Effects of gibberellic acid applications on induction of partenocarpy in black myrtle fruits

Myrtle (Myrtus communis L.) is an evergreen aromatic and medicinal bush native to the Mediterranean Basin. It has long been considered an important fruit since ancient times especially because of its use for medical purposes. Myrtle oil is also conventionally produced from the leaves by traditional distillation methods. Myrtle fruits are consumed fresh by people of the Mediterranean Basin. The common complaints by the consumers is the small fruit size as well as the high number of seed in fruits. The main aim of this study was to test the impact of the application of gibberellic acid (GA₃) on seed counts and seedlessness (parthenocarpic fruit) in black myrtles by utilizing 50, 100 and 200 ppm GA₃ applications. GA₃ was applied as spray to the leaves a week before bud break and blooming period. None of the three GA₃ applications at the bud break stage had any significant effects on fruit characteristics whereas some GA₃ applications at the blooming period reduced seed numbers and fruit set in considerable amounts. The highest seed numbers per berry were recorded 14.72 from 200 ppm GA₃ and 12.96 from 100 ppm GA₃ applications at bud break stage. On the other hand, average seed numbers per berry were reduced to 3.01, 2.80 and 3.96 by bloom applications of 50, 100 and 200 ppm of GA₃, respectively.