Every year the Environmental Working Group posts its list of foods high in pesticides. To download your own copy, go to www.ewg.org and click on the shopper’s guide to obtain your copy.
In the meantime, I am listing the foods:
Clean Fifteen 2013 (Lower in pesticides) *
asparagus  avocado  cabbage   cataloupe  corn  eggplant  grapefruit  kiwi mangoes  mushrooms onions   papayas   pineapples  sweet peas (frozen) sweet potatoes
*These are the foods that I do not always buy organically, because they are lowest in pesticides.
Dirty Dozen 2013 (Produce highest in pesticides)
Apples   Celery   Cherries   Tomatoes  Cucumbers   Grapes   Hot Peppers   Nectarines (imported)  Peaches  Potatoes (white)  Spinach  Strawberries  Sweet Bell Peppers
Collards & Kale, Summer Squash & Zucchini (These contain pesticides of special concern)
(I make a special effort to buy these organically, especially when they cannot be peeled, like grapes. es)