authorDeterminationof Optimum Duration and Concentration ofStevia(SteviarebaudianaBert.) Seed Primingwith Boric Acid(H3BO3)

Abstract

In order todetermine optimal durationandconcentrationof Steviaseed primingwith boric acidforimprovinggermination, an experimentalfactorialcompletely randomizeddesignwith threereplications was conducted inthelaboratoryof SeedScience and Technology,ShahedUniversity ofTehranin 2015. The first factor wasdifferent concentrations ofboric acid (0,0.5,1.0,1.5and2.0percent)and the second factorwas primingduration(0,8,16,24and32hours). Effectsof concentration and primingduration withboric acidweresignificanton germination percentage,mean germination time, germination rate,germinationenergy, germinationuniformity,meandailygermination,germination dailyspeed,germination value,seedling lengthandseed vigor index.The highest values for germination percentage, germination rate,germinationenergy, means of daily germination, germination value and seedling vigor index were observed after 24 hours of boric acid priming. The highest germination percentage, germination rate, germination potential, germination value and seed vigor index were obtained in 2.0% boric acid priming. 24 hourspriming at1.0% concentration ofboric acidhad the highest germinationuniformity.The seedlinglengthwashighest in24 hourspriming at 1.5% concentration of boric acid.In general, Stevia seed priming with 1.5 to 2.0%of boric acid for 24 hours had positive effects on germination indexes and seedling growth.

Keywords

• Boric acid
• germination
• micronutrients
• nutri-priming
• seed vigor