Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 15, 2005
Publication Date: November 6, 2005
Citation: Ritchie, J.C., Gitz, D.C. 2005. Root growth of eastern gamagrass: A three-year study [abstract]. Abstracts of the American Society of Agronomy. Paper No. 287-7.
Eastern gamagrass cv. “Pete” [Tripsacum dactyloides (L) L.] seeds were planted in a 30 x 30 m plot in 0.75 m wide rows on May 15, 2002. Twelve minirhizotron access tubes (1.5 m long) were installed parallel to the rows at 45 degree angle and installed in pairs either in or midway between the rows. Root images were collected at 13.5 mm intervals to a depth of approximately 1 m (100 images for each tube). In situ images were collected at approximately 1-week intervals in 2002, 2-week intervals in 2003, and 3-week intervals in 2004 using a Bartz minirhizotron imaging system. One month after emergence total root occupancy (percentage of images in a tube with roots) was 1.5 and 0.0% for within and between rows, respectively. By the end of the first year root occupancy was 45% within the rows and 15% between rows. Several tubes had a few roots reaching a depth of 1 m. At the end of the second year approximately 50 and 40 % of the images for the within and between row respectively had roots with many reaching 1 m at the in-row sites. At the end of the third year occupancy was similar to the second year but the numbers and size of roots had increased. This study shows how rapidly roots develop in eastern gamagrass plants and is suggestive of a fan-like distribution of roots under the developing crowns.