Off-target weed herbicide spray drift damages more than half of NSW’s cotton crops

More than half the cotton crops planted across southern NSW have been damaged by off-target weed herbicide spray drift, according to Cotton Australia.

About 30,000 hectares of the 57,000 hectares of cotton growing across the Murrumbidgee and Lachlan areas had been affected.

Cotton Australia’s regional manager in Griffith, Honi Anderson, said drift from Group I herbicides such as 2,4-Dichlorophenoxyacetic acid (2,4-D) being used to control summer weeds in fallow paddocks was harming cotton crops.

“In the crops that I’ve looked at it’s definitely Group I damage, but it’s very difficult to pinpoint what crops or what fallow situations it’s coming from,” Ms Anderson said.

“The weather conditions have not been helping keep those sprays effectively stay on the property they are intended for.”

Ms Anderson said the damage was extremely widespread this season and very few crops had not been impacted.

“In some crops the damage is low to moderate, some would be quite severe and in others it’s quite patchy,” she said.

Ms Anderson said she had been flooded with calls over the past six weeks from growers and agronomists identifying damage.

“Depending on the severity, it looks quite ugly and it’s quite distinctive,” she said.

“It’s like a witches hand effect on the leaf, the leaf shrivels up and cups over.

“Low level damage can just be a slight cupping and bubbling of the leaf.”

Ms Anderson called for growers, agronomists and contractors to utilise the online Cotton Map tool which identified the location of cotton crops.

“It’s important growers are communicating with their neighbours that they are growing cotton as it’s a very sensitive crop,” she said.

The full impact of the off-target spray drift would not be known until picking.

“Some of the plants I have seen with severe damage are throwing squares off and that is definitely going to have an impact on yield,” Ms Anderson said.

“Other crops, where damage is quite light, it shouldn’t have an impact.

“But the compounding issue is crops were generally planted late due to it being wet, so that coupled with spray drift issues isn’t helping yield potential.”

Cotton crop cops it

Murrumbidgee grower Ben Dal Broi reported moderate damage occurred in the 100 hectares of cotton growing on his Benerembah property.

“We’re hoping that we might be able to get away with very light damage at picking, but the thing that concerns me is that should we have another event it could be much more damaging and that would really affect our profitability,” Mr Dal Brio said.

He said the impact of off-target spray drift was much worse on his property this season due to the wet summer and croppers spraying weeds.

“People need to be very careful about the conditions they spray under, they need to very careful when they spray at night — particularly when there is a temperature inversion as the chemical can drift a long way and affect crops a distance away,” Mr Dal Broi said.

He said it had been a harder season for cotton than the two prior seasons, but still hopes to average 10 bales a hectare.

“We had a slower start with the wet winter and it was very difficult to get on the paddocks and get beds up and prepared for sowing,” he said.

“So the cotton was planted later, and then we had some insect damage so we lost some of the fruit.

“But since then it has been much warmer and the crop had lifted its head and is powering away.”