Dual Effect of Audible Sound Technology on the Growth and Endogenous Hormones of Strawberry

Abstract

ABSTRACT

Sound waves could improve the growth and increase yield. However, it could be a form of environmental stresses. Therefore, the aim of this study was to investigate the effect of audible sound on the growth and endogenous hormones of strawberry plants (Fragaria_ananassa). Five endogenous hormones, namely indole-3-acetic acid (IAA), gibberellin (GA), abscisic acid (ABA), jasmonic acid (JA) and Zeatin Riboside (ZR) have been investigated. Plants exposed to sound frequency of 0.1 - 1 kHz and sound pressure level (SPL) of 70 - 100 dB for 2 hours, 3 hours and 5 hours at different growth stages. Results revealed that plants have different responses to sound waves at different growth stages. Acoustic frequency could accelerate the blooming and the flowering rates in a short run. In contrast, exposing plants to sound for more than 3 hours per day for a long run more than 40 days could inhibit the growth. However, sound treatment could significantly accelerate the blooming and the flowering rates. The maximum concentration of ABA was in leaves of the treated plants for 90 days, each day for 5 hours. Whereas, mean of IAA levels in leaves of control plants was insignificantly higher than those of the treated plants for 5 hours and 2 hours after 90 days of sound treatment. Moreover, no significant difference was found in the concentration of JA in leaves between all treated plants and control plants after 75 and 90 days. In conclusion, audible sound could stimulate or inhibit the growth of strawberry plants.