(19)

(11)

EP 0 397 665 A1

(12)

(43) Date of publication: 22.11.1990 Bulletin 1990/47 (21) Application number: 88910372.0 (22) Date of filing: 15.11.1988

(51) International Patent Classification (IPC):  A01C 1/ 00( . ) A01H 4/ 00( . ) (86) International application number: PCT/US1988/003934 (87) International publication number: WO 1989/005575 (29.06.1989 Gazette 1989/14)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 18.12.1987 US 19870135034 (71) Applicant: UNIVERSITY OF FLORIDA Gainesville, Florida 32611 (US)	(72) Inventors: GRAY, Dennis, J. Leesburg, FL 32748 (US) CONGER, Bob, V. Knoxville, TN 37901-1071 (US) (74) Representative: Hedley, Nicholas James Matthew  Stephenson Harwood One, St. Paul's Churchyard London EC4M 8SH London EC4M 8SH (GB)