Size of the prickles on fruit leads me to think that it may be Datura metel. Besides D. stramonium is not found generally wild in tropical areas.
Dr. Gurcharan Singh
Retired Associate Professor
SGTB Khalsa College, University of Delhi, Delhi-110007
Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018.
Phone: 011-25518297 Mob: 9810359089http://people.du.ac.in/~singhg45/