Reducing spray drift - Keeping it in the paddock

John Kassebaum,

Biosecurity SA

Keywords: spray drift, chemical residue, sensitive crops, regulations

Take Home Messages:

• Biosecurity SA has been working with stakeholders on actions to reduce the risk of economic damage to commercial vineyards and other sensitive crops from off-target drift of herbicides and has held preliminary consultations on possible further actions, including regulation.
• Stakeholders have recognised that off-target drift is a wider issue for the whole community, not limited to damage to vineyards and other sensitive crops and have demonstrated significant good will in seeking to work together to achieve solutions that benefit all those within regional communities.

Introduction

Biosecurity SA is seeking comment from stakeholders on proposed amendments to the Agricultural and Veterinary Products (Control of Use) Regulations 2004 to reduce the risk of economic damage to commercial vineyards and other sensitive crops from off-target drift of Group I herbicides.

The proposal;

• Applies to Group I herbicides only,
• Requires users to keep records of chemical application
• Requires users to be trained in preparation and use of chemicals

Advice is sought on

• Whether the proposal should apply to the whole state or parts thereof,
• Whether the PIRSA Biosecurity Code of Practice Summer Weed Control should be voluntary or mandatory.

Copies can be downloaded from http://www.pir.sa.gov.au/biosecuritysa/ruralchem.

Questions or comments about the review can be directed to John Kassebaum (see end of paper for contact details)                                     

Submissions will be accepted up to 5.00pm on Thursday 28 February 2013.

Issues

Off site movement of airborne herbicide can cause economic damage to other producers’ sensitive crops. This damage can be in the form of yield loss, retarded development or market loss or downgrade. There is also the risk that chemical residues can potentially impact on specific markets.

Risk is greatest when high volumes of herbicide are used over a short period of time across regions adjacent to large areas of actively growing sensitive crops.

This situation arises when broad-acre farmers use Group I herbicides between September and April to control summer weeds near grape growing and horticultural regions.

Grapevines and some other broad-leaved plants are very sensitive to this chemical group and display visible symptoms of damage at extremely low concentrations. Often this visible plant damage is the main, or only, indicator of a spray drift event.

 Group I herbicides produce generally similar symptoms. It is often difficult to identify the exact source of the herbicide drift and, therefore, to identify the particular herbicide that has been used. 2,4-D is often considered to be the offending herbicide and has been detected multiple times in analytical tests.

Biosecurity SA continues to receive reports of economic damage to grapevines and other sensitive crops caused by Group I herbicides across South Australia, with the majority from the Riverland and Clare regions.

 This damage is the result of a combination of factors including proximity to grapevines and other sensitive crops, the competency of the user, the appropriateness of the application equipment and its operation and the weather conditions at the time of spraying.

Current Situation

The APVMA has already withdrawn approval for the use of products containing high volatile forms of the Group I herbicide 2,4-D from 1 September to 30 April each year and has imposed detailed record keeping requirements through label instructions. However low and non-volatile forms of 2,4-D and other Group I herbicides can be used all year round without the legal requirement to keep detailed records of use, unless they are used by commercial applicators licensed under the Controlled Substances Act 1984. Further changes to the availability and label instructions for some Group I herbicides are likely with chemicals such as 2,4-D and MCPA currently under review by the APVMA.

There are currently no training requirements on primary producers in South Australia for use of Group I herbicides.

Biosecurity SA continues to receive reports of damage to viticulture and other sensitive crops. This damage has been directly linked to the use of Group I herbicides between September and April. Whilst the extent of damage has varied from season to season, some level of damage has occurred in most years.

Biosecurity SA has worked with the wine industry and the broad acre farming sector over a number of years to understand the risk and extent of economic damage to viticulture and sensitive crops and the importance of Group I herbicides for summer weed control to broad-acre production systems. Technical experts in chemical application and meteorology have been consulted on the range of possible causes of damage, changes to application technology and the influence of weather conditions.

In 2011, Biosecurity SA developed a Code of Practice – Summer Weed Control in conjunction with the Mid North Spray Drift Committee. The Code is not a legal document, but an educational tool to promote current best practice. 

This code was distributed to producers and chemical resellers in the Mid-North during the summer of 2011/21012 and to a lesser extent to producers and chemical re-sellers in the Riverland and Mallee.

From July to September 2012, Biosecurity SA met with industry representatives from the Riverland/Mallee, the Mid North, Yorke Peninsula, the Barossa Valley and the Limestone Coast and contacted representatives from Eyre Peninsula, to inform policy development and operational plans for 2012/13 to minimize economic damage to vineyards and sensitive crops.

In 2012/2013, Biosecurity SA will continue to work towards reducing the risks posed by Group I herbicides as follows:

• Update the ‘Code of Practice – Summer Weed Control’ including the version for in-tractor reference.
• Promote the code widely to producers, chemical re-sellers, training providers and consultants.
•  Provide media releases at critical times in the season to remind growers of best practice principles and the associated risks.
• Conduct benchmark/educational audits of chemical users in the highest risk areas of the Riverland/Mallee, Mid North and Barossa regions.
• Conduct regulatory audits of users of high volatile ester (HVE) 2,4-D products that are banned from use from 1 September to 30 April,
• Record and investigate spray drift Incidents.
• Investigate the provision of temperature inversion advice with industry and the Bureau of Meteorology.
• Support industry initiatives to increase the number of local weather stations.
• Encourage workshops and new training courses on application technology and understanding weather conditions.

