Bachelor of Science, HansRaj College, Delhi, 1984. Master of Science, Panjab University, Chandigarh, India, 1986. Doctor of Philosophy, Delhi University, 1993.
Junior research fellow department botany University Delhi, 1987-1989, senior research fellow department botany, 1989-1993, research scientist, 1993-1994. Postdoctoral fellow Lakehead University, Thunder Bay, Canada, 1995-1997. STA fellow PERC, Sapporo, Japan, 1997-1998.
Assistant professor KVL University, Copenhagen, 1998-1999. Associate professor Panjab University, Chandigarh, India, since 2000. Visiting scientist Hokkaido Tokai University, Sapporo, 1995, Virginia Polytechnic Institute, Blacksburg, 1997.
Visiting professor Second Napoli (Italy) University, 1996.
Member Ecological Society of America, Botanical Society of America, Weed Science Society of America, International Society Chemical Ecology, International Weed Science Society.