Study on the environmental factors affecting seed germination and seedling emergence of Eclipta prostrata

Experiments were conducted to evaluate the effects of temperature,light,pH,osmotic stress,salt stress and seed burial depth on seed germination and seedling emergence of Eclipta prostrata.It was found that seed germinated at a range of temperatures from 25 to 40 ℃.Seed germination was strongly stimulated by light,suggesting that seeds of this species are photoblastic positively.Seeds could germinate(93% to 100%)at pH ranged from 4 to 10.Also seed could tolerate wide ranges of salt stress,and germination occurred even at 0.15 mol·L-1(42.22%),while it was highly sensitive to water stress,under which the germination rate would decrease from 97.78% to 4.44% with the descending of water stress from 0 to-0.5 MPa.Seeds sown on the soil surface gave the greatest seedling emergence rate(92.50%)in plastic trays,and no seedlings emerged when seeds were buried in soil at depths of 0.5 cm.This study illustrates the role of seed burial by tillage as one important tool for the management of E.prostrata.