The evolution of weed control practices now places an extremely high emphasis on eradication of new weed incursions before their populations are beyond expiration. A key component of weed eradication is destroying or controlling the weed seed bank. Essential oils have been shown to exhibit herbicidal activity and have been previously used for weed seed bank control. Carbon (sugar) has been shown to increase microbial activity and has also been linked to reducing seed bank germination. This trial examined applications of an essential oil (pine oil) at a range of rates (0, 1%, 2.5%, 5%, 10% and 20%) with and without carbon (sugar at 0.31 kg C ha-1) and compared this to a herbicide treatment applied as a pre-emergent herbicide (1, 2 and 3 L ha-1 of flupropanate, active ingredient) on the germination of cane needle grass seeds. The results show a strong dose response for decreased seed germinations with increased pine oil concentration with only 1 seed germinating at 20% pine oil concentration. No direct response was observed for carbon addition but it did result in a response through time with reduced seed germination with carbon at high pine oil rates. Flupropanate granules applied as a pre-emergent herbicide did not produce the expected dose response effect or high levels of cane needle grass control. This may have been due to the active ingredient being leached out by high watering rates before the cane needle grass had germinated.
McLaren, D.A. and Butler, K.L. (2016). A pot trial to assess the effects of pine oil, sugar and granulated flupropanate on cane needle grass (Nassella hyalina) seed banks. Plant Protection Quarterly 31(2), 38-43.