Hello,
I am a graduate student in agriculture and business management,and want to pursue my masters in agribusiness management in USA.I got through my toefl exam.I want to know if there are universities which require only toefl/ielts to do masters in agribusiness.I didn't give my GRE yet.will there be any problem if I don't submit the gre scores during visa interview?please suggest me whether I should write gre or not.

I think it goes school by school. There may be some schools that don't require a GRE score, but all the universities I know do require it. Check the websites of the specific schools you are applying to.

This website says it depends on the school too.
Student Visas (http://travel.state.gov/visa/temp/types/types_1268.html#apply)

Is G.R.E mandatory for U.S visa