The tree will drop many small-sized fruit at about the same time, making for a dramatic, and often alarming, show. But the tree should have plenty more fruit staying on the tree that will be in better position to share the tree's resources. Pears generally are not self-fruitful, either, so at least two cultivars are needed. Generally, any two cultivars will be compatible. Kieffer,' 'Duchess,' and 'Bose' will set some fruit without benefit of cross-pollination, but will produce best among other cultivars.
Tart cherries are self-fruitful, but sweet cherries are more complicated.
The sweet cherry 'Stella' is self-fruitful. Other sweet cherries need to be cross-pollinated, and some can only be pollinated by certain other cultivars. Peaches, nectarines and apricots are generally self-fruitful, but fruit set may be enhanced by having more than one tree. Unfortunately, these trees are often quite susceptible to winter and spring frost injury in Indiana, resulting in poor or no fruit crop most years. In order for adequate cross-pollination to take place, trees should be within 50 feet of one another.