Using atmospheric plasma to increase wettability, imbibition and germination of physically dormant seeds of Mimosa Caesalpiniafolia

Abstract

In this study, we analyzed seed wettability as well as imbibition and germination after treatment with atmospheric pressure cold plasma (APCP) using dielectric barrier discharge (DBD) in seeds that have very low germination rates. To aid industrial applications, several seeds were simultaneously treated with plasma within a space between two coaxial glass tubes sandwiched by two metal mesh screens that produced high-voltage pulses at 17.5kV with a frequency of 990Hz. Three treatment times (3min, 9min and 15min) as well as untreated seeds were used to conduct the wettability, imbibition and germination tests. The wettability and imbibition were found to be directly related to the treatment duration, but saturation of the imbibition was found for treatment durations greater than 9min. Plasma treatment was also effective in improving germination, but shorter treatment duration presented greater germination. This apparent contradiction is explained by the cell damage caused by the increased exposure to plasma, as observed in other studies. The results suggest that there must be an optimal wettability and imbibition condition that ensures that excessive moisture does not harm the germination process.

Keywords: Atmospheric plasma; DBD; Impermeable integument; Seed dormancy.