Panic grasses are summer grasses — germinating from spring and throughout the warmer weather months with summer rain, then flowering through to autumn.
Agriculture Victoria leading biosecurity officer Kate Cunnew said Victoria had a number of endemic panic grasses, native and introduced, including hairy panic and Hillman’s panic grass, which is considered an agricultural weed.
“Many Panicum species are palatable to stock, however, they may also have a toxic component that could cause liver issues and photosensitisation in livestock,” Ms Cunnew said.
“Problems are more likely to occur when stock are young, where panic grass forms a larger proportion of their diet, or where hungry stock are introduced to the plant.
“Any stock grazing areas with panic grass should be monitored regularly and removed from contaminated paddocks if any symptoms of toxicity appear.
“A key management issue with panic grass is the mobility of the seed head. Panic grasses in the northern region produce large, open, loose branching heads, which are perfectly adapted to spreading by wind.”
Ms Cunnew said in suitable conditions this can result in large amounts of seed heads spreading from farmland to pile up against fences, along roads and against buildings, causing a significant nuisance to the community.
“Prior to any control or treatment programs, it is important for landowners to identify which species they have and ensure they understand their legal obligations when managing weeds in areas with native vegetation.”
Information on native vegetation management and removal requirements can be sought from your local council.
Ms Cunnew said control options to consider include mowing and slashing to reduce seed spread, complemented with improved pasture practices.
“Promoting suitable pasture species through pasture practices such as top dressing, over-sowing, and grazing management is important to maintain cover and will assist in out-competing undesirable panic grasses.
“In cropping situations, management of fallow is important to reduce seeding events. Consideration should be given to prevent a green bridge, for example by using chemical fallowing to reduce the infestation load.”
For more information, visit the Agriculture Victoria website or phone 136 186.