External Silicon Application Reduces Flower Bud Abscission in Pistachio (Pistachio vera) by Endogenous Hormones Levels and Antioxidant Enzymes Activity
Journal of Nuts, cilt.17, sa.2, ss.167-180, 2026 (Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 17 Sayı: 2
- Basım Tarihi: 2026
- Doi Numarası: 10.60680/jon.2026.1231132
- Dergi Adı: Journal of Nuts
- Derginin Tarandığı İndeksler: Scopus, CAB Abstracts, Directory of Open Access Journals
- Sayfa Sayıları: ss.167-180
- Anahtar Kelimeler: ABA, Flower drop, Foliar application, IAA, Pistachio, Silicon
- Çukurova Üniversitesi Adresli: Evet
Özet
Pistachio is one of the most important nut crops in Iran, which plays an important role in the economy of its producers. Suitable nutrition along with adequate pollination in this crop can increase yield. Flower and fruit abscission are one of the major limiting pistachio (Pistacia vera L.) productivity. Therefore, Strategies that can regulate plant hormones and antioxidant systems are essential to mitigate abscission and improve yield stability. In this study investigated the effect of foliar-applied silicon (Si) on the activity of antioxidant enzymes such as peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) as well as the endogenous hormonal levels of indole acetic acid (IAA) and abscisic acid (ABA). Treatments included silicon concentrations of 0, 5, and 10 g L-1, on two commercial pistachio cultivars (‘Fandoghi’ and ‘Akbari’) at 15 and 30 days after full bloom (DAFB) during the ‘ON’ year 2023. The results showed that the highest POD (1.463 nmol min-1 mg-1 protein) and CAT (1.3 nmol min-1 mg-1 protein) activities were observed in ‘Akbari’ at 10 g L-1. Moreover, the highest IAA concentration (>1400 μM) observed in ‘Akbari’ at 5 g L-1 Si. Both cultivars exhibited the lowest ABA levels at 10 g L-1, suggesting a strong inhibitory effect of Si on ABA biosynthesis or accumulation. Silicon (Si) treated in this research is not yet widely used by horticultural producers commercially. Overall, foliar silicon application significantly enhanced antioxidant enzyme activity, increased IAA levels, and reduced ABA concentration, thereby potentially mitigating flower bud abscission in pistachio.