The Proposed Approach

Specific Herbicides

It is proposed that regulations apply to users of products containing Group I herbicides 2, 4-D, 2,4-DB, MCPA, dicamba, triclopyr, picloram, clopyralid and fluroxypyr.

Group I herbicides are the only herbicides that have been consistently implicated in reports to Biosecurity SA of off-target damage to grapevines. These herbicides are approved for use for weed control in and after winter crops including weed control over summer.

NB This proposal is not intended to apply to home garden products containing Group I herbicides.

General Competency

It is proposed that regulations be amended to require all users of the listed Group I herbicides to hold a current statement of attainment for a prescribed qualification incorporating the competency (AHCCHM303A) ‘Prepare and Apply Chemicals’.

Lack of training and knowledge in the basics of safe and effective chemical application or its application is a contributing cause to the economic damage of grapevines and other sensitive crops.

This proposal seeks to ensure that all users of these chemicals are competent in the basics of safe and effective chemical application, i.e. they will have the ability to interpret and apply the mandatory instructions on product labels to manage spray drift.

 An estimated 90% of broad-acre farms have a person on the property with current accreditation.

If the implementation of this proposal does not lead to a significant reduction in economic damage to vineyards and other sensitive crops, additional training requirements may be considered to ensure that all users of these chemicals including those who attained their competency some time ago, are competent in applying the latest information on low drift application technology and the measurement and assessment of weather conditions for suitability for spraying.

Record Keeping

It is proposed that the regulations be amended to require all users of the listed Group I herbicides to keep accurate and complete records of use for a minimum of two years.

It is extremely difficult to establish whether damage is a result of poor practice or whether current best practice must be revised without accurate and complete records of chemical use.

The purpose of this regulation is to ensure all users of these chemicals keep appropriate records to validate compliance with best practice or identify instances where improvement in chemical application is required.

Most broad-acre farmers already keep records of chemical use for these purposes.

Wind speed and direction at the time and place of application are critical. The use of portable weather measuring instruments or automatic weather stations is encouraged as regional weather reports are not precise enough. How these records are kept will be up to the user. Biosecurity SA will be providing templates that can be used to capture the key information.

Application to Specific Regions

It is proposed that these regulations will either be applied to 1. the whole state, or 2. the whole state excluding the following South Australian Government regions:

• Far North
• Eyre and western north of the district councils of Tumby Bay and lower Eyre Peninsula; and
• Murray and Mallee north of the district councils of Mid Murray, Loxton Waikerie, Berri Barmera and Renmark Paringa.

The objective of this proposal is to include all major Group I herbicide use that could potentially cause damage to vineyards and other sensitive crops, while minimising cost and compliance issues for both users and Biosecurity SA.

Vineyards and other sensitive crops are widely distributed throughout the state, except for the upper and western Eyre Peninsula and the far north of the state.

Biosecurity SA initially considered an alternative proposal to set zones around each viticultural region. On further analysis and following preliminary consultation this was rejected because:

• There is potential for long distance drift, of the order of 100km in the right conditions.
• Having multiple boundaries creates complex boundary issues.
• With drift, damage is not necessarily caused by those closest to sensitive areas.
• With smaller zones, poor practice outside the zone can still cause damage, which identifying these users would not be possible; and
• If zones are increased to the furthest possible distance, then the zones begin merging around the State, increasing boundary complexity and negating the benefits of trying to have a zoned approach.

Impacts

The Wine and Horticulture Sectors

Ongoing economic damage to grapevines and other sensitive crops can result in setbacks in development and yield loss. It can also result in quality down grade or loss of organic status. Damage to grapevines in single vineyard wines could affect the whole vintage.

Ongoing reports of damage to grapevines and other sensitive crops from herbicide use also risks damage to South Australia’s reputation for premium food and wine and the local wine industry in particular. Access to some export markets may become more difficult or potentially closed.

Biosecurity SA has investigated 85 incidents over the past nine years. It is believed that the extent of damage is more widespread as most cases are not reported. They are either not pursued due to difficulties in identifying the source or dealt with privately.

The proposed regulatory changes, in combination with other actions by farmers, community action groups, consultants, chemical resellers and Biosecurity SA aim to reduce the direct damage and market risks to grapevines and other sensitive crops.

Users of Group I herbicides particularly the Grains Sector

There are minimal additional costs to an estimated 90% of farms that already keep chemical application records and have competent staff.

These proposals impose additional costs on the estimated 10% of farms that do not keep chemical application records or have at least one person demonstrably competent in chemical use at AQF-3 level.

For these 10% there is an initial cost estimated at between $340 (fee for online training course) and $1000 (fee for training, travel and attendance time) to obtain a prescribed qualification incorporating the competency (AHCCHM303A) ‘Prepare and Apply Chemicals’ and an annual cost estimated at $400 p.a. to maintain chemical records.

There are benefits for the farm in maintaining records of chemical use and gaining competency in chemical application. Records can inform efficacy, crop tolerance and resistance issues while improved and efficient application practices can save on chemical use.

The prime benefit to the grains industry is avoidance of additional restrictions and associated costs or loss of access to these chemicals if significant off site damage continues. It is difficult to assign a dollar value to the loss of access to these chemicals.

Contact details

John Kassebaum

Biosecurity SA

08 8207 7962

John.kassebaum@sa.gov.au