With recent rains widespread across Tasmania's agricultural areas, farmers will be looking forward to a busy time as they prepare for the coming season. But there are a few things that they should keep in mind. DPIPWE (Department of Primary Industries, Parks, Water and Environment) Regional Weed Management Officer Kiowa Fenner advises that the risk of weed invasion, and the impact weeds have on farmland and the environment can dramatically increase as rains fall on drought affected land. ‘Because of their greater competitiveness, weed species readily invade bare areas of ground which have been denuded of vegetation by prolonged drought or other causes.' Ms Fenner said. Weeds already on the property may quickly spread to new areas, and weed densities can rapidly increase.
Farmers with cropping land are advised to be particularly aware of risks from weed imports in contaminated seed at sowing time and weed seed being spread from contract machinery. Graziers should be alert for weed spread through contaminated fodder, ‘weed seed may be inadvertently spread around a property at the time of feeding, or in the animals' dung, days after the contaminated fodder has been eaten' said Ms Fenner. ‘Animals introduced onto a property, either in a restocking program or returning from agistment, can also introduce weeds.'
The presence of livestock on a property can encourage some weeds to establish to the detriment of desirable species where the weeds are unpalatable and are therefore not readily grazed.
Ms Fenner says ‘It is important to have a strategy in place for combating potential weed problems before, not after, they occur.' ‘Things producers should consider include:
- Check the origin of your hay or grain stockfeed:
- Has it come from a known weed infested area?
- Ask the supplier for written certification on any potential weed content.
- Where possible source locally grown feed to reduce the chance of introducing new weeds that are not already present and known in your locality.
- Keep records of purchased hay or grain stockfeed:
- content
- location sourced
- producer
- date purchased
- transporter and
- feed-out area.
- Feed-out in a confined area away from drainage lines (stock containment areas) to reduce the likelihood of weeds being spread throughout your property.
- Monitor feed-out areas regularly and be suspicious of unfamiliar plants that germinate.'
- Building up stock numbers when recovering from an emergency is also another high risk activity that can introduce weeds. Quarantine new stock for up to 14 days, allowing time for viable seed to pass through the animal.
- Check for weed seed in fleece and continue to check for the weeds in areas with new stock.
- Where possible, purchase shorn sheep.
Early identification and control are the first and most important steps in weed control and eradication. Keep a close watch for unknown plants and have them identified early. Don't let them establish and set seed . An accurate assessment of the situation and a well planned long term strategy will form the basis of an effective post-drought weed control program.
For more information contact your DPIPWE Regional Weed Management Officer on 1300 368 550.