A Will of the Wisp

By Paul Clough, Solicitor 

On the 23rd June 2010, a decision of Justice Lyons was delivered in the Supreme Court of Queensland on spray drift from an agriculture aircraft. The case was cited as GEJ &MA Geldard Pty Ltd v DN Mobbs & Ors 2010 Qsc 220.

THE FACTS
The plaintiff was a cotton farmer in the Condamine area of South Queensland. The active defendants were a crop dusting operator and its pilot. It was common ground that the defendants sprayed a cocktail of chemicals, Metsulfuron, Grazon and Brushwet on two properties, Sherwood and Wallumba, on 15th December 2005. The plaintiff’s resident agronomist, Ed Offner, at the plaintiff’s two properties, Elgin and Noonameena, noticed yellowing symptoms on the cotton on 19th December 2005, four days after,the spraying of the two neighbouring properties, Sherwood and Wallumba. This yellowing alerted the plaintiff to possible crop damage and investigation was undertaken as to why this had occurred. The intriguing aspect is that it was common ground that Sherwood and Wallumba were 20 kilometres NNE from the nearest edge of either Elgin or Noonameena. The plaintiff alleged that spray drift from the spraying of wattle trees in the northern properties affected his cotton crop.
The judge decided that the essential factual questions for her determination were:

  1. Whether the spraying of Sherwood and Wallumba affected the Gerard’s cotton crops on Noonameena and Elgin?
  2. What was the effect on those crops?
  3. Whether the effect of the spraying on the cotton crops was due to the negligence of the named defendants?
  4. What was the extent of the financial loss suffered if any?

A map of the area was provided in the judgment and obviously many photographs were tendered in evidence. It is to be noted from the map that the township of Condamine lies close to a direct line between Sherwood and Elgin.
There were six experts having various academic qualifications in the agricultural field of study. Three of the experts claimed to have investigated, had an interest in or had expertise in drift management. A pilot was called for the plaintiff, the defendants’ solicitor objected and that person’s evidence was not taken into account. None of the experts had flying experience, map reading experience, meteorological training and most certainly not crop spraying flying experience.
The first essential factual question was further divided into a number of specific questions for consideration. These were:

  1. What chemicals were sprayed by the pilot?
  2. What was the temperature, humidity and wind velocity at the time of the spraying?
  3. What was the strength of the chemicals sprayed?
  4. At what height was the spray delivered over the wattle trees?
  5. What concentration of chemicals drifted from the spray site to the cotton crops?

As the evidence was adduced another important question arose. It was:

  1. Were there any other herbicides sprayed over the cotton crop that could have affected the cotton?

The First Question
From the judgment, the evidence is clear that the defendant pilots sprayed a cocktail mix of three herbicides; Metsulfuron (Ally), Picloram & Triclopyr (Grazon) and Brushwet in about 10 to 14 times the recommended spray application. Metsulfuron is a sulfonylures type herbicide, Picloram is an auxin type herbicide.

The Second Question
There was evidence of wind speed, temperature and humidity from each of the two pilots for the defence. It is important to be aware that spraying was conducted from 0640 to 0800 hrs and from 0950 to 1330 hrs. The gap period was due to high winds according to the pilots. The wind recorded by the pilots could be termed light and variable, or as the Court accepted their evidence, from SE/E/NE 6kts or below.
There was evidence for the plaintiff taken from 3 automatic weather stations at Hopelands, Alderton and Miles. These stations are located about 50kms from the spray site in a South East, South West and Northern direction from the spray site. Only the winds, temperature and humidity of Hopelands and Alderton were mentioned in the judgement. It was said that the weather stations were relatively consistent with each other at about N/NE/20 30kms/hr. What times of observation was not alluded to in the judgment. The judge preferred the winds from the weather stations mentioned rather than the pilot’s estimate at the spray site. The humidity and temperature seemed to be of little relevance to the judge. There was no other evidence of the winds at the spray site other than the evidence of the pilots. The judge decided the pilots sprayed in conditions of high winds and above the recommended wind velocity for spraying.

The Third Question
The strength of the cocktail mix was well over the recommended levels on the labels of the chemicals. It was said to be “off label”.

The Fourth Question
The judge preferred the evidence of the experts called for the plaintiff over the direct evidence of the pilots as to the chemical spry height. Apparently there were high trees dotted about the 400-500 hectares of the spray site. The wattle trees being sprayed with herbicide were regrowth at about three to four metres high. The pilots said that they sprayed about 1 to 1 ½ metres above the wattle regrowth. The experts Bullen and Somervaille assumed a greater release height of between 10 to 20 metres. Photographs indicated that tree heights of random trees were up to 18 metres tall according to the judgement. The judge considered the release height varied and may have been considerably higher than six metres because of damage to some of the tall trees. The explanation and direct evidence of the pilots was rejected and assumptions and estimates of height and some damage to tall trees was acted upon by the judge. It is suggested that the judge did not apply the correct criteria to this element - “was the release height of 6 metres proved on the balance of probabilities” - by the pilots rather than assumptions and selective photographs and tree height estimates used as the basis for judgement well after the spraying event.

