Abstract Tissue testing of com leaves for nitrogen (N) concentration is not widely used because it is easier and perhaps more economical to apply sufficient fertilizer than to risk a yield reduction because of an N deficiency. Environmental concerns related to N fertilizer will require producers to improve N management practices to reduce the potential for nitrate leaching. Applying fertilizer N on an “As Needed”; basis rather than using a “Lump Sum”; approach has both environmental and economic advantages. Corn leaf disk N concentrations and SPAD 502 chlorophyll meter readings from N rate studies were compared at silking for a variety of hybrids at several locations. Data indicated that chlorophyll meter readings correlated well with leaf N concentrations for a given hybrid and location. Calibration of chlorophyll meters to determine crop N status may not be practical because of the unique “greenness”; characteristics of different hybrids. However, normalization procedures can be used to standardize the ...
[1]
L. Dumenil.
Nitrogen and Phosphorus Composition of Corn Leaves and Corn Yields in Relation to Critical Levels and Nutrient Balance
,
1961
.
[2]
J. Hanway.
How a corn plant develops
,
1966
.
[3]
S. W. Melsted,et al.
Critical Plant Nutrient Composition Values Useful in Interpreting Plant Analysis Data1
,
1969
.
[4]
G. Schuman,et al.
Automated Total Nitrogen Analysis of Soil and Plant Samples1
,
1973
.
[5]
I. Zelitch.
The Close Relationship Between Net Photosynthesis and Crop Yield
,
1982
.
[6]
EFFECT OF TEMPORARY N STARVATION ON LEAF PHOTOSYNTHETIC RATE AND CHLOROPHYLL CONTENT OF MAIZE
,
1985
.
[7]
Effect of N fertilizer rate and nitrapyrin on leaf chlorophyll, leaf N concentration, and yield of three irrigated maize hybrids in Nebraska
,
1989
.
[8]
Matthijs Tollenaar,et al.
A nondestructive method to monitor leaf greenness in corn
,
1991
.