Abstract
Corn planted on different dates from mid-May to late-June over 4 yr was evaluated for whole plant dry matter yields, grain component yields, and plant nutrient N, P, and K concentrations. Mid-May plantings resulted in greater maturity of both whole plant and the grain component of the whole plant at harvest. No whole plant yield advantage resulted from the earliest planting compared with the late-May or early-June planting, though grain yields were higher. Plantings later than 6 June resulted in significantly lower yields of both whole plant and grain. Plant nutrient levels tended to be higher in the late-planted corn, but the earliest two plantings tended to yield the most harvested nutrients. Extremely slow germination reduced the expected advantages of early plantings.