The study looked at different traits in tomatoes to see which ones have the biggest impact on fruit yield. They found that traits like the number of fruits per plant and the weight of each fruit have a direct positive effect on fruit yield. Other traits like the number of branches and the time it takes for the plant to flower also play a role, but in a more indirect way. This means that if you want to improve tomato yield, focusing on traits like fruit number and weight would be most effective.