Spray drift damage - What do you do now?

You suspect your rice crop has spray drift damage - What do you do now?

For growers, the impact of spray drift of herbicides is of major concern due to the loss of production, loss of income and a reduction in profitability. The impact on the environment and contamination of the harvested grain in the market place may also be of significance.

Identify spray drift early

Rice as a non-target crop, is more susceptible to herbicide spray drift early in its growth stages. However, the effect of spray drift of herbicide will vary over the crop area according to the amount of the herbicide received by the rice plants. On some areas, the herbicide activity may be terminal and on other areas, growth may be slow or non-existent for some time. Recovery may occur, with a reduction in yield and/or a delay in maturity. The effect of spray drift and the amount of the herbicide received by the plants will be influenced by the environmental condition during and after the spray drift event, mainly the wind direction and wind strength.

Call your agronomist

It is important to get an early assessment, by an independent and qualified agronomist, of the impact of a spray drift situation. Recommendation should be sought on re-sowing or draining as remedial measures to maintain production and profitability.

Information gathering

Pinpointing the source of spray drift will require a degree of evaluation and investigation. The damage caused and the symptoms exhibited by the rice crop and other affected areas needs to be observed to determine a possible active ingredient of the spray drift source.

The source of the spray drift may also be determined by contacting neighbors and seeking advice as to whether spray application have been undertaken, or whether spray application equipment has been sighted in the area. Note inversion may cause damage up to 6km from the intended site. The NSW Pesticides Regulation requires that records be kept of pesticide use. These records may be available from spray applicators to pinpoint the source of the spray drift.

Record information on accurate meteorological data at the time and after the spray event and document people and professionals who have inspected the spray drift area. In general, it is essential to record and document as much information as possible. Plenty of photos are recommended. This information may form the basis of an early resolution to the matter, or be used as evidence.

Rice Crop Australia insurance (the Policy offered to rice growers) will only cover ground spraying by other parties and requires a report. 

Once the source of the spray drift is determined and sufficient information has been gathered and recorded, a satisfactory resolution to the matter between the local parties to maintain production and profitability is the best outcome. The reimbursement of additional costs in rectifying the damage and recovery of revenue lost due to production shortfall may be negotiated.

Notification, sampling and analysis

As a last resort if a satisfactory resolution cannot be negotiated then information gathered in pinpointing the source of the spray drift will be helpful when notifying the Environmental Protection Authority (EPA) of a possible pesticide misuse. In NSW, the EPA is authorised to investigate pesticide misuse.

Click here for more information or call the Environment Line 131 555 to make a report.

Once notified, an EPA officer may visit the impacted area to assess the situation and take samples for laboratory analysis. The EPA is qualified in determining which laboratory is appropriate and which chemicals are to be tested for presence in the various samples taken. The collection of samples is required as soon as possible after herbicide damage and the name of the suspected herbicide is required for analysis.

The EPA may provide additional services such as advice on best practices for pesticide use or facilitate communication among the people involved. Only where appropriate, where evidence is obtained, will the EPA investigation into pesticide misuse lead to prosecution.

In general, contact and cooperation with the EPA may support any resolution to a spray drift situation.

Reporting

A report should be developed by a qualified and independent professional, of all the information relating to the spray drift situation. Information is this report should include all the information gathered above, as well as:

  1. property details and location of the spray drift area (property and paddock maps);
  2. contact details of professionals and other people who have inspected the spray drift site;
  3. details of soil types, irrigation layouts, water supply and drainage infrastructure, recirculation infrastructure, (maps, photos, farm plans);
  4.  reports of the laboratory analysis, other reports, interviews and other relevant information;
  5. rice cropping history of the landholder and the property, as well as management to date, to assist in an estimate of crop yield loss;
  6. recommendations such as the documentation of the management activities throughout the entire growing season (NIR tissue testing, NDVI mapping, fertilizer topdressing, yield data at harvest).

Resolution

A detailed report may form the basis for a resolution to the spray drift situation and any agreement to maintain production and profitability. An independent professional may be employed to facilitate these actions and be present to record any resolution or details of any agreement.

Minimise the risk of spray drift. Use best management Practice for Spray application. Think about the chemical that you are spraying and its potential impact on nearby crops. Think about where you are spraying the chemical in relation to sensitive crops. Think about the effect of weather conditions around the time of spraying.

Spray drift damage is often not uniform across the bays of the rice crop.

Spray drift damage is often not uniform across the bays of the rice crop.

Roadside vegetation can show signs of spray drift

Roadside vegetation can show signs of spray drift

Rice seedlings affected by spray drift

Rice seedlings affected by spray drift

Rice ring seedling counts can be used as a measure of damage

Rice ring seedling counts can be used as a measure of damage

Photos of plants not affected compared to affected are useful

Photos of plants not affected compared to affected are useful

Spray drift damage from glyphosate on rice seedling (A), and rice panicle (B)

Spray drift damage from glyphosate on rice seedling (A), and rice panicle (B)

Shortened internode length is an indicator of glyphosate damage

Shortened internode length is an indicator of glyphosate damage

This fact sheet has been developed with the assistance of Daryl Gibbs, Consultant Agronomist, Gibbs Rural Services Pty. Ltd. Phone 0427 487 939