Figure 5. Dissected corn plant at the R1 growth stage and developing ears.
Photos courtesy of Iowa State University.
Daily extraction of nutrients from soil continues during R3 to R6, but is considerably less than daily nutrient extraction during V6 to R1. This seems counter-intuitive because nutrient demand to support kernel growth is very high from R3 to R6. Corn root growth mirrors vegetative corn shoot growth. Corn roots are close to their maximum size at about VT, and new corn root growth slows dramatically (Ordóñez et al., 2018). Young, newly formed corn roots are responsible for the majority of nutrient uptake from soil. Very little new root growth between R3 and R6 causes corn to have a relatively low ability to extract additional nutrients from soil. The corn plant compensates for this limited nutrient extraction from soil by transferring nutrients stored in vegetative plant tissue (the main stalk and older leaf tissues) to the ear. From an agronomic perspective, good early vegetative growth is a critical requirement for high corn yields. Nutrients stored in vegetative tissues are later moved to the ear to feed latter-stage kernel growth. If corn plant growth during vegetative stages is stunted, it is highly likely that late-season growth will also be poor, resulting in lower grain yield.
1Stephen D. Strachan, Ph.D., DuPont Technical Fellow
2Mark Jeschke, Ph.D., Pioneer Agronomy Information Manager
The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary.