Conducted by: Greg Roth, Scott Harkcom, Shaun Heinbaugh and Mark Antle
Location: Rock Springs, PA
Sponsor: William Shyman, Great Plains Manufacturing, Inc., Scott Brown, C.B. Hoober Case IH, Inc.
To evaluate differences in yield, height, moisture and stand establishment in twin- row corn using a Great Plains Precision Seeder and single-row corn with 30 inch row spacing.
The Great Plains Precision Seeder has the ability to plant corn, small grains, soybeans, and forage crops at a variety of row spacing and configurations. Research in Ontario shows yield advantages to twin-row corn have occurred in some fields but have been somewhat inconsistent across the various years and locations where trials were conducted (Stewart, 2000). One of the advantages of twin row corn grown at 30 inch row spacing is that no major modifications of harvesting and spraying equipment are necessary when converting from single-row 30 inch spacing. The other potential advantage of the Precision Seeder is that a number of different crops including alfalfa, wheat and soybeans can be planted with the same machine.
In this study, the Great Plains Precision Seeder (GPPS) and a John Deere 1780 (JD) corn planter were compared. The JD planter was configured to plant 30 inch single rows and the GPPS was setup to plant twin rows 7.5 inches apart and centered on 30 inches. These two configurations were evaluated in a replicated strip trial with plots that were 15 ft wide (six single rows wide (JD planter) and 12 twin rows spaced 7.5 inches on 30-inch centers) and nearly 2,300 feet in length. Each treatment was replicated 8 times in the field. The experiment was planted on May 24, 2002 with the seeding rate on both planters adjusted to drop 28,500 seeds/acre with a final stand target population of approximately 26,000 plants/acre. No insecticide or starter fertilizer was used in either planter. Pioneer brand 36B08 (102 day RM) seed was no-till planted using both planters.
Plant population counts were taken at 12 and 19 days after planting to compare differences in late emergence rates between the two planters. In each replication, 100 ft sections were measured and the plants were counted and averaged between treatments. At physiological maturity, 10 plant height measurements per replication were averaged then compared between treatments.
Plots were harvested for grain using a 6 row combine equipped with a calibrated yield monitor and moisture meter. Yields were calculated by using the grain weight, length and moisture of each plot and adjusting to 15.5% moisture. Yield, height, and moisture data were analyzed using SAS.
Plant stands were significantly higher for the JD corn planter (Table 1). This appeared to be mostly due to skips with the precision seeder. Approximately 16% of the plants were missing in the precision seeder stands. The plant spacings in the precision seeder plots appeared uniform except for the missing plants. Nelson and Smoot (2001) also reported lower populations with a precision seeder in twin row corn.
The percent of the stand that emerged between the day 12 and day 19 was similar for both planters. This suggests that seed depth was consistent for both planters. Observations in the field appeared to confirm this. Yield differences were not significant between the planters despite the lower population for the precision seeder. The average yield for both treatments was 108 bu/acre, which was above average for fields on the research farm. The lack of yield differences may have been related to the heat and drought stress experienced by the crop. There were no significant differences in height or moisture between treatments. The height of this corn was relatively short and leaf area development was limited. We did not encounter any harvesting problems using a conventional 6 row corn head.
Table 1. Early (12 DAP) and late (19 DAP) stand counts, emergence rate, and late emergence rate of no-till corn grown in twin rows planted with a Great Plains Precision Seeder and 30 inch single rows using a John Deere 1780 corn planter in Centre County, PA in 2002.
|12 DAP Count|
|19 DAP Count|
|Late Emergence Rate *|
|* emerged after June 5|
|Single 30 in. row||28500||22128||77.6||25483||89.4||13.2|
Table 2. Corn height, grain moisture and grain yield of no-till corn grown in twin rows planted with a Great Plains Precision Seeder and 30 inch single rows using a John Deere 1780 corn planter in Centre County, PA in 2002.
|Single Row @ 30"||60.1||21.3||107.7|
We found similar yields with the Precision Seeder compared to the single row conventional no-till corn planter in this study. The precision seeder performed well except for the seed drop skip issue. Additional trials would be useful to better estimate the potential of twin row corn at similar populations to single row corn.