Submitted to: Grass Symposium
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2000
Publication Date: July 1, 2000
Citation: RHODEN, E.G., KRIZEK, D.T., REEVES III, J.B., RITCHIE, J.C. INFLUENCE OF ROOT REMOVAL ON REGROWTH OF SHOOTS AND ROOTS AND COMPOSITION AND FORAGE QUALITY OF GREENHOUSE-GROWN GAMAGRASS PLANTS. GRASS SYMPOSIUM. 2000.
This study was conducted to determine regrowth and changes in composition and forage quality of greenhouse-grown eastern gamagrass [Tripsacum dactyloides (L.) L.] plants. On Aug. 18 (H1), the root mass of 5-month old plants was pruned back by 1/4, 1/2 or left uncut and the plants transferred from 15 cm-diameter pots to 20 cm-diameter pots having a depth of 40 cm. Plants were grown in a peat-vermiculite mix and fertilized weekly. Shoots were clipped to 25 cm on Aug. 18 (H1), Sept. 16 (H2), Oct. 7 (H3), and Oct. 28 (H4). Tops were clipped to the crown on Nov. 21 (H5) and total shoot and root biomass determined. For each harvest, shoot biomass was determined and analyses were run for neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, and crude protein (CP). Plants were vegetative at H1 and H2, in flower by H3, starting to become dormant by H4, and mostly dormant by H5. Removing 1/2 of the root mass significantly reduced shoot biomass at H1 and H2 as compared to unpruned controls or those cut back 1/4 but had no effect at H3-H5. Removing 1/4 and 1/2 of the roots reduced biomass of roots at H5 by 24% and 62%, respectively. Root removal had no significant effect on NDF or ADF at H1-H5 or CP for H1-H4; CP levels ranged from 14% to 19%. Removing 1/2 of the roots slightly elevated lignin content at H1; otherwise there was no effect. This study demonstrates the resilience of gamagrass with reduced root mass for regenerating shoots and roots and maintaining excellent forage quality.