EVALUATION OF SOME SEED DORMANCY BREAKING METHODS ON GERMINATION OF Rhynchosia capitata (Roth DC)

Dormancy of weed seeds is a significant feature contributing to their survival rate since it helps the weeds to avoid herbicides and other weeding practices along with unfavorable environmental conditions. We investigated the effects of different dormancy breaking treatments on the germination of Rhynchosia capitata (Roth DC), a common summer annual weed, which is emerging as a weed threat in farming areas of Southern Punjab, Pakistan. Different dormancy breaking methods i.e. dry heat, hot water, stratification, soaking in HCl, HNO3, and H2SO4 were evaluated in 2010 at the department of Agronomy, the University of Agriculture, Faisalabad, Pakistan. Results indicated that R. capitata seeds show signs of physical dormancy that is mainly due to the impermeability of their coat. Acid scarification treatments were very efficient in breaking dormancy and promote germination. Various seed treatments with dry heat, hot water and stratification were ineffective in breaking dormancy of R. capitata seeds.