Enhancement of germination and early growth of different populations of switchgrass (Panicum virgatum L.) by compost humic acids

Abstract

Compost humic acids are known to exert significant bioactive effects on soil organisms including plants. Three humic acids isolated from a green compost (GC-HA), a mixed compost (MC-HA), and a coffee compost (CC-HA) were tested at concentrations of 10, 50, and 200 mg L-1 on the germination and early growth of four switchgrass populations, Shawnee, Alamo, Shelter, and Dacotah. Experiments were performed in a climatic chamber under controlled conditions. An increase of germination percentage and a stimulation of primary root and shoot growth were observed as a function of the population, the plant part examined, and the HA type and dose applied.