Fig. 5. Production Field of Keystone Hybrid Seed after Complete Detasseling 
to shed pollen freely will result in the 
contamination of seed for several yards 
in all directions. 
Harvesting — The utmost care is 
used during the harvesting of KEY¬ 
STONE seed fields. All seed is 
harvested by hand under careful 
supervision to assure that seed from 
the pollen rows is not mixed with the 
seed corn. Any ear dropped to the 
ground before harvest time is discard¬ 
ed regardless of where it is found. 
The seed is transferred directly from 
the fields to the point where it is to 
be processed. 
PRODUCTION OF KEYSTONE HYBRIDS 
KEYSTONE HYBRIDS are produced by qualified 
growers who are experienced in the methods employed 
in hybrid production. All production is under the 
direct supervision of our own agronomist to insure that 
every precaution is taken and that only the most precise 
and thorough production methods are used. 
Isolation — Complete isolation of hybrid production 
fields is important in prohibiting contamination by 
wind cross-pollination. By keeping KEYSTONE 
production fields forty to sixty rods away from any 
other type of corn, this danger is eliminated, thus 
maintaining the purity of the stock used. 
Soil Conditons — ALL KEYSTONE HYBRIDS are 
produced on soils of high fertility, for the most part 
the fertile soils of the Missouri and Mississippi river 
bottomlands. The fields have not been in corn the pre¬ 
vious year, thereby shutting out the possibility of con¬ 
tamination by volunteer corn. Production on fertile 
soil results in strong virile seed with a high germination. 
Planting — In planting the foundation seed of 
KEYSTONE HYBRIDS the stocks are planted in the 
ratio of four to two,- that is, four rows of ear parent to 
two rows of pollen parent. Separate planters are used 
for planting the ear parent and pollen parent, avoiding 
the danger of mixing the parental lines through faulty 
cleaning of planter boxes. 
Detasseling — Able crews of experienced men are 
employed during the detasseling season in KEYSTONE 
production fields. The fields are covered daily, " rain 
or shine” during the entire season, from the time the 
first tassel appears until the tassels have been removed 
from all the ear parent plants in the fields. Complete 
and timely detasseling is by far the most important factor 
in hybrid corn production. Allowing only one tassel 
All known modern methods of production from 
planting to harvesting are followed carefully by 
CORNELI SEED COMPANY leaving nothing undone 
to make KEYSTONE HYBRID CORN conform to the 
same quality for which other KEYSTONE SEEDS have 
been famous for nearly a century. 
Fig. 4. Keystone Hybrid 38 in Field Trials in Carroll County, 
Missouri 
