Controlling summer weeds or a holiday at the beach? – an important decision

After a very relaxing Christmas we decided to head toward Esperance (W.A.) to spend New Year with some friends.

One thing that really stood out during the trip was how much fleabane was emerging from stubbles. Closer inspection of paddocks also revealed melons up to 50cm across.  

A healthy stand of fleabane regrowing after harvestYes it is sad that I noted this while on holidays, however this is the lot of an agronomist.

Some paddocks were visibly moisture stressed while others are looking healthy and growing actively.

All of these weeds germinated with the spring rains that have produced such good crops in southern Australia.

These weeds will be sucking moisture from the soil which can mean the difference between planting the 2014 crop on time or waiting for more rain. This will be particularly important for those earlier sown crops like canola and lupins.

Although harvest has just finished for some, and continuing for others across southern Australia these weeds must be dealt with as soon as possible.

A few reminders for good control in summer include:

• Don’t spray stressed weeds – this can be a combination of:
  • moisture – check plants are fresh and springy in the morning
  • heat – temperatures above 30°C can stop plants growing
• Control weeds as early as possible – size & stress
• Keep herbicide rates at the upper end of the label rate
• Keep application volumes and droplet size up
• Use the best quality water available – if in doubt have it tested
• Spray in the morning, but avoid still conditions which often mean inversions. Spraying at night might seem like a good idea but you have to deal with inversions and shifting wind directions

For more information see GRDC Summer fallow spraying Fact Sheet 

Here it is easy to see the fresh shoots post harvest