Pioneer Maturity in Northern iowa 
9 Pioneer hybrids recommended for northern Iowa 
are classified under three groups: (1) early maturing, 
(2) medium maturing, and (3) late maturing. These 
groupings are made to meet; first, climatic conditions; 
second, various soil types and conditions peculiar 
to northern Iowa; third, date of planting; and fourth, 
personal demands of the farmers. 
The early maturing group. Pioneer 355 and 357, 
should be used for late plantings; for slow soils if 
planted around May 15th-25th; and for locations 
where the first freeze occurs unusually early in the 
fall. Under these conditions, with normal weather, 
the early maturing group of hybrids will ripen and 
produce good, sound com. 
Under average northern Iowa climate and average 
soil fertility, medium maturing Pioneer 352 will 
mature ahead of the average first freeze if planted 
by the middle of May. Pioneer 352 should not be 
planted too late on slow or poor soil. 
The late maturing group. Pioneer 322, 324, 335, and 
349, is recommended for rich or fast soils; early plant¬ 
ings on soils of average to high fertility; and for 
silage or fodder corn. None of these hybrids should 
be planted late on slow or poor soil. 
The above recommendations are based on over¬ 
age temperature and rainfall for northern Iowa. 
These two factors, in abnormal seasons, vary the 
maturity of corn considerably. 
CUYTOH 
ACRSOa 
PIONEER HYBRIDS 
FOR NORTHERN IOWA ARE 
ADAPTED IN THE 
SHADED AREA 
WAPULO 
MONROE 
PIONEER 
