Van Gogh painted three almost identical versions of the composition. Another painting of the cypresses (New York, Metropolitan Museum of Art) was painted earlier in July 1889, and was probably painted directly in front of the subject. (http://arthistoryproject.com/artists/vincent-van-gogh/a-wheatfield-with-cypresses-september-1889/)
See also:
http://curiator.com/art/vincent-van-gogh/wheat-field-with-cypresses
http://curiator.com/art/vincent-van-gogh/wheat-field-with-cypresses-1
http://curiator.com/art/vincent-van-gogh/cypresses
http://curiator.com/art/vincent-van-gogh/wheatfield-with-cypresses