Effects of Foliar Gibberellic Acid Applications on Vegetative Growth of Pear, Apple and Cherry Seedlings

Abstract

The objective of the study was to see whether the growths of pear (Pyrus comminus), apple (Malus domestica) and cherry
(Prunus avium) seedlings could be expedited with th e applications of gibberellic acid (GA 3). The apple and pear seedlings
growing in open field or und er low plastic tunnels were spray ed ones or twice with different levels (0, 200, and 4 00 ppm) of
GA3. The cherry seedlings growing in open fi eld were also subjected to the same GA 3 treatments. The treated seedlings were
evaluated in terms of seedling diameter and length at the end of the growing season. GA3 sprays significantly increased lengths
of pear and cherry seedlings. The effects of plastic covering on seedling diameter and length were both significant for pear and
cherry seedlings. None of the treatm ents yielded plants with higher lengths an d larger diameters as compared to control in
apple seedlings. The pear seedlings grown under plastic tunnel were significantly taller and ticker than the ones growing in the
open field. Maximum plant height (38.11 cm) and stem thickness (6.6 mm) in p ear seedlings were obtained with 2 x 400 ppm
GA3 and with 1 x 400 ppm GA3 applications in combination with plastic tunn elling, respectively, while m inimum values for
the mentioned parameters were observed in control. The highest length (39.7 cm) was recorded in cherry seedlings treated with
1 x 400 pp m GA3 applications, but all GA3 applications resulted in reduced stem thickness in cherry seedlings. No treatments
yielded seedlings that could be grafted in the late fall of the same season.