Ohio State University Extension Bulletin

Agronomic Crops Team On-Farm Research Projects 2000

Special Circular 179-01


Early Season Hail Damage in Corn:
Effects of Stalk Bruising and Tied Whorls

Todd Mangen, Graduate Research Associate
Peter Thomison, Extension Agronomist, Corn

Objective

To determine effects of tied whorls and stalk bruising caused by early season hail damage on corn performance at four on-farm sites. Various agronomic performance parameters including yield, nubbin ears/barren plants, lodging, and silking/pollen shed dates were evaluated.

Background


Cooperator: Pendleton Seymore Delay A Delay B
Variety: Pioneer 33J24 Davis 2711 Pioneer 33J24 Pioneer 33J24
Planting Date: 4/29/00 5/1/00 4/26/00 4/30/00
Planting Rate (seeds/acre): 29,900 26,000 29,000 29,000
Tillage: Conventional Conservation Conventional Conventional
Fertilizer applied N-P-K
(lbs/A)
170-78-92 168-78-78 187-69-90 187-69-90
Previous Crop Soybean Soybean Soybean Wheat
Soil Type: Crosby Silt
Loam
Kokomo Silty
Loam
Miamian Silt
Loam
Miamian Silt
Loam


Methods

On June 5, 2000, a hail storm caused severe injury to corn fields in Fayette County, Ohio. Hail resulted in nearly complete defoliation as well as severe stalk bruising. A week after the hail injury occurred, a high percentage of plants exhibited tied whorls. While there is extensive information on defoliation effects on corn growth and agronomic performance, little information exists on effects of bruising and tied whorls on subsequent plant growth and survival.

On June 12, plots consisting of 30 feet of row, replicated eight times, were established at each of four on-farm sites. Plants were rated according to a predetermined scale using four different categories (normal growth, tied whorl, abnormal growth, and dead) on three dates following the hail injury. Plots exhibiting major damage were associated with extensive hail-induced stalk bruising and scarring, whereas plots with minor damage were associated with little or no stalk bruising. Plots with major damage were completely defoliated, whereas plots with minor damage exhibited 80 to 90% defoliation based on visual estimates.

Data was also recorded for plant heights, silking/pollen shed dates, barren plants (including plants with poorly developed ears), and lodging. Stalk lodging and barrenness were expressed as a percentage of final plant stand. On September 19, plots were hand harvested, and yields were adjusted to 15.5% moisture. It was not possible to randomize treatments because replicates were adjacent rows. Standard errors were computed for grain yield data to provide a measure of variability across replicates within treatments (plots with major and minor damage).

Results

  Pendleton Seymore Delay A Delay B
  Major Minor Major Minor Major Minor Major Minor
Growth stage
when damage
occurred
V6 V5 V7 V5
Leaves damaged1 100 90 100 80 100 90 100 90
Tied Whorls, %2
12 June
53 20 56 44 36 40 61 22
23 June
24 6 6 1 13 9 8 5
6 July
9 3 0 0 6 7 1 2
Canopy Height (in.)
12 June
11.0 14.0 4.9 12.8 24.6 23.4 12.0 33.6
23 June
33.6 45.6 14.7 23.8 38.7 41.2 28.1 52.0
6 July
64.9 79.7 37.3 53.5 69.9 73.7 62.7 93.3
Silking, %2
13 July
- - 0 0 - - 32 86
18 July
- - 12 31 - - 63 100
21 July
- - 32 71 - - 77 100
25 July
- - 58 90 - - 84 100
1 August
- - 85 100 - - - -
Final Stand (plants/A) 28895 28895 16408 23087 26717 26572 25846 26717
Barren Plants, %2 12.3 8.5 18.8 5.0 13.8 11.3 16.8 10.8
Lodging, %2 1.5 0.5 0.0 0.8 0.5 0.5 0.5 0.5
Grain Moisture, % 21.3 18.9 28.9 25.7 18.9 19.2 21.3 19.6
Yield (Bu/A) 159.8 194.1 93.3 186.5 164.8 176.7 147.5 169.5
S.E. (yield) 4.8 10.1 11.8 3.0 10.0 7.8 10.8 12.3
1 Visual estimate percent.
2 Percentage of final stand.

Summary

During the three- to four-week period following the hail storm, the number of plants exhibiting tied whorls decreased. Plots that received major damage from hail exhibited 36 to 61% tied whorls on June 12, which decreased to 0 to 9% by July 6. Also, canopy heights of plots with major damage were 3.8 to 30.6 inches shorter compared to plots with minor damage on July 6. Silking was delayed by approximately 1 to 1.5 weeks in the plots with major damage vs. plots with minor damage. Severe stalk bruising did not increase lodging; lodging was negligible across farm sites, averaging less than 2%. Kernel moisture at harvest was generally higher in plots with major damage (in three of the four fields), and yields were lower compared to the plots with minor damage.

Yields of plots with major damage ranged from 93.3 to 164.8 bu. per acre compared to yields ranging from 169.5 to 194.1 bu. per acre in plots with minor damage. One site experienced large stand losses (Seymore), which contributed to the greater yield difference between plots with major and minor injury, compared to the other three sites. Overall growing conditions following hail damage were favorable; more stressful conditions following the hail storm might have retarded the regrowth of damaged plants and increased differences in yield between plots exhibiting major and minor damage.

For additional information, contact:

Todd Mangen, Graduate Research Associate
Horticulture and Crop Science
The Ohio State University
2021 Coffey Road
Columbus, Ohio 43210
614-292-2001
mangen.8@osu.edu


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