Evaluation of Herbicide Tolerance in Rivercane (Arundinaria gigantea).

Rivercane (Arundinaria gigantea), is a bamboo native to North America that serves many environmental and cultural purposes. Canebrakes were once plentiful throughout the forests and bottomlands of the Southeast and provided wildlife habitat, soil stabilization, and buffers for sensitive ecosystems. During the last 70 years, these stands have been reduced to 2% of their original land area. Restoration efforts using transplants and seedling establishment are hampered by a number of problematic weeds and exotic species. These weeds compete for water and light, negatively affecting rivercane performance. Evidence from a number of field studies has indicated that preventative measures (pre-emerge herbicides) are effective in controlling small-seeded broadleaf and grassy weeds in 4-6 month old rivercane transplants. Dicamba, MCCP and 2,4-D have shown effective control of broadleaf weeds and shrubs such as privet (Ligustrum), wild rose (Rosa), and briar (Rubrus) without negative effects on rivercane transplants. Sedges (Cyperus), johnsongrass (Sorghum), dallis and bahiagrass (Paspalum), crabgrass (Digitaria), foxtail (Setaria), and bermudagrass (Cynodon) species are particularly difficult to control when establishing rivercane. Field studies were conducted to determine weed control efficacy and rivercane seedling tolerance using eight herbicides from multiple herbicide families. Data from 2010 indicated that fluazifop caused significantly less damage to plants than: nicosulfuron, imazapic, and pyridinesulfonamide after 28 days. No herbicide treatment was different from the control (no herbicide). A repeat study in 2011 indicated that halosulfuron and no herbicide (control) were better than: nicosulfuron/metsulfuron, pyridinesulfonamide, nicosulfuron, sethoxydim, and fluazifop. The use of these herbicides may be successful at reducing certain weed competition, but specific recommendations cannot be made. Studies have indicated that winter planting with a pre-emerge herbicide increases survival rate. No herbicides are currently labeled for use in rivercane.