Peter Thomison, Extension Specialist, Corn Production Systems
Allen Geyer, Research Associate, Horticulture and Crop Science
To evaluate differences in stalk rot, lodging, grain yield, and moisture among hybrids planted at varying plant populations in a field with a history of Gray Leaf Spot.
| Cooperator: | Riverview FFA | Row Width: | 30 inches |
| Nearest Town: | Warsaw | Plot Length: | 25 feet |
| Major Soil Type: | Chagrin Loam | N-P-K Fer- | |
| Previous Crop: | Soybean | tilizer (lbs): | 200-40-40 |
| Planting Date: | 5/24/02 | Soil Test (pH, | |
| Harvest Date: | 11/13/02 | P, K): | 6.2, 89, 551 |
| Planting Rate: | 26000 and 40000 seeds/A |
Six Pioneer Brand hybrids with varying stalk strength and Gray Leaf Spot resistance were planted with three replications in a split plot design, with seeding rate as the main plot and hybrid as the split. The plots were planted in a field that has a history of Gray Leaf Spot pressure at the Riverview FFA farm, near Warsaw in Coshocton county. The plots were four rows by 25 feet long, with the center two rows harvested.
The hybrids were rated from 4 to 7 for stalk strength and 5 to 6 for Gray Leaf Spot resistance by Pioneer (with 9 being the best).
Table 1. Agronomic Performance of Corn Planted to Varying Plant Densities Under Gray Leaf Spot Pressure, Warsaw, Ohio, 2002.
| Seeding | Final | Test | |||||
| Brand/Hybrid | Rate | Yield | Moisture | Stand | Lodging | Emergence | Wt. |
| seeds/A | Bu/A | % | plants/a | % | % | lbs/bu | |
| Pioneer Brand 33J56 | 26,000 | 142.2 | 22.3 | 29,800 | 13.3 | 99.3 | 58.0 |
| Pioneer Brand 33G26 | 26,000 | 145.6 | 23.1 | 27,267 | 15.0 | 96.3 | 60.5 |
| Pioneer Brand 34M94 | 26,000 | 141.8 | 19.9 | 27,600 | 7.7 | 98.0 | 57.2 |
| Pioneer Brand 33D31 | 26,000 | 143.2 | 24.0 | 28,267 | 10.3 | 98.7 | 56.6 |
| Pioneer Brand 34H31 | 26,000 | 152.1 | 21.1 | 28,033 | 16.0 | 99.0 | 60.8 |
| Pioneer Brand 34B23 | 26,000 | 135.0 | 21.5 | 28,600 | 8.3 | 97.0 | 59.4 |
| Pioneer Brand 33J56 | 40,000 | 135.2 | 22.1 | 41,200 | 53.3 | 99.0 | 58.0 |
| Pioneer Brand 33G26 | 40,000 | 160.6 | 21.7 | 39,867 | 58.0 | 98.7 | 59.8 |
| Pioneer Brand 34M94 | 40,000 | 152.4 | 19.0 | 38,067 | 67.3 | 97.3 | 57.3 |
| Pioneer Brand 33D31 | 40,000 | 146.2 | 24.2 | 37,667 | 11.7 | 99.0 | 56.4 |
| Pioneer Brand 34H31 | 40,000 | 150.7 | 22.2 | 37,867 | 5.7 | 99.3 | 59.5 |
| Pioneer Brand 34B23 | 40,000 | 157.9 | 21.6 | 38,633 | 61.3 | 97.7 | 59.1 |
| LSD (0.05)* | |||||||
| Seeding Rate (S) | NS | NS | 167 | NS | NS | NS | |
| Hybrid (H) | NS | 0.9 | 1,599 | NS | NS | 1.0 | |
| S x H | NS | NS | NS | 35.9 | NS | NS | |
There was very little Gray Leaf Spot present this year due to the dry conditions throughout the growing season.
For additional information, contact:
Peter Thomison
Department of Horticulture and Crop Science
The Ohio State University
202 Kottman Hall
2021 Coffey Road
Columbus, OH 43210
614-292-2373
thomison.1@osu.edu