The effects of GA3 treatment on yield, carbohydrate, and endogenous hormone changes in Memecik olive cultivar
In this experiment, 100 ppm gibberellic acid (GA3) was applied to Memecik olive trees in the middle of June in the `on' (bearing) year to research the effects on yield, reducing sugar amount, and endogenous hormones with the purpose of bearing fruit regularly. The yield was 19.33 kg/tree in control plants and 17.33 kg/tree in GA3-treated plants in the `on' year. The yield was 7.17 kg/tree in GA3-treated plants and 4.00 kg/tree in control plants in the 'off' year. While GA3 treatment was not very effective on the decrease of fruit amount in the `on' year, it increased fruit amount in the `off' year. Moreover, GA3 treatment did not significantly affect total reducing sugar amount, but it affected endogenous hormones. Total reducing sugar amount was determined at the 4% level in both years (`on' and `off'). Glucose content was determined to be higher than sucrose and fructose in all plant organs and during flower bud formation periods (induction, initiation, and differentiation). Furthermore, GA3 treatment increased abscisic acid, GA3, indole-3-acetic acid, and zeatin levels during flower bud formation periods and in all plant organs (leaf, node, and fruit) in both years.
___
- Boulouha B, Wallali LD, Loussert R, Lamhamedi M, Sikaoui L
(1993). Effects of growth regulators on growth and fruiting of
olive (
Olea europaea
L.). Al Awamia 70: 74-96.
- Camara MM, Diez C, Tarija ME (1996). Free sugar determination by
HPLC in pineapple products. Z Lebensm Unters Forsch 202:
233-237.
- El-Naby SKMA,
El-Sonbaty MR
, Hegazi ES,
Samira MM,
El-Sharony
TF (2012). Effect of gibberellic acid spraying on alternate
bearing of olive trees. J Appl Sci Res 8: 5114-5123.
- Fernandez-Escobar R, Benlloch M, Navarro C, Martin GC (1992).
The time of floral induction in the olive. J Am Soc Hortic Sci
117: 304-307.
- Haberman A, Bakhshian O, Cerezo-Medina S, Paltiel J, Adler C,
Ben-Ari G, Mercado JA, Pliego-Alfaro F, Lavee S, Samach A
(2017). A possible role for flowering locus T-encoding genes
in interpreting environmental and internal cues affecting olive
(
Olea europaea
L.) flower induction. Plant Cell Environ 2017;
40: 1263-1280.
- Lavee S, Ben-Tal Y, Klein I, Epstein E (1983). Regulation of Fruiting
in Olives. Bet-Dagan, Israel: Institute of Horticulture,
Agricultural Research Organization, Volcani Center.
- Proietti P, Tombesi A (1996). Effects of gibberellic acid, asparagine
and glutamine on flower bud induction in olive. J Hortic Sci
71: 383-388.
- Ramezani S,
Shekafandeh A,
Taslimpour MR (2010). Effect of GA
3
and zinc sulfate on fruit yield and oil percentage of ‘Shengeh’
olive trees. International Journal of Fruit Science 10: 228-234.
- Rotundo A, Gioffree D (1984). The effects of GA
3
on the productivity
of two olive cultivars. Tecnica Agricola 34: 187-202.
- Schlenk H, Gellerman JL (1960). Esterification of fatty acids with
diazomethane on a small scale. Anal Chem 32: 1412-1414.
- Stutte GW, Martin GC (1986). Effect of light intensity and
carbohydrate reserves on flowering in olive. J Am Soc Hortic
Sci 11:27-31.
- Topçuoğlu F, Ünyayar S (1995). Determination of growth substances
(auxin, gibberellic acid, abscisic acid and cytokinin) production
and biological activity in white rot fungus
Phanerochate
chrysosporium
ME 446. Malatya, Turkey: İnönü University
Araştırma Fonu (in Turkish with English abstract).
- Ulger S, Sonmez S, Karkacier M, Ertoy N, Akdesir O, Aksu M
(2004). Determination of endogenous hormones, sugars and
mineral nutrition levels during the induction, initiation and
differentiation stage and their effects on flower formation in
olive. Plant Growth Regul 42: 89-95.