Submitted to: Horticultural International Congress Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 10, 2001
Publication Date: August 11, 2002
Citation: KRIZEK, D.T., GITZ, D.C., RITCHIE, J.C., REDDY, V. BIOMASS ACCUMULATION AND PARTITIONING OF EASTERN GAMAGRASS GROWN UNDER DIFFERENT TEMPERATURE AND CO2 LEVELS. IN: ON-SITE PROGRAM XXVITH INTERNATIONAL HORTICULTURAL CONGRESS PROCEEDINGS. 2002. ABSTRACT. P. 286-287. Interpretive Summary: NONE REQUIRED
Technical Abstract: Eastern gamagrass [(Tripsacum dactyloides (l.) L.)] is a robust, warm season, perennial bunch grass. It produces high yields of palatable and digestible forage with a protein content comparable to alfalfa. It is an attractive species for use in sustainable agriculture because of its ability to penetrate compact soils. It has one of the highest photosynthetic rates of any C4 species but data on temperature x CO2 interactions are lacking. This study was conducted to determine the effects of CO2 on growth, biomass accumulation and root/shoot carbon allocation under a range of growth temperatures. Eastern gamagrass (cv. Pete) plants were grown in soil bins containing sand:vermiculite (1:1), fertilized weekly with a complete nutrient olution in Soil Plant, Atmospheric Research chambers maintained at 370 or 740 umol/mol CO2 and 20/14, 27.5/21.5 or 35/29 C day/night temperature, and grown from mid-May to mid-October. Two cuttings were taken during the season. During the final harvest, roots, crowns, and leaves from each individual plant were collected. Biomass accumulation of roots, crowns, and leaves increased with temperature. CO2 enhanced accumulation was modest, restricted to shoots, and observed only at higher temperatures and later in development. Results suggest little effect of CO2 enhancement on vegetative growth at realistically anticipated CO2 levels over the course of a single growing season, although the potential for a cumulative response was demonstrated.