oil for uniformity of dominant high oil genetics although segregating for cob color glume color and plant height in test crosses p55 synthetic has consistently expressed high oil across different environments p55 is an early medium maturity flowering synthetic hybrid broadly adapted to the corn growing areas of the northern united states and southern canada p55 has expressed high oil and excellent cold soil seedling vigor that conditions low grain moisture in the grain of the male sterile hybrid grain parents in field tests of the topcross u00ae grain production system using p55 as the pollinator and a male sterile hybrid grain parent plants of both varieties were allowed to grow unmolested to maturity both varieties were allowed to continue to grow and natural cross pollination occurred by the action of wind as is normal in most grasses including corn i e excluding wheat of course only pollen from the male parent synthetic hybrid p55 was available for pollination of the male sterile hybrid grain parent the tassels or pollen bearing flowering parts of the grain parent having been rendered sterile by genetic cytoplasmic mechanisms the fields where high oil topcross u00ae grain was produced were well isolated from other corn fields to prevent any accidental contamination with ambient pollen such isolation techniques may be accomplished by timed delay with other hybrid corn production fields or by using a space distance pattern of more than 70 m from normal corn well known to those skilled in the art of the seed corn industry both varieties comprising the corn seed blend were allowed to continue to grow and be harvested the ears harvested from the male sterile grain parent expressed the higher grain yield potential of the elite.