Paraquat & Diquat Review

Ref: MG/RT/GG24094

29 October 2024

Chemical Review

Australian Pesticides Veterinary Medicines Authority

GPO Box 3262

SYDNEY NSW 2001

By Email: chemicalreview@apvma.gov.au

 

Dear Sir/Madam

Re: Paraquat & Diquat Review

AgForce Queensland Farmers Limited (AgForce) is a peak organisation representing Queensland’s cane, cattle, grain and sheep, wool & goat producers. The cane, beef, broadacre cropping and sheep, wool & goat industries in Queensland generated around $10.4 billion in on-farm value of production in 2021-22. AgForce is the leading voice for Queensland producers and strives to ensure the long-term growth, viability, competitiveness and profitability of these industries. Over 6,000 farmers, individuals and businesses provide support to AgForce through membership. Our members own and manage around 55 million hectares, or a third of the state’s land area. Queensland producers provide high-quality food and fibre to Australian and overseas consumers, contribute significantly to the social fabric of regional, rural and remote communities, as well as deliver stewardship of the state’s natural environment.

AgForce is a member of Grain Producers Australia (GPA), as well as NFF and actively participate in their members’ council, policy council and pesticide subcommittee. AgForce has been heavily involved with the development of the GPA submission and fully endorses their submission, as well as Grain Growers’ submission, as the two peak federal registered organisations for grain producers in Australia.

We thank the Australian Pesticides & Veterinary Medicines Authority (APVMA) for the opportunity to represent Queensland’s broadacre grains and cane farmers as part of the paraquat and diquat review. Paraquat, diquat and all formulations containing these chemistries are critical in our cropping systems and the proposed changes would be catastrophic to industry.

Over the last 3 decades the grains industry has made enormous progress using low till cropping systems to improve soil health, retain soil moisture and enhance overall sustainable farming practices. The removal of paraquat would be counterproductive to these sustainable farming practices, accelerating further weed resistance and undermining soil carbon sequestration and climate change mitigation efforts through increasing the need to return to tillage as a weed removal tactic.

AgForce acknowledges these factors are not normally considered in the three pillars of safety, efficacy and trade used by the APVMA to review products, but they are consistent with environmental, social and governance (ESG) methodologies that our trading partners consider when evaluating our grain products.

AgForce believes in the importance of an independent and robust regulator. The decision to expedite the review process for paraquat by the APVMA was influenced by the Minister for Agriculture, Fisheries and Forestry, Murray Watt¹
 

It is our view that this political interference has seen the review produce preliminary findings that do not align with the regulator’s ethos that decisions are backed in sound science, data and case studies. We are concerned that this unwarranted political interference has forced the APVMA to make determinations on  environmental product safety based on an unacceptably low threshold of available data.

In its review of paraquat and diquat, AgForce is concerned that the APVMA has not followed a sufficiently rigorous and systematic process for evaluating environmental risks, particularly in terms of determining the likelihood of causing harm. This is due to a paucity of relevant data, real-world Australian data to accurately determine the severity of the potential consequences. We refer the APVMA to the report by the Australian Environmental Agency (Consideration of APVMA Technical Review Reports for Paraquat and Diquat, 18 October 2024), which explores several aspects around the toxicity endpoints applied by the APVMA and how the European Food Safety Authority (EFSA) framework approach is insufficient with respect to assessing exposure to Australia’s unique mammalian fauna. To complement this, AgForce has provided real-world data on the actual use of paraquat/diquat products, as presented in our AgForce Paraquat and Diquat Survey, 2024

GRAINS & BROADACRE CROPPING

AgForce proposes the following:

1. A two year stay on any changes to approved use patterns for paraquat and diquat products, while industry undertakes the appropriate scientific research
2. Optical Spot Spray Technology (OSST) use patterns should be retained for grains and cane broadacre cropping
3. Broadacre boom application use patterns should be retained for grains and cane broadacre cropping

1. A Two-Year Stay on any Decisions

AgForce strongly believes there are major gaps in the science and methodologies used to come to the proposed decisions. We are seeking a two-year stay on any decision while industry undertakes the appropriate scientific research required to ensure decisions are being made in sound fact. The regulator should not be making decisions on critical chemistry without a solid basis of data and facts that originate from trial work and research in Australian cropping districts that utilise the chemistry. Lab findings and assumed animal behaviours based on European birds and mammals is not sufficient with respect to assessing exposure to Australia’s unique mammalian fauna.¹

Monitoring for exposed mammals and bird species should be undertaken within specific regions and appropriate conservation efforts should be implemented if deemed the species is at risk. A blanket ban on critical chemistry on the assumption that mammals or birds could interact with paraquat or diquat is unacceptable to industry.

Moreover, as demonstrated from Question 6 of the AgForce survey, the proposed label changes for paraquat and/or diquat will significantly negatively impact 87.4% of respondents.

