Distribution of Water-Soluble Carbohydrate Reserves in the Stubble of Prairie Grass and Orchardgrass Plants

A greenhouse study was undertaken to investigate the distribution of water-soluble carbohydrates (WSC) within the lower 100 mm of 'Kara' orchardgrass (Dactylis glomerata L.) and 'Matua' prairie grass (Bromus willdenowii Knnth.) stubble through four distinct regrowth cycles. Water-soluble carbohydrate levels were consistently higher in prairie grass tillers compared with orchardgrass tillers. A decrease in WSC levels with increasing stubble height was observed for vegetative tillers of both species. However, the WSC concentration gradient was better defined for orchardgrass, with a clear decrease in WSC concentration between the 21-to 30-and 31-to 40•mm segments, and 77% of WSC content contained within the O- to 30-mm stubble height range (with 0 mm representing the base at ground level). The WSC concentration gradient for prairie grass was less clearly defined, with a relatively high WSC concentration throughout the 0-to 100-mm stubble height range