how tough is it to get into UC davis college of agriculture?

Colleges and Universities A-Z Cornell University
1

I want to do a major in agricultural science and wanted to know the basic requirements to get into UC davis like the average SAT score the required IB score etc

2

You have posted in the Cornell University thread.

Here is the UC Davis Student profile link: https://www.ucdavis.edu/admissions/undergraduate/student-profile/

Also the UC Website lists the Freshman profile for 2017:

Admit rate — Overall 43.6%
Admits: 30,945
Applicants: 70,968
California Residents (% of admits): 59.7%

GPA and test scores of middle 25%-75% students:

High School GPA (capped weighted): 3.95 - 4.25
ACT Composite Score: 26 - 32
ACT English Language Arts : 24 - 30
SAT Evidence Based Reading & Writing: 590 - 680
SAT Mathematics: 600 - 750
SAT Essay: 15 - 18

This data is not major specific so cannot draw any specific conclusions except higher stats will be need for more competitive majors (Engineering/CS/Biology). The best overall chances you want to at the average or above.