In this section:

Farmers must tackle weeds

24 January 2007

Good rains over the past week have encourage rapid weed germination and farmers throughout the state should tackle the problem early, said Rural Solutions SA senior consultant Tom Yeatman.

“I urge grain farmers to control weeds when they are small and young, and can be easily killed with low rates of chemical. This strategy will give the most reliable results,” Mr Yeatman said.

“Although farmers are trying to avoid spending where ever possible, delaying taking action will result in the need to control larger, drier, dustier weeds which are harder to kill.“

It is critical for farmers to plan and take immediate action now.

“Remember the lessons from the prolific summer weed growth in 1993,” Mr Yeatman said. “In that year farmers learnt the importance of not delaying weed control, and particularly the consequence of letting wireweed and melons grow uncontrolled. This resulted in growth that was expensive not only to control chemically, but also to cut up with disc ploughs to allow seeding.”

Mr Yeatman said consideration also needs to be given as to how weeds are controlled and the on-going costs associated with their control. For example, if weeds are controlled with cultivation it can lead to more subsequent weeds germinations and the need for further control measures. He also said cultivation also reduces soil cover and breaks up the surface soil resulting in increased exposure to soil erosion.

“Many paddocks have minimal surface cover to protect the soil from wind and water erosion,” he said. “Cultivation now will leave paddocks exposed with up to five months to go before emerged crops provide protective cover.

“Although cultivation may be slightly cheaper than spraying, the true cost of cultivation needs to be considered, which includes soil and nutrient loss following soil erosion, moisture loss, encouraging further weed germination, and damage to soil structure.

“Priority in weed control needs to be given to those paddocks to be cropped this year, as well as with the best yield potential.”