Physiological Basis of Sprouting Potential in Bermudagrass (Cynodon dactylon L.)

Despite the popularity of bermudagrass (Cynodon dactylon L.) around the world, there are few studies that report genotypic and seasonal variation for sprouting of stolons used in pasture establishment or revegetation of disturbed land. This study investigated the genotypic/seasonal variation and the physiological basis of sprouting from nodes of aboveground stolons among 12 bermudagrasses. Sprouting percentage, total nodes per m² (Nds), stolon diameter (SD), total aboveground biomass (TaB), and concentration of water soluble carbohydrate [WSC], concentration of starch [starch], concentration of non-structural carbohydrate [NSC], and concentration of crude protein [CP] were determined in different seasons including winter 2013, winter 2014, spring 2014, summer 2015, and fall 2015. Sprouting percentage for stolons sampled in spring and summer was higher than that for winter and fall. Large genotypic variation for sprouting was observed ranging from 44.1 to 80.2% of all nodes when averaged across seasons. Sprouting percentage among genotypes was strongly associated with SD, TaB, and Nds; and weakly associated with concentrations of photoassimilates such as [WSC], [starch], and [CP] in the aboveground biomass. However, when these photoassimilates were calculated as an amount per node, sprouting percentage was highly correlated with water soluble carbohydrate (WSC) (r = 0.80), crude protein (CP) (r = 0.82), and WSC + CP (r = 0.88). These data suggested that the size and/or maturity of the axillary buds at nodes and the available assimilate supply was underlying the sprouting potential of the bermudagrasses, however, more research under field conditions is required to validate this claim.