Germinação de sementes de nogueira-macadâmia submetidas à incisão e imersão em ácido giberélico

Abstract

The objective of the present work was to evaluate the emergency of macadamia nut seedlings through incision and immersion of the seeds in the gibberellic acid. Seeds of IAC-Campinas B cultivar, extracted from mature fruits, were standardized according to size and health. They were immerged in recipient filled with water. In 80 seeds a 0.5 cm incision was done in the peel, longitudinally in relation the embryo, leaving the almonds exposed. The other 80 seeds were kept intact. Soon after, the seeds were submerged in different concentrations of gibberellic acid: 0, 150, 300 and 450 mg L-1, for 90 hours, with oxygen system. After that period, the seeds were placed in plastic trays, among layers of autoclaved sand, and preserved in laboratory with controlled temperature (around 25ºC). The trays were humidified daily. After 180 days, the emergency percentage, average length of the roots, average length of the aerial part and average total dry mass of the seedlings were evaluated. It was concluded that the incision and immersion of the seeds of macadamia nut gibberellic acid were harmful to the emergence and development of the seedlings.