The invention provides a rapid and efficient method and assay for monitoring yield enhancement in a plant using a measure of silk number. The plant is transformed with a prospective gene associated with yield enhancement. The transformed plant is grown along with non-transformed control plants until silk growth is apparent. The change in the number of silks in the transformed plant correlated to the change in yield for the plant. Therefore, changes in yield enhancement can be estimated in the transformed plant prior to harvest of mature plant tissues.