Celery – Due to peak consumer demand around Thanksgiving and Christmas, 75 percent of the crop is grown during the fall and winter, when rain and wind promote the growth of bacteria and fungal diseases. And because we eat the entire stalk, it must be sprayed repeatedly to ward off pests.
Strawberries – Strawberries are not only sweet and juicy, but also delicate and prone to disease, including fungal attacks that can turn them to mush during transit and storage. “With apples and peaches, a lot of spraying is cosmetic to get blemish-free fruits,” says Richard Wiles, senior vice president for policy at the Environmental Working Group. “With berries, you’re just trying to get them across the finish line into the store before they go bad.”
Apples – Apples are susceptible to more than 30 insects and at least 10 diseases. And fungicides and other chemicals are added after picking to prevent tiny blemishes that can accumulate during storage of up to nine months.
Peaches – Farmers may spray peaches every week or two from bloom to harvest – and peach fuzz can trap pesticides.
Bell peppers – Sweet bell peppers have no bitter compounds to serve as built-in insect repellents.
Onions – Onions manufacture their own protective chemicals, a series of unpleasant-tasting sulfur compounds that discourage insect munching. Though farmers may spray early in the growing season, residues are removed when the dry outer layer of the bulb is shed during harvest.
Avocados – Most of the pesticides used to treat avocados accumulate on the peel.
Sweet corn – Corn is husked before eating, eliminating residues on the outside.
Asparagus – The spears spring up so fast, there’s little time for insects to attack.