Degree Type


Date of Award


Degree Name

Master of Science



First Advisor

Roger Elmore


How a Corn Plant Develops (Ritchie et al., 1986) was a popular reference for dry matter and nutrient accumulation; however, the data it contained was done in the late 1950's and was out of date. Defining modern corn dry matter and nutrient accumulation patterns is important in determining nutrient removal rates, as well as what development stage a specific nutrient is required and at what levels. To quantify changes in dry matter and nutrient accumulation between then and now, ten popular hybrids, two from each decade from 1960 to 2000, were planted at typical planting densities for each respective decade in 2007 and 2008 near Ames, Iowa. Above-ground whole plant samples were collected ten times throughout the growing season at V6, V10, V14, VT, R1, R2, R3, R4, R5, and R6. At each sample date, above ground dry matter, nitrogen, phosphorus and potassium accumulation were determined.

Total dry matter accumulation was 14.7 and 22.3 Mg ha-1 for the 1960's era hybrids and the 2000's era hybrids, respectively. At R6, nitrogen, phosphorus and potassium uptake was 214, 40 and 122 kg ha-1 for the 2000's era hybrids and 177, 28 and 92 kg ha-1 in the 1960's era hybrids. Grain yield was also greater with the 2000's era hybrids than in hybrids from the 1960's. The results show increased dry matter and nutrient accumulation in new hybrids relative to the older hybrids, despite similar accumulation patterns.


Copyright Owner

Matt Boyer



File Format


File Size

75 pages

Included in

Agriculture Commons