DAMINOZIDE RESIDUE PRESENT IN APPLE FRUIT AFTER LONG AND SHORT-TERM EXPOSURE

Daminozide residues were determined in ppm or ppb on 'Starking', 'Red King', 'Rome' and 'Golden Delicious' apples after repeated long term exposure (21 years) and on 'Top Red' apples after short term (1 year) exposure. Application rates varied from 2.2 to 9.0 kg/ha for short term exposure and 2.2 to 4.5 kg/ha for long term exposure. Two and three years after cessation of the daminozide spray program no daminozide residues were found in 'Top Red' regardless of the rate applied or analytical procedure used. Daminozide residues (< 1 ppm) were present in 'Starking', 'Red King', 'Rome' and 'Golden Delicious' one year after cessation of the spray program. The cultivar 'Rome' had consistently higher daminozide residue levels followed by 'Golden Delicious', 'Red King' and 'Starking'.