In the mid-1990s everyone was trying to increase yield and populations in hybrid corn with narrow rows, mostly using 15 inch rows. But that usually required a specialized head to harvest the corn crop. By using twinned rows of corn 7.5 inches apart on 30-inch centers one can create narrow rows but still use a 30-inch corn head to harvest. On farm yield trials have been conducted for the last three years comparing twinned rows on 30-inch centers to conventional 30-inch rows in western Ohio. We used the Great Plains Precision Plant drill to plant the twin rows and a John Deere no-till planter to plant in 30-inch rows. Two Pioneer hybrids were used, one a hybrid adapted to high populations and one with a flexible ear preferring lower populations. Seeding rates from 30,000 seeds per acre up to 50,000 were used in both twin and 30-inch rows. Over the three years we only had the expected results one year; that is we did get a yield response to twin-rows and higher populations. In general we see that you can boost your seeding rate to about 36,000 to 37,000 and expect a slight yield boost (maybe 5%). But you don't need to be in twin rows to do this, it can be done in 30 inch rows. You do need to watch your hybrid choice and choose one that will withstand higher populations from a lodging standpoint. We also conducted a silage trial in 2005, but saw yield decrease above the 37,000 seed drop, even in twin-rows. Growing corn with the Precision Plant drill did not reduce yield, even when planting in 30-inch row widths. The drill may be an excellent choice for a producer needing a multi-purpose planter to produce wheat, soybeans or corn.