The Clean 15 contain the least pesticide residue, meaning if budget or availability is an obstacle to buying organic, you can buy conventionally grown varieties of these fruits and vegetables.

Onions
Sweet corn
Pineapples
Avocado
Asparagus
Sweet peas
Mangoes
Eggplant
Cantaloupe (domestic)
Kiwi
Cabbage
Watermelon
Sweet Potatoes
Grapefruit
Mushrooms