THE EFFECT OF HARVEST CUTTING HEIGHT AND HYBRID MATURITY CLASS ON FORAGE NUTRITIVE VALUES AND RATOON REGROWTH POTENTIAL OF SORGHUM SUDANGRASS IN THE TEXAS HIGH PLAINS

Sorghum Sudangrass (Sorghum x drummondi), a crop that is drought tolerant and readily regrows, is an option that producers in the Texas High Plains are turning to as water limitations become more prevalent. The objective of this study was to i) investigate the effect of clipping height on yield and ratoon production, and ii) evaluate the forage nutritive values of a single harvest versus ratoon harvest system of sorghum sudangrass varieties under limited irrigation in the Texas High Plain. Seven different sorghum sudangrass hybrids were cut to leave 10 and 20 cm of stubble and allowed to regrow. Cutting height did not affect yields, with cumulative yields in 2019 ranging from 8.99 to 16.23 Mg ha-1 and 7.59 to 13.09 Mg ha-1 for the 10 and 20 cm cutting height, respectively; and cumulative yields in 2020, ranging from 4.61 to 7.84 Mg ha-1 and from 3.95 to 8.15 Mg ha-1 for the 10 and 20 cm cutting height, respectively. A ratoon crop was only achieved with the early maturing hybrids in this study. Forage Nutritive values were greatest with the early maturing hybrids and their ratoon crops; however, overall yield was greater for the longer maturing hybrids.