Honey bees improve, or supplement, pollination for most plants they visit. However, honey bees are considered negligible pollinators for the following crops: soybean, peach, field beans, snap beans, tomato, corn, cotton, peanuts, pecans, canola, and alfalfa. In cases like these, the plant is either independent of insect pollination in general or dependent on other pollinators. – Keith Delaplane, University of Georgia