Corn Era Hybrid Dry Matter and Macronutrient Accumulation across Development Stages

Abstract

Core Ideas Evaluating corn dry matter and macronutrient accumulation patterns across era hybrids is necessary to understand changes in plant nutrient requirements and effects on accumulation timing and fertilization management. Era hybrids differed in dry matter and nutrient accumulation, with differences in nutrient content mainly related to dry matter production. Dry matter and P accumulation was linear, however, N and K accumulation slowed during the reproductive stages. Although the absolute dry matter production and nutrient content was greater with the most recent hybrids, relative to the maximum dry matter and N, P, and K content and the accumulation rate (cumulative growing degree unit‐based) remained the same across era hybrids. Results indicate that overall dry matter production and yield potential has been mainly responsible for changes in corn macronutrient requirements with development of new hybrids. Evaluating corn (Zea mays L.) aboveground dry matter (DM) and macronutrient accumulation patterns across era hybrids is necessary to understand changes in plant nutrient requirements and effects on accumulation timing and fertilization management. Two popular hybrids for each of five era‐decades from 1960 to 2000 were grown in 2007 and 2008. Whole plant samples were collected at 10 development stages, with dry matter (DM), N, P, and K determined. Era hybrids differed in DM and nutrient accumulation, with differences in nutrient content mainly related to DM production. The 1960 to 1990 era hybrids were more similar in DM and nutrient content across development stages compared to the 2000 era hybrids which had the greatest content. Dry matter and P accumulation was linear (V6–R5 stages), however, N and K accumulation slowed during the reproductive stages. While the fraction of maximum plant content at R1 averaged 48, 71, 58, and 83% across hybrids for DM, N, P, and K, respectively; the ranges were 43 to 52% for DM (1990 and 1960), 64 to 78% for N (1990 and 1960), 55 to 60% for P (2000 and1960), and 69 to 93% for K (1990 and 1960). Although the absolute DM production and nutrient content was greater with the most recent hybrids, relative to the maximum DM, N, P, and K content and the accumulation rate, growing degree unit based, remained the same across era hybrids. This indicates that overall DM production and yield potential has been mainly responsible for changes in corn macronutrient requirements with development of new hybrids.