This presentation will help growers, consultants, and other agricultural practitioners in the northeastern United States select or recommend seeding rates for grain corn production on silt loam soils. New hybrid releases in the late 2000s compared with older hybrids respond more favorably to high seeding rates because new hybrids lodge less, have improved drought tolerance, and may respond to higher rates in narrow rows. Despite these improved traits, Cornell University still recommends seeding rates of 30,000 kernels/acre, similar to recommendations in the early 1990s. We will present studies conducted in New York on silt loam soils over the last 20 years that repeatedly have shown that seeding rates of about 30,000 kernels/acre result in close to optimum yields. We will highlight recent field-scale studies (farmer-researcher partnerships) in 2 dry years that show that two recent hybrid releases had maximum relative profit at seeding rates above 30,000 at only 1 (40,000 kernels/acre) of 8 comparisons in 30-inch rows, at 2 (32,800 kernels/acre) of 4 comparisons in twin rows, and 2 (34,500 and 38,700 kernels/acre) of 4 comparisons in 20-inch rows. Based on results of these studies, recommended seeding rates in New York will not change. Nevertheless, because of inconsistent responses across years, sites, and hybrids, we recommend that growers test the response of new selected hybrids to seeding rates on their different fields. Growers can now easily conduct replicated strip-tests on new hybrids at different seeding rates because of the ease in varying seeding rates with new corn planters and the prevalence of yield monitors on most combines. The results of seeding rate studies by growers could also lead to implementation of variable seeding rates within fields.
