Steve D. Ruhl, Agriculture and Natural Resources Extension Agent
Ed Lentz, Extension Agronomy Specialist
To evaluate the effect of seeding rate on yield of Roundup Ready soybeans.
| Cooperator: | Tom Weiler | Soil Test: | pH 6.5, P 104 ppm |
| County: | Morrow | K 208 ppm | |
| Nearest Town: | Chesterville | Fertilizer: | None |
| Drainage: | Naturally well-drained | Planting Date: | May 1, 2001 |
| Soil type: | Chili loam | Planting Rate: | See table |
| Tillage: | Conventional till | Row Width: | 10-inch |
| Previous Crop: | Corn | Harvest Date: | October 2, 2001 |
| Variety: | Pioneer 93B01 | Herbicides: | Roundup Ultra 1 qt/A + AMS |
Three population rates were used to determine the effect of seeding rate on yields. They were 120,000, 162,500, and 227,500 seeds per acre. The seed used was rated at 85 percent germination. The population rates were replicated four times in a randomized complete block design. Individual plot size was approximately 1/4 acre. The soybeans were planted in 30-foot-wide strips for a length of about 360 feet. A 20-foot-wide strip was harvested the length of the strip and weighed using a weigh wagon.
Harvest population was determined by counting the soybean plants in 1/1,000 of one acre between two rows in each individual treatment.
| Table 1. Soybean Population and Yield1. | ||
| Treatment | Harvest Population | Yield |
| (seeds/A) | (plants/A) | (bu/A) |
| 120,000 | 95,750 a | 42.9 a |
| 162,500 | 114,000 b | 41.8 a |
| 227,500 | 162,000 c | 42.0 a |
| LSD (0.05) | 17,329 | NS |
| F-test | 46.7 | < 1 |
| CV (%) | 8.1 | 3.4 |
| 1 Means followed by the same letter are not significantly different. | ||
A uniform stand was achieved for all the seeding rates. No significant difference in yields was found for any of the three population treatments. Weed control in all the plots was very good. No yield differences may be attributed to excellent growing conditions later in the season and lack of competition with weeds.
The authors would like to thank Todd Swetland and Pioneer Hybrids for providing the soybeans used in the study. Also, thanks to Tom Weiler for cooperating in this study.
For additional information, contact:
Steve Ruhl
Ohio State University Extension, Morrow County
871 W. Marion Rd., Suite 102
Mt. Gilead, OH 43338
419-947-1070
ruhl1@postoffice.ag.ohio-state.edu