It can become really expensive to ensure everything that you eat is organic and also sometimes quite tricky to find, so I have been researching which fruit and veggies are the most important to try to make sure that they are organic...
The ones that have been shown to have the highest amount of pesticides are the following (most are found with over 60 different types of pesticides, crikey!)
Apples, Celery, Cucumbers, Grapes, Leafy greens, lettuce and spinach, Tomatoes, Strawberries, Blueberries, Pears, Bell peppers, Peaches, Necterines, Cherries and Potatoes.
Just knowing this I find helps at little, as you can supplement the non-organic fruit and veggies being mindful to the list above.
If your in Mallorca I can really recommend visiting Valldemossa market on a Sunday, head to the back left hand corner and there's a lovely stall selling seasonal organic fruit and vegetables from the Island.