An analysis of tomato yield was made by partitioning yield into component parts. Yield was first broken down into the variables, number of fruits and fruit weight. The variable, number of fruits, was further partitioned into number of clusters and number of fruits per cluster.

The experimental material consisted of six inbred lines and all possible F₁'s from these lines (not including reciprocals). The parents collectively exhibited a tremendous range of expression for all characteristics. At the two extremes were the parents L. pimpinellifolium, with an average of 1,287 fruits per plant and an average fruit weight of 0.5 grams, and Matchless, a variety of L. esculentum, with a plant average of 16 fruits and an average fruit weight of 142.6 grams.