Crop Management Research
Variable Hybrid Selection in Corn
Tawainga W.
Katsvairo, William J. Cox, Michael Glos, Harold M. Glos and Dill Otis
Dept. of Crop
& Soil Sciences
Corn yields often show significant spatial
variability, which may provide an opportunity to select hybrids according to
the yield potential for distinct regions within a field. Very few studies
have evaluated this potential. We conducted field-scale research at two
sites on a dairy farm, in Onondaga county, and three sites on two cash crop
farms, in Seneca county, to determine the feasibility of variable hybrid
selection in 1999, 2000 and 2001. The fields ranged in size from 14 acres to
24 acres. We chose Pioneer 3752 and 37M81, because the two hybrids had shown
yield differences between sites. We used a split-planter approach where
alternating strips of each hybrid were planted, and yields were measured
using combine with yield monitors and differential GPS. Detailed information
on the management of the field trials were reported previously (Vol.12,
No.5, p. 1-5).
Corn yield showed spatial variability at 12 of 15
site-year comparisons with significant spatial variability at all sites in
1999 and 2001, the dry years (Vol.12, No.5, p.1-5). Corn also yielded
differently at the Onondaga and Seneca sites in 1999 and 2001 (Table 1).
37M81 vs. 3752 had greater yields at the Onondaga sites, while 3752 had
greater yields at the Seneca sites. Weather conditions and management
practices were mostly the same across sites, so different soil types and
fertility levels from manure application presumably contributed to corn
yielding differently at the Onondaga and Seneca sites. Corn yield, however,
had field location x hybrid interactions in only four of 15 site-year
comparisons, which indicates that the hybrids had similar relative yield
differences throughout most fields. Corn thus yielded differently at the
Onondaga and Seneca sites, presumably because of different soil conditions
across sites, but few field location x hybrid interactions, despite spatial
variability for corn yield at most sites.
Corn yield did have field location x hybrid
interactions at the Onondaga 1 site in 1999 and 2001, which suggests that
variable hybrid selection would be attractive within this field. Also, the
spatial relationship of corn yields had high temporal stability (r = 0.88)
in dry years, with yields above 145 bu/acre in western and
northeastern regions and yields below 95 bu/acre in southeastern regions in
1999 and 2000 (Fig.1). In 1999, 3752 compared with 37M81 yielded the same
or greater in the northeastern region, while 37M81 yielded greater or the
same in the central portion of the field (Fig.1). In 2001, 37M81 compared
with 3752 yielded greater in the southern central region of the field and
the same in the remaining areas of the field. Although there was a field
location x hybrid interaction at the Onondaga 1 site in the dry years,
variable hybrid selection would not be the appropriate management practice
because 37M81 vs. 3752 yielded the same or greater in most areas of the
field.
Conclusion
Hybrids responded differently for the Onondaga (manured)
vs. Seneca (non-manured) fields. The yield advantages was in some cases
quite high and would greatly affect the bottom line. Yield monitors and
split-planter trials therefore provide very valuable information on local
hybrid performance, which will readily play for investment in the
technology. We do not see much justification for the use of site-specific
hybrid planting within fields, as yield advantages of one hybrid over
another tend to be consistent in a field.
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Publications
- Katsvairo, T, W.J. Cox, H.M. van Es, and M.A. Glos.
2003 Spatial yield responses of two corn hybrids to two N levels. Agronomy
Journal (accepted for publication). (view)
- Katsvairo, T, W.J. Cox, and H.M. van Es. 2003. Spatial
growth and soil responses of two corn hybrids to two N levels. Agronomy
Journal (accepted for publication).
- Katsvairo T.W., W.J. Cox and H.M van Es. 2002. Tillage
and rotation effects on soil physical characteristics. Agron. J. 94:
299-304.. (view)
- Karunatilake, U., H.M. van Es, and R.R. Schindelbeck.
2000. Soil and crop response to plow and no-tillage after alfalfa-maize
conversion on a clay loam soil. Soil and Tillage Res. 55/1-2:31-42
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