Role of GA3 Application and Time of Sowing on Seed Germination of Hypericum perforatum Linn.

Hypericum perfortaum L. (Family: Hypericaceae), commonly known as "St. John's Wort" is an important medicinal plant valued for its anti-depressant activity. In the present work role of GA₃ application and time of seed sowing on seed germination of Indian populations of Hypericum perforatum growing in Himachal Pradesh was studied. Seeds were sown on four different dates viz D₁ (February 13), D₂ (March 1), D₃ (March 15) and D₄ (April 1) and treated with different concentration of GA₃ solution. The results showed that seeds sown on 15th March (D₃) gave the maximum germination of 57.15 per cent, shortest peak germination period of 21.55 days (D₃), the earliest germination initiation of 14.4 days and the shortest seed germination period of 33.55 days (D₃). Seeds treated with 150 ppm GA₃ (T₄) gave the highest seed germination percentage (45.63), which is significantly higher than 29.19 per cent seed germination in untreated seeds. The results suggested that time of sowing have a positive effect on seed germination and seedling vigour in Hypericum perforatum L.