Spinach jumped into the second spot this year with twice as much pesticide residue by weight than any other crop on the Dirty Dozen list. Four pesticides -- one insecticide and three fungicides -- were responsible for the bulk of the residues detected on spinach.
Nectarines remained in the third spot on the list. Nearly all samples of strawberries, spinach, peaches, nectarines, cherries and apples tested positive for residue of at least one pesticide, according to the group.
Last year, apples came in at No. 2 after having been a list leader for the past five years. This year, apples fell to the fourth spot on the list.
Peaches moved down one ranking this year after claiming the No. 4 spot in 2016.
Pesticides on conventionally grown pears have increased dramatically in recent years, according to the latest tests by the USDA. Pears now rank sixth on the list, up from 22nd previously.
Cherries remained at the No. 7 spot on the Dirty Dozen list.
Grapes moved down this year from No. 6 to No. 8, according to the report.
Celery fell this year to the No. 9 spot after being ranked fifth last year.
Tomatoes also moved down one ranking this year after claiming the No. 9 spot in 2016.The USDA rotates what food it tests for pesticides with a special focus on produce that kids consume.