DETERMINATION OF OPTIMUM CONCENTRATION AND TIME PRIMING OF STEVIA SEED WITH BORIC ACID (H3BO3) MICRONUTRIENT

Mehdi Aghighi Shahverdi

Faculty of Agriculture, Shahed University, Tehran, Iran; (Iran, Islamic Republic of)

Heshmat Omidi

heshmatomidi@yahoo.com
Agricultural College and Medicinal Plant Research Center, Shahed University, Tehran, Iran; (Iran, Islamic Republic of)

Abstract

In order to determine anoptimal duration and concentration of priming of stevia seed with boric acid for improving
germination, an experimental factorial completely randomized design with three replications was conducted in
the laboratory of Seed Science and Technology, Shahed University of Tehran in 2015. The first factor was different
concentrations of boric acid (zero, 0.5, 1, 1.5 and 2 percent) and the second factor of priming time (0, 8, 16, 24 and 32
hours). Effects of concentration and duration of priming with Boric acid was significant on germination percentage,
germination mean time, germination rate, germination energy, germination uniformity, germination mean daily,
germination daily rate, germination value, seedling length and seed vigor index. The highest germination percentage,
germination rate, germination energy, germination mean daily germination value and seed vigor index was 24 hours
priming and the highest germination percentage, germination rate, germination potential, germination value and seed
vigor index in priming of 2% Boric acid were obtained. Germination uniformity highest in 24 hours at 1% concentration
priming of boric acid (5.51). Seedling length in 24 hours at 1.5% concentration priming with boric acid was
highest average 1.02 cm. Generally Stevia seed priming with boric acid for 24 hours at concentrations of 1.5 to 2
percent had positive effects on germination indexes and seedling growth.

Keywords:

boron,, germination,, micronutrients,, nutripriming,, seed vigor