|Luchiari, Ariovaldo - EMBRAPA BRAZIL W/SWCRU|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 23, 2001
Publication Date: August 23, 2001
Citation: Shanahan, J.F., Luchiari, A. Schepers, J.S., Johnson S. 2001.Use of chlorophyll fluorescence techniques to detect stresses in corn. American Society of Agronomy Abstracts. #150040. CDROM Technical Abstract: The objective of this study was to evaluate the use of chlorophyll fluorescence techniques versus the SPAD chlorophyll meter as a means of detecting crop N and water stresses. The work was conducted near Shelton, NE during the 1999, 2000 and 2001 growing seasons. Treatments consisted of a factorial combination of 12 corn hybrids, 2 water levels (deficit and full irrigation) and 2 N levels (deficit and full N). Leaf chlorophyll content and chlorophyll fluorescence were determined with a SPAD chlorophyll meter and WALZ PAM-2000 fluorometer on a weekly basis, beginning at the V-6 growth stage. Grain yield was also determined at maturity. Chlorophyll fluorescence measurements during mid grain filling were more highly correlated with grain yield variability than SPAD assessments. These results suggest that fluorescence measurements are a more sensitive indicator of stress in corn than SPAD measurements. Fluorescence measurements are also a better means of detecting differences in photosynthetic efficiency among corn hybrids.