Need weed economics in onion :making a design to remove weeds from onion farms

I am research student  trying to make a design intervention which will be helpful to remove weed from onion farm.
My research indicates that, weed causes 90% yield loss in  onion.
Can any one tell me how much money do farmers spent on weed removal including cost of herbicides & cost of manual weeding in onion.
I am in need of urgent help.
So kindly share your suggestions and experiences which can be more helpful.

Tushar Pawar
Ist year- M.Des
Centre for Product Design & Manufacturing
Indian Institute of Science,
Bangalore - 560012
+91 9611163620

per acre 5000

Hi Tushar, did your research found any solutions for the problem you have identified.

Please share.