Viability of shelled rubber (Hevea brasiliensis Muell. arg.) seed treated with peg 6000 at different drying times in storage period

Abstract

Background and Objective: Storage of rubber recalcitrant seeds are very complex and dilemma, they can not be dried to under 30% moisture content and will deteriorate at low temperatures. In this condition metabolism remains active and germination process continue even in a resting state and when seeds were desiccated water content decreased, sub cellular changes began to occur, resulting in rapidly declining of seed viability. The aim of this study was to determine the viability of shelled rubber seed by PEG 6000 treatment at different drying times during storage period. Materials and Methods: This study was conducted using factorial design of two stage nested consisting of the factor at the first stage was the drying time from 00:00-06:00 am and 06:00-12:00 am and factor in the second stage was PEG 6000 (0, 15, 30 and 45% w/v) with two replications, where each unit consists of 75 seeds (clone PB 260). The parameters observed were: germination (%), speed of growth (%/etmal), vigor index (%) and the maximum growth potential (%) in germination phase. Results: At the germination phase, all variables had no significant effect, with the germination percentage were above 95% (96.58%), speed of growth were 20.87%/etmal, vigor index were 96.00% and maximum growth potential were 95.92%. Conclusion: The results showed that the viability of shelled rubber seed by PEG 6000 treatment at different drying times during storage period was not significantly different in the germination phase at 96.58%.