaki and Dyospyros lotuspersimmon through stratification and treatment of the seeds with gibberellic acid, at different environmental temperatures. In the first experiment, the seeds were placed between layers of moist sand in Petri dishes, and kept in a BOD chamber at a temperature of 4 ºC for 15 and 30 days; as well as the control, where seeds were immersed in water for 10 min. The seeds were then placed onto plastic trays containing coarse sand in a BOD chamber, at a controlled and constant temperature of 15, 20, 25 or 30 ºC for 60 days, when the emergence percentage was evaluated. In the second experiment, the seeds were stratified for 30 days and then left to soak in beakers containing solutions of gibberellic acid of 100, 200 and 300 mg L-1, in addition to the composite control using only distilled water. The seeds were placed on plastic trays containing coarse sand, and kept for 60 days in a BOD chamber at a controlled and constant temperature of 20.5 ºC for Diospyros kaki and 24.6 ºC for Diospyros lotus. The process of stratification for 30 days increases seedling emergence by 13.94%. A temperature of 20.5 ºC results in 47.62% emergence in the speciesDiospyros kaki, and 24.6 ºC results in 44.49% emergence inDyospyros lotus. It is not necessary to treat the seeds with gibberellic acid.