Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 2004
Publication Date: November 4, 2004
Citation: Gitz, D.C., Kim, S., Baker, J.T., Reddy, V. 2004. Effects of light history and temperature on corn quantum yield [abstract]. Agronomy Abstracts, ASA-CSSA-SSSA Annual Meeting. 2004 CDROM. Technical Abstract: Corn (Zea mays L.) cv. Pioneer 3733, was grown hydroponically on a 50 % sand:vermiculite mix in sunlit SPAR (Soil Plant Atmospheric Research) chambers maintained at 19/13, 25/19, 31/25, 35/29, or 38.5/32.5 degrees day/night and at 370 or 750 umol / mol CO2. Corn seed of the same type and lot number was planted in an irrigated field plot. In both the field and chamber grown plants the quantum yield of PS II as Fv/Fm of was inversely correlated with previous day's PAR. In the chamber grown plants, this effect was most pronounced at lower temperatures. In a second experiment, chamber plants were grown at 31/25 degrees and the apparent CO2 assimilation rate to light was determined following a clear and a cloudy day. A preceding day of high light (following the clear day) depressed photosynthetic rate the following morning. The results suggest high light intensity coupled with growth at low temperatures or with moderately low night temperatures characteristic of field settings may depress photosynthetic performance into the next day.