Cotton Australia has estimated that 30,000 hectares of cotton crops in the Riverina have been damaged by herbicides this season, which have drifted onto cotton properties from spraying operations on neighbouring farms.
Cotton Australia representative for the area, Honi Anderson, said the damage is far more widespread than in previous years, and is affecting crops across southern NSW.
“The crops in general have experienced varying degrees of damage from Group I herbicide,” she said.
“What I saw last year, was probably more on the severe side, but certainly less of a geographical area, than what we’re seeing this season.”
Ms Anderson said, she believes most of the damage at this stage is cosmetic, but the full extent of the damage done, won’t be known until harvest time.
Cotton Australia estimates up to 30,000 hectares of cotton have been affected in southern NSW. Photo Honi Anderson
And farmers in the region have already battled through a tough spring.
“It was very wet and it was very hard for growers to get their preparation done in time,” said Ms Anderson.
“So to have this sort of impact, compounding what is already a tough season is not great.”
Elders senior cotton agronomist Heath McWhirter said, efforts are being made to determine the source of the sprays.
“We’ve got some tests at the moment going out, which will determine if it’s a 2, 4-D product or if it’s an MCPA product, just so we know the origin,” he said.
“Then we will know which group of people we need to educate, in terms of their spraying regime.”
Mr McWhirter said he believed the damage was likely caused by farmers trying to control weed growth in fallow paddocks, and that cotton plants are particularly sensitive to these types of herbicides.
“The hormone makes the cells elongate quicker than what they typically would, and they’ll twist, and abort squares which would have then turned into a flower and then turned into a cotton boll,” he said.
Honi Anderson said, spray drift is an issue for cotton farmers every year, and it’s a problem they are trying to educate people about.
“The key to avoiding spray drift, is awareness,” she said.
“People can use an online tool called Cotton-Map, which shows them where sensitive crops such as cotton are being grown.”
But agronomist Heath McWhirter also believed incorrect herbicide application may have had a lot to do with the widespread damage.
“It just seems people are spraying in not ideal conditions. So spraying at night, or spraying in inversion and not having the right application setup,” he said.
“They might have the boom height too high, the nozzle selection too fine, or their boom pressure too high. They may not have a drift mitigation spray added to the tank, they might be selecting the wrong products, which are on the more volatile end of the group i spectrum.”
Spray damage causes the leaves to twist and distort, and severe damage can affect the plant's ability to produce cotton. Photo Honi Anderson
Cotton Australia is encouraging cotton farmers to talk to their neighbours about the sensitivity of their plants, and along with agronomists in the area, they are working to educate people about the safest spraying practises.
“It is disappointing that this seems to happen season after season,” Ms Anderson said.
In the meantime, farmers are just grateful the damage is primarily cosmetic, and they are hoping the spray hasn’t affected the harvest.
