1. Evaluating “Ultra-Early” Corn Hybrids
Peter Thomison, Rich Minyo, Alex Lindsey,
and Allen Geyer
Horticulture and Crop Science
Ohio State University

4. Ultra-Early Corn Hybrids
A challenge to successful cover crop establishment in Ohio is the relatively narrow window for planting cover crops after corn harvest in the fall.
Planting ultra-early hybrids results in an earlier corn harvest that allows earlier cover crop seeding and establishment.

5. What are “Ultra-Early Hybrids” in Ohio?
Commonly grown maturities are:
105 to 114 d
Approx to 2800 GDDs*
“Ultra-early” hybrids“ (very early hybrids)
Maturities less than 100 days (~2400 GDDs)
About days (approx GDDs)
Variable across state N vs. S, NW vs. NE
*GDDs calculated using the 86/50 degrees F cutoff method

6. Ultra-Early Corn Hybrids
Advantages
Mature earlier.
Dry down faster (energy conservation).
Higher prices and premiums for early deliveries.
Allow livestock producers to apply manure earlier and plant cover crops.
Disadvantages
Lower yield – “98 days 98 bushels”?
More vulnerable to heat/drought stress ?
More susceptible to diseases and insects?
Stalk and grain quality marginal?

7. Ultra-Early Corn Hybrids
Corn breeders have improved the agronomic performance of short-season hybrids making them more competitive with commonly grown maturities within a zone of adaptation.
Other factors, e.g. transgenic insect resistance.
Corn acreage in Manitoba, Canada increased nearly 100% from 2015 to 2018.
 496,626 acres of corn for grain planted in 2018.

8. Relative Maturity of Hybrid Entries 2017 Ohio Corn Performance Test
Early Season Test
Full Season Test
Total entries=124
NE/NC NW
Total entries=140

9. Relative Maturity of Hybrid Entries 2018 Ohio Corn Performance Test
Early Test
Full Season Test
NE/NC NW
Total Entries=137

10. Relationship of Yield to Relative Maturity (days), NC/NE Ohio, 2018

11. Ultra-Early Corn Hybrid Tests
Objectives
To compare the agronomic performance of ultra-early hybrids with commonly grown maturities.
To assess the economic returns of ultra-early hybrids and commonly grown hybrid maturities.

12. Ultra-Early Corn Hybrids Goal
To determine if ultra-early hybrids that are much earlier than hybrids commonly grown in Ohio offer advantages in cover cropping systems for corn production.

13. Ultra-Early Corn Hybrid Test Materials and Methods
Field studies were conducted in 2016 and 2017.
Wooster and Bucyrus, OH.
10’ x 25’ plots, 4 30-inch rows, four replications per site.
Planted 34,000 seeds per acre after soybeans.

14. Ultra-Early Corn Hybrid Test Materials and Methods
Ultra-early hybrids were evaluated from eight brands: Beck’s, DeKalb, LG Seeds, Pioneer, Rupp, Seed Consultants, Steyer and Syngenta. Hybrids were the same across sites within each year.
12 (2016) and 14 (2017) ultra-early hybrids were rated 90 to 95 days with GDDs of 2170 to 2430.
19 (2016) and 28 (2017) ultra-early hybrids were rated days with GDDs of
A common set of 5 elite commonly grown maturity hybrids were included with maturity ratings ranging of 104 to 109 and GDDs of 2530 to 2600.

15. Ultra-Early Corn Hybrid Test Materials and Methods
Two sets of commonly grown maturity hybrids were planted
one set was harvested when the ultra-early corn achieved harvest moisture (23-24%) – HD1.
the other set of commonly grown maturity hybrids was harvested when they achieved harvest moisture – HD2.
Final stand, grain yield, test weight, moisture, stalk lodging and ear rots in the center two rows of each plot were determined at harvest.

16. 2016 and 2017 Ultra-Early Corn Hybrid Tests
Dates
Bucyrus
Wooster
Planting
5/24/16
6/2/17
---
5/23/17
Harvest
10/12/16
10/18/17 & 11/9/17†
10/14/17 & 10/27/17†
† A second set of common maturity hybrids were harvested on the later date indicated.

