Control of the invasive liana, Hiptage benghalensis
Weed Biology and Management
The liana, hiptage (Hiptage benghalensis), is currently invading the wet tropics of northern Queensland and remnant bushland in south-eastern Queensland, Australia. Trials using seven herbicides and three application methods (foliar, basal bark, and cut stump) were undertaken at a site in north Queensland (158â€šÃ„Ã¢700â€šÃ„Ã¢hiptage plantsâ€šÃ„Ã¢haâ€šÃ Ã1). The foliar-applied herbicides were only effective in controlling the hiptage seedlings. Of the foliar herbicides trialed, dicamba, fluroxypyr, and triclopyr/picloram controlled >75% of the treated seedlings. On the larger plants, the cut stump applications were more effective than the basal bark treatments. Kills of >95% were obtained when the plants were cut close to ground level (5â€šÃ„Ã¢cm) and treated with herbicides that were mixed with diesel (fluroxypyr and triclopyr/picloram), with water (glyphosate), or were applied neat (picloram). The costings for the cut stump treatment of a hiptage infestation (85â€šÃ„Ã¢000â€šÃ„Ã¢plantsâ€šÃ„Ã¢haâ€šÃ Ã1), excluding labor, would be $A14â€šÃ„Ã¢324â€šÃ„Ã¢haâ€šÃ Ã1 using picloram and $A5294â€šÃ„Ã¢haâ€šÃ Ã1 and $A2676â€šÃ„Ã¢haâ€šÃ Ã1, respectively, using glyphosate and fluroxypyr. Foliar application using dicamba for seedling control would cost $A1830â€šÃ„Ã¢haâ€šÃ Ã1. The costs range from 2-17 cents per plant depending on the treatment. A lack of hiptage seeds below the soil surface, a high germinability (>98%) of the viable seeds, a low viability (0%) of 2â€šÃ„Ã¢year old, laboratory-stored fruit, and a seedling density of 0.1â€šÃ„Ã¢seedlingsâ€šÃ„Ã¢mâ€šÃ Ã2 12â€šÃ„Ã¢months after a control program indicate that hiptage might have a short-term seed bank. Protracted recolonization from the seed bank would therefore be unlikely after established seed-producing plants have been controlled.