Corn Response to Seed-Placed Fertilizer As Affected by Planting Date and Hybrid Maturity.

Corn (Zea mays L.) growth can be influenced by many factors, such as planting date, hybrid maturity, and a lack of nutrient under different climate conditions. In Minnesota, early-season growth may help improve corn yield and grain quality because the growing season is short. The objectives of this study were to determine the impact of planting date, hybrid maturity, and starter fertilizer on corn growth, grain yield, and grain quality. Small-plot experiments were conducted at two locations in 2010 and 2011 on soils that tested medium to very high in soil P. Treatments consisted of three corn hybrids with relative maturity ratings of 94, 99, and 104 d in three planting dates ranging from late April to late May with and without starter fertilizer (64 kg ha-1 of 10-15-0) banded on the seed with the planter. Starter fertilizer increased corn leaf height at the eight leaf collar stage, and this was consistent across hybrids and planting dates. Starter fertilizer advanced the date of silking for the late-maturity hybrid at one location in 2010, and in 2011 resulted in a 1 to 2 d advancement of silking date regardless of hybrid and planting data at both locations. Planting date and hybrid consistently affected grain yield across locations. Yield was affected by starter fertilizer at both locations, but this was not consistent across hybrids and planting dates. These results suggest that in high P-testing soils there is no consistent benefit to P-based starter fertilizer, and that this is consistent across contrasting hybrid maturities and planting dates.