17. Ultra-Early Corn Hybrid Test Statistics
Randomized complete block design with four replications of hybrid.
Data analyzed using contrasts (α=0.05) in SAS 9.4 to compare maturity groups.
Three sets: days, days, and days
Two sets: days (ultra-early) and days (commonly grown maturities)
Contrasts used to compare the effect of harvest date on the commonly grown hybrid group ( days).

18. Relationship of Yield to Hybrid Relative Maturity, Bucyrus, OH, 2016

19. Relationship of Yield to Hybrid Relative Maturity, Bucyrus, OH, 2017

20. Relationship of Yield to Hybrid Relative Maturity, Wooster, OH, 2017

21. Ultra-Early Corn Hybrid Test Trends
Increasing relative maturity was associated with higher yields.
Strength of relationship variable across sites.
Grain yield increased at the rate of 2.9 and 1.4 Bu/A/Day in 2016 and 2017, respectively, at Bucyrus and 1.6 Bu/A/Day in 2017 at Wooster.

22. Grain Yield, Moisture, Test Weight and Return for the First Harvest Dates Averaged Across Three Sites ( )

23. Grain Yield, Moisture, Test Weight and Return for the First Harvest Dates Averaged Across Three Sites ( )

24. Grain Yield, Moisture, Test Weight and Return for the First Harvest Dates Averaged Across Three Sites ( )

25. Grain Yield, Moisture, Test Weight and Return for the First Harvest Dates Averaged Across Three Sites ( )

26. Grain Yield, Moisture, Test Weight and Return for Harvest Dates 1 and 2, Averaged Across Bucyrus and Wooster, 2017

27. Ultra-Early Corn Hybrid Test Trends
The ultra-early hybrids yielded 11% less than the commonly grown maturity hybrids. The d and d hybrids yielded 13% and 8% less, respectively, than the commonly grown maturity hybrids.
The ultra-early hybrid return was $29.05 per acre less than the commonly grown maturity hybrids.
The grain moisture of the ultra-early hybrids was 5.7% less than the commonly grown maturity hybrids.
The grain test weight of the ultra-early hybrids was 7.4% greater than the commonly grown maturity hybrids.
Although yields did not differ between the early and normal harvest dates for the commonly grown hybrid maturity hybrids, returns were reduced 11% on the earlier harvest date.

28. Ultra-Early Corn Hybrid Test Conclusions
After factoring in drying costs, the economic return of the d ultra-early hybrids was comparable to that of the commonly grown maturity hybrids when harvested on the earlier date.
The greater economic return of the commonly grown maturity hybrids was reduced when they were harvested early.

29. Ultra-Early Corn Hybrids Conclusions
Some ultra-early hybrids have yields comparable to commonly grown maturities.
Little or no stalk lodging and ear rot.
Only three site-years, more performance data needed.

30. Materials and Methods 2018 Ultra-Early Corn Hybrid Test
Location
Bucyrus
Wooster
Planting Date
5/11
5/12
Harvest Date
9/29 & 10/24*
9/30 & 10/18*
Seeding Rate
34,000
Previous Crop
Soybean
Corn
Tillage
Minimum Till
N Fertility
207 lbs/A
* A second set of check hybrids were harvested on the second date indicated.

31. 2018 Ultra-Early Corn Hybrid Test Grain Yield and Moisture
Days
Yield
Grain Moisture
90-95
224 ( )
17.9 ( )
96-100
231 ( )
18.7 ( )
253 ( )
21.1 ( )
out yielded ultra early hybrids (~11%)
day hybrids yield slightly more than day hybrids (~3%).

32. Acknowledgements
A Conservation Tillage and Technology Mini-Grant helped fund this evaluation.

33. Any questions or comments?
THANK YOU
Any questions or comments?

34. Ultra-Early Corn Hybrids Conclusions
More variability in yield among ultra-early hybrids than commonly grown maturities.
Harvest grain moistures of early maturity hybrids not consistent with maturity ratings.