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Corn Seeding Rates Trial

Collaborating Producer: Koos & Barbara Bos, Peace River

Research Coordinator: Dr. Akim Omokanye

From: Peace Country Beef & Forage Association 2015 Annual Report

Plant population refers to the number of plants per acre; planting or seeding rate refers to the number of seeds planted per acre. Optimum plant population depends on factors such as hybrid, moisture stress level, soil fertility, and yield goal. In the Peace, for silage or grazing, the suggested seed rate has been 30,000 kernels per acre for years and the recommendation has been based on studies carried out elsewhere, outside of the Peace region. In collaboration with Koos & Barbara Bos, PCBFA carried out a trial to examine optimum seeding rate for corn grazing or silage production.


The trial site was at Koos & Barbara Bos, near the Peace River Airport. The site has had corn for 6 years and has not received any fertility in the last 4 years, so no fertilizer was applied to this year’s corn crop.

DuPont Pioneer 39F44 corn hybrid (Roundup Ready corn) with 2000 corn heat units (CHUs) requirement was seeded on May 17 with a 12-row corn planter at 22” seed row spacing. There were 4 treatments (seeded kernels per acre) consisting of:

1) 38,049 kernels/acre

2) 36,146 kernels/acre

3) 34,425 kernels/acre

4) 32,858 kernels/acre

Spraying to control weeds was done with Roundup®. According to Alberta Agriculture and Forestry (, the calculated CHUs from seeding date (May 17) to corn forage harvest date (October 6) was 2005 for Peace River area, while the long-term average for the same period (May 17-October 6) was 1904.

Corn forage yield was determined from several 23.8’ row lengths when most cobs were at the half milk line stage. Plant height was measured and the number of cobs per plant counted at harvest. Notes were also taken on cob development and kernel stage. Wet corn forage samples (whole plant) were analyzed by A&L Canada Laboratories Inc., London, Ontario