Researchers have to attempted to determine the best timing for pix applications since it was first introduced in the late 1970's, Most work combined rates and timings, since it is difficult to separate the two. The growth regulator Pix was first tested under field condition in California during the 1977 growing season and grower acceptance has continued to increase since its registration in 1981. Pix has been evaluated in numerous University of California research trials, and its increased use is related to a better understanding of the products capabilities and how it is best applied.