Given this clear and compelling statistic, it would be highly reasonable for the APVMA to allow a stay on changes to registered paraquat and diquat use patterns, to allow industry the opportunity to provide the APVMA with data from a rigorous exploration and discovery phase conducted in an Australian context.

2. Optical Spot Spray Technology (OSST) Use Pattern should be retained

The data collected by AgForce’s Application Survey² confirms that the growers with OSST had a median percentage treated area in fallow paddocks of 7.5%. The average treated area using OSST is 9.12%.

The median rate used by growers through OSST systems is equivalent to around 230g of active ingredient (ai) per 100L. The average rate is slightly higher at 241g of active ingredient per 100L. 

The majority (93%) of survey respondents using OSST saw a reduction in the amount of active ingredient applied per hectare compared to broadcast or boom spray applications on their properties. The average reduction in active ingredient applied per hectare through OSST, rather than boom sprays was around 54% on a same farm comparison basis.

From the AgForce survey, Question 8 shows that less than 46.5% of respondents used the maximum rate of a 250g/L paraquat product (2.5L product per 100L water). Question 9 shows that approximately 40% of survey respondents treated less than 5% of a paddock with paraquat using OSST. At the maximum specified rate for a 250g/L paraquat product (2.5L product per 100L water), this is equivalent to 31.25g ai/ha. At this low concentration, small Australian marsupials and granivorous birds are unlikely to be at serious risk of harm, considering that the APVMA thresholds were 300g ai/ha for small marsupials and 175g ai/ha for granivorous birds (page 89 of the APVMA Paraquat Review Technical Report).

From page 12 of the APVMA report ‘Paraquat and Diquat – Summary of Assessment Outcomes in Proposed Regulatory Decisions’, up to 231g ai/ha per season was supported for boomspray treatment of wild oats using paraquat as an aid to cultivation (crop, pasture or fallow establishment). Based on the AgForce survey, if applying only 31.25g ai/ha when treating 5% of a paddock using OSST, it would be possible to spot spray a paddock 7 times without exceeding 231g ai/ha per season – even assuming no degradation of paraquat residues. In light of this new data provided by the AgForce survey, it is appropriate to question why the APVMA has determined that optical spot spray technologies are not supported (environment) in a fallow situation.

3. Broadacre Boom Application Use Pattern should be retained

Fallow boom spray applications, spray topping and crop desiccation use patterns are all critical for Queensland cropping production systems. The proposed regulatory decision to not support these use patterns based on environmental concerns only further solidifies our stance that correct scientific analysis of the mammals, macropods and bird species occupying cropping paddocks needs to be conducted.

The AgForce Paraquat and Diquat Survey indicated the median boom spray application rate in fallow is 500g of active ingredient per hectare. The average broadcast application rate is slightly lower in fallow at 435g of active ingredient per hectare.

Residue data supports a 7-day withholding period and in the last 10 years of maximum residue limit (MRL) testing we have never exceeded the MRL limit. The 7 days withholding period should remain with no changes. 

We note that the APVMA Paraquat Review Technical Report has confirmed the current Australian MRL of 0.05 mg/kg in cereals and 1 mg/kg for pulses. These limits ensure that the levels of paraquat in grains are safe for consumption and comply with food safety standards. Farmers’ observance of these MRLs strongly indicates that any crop seeds consumed by granivorous birds will contain residues drastically below 26.4 mg/kg bw/d, which is the recommended allowable limit (RAL) of paraquat for birds from short-term dietary toxicity studies (Table 7, page 11 of the AEA Report). In the example of a quail weighing 27.6 grams, with an average daily intake of 7.3g (Table 6 of the AEA report), the daily dose of paraquat would be 0.000365 mg based on an MRL of 0.05 mg/kg cereal. This indicates that the risk to granivorous birds from cereals treated with paraquat is negligible and is consistent with the findings of the AgForce Survey Question 11, where 95.2% of respondents had not observed any impacts on wildlife due to the use of paraquat on their farm.

SUGARCANE CROPPING

Background

Paraquat or in combination with diquat, is one of the most important herbicides in a sugarcane farmer’s ‘toolbox’ to manage weeds. The chemical is used during all stages within a sugarcane cropping system being the fallow, plant cane and ratoon cane crops. The herbicide use in hectares is greatest in the plant cane crop, with the chemical being used less in ratoon crops and in the fallow.

The product is tank-mixed in combination with other herbicides and usually not used as a stand-alone chemical. The herbicide is used as a knockdown chemical to control weeds up to 5cm high during the different stages in the sugarcane cropping system.

The key target weeds paraquat is used for controlling are: Awnless Barnyard Grass (Echinochloa crus-galli), Summer Grass (Digitaria sanguinalis), Guinea Grass (Pancium maximum var Guinea), Hamil Grass (Pancium maximum var Hamil) and Green Summer Grass (Digitaria ciliaris), Sicklepod (Senna obtusifolia), Blue Top (Ageratum houstonianum), Phyllanthus and Calapo (Calopogonium mucunoides).³ We question the extent to which sprayed weeds would be of interest to Australian marsupials or bird species as a feed source – such understanding is critical to determining likelihood of serious harm from ingesting paraquat and/or diquat.

