Pesticides are poisons to kill pests, not to prolong the life of the produce. Herbicides kill weeds.....
What you are thinking of (I assume) is preservatives, for example washing salad leaves in chlorinated water or coating apples in a waxy substance. These are effective in making the produce last longer but I'm not sure if they would affect organic rating, so it could be possible to buy organic produce that has been treated to make it last longer.
Fruit and veg don't hang around for long in my house as they get eaten up, so I don't know form experience!