Spray drift incidents flare in summer cropping zone

Liz Wells, January 16, 2017

SPRAY drift incidents have flared in the summer cropping zone of eastern Australia as a late storm season triggers weed growth, prompting farmers to ramp up herbicide applications.

Cotton crop showing signs of spray drift damage.

Cotton crop showing signs of spray drift damage.

Cotton Australia regional manager for the Darling Downs, Mary O’Brien, said after a quiet start to the season there had been a number of recent major incidents where weather inversions had caused herbicide to drift from spraying activities, causing off-target damage to susceptible crops.

“Every season is different. Last season we had a lot of early season spray drift. However, this season we have had a lot of insect pressure in the first half, but since then there has been an easing off in the focus on insects and an increase in herbicide use and we have started getting drift,” she said.

“It is a bit to do with storms. There wasn’t much storm activity in the first half.”

Ms O’Brien said because cotton crops were being hit by spray drift later in the season at the vulnerable flowering and fruiting period it was difficult to say what the impact on yield would be.

Mary O'Brien

Mary O’Brien

“If damage occurs in the early part of the season there is potential for the crop to grow out. But the problem in the second half of the season when the crop has fruit and flowers is there is potential to lose significant yield,” she said.

“How much yield will you lose? Well, how long is the summer going to be? Do you have enough water to carry it through. Last year we had a nice long summer, it was still 30 degrees in May. But we don’t know what it will be this year.”

Ms O’Brien said spray drift incidents were often not caused by an individual operator, but the combined effect of a number of operators spraying at the same time in conditions conducive to inversion, often at night or in the early hours of the morning.

“The main problem is when we have a rain event or storms it is not just one farmer spraying, it is everyone usually spraying at the same time,” she said.

“Even if operators are minimising their losses into the air, there is still a small amount of ‘fines’ (tiny droplets) that get into the air. In the situation when everyone is spraying together it becomes what I refer to as ‘community drift’. Everyone is contributing a tiny amount and we end up getting some major events.”


Cotton Australia’s checklist for preparing to use herbicides:

  • Read and follow label instructions – it is a legal requirement
  • Monitor weather conditions before, during and after spray application
  • Use a nozzle that produces coarse or larger droplets
  • Check for cotton fields that could be potentially impacted by your 2,4-D spray
  • Notify your neighbours – even during reasonable conditions for spraying, some spray droplets could travel up to 20km or more if the spray equipment is not used correctly, and even further in some instances of unfavourable conditions, such as during surface temperature inversions or night-time spraying
  • Minimise boom height when spraying
  • Ensure spray contractors are fully trained and accredited


What to do if impacted by spray drift:

It is critical for growers to report damage to the authorities when it occurs.

Three easy steps to report damage:

  1. Contact your nearest Cotton Australia Regional Manager
  2. Contact the federal regulator, APVMA:

Submit an adverse incident report: online tool or pdf

Read more about the APVMA’s reporting program

  1. Contact your state regulator:

– Biosecurity Queensland: Click here for more information or call 13 25 23 to make a report

– NSW Environmental Protection Authority (EPA): or call the Environment Line on 131 555 to make a report


Spray workshops for growers and spray applicators will be held this week in southern Queensland at Goondiwindi, Wednesday, January 18; Westmar, Thursday, January 19; and Condamine, Friday, January 20.

The events will be hosted by MCA Ag with support from Cotton Australia, Mary O’Brien Rural and DeadSure.

More info/register at:


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