Current Use Patterns by Industry

The current label rates for paraquat use in sugarcane are as follows:

• Paraquat concentration of 250 g/L: 1.2L-1.6L/ha
• Paraquat concentration of 360 g/L: 0.835- 1.1L/ha

Sugar Research Australia (SRA) conducted an industry wide survey concerning the use of paraquat. 4 Key survey findings are as follows:

• The survey confirmed that most growers use paraquat at a rate of 0.9-1.2 L/ha.
• No grower surveyed has observed any negative impact of paraquat on wildlife.
• 59% of growers spray paraquat twice in plant cane (the majority do one boom spray application and one directed spray application).
• On average 88% of growers are very and extremely concerned about their farm profitability if paraquat is removed from use in plant and ratoon cane.
• In fallow, 52% of growers currently do not use paraquat. 
• In plant cane, 80% of growers will consider using pre-emergent herbicides, 64% using tillage and 59% using other post-emergent herbicides, in the absence of paraquat. 
• In ratoon cane, 73% of growers will consider using pre-emergent herbicides, 65% post-emergent herbicides and 33% using tillage, in the absence of paraquat.
• In the absence of paraquat, growers are considering using additional pre-emergent herbicides and additional tillage operations.

The herbicide is applied through a boom spray over the top of the crop in the fallow or early ratoon crop, or as a directed spray low in the canopy in the interspace in both the plant and ratoon crops. No aerial application of paraquat is undertaken by the sugarcane industry. 

Environmental Concerns

The Australian sugarcane industry has been under significant pressure over the past few decades, due to Reef Regulations concerning sediment, nutrient and pesticide use. The loss of paraquat in a cane farmer ‘toolbox’ to manage and control weeds means that there will be a significant shift to more tillage and an increase in the use of residual herbicides; potentially causing increased sediment and herbicide run-off into the Great Barrier Reef lagoon.⁵

The loss of paraquat to the sugarcane industry will have significant perverse outcomes on the environment and undo the efforts undertaken by the industry to reduce its environmental impact over the past two decades. Research undertaken by Di Bella et al (2015), O’Brien et al (2014) and O’Brien et al (2015)⁶ highlights the herbicides of concern identified in the Herbert Water Quality monitoring program. The results of this research indicate the importance of selecting the most suitable herbicide to minimise environmental impacts.

From an animal health perspective there are no known recorded cases which resulted in negative impacts of birds or mammals, due to the use of paraquat. The SRA survey further solidified this finding with farmer observations reporting no adverse impacts on bird species or other animals on sugarcane farms.

CLOSING COMMENTS

Public consultation is paramount to understand how chemistry is used in the paddock and to be able to share the real-world practices that deviate from assumption and lab trials. AgForce appreciates the regulator’s openness during the review process, but would like to see an expansion of scenarios that can be considered as part of the review process.

We propose that the APVMA expand its review process to consider criteria on benefits provided by agricultural chemicals, as well as the risks to the agricultural sector (and to food and fibre production) if critical chemical use patterns are unavailable. 

Removal of chemistry as a just in case theory is absurd.

AgForce supports safe handling of chemicals. Our survey indicates that 86.7% of participants already use paraquat or diquat in a closed loop systems. This tells us that most farmers are already doing what they can to protect themselves, their workers and their families from unnecessary chemical exposure. We would support further industry consultation around increasing adoption of closed loop systems.

Many primary producers go to great lengths to train themselves and staff in safe chemical handling and spray operations. They have a regulatory obligation per label requirements for application and storage. Increasing attendance to chemical handling courses and certification could see further safety risks managed.

The general population and residential users have access to many AgVet chemistries with no oversight or regulatory obligation. Our wish is to see greater policing by the regulator to ensure this chemistry can be protected for agricultural and commercial production systems into the future.

We look forward to future collaboration with the regulator to understand what information and data may be missing for future reviews, so we can undertake the work well in advance.

Should you have any questions pertaining to this submission, please contact Ruth Thompson, Grains Policy Director on 0427 472 467 or via email: thompsonr@agforceqld.org.au.

 

Yours faithfully

Mike Guerin

Chief Executive Officer

¹ Australia Environment Agency Pty Ltd – Consideration of APVMA Technical Review Reports for Paraquat & Diquat

² AgForce Paraquat & Diquat Member Survey agf-paraquat-diquat-survey-2024-results.pdf 

³ SRA Weed Manual Weed-Management-Manual_2021_Web_F.pdf

⁴ SRA Response on Paraquat Herbicide Usage Survey 2024 Paraquat-Survey-report.pdf

⁵ Herbert Water Quality Monitoring Project SRA contract_ HWQMP Final Milestone Report

⁶ Targeted extension strategies to improve water quality outcomes in the Australian sugar industry Microsoft Word - REIS Issue 11 No 1.docx