The Fifth Question
The objective evidence of the testing samples was ignored by the judge. Only two cotton leaf samples from the affected cotton were sent for testing. One tested positive for Metsuifuron. It was said of the other, “all levels were below the level of detection in the Elgin 3A sample”. Neither Picloram nor Trilopyr was mentioned.
Three Wilga tree samples collected from trees at intervals between the spray site and the cotton crop were tested. All these samples tested for Metsulfuron but Picloram was below the level of detection in all samples. More importantly, all Wilga tree samples contained the herbicide 2,4-D, which was not sprayed by the defendants.
What can be made of this evidence on the balance of probabilities? Clearly Tricopyr and Picloram did not reach the cotton crop on this objective analysis evidence. Additionally, a very weak concentration of Metsulfuron was present at 16 to 19kms from the spray site. 2,4-D was present in the Wilga trees adjacent to the cotton crop.
There was no evidence presented by the experts or anyone else to explain why the alleged spray components separated such that the Triclopyr and Picloram, the auxin herbicides, did not travel the 20kms, whereas a weak concentration of Metsulfuron did travel the distance. I will return to the 2,4-D in the testing samples later.
The experts gave evidence of varying strengths of herbicide necessary to cause damage to the cotton. The consensus seemed to be that .1 or 1/10th of a gram was enough to damage cotton. The judge accepted this sufficient for subclinical damage to occur. The objective analysis indicated that Metsulfuron tested in the trees at 16 to 19kms at .01. The judgement did not relate that reading in the test sample of .01 to the necessary level of .1 or 1/10th of a gram. It can be said that, on the balance of probabilities, that Metsulforan was not present in the cotton crop at the requisite level of the test sample, which was .01 gram, whereas the necessary level for damage was .1 or 1/10th of a gram. The judge’s finding skirted around the standard of proof when it was said, “That it is not possible to estimate with any accuracy the exact quantity of Metsulfuron which drifted”.

The Final Question
This question,“Were there any other herbicides sprayed over the cotton crop that could have affected the cotton crop”. The answer to that is clear “yes”. Consider the following evidence:

  1. Ed Offner, the plaintiff’s cotton crop agronomist, gave evidence of his observation of hormone damage consistent with 2,4-D on 5 December 2005, 10 days before spraying.
  2. The plaintiff’s director, Geldard, gave evidence that from 17-28 November 2005 all fields were sprayed over the top with “Roundup Ready” herbicide.
  3. The two Wilga tree samples at 16 to 19kms from the spray site all showed traces of 2,4-D.
  4. The evidence was that 2,4-D and Picloram were both auxin type herbicides, but that Picloram was not present in the cotton samples to a detectable level. Preston, an expert, commented upon this anomaly.
  5. Metsulfuron had been used on the cotton by the plaintiff previously. The experts sought to explain this away by assumptions as relating to the earlier Metsulfuron spraying without an objective pattern of evidence.

There is a fascinating aspect of the judgement at paragraphs 134, 137 and 149. It is worth reproducing all of them for you, dear reader, to compare.

“Paragraph 134    There is clear evidence that it was the Metsulfuron which was responsible for the significant damage observed and not an auxin such as 2.4-10, Picloram or Triclopyr.”

“Paragraph 137    When referring to the absence of Picloram & Triclopyr it is clear that symptoms consistent with damage from these herbicides were actually observed in the crops.”

“Paragragh 147(xx)    Auxin like symptoms were also prevalent in the cotton crop and the herbicide (Grazon) is in Group 1.”

Your correspondent comments that it is difficult to accept that the plaintiff’s case has been proved on the balance of probabilities that it was the spraying of the two properties Sherwood and Wallumba that caused the crop damage the plaintiff complained of. On the contrary, it is more probable than not that 2,4-D, or Metsulfuron, having been sprayed at an earlier date may have caused the alleged damage.

The wind issue raises some fundamental contradictions. The report of the Air France Concorde accident on 25th July 2000 is relevant. That report dealt with wind velocity changes between 1400hrs and 1442hrs. When the Supersonic aircraft was ready to taxi at 1400hrs, the wind was calm. At 1442hrs when the aircraft was cleared for take-off, the wind had become a tailwind of 8kts or about 14kph. The distance between the ramp site for the Concord is about ¾ of a kilometre from the take off point, 26R threshold. Such is the fickle nature of wind velocities that to accept a wind velocity 50kms from the site of a spray as evidence of the wind at the spray site is bordering on nonsense. Additionally, if it was accepted by the judge that the wind was five metres a second, for the chemicals to have been borne on this wind over hill and dale, it would have taken, 20,000 metres divided by fiive metres a second, about 4,000 seconds, which equates to about 66 minutes, or about an hour of suspended animation to arrive at the cotton fields. That’s incredible.

Watch this space…