Texas Supreme Court Analyzes Herbicide Drift Case

Last week, the Texas Supreme Court issued an opinion in Helena Chemical Co. v. Cox, a case pitting cotton farmers against an aerial herbicide applicator. [Read opinion here.]


Plaintiffs grow cotton in Mitchell County, Texas.  They allege that defendant, Helena Chemical Company (“Helena”), supervised aerial application of Sendero, a herbicide primarily used to kill mesquite trees, on the Spade Ranch.  Plaintiffs claim that the Sendero sprayed on the Spade Ranch over several days in 2015 and 2016 drifted and damaged their cotton crops.  They blame this drift for reduced yields on over 14,000 acres of cotton across hundreds of miles in Mitchell County.  The plaintiffs gathered only “limited evidence” of the damage at the time it was noticed and at the time of harvest.  Many of the plaintiffs filed insurance claims attributing their crop losses to drought or other adverse weather conditions.  The fields they claim were damaged are located between 1.8 miles and 25 miles from the locations on the Spade Ranch where Helena sprayed the Sendero.  The Court noted that location of the fields “follows no discernable pattern” noting that “some fields are bunched together, while some are isolated many miles.”

The plaintiffs claim, and Helena does not dispute, Sendero is highly toxic to cotton plants, and should only be applied with the risk of drift is minimal, which is stated on the label.  The plaintiffs allege Helena did not follow the label instructions and instead sprayed when weather conditions, including wind, temperature, and humidity, were problematic. They also allege the Sendero was sprayed at too high of an altitude, resulting in drift.

After Helena’s application, the plaintiffs filed a complaint with the Texas Department of Agriculture (TDA).  A TDA inspector investigated and found the Spade Ranch application of Sendero was a possible cause of their crop damage.  He found “markers” for aminopyralid and clopyralid, the active ingredients in Sendero, but was unable to find a consistent pattern or drift pattern of crop damage over the large area where the fields were located.  TDA’s inspector conducted a visual inspection but did not conduct any laboratory tests.  When deposed, the inspector could not explain the difference between “markers” for aminopyralid and clopyralid.


Plaintiffs filed suit against Helena seeking damages for their cotton crop, as well as mental anguish damages and punitive damages.

Helena filed a number of dispositive motions.  The trial court granted Helena’s motion for partial summary judgment and dismissed the claims of mental anguish, gross negligence, and punitive damages.  The court then granted Helena’s Motion to Strike the plaintiffs’ expert witnesses as to causation, and granted Helena’s summary judgment motion on causation, rendering judgment for Helena.

The plaintiffs appealed, and the Eastland Court of Appeals reversed, holding that the expert testimony should have been admitted and, had this evidence been in the record, summary judgment for Helena on the causation issue would have been improper.  The Court of Appeals did affirm the partial summary judgment on claims of punitive damages and mental anguish damages.

Helena sought review from the Texas Supreme Court.

Texas Supreme Court Opinion

The Texas Supreme Court sided with Helena, issuing a take-nothing judgment on all claims.  [Read Opinion here.]

The issue before the Court was whether the plaintiffs’ evidence raised a genuine issue of material fact as to causation.  The key inquiry into that question is “whether the plaintiffs’ experts offered reliable evidence of causation.”  To analyze this, the Court considered the testimony of the plaintiffs’ experts as though admitted, and then asked if this evidence raised a genuine issue of material fact as to causation.

The Court noted that it was important to emphasize the injury for which the plaintiffs seek recovery here is not damage to the cotton plants such as wilted leaves, but instead it is the financial injury caused by decreased revenue from a reduced yield at harvest. Because of this, the Court stated, “it is not enough for the plaintiffs to show that drifting herbicides reached their plants and ‘damaged’ them in some way.  Instead, they must show that Helena’s application of Sendero caused their plants to yield less cotton at harvest.”  At the summary judgment stage, they must offer some evidence to create a genuine issue of fact as to whether Helena’s application of Sendero caused the reduced crop yield.

Lay testimony of plaintiffs

Plaintiffs argued that in addition to the expert testimony, the lay opinions of the farmers themselves about the cause of their crop failure can provide evidence of causation.  The Court disagreed, noting that “determining whether a particular application of aerial herbicide substantially contributed to the failure of crops miles away requires knowledge and analysis of scientific matters beyond the competence of laymen.”  There could be a number of reasons that plants “become sickly or die,” and the “expected aerial migration of herbicide particles over vast distances due to weather conditions and spray techniques” is simply not a matter in which lay people are generally familiar.  Thus, this testimony could not prove causation.

Field by field analysis

Helena argued that the plaintiffs must show toxic exposure at a sufficient dose for each “field” for which they seek recovery.  Helena asked the Court to rely on the USDA FSA’s “field” designations to enforce this requirement.  The Court rejected this argument.  “Although the USDA’s field designations provide a convenient way to categorize vast swaths of farmland, we cannot say that as a matter of law every plaintiff in a crop-loss case must proffer field-by-field proof using the USDA’s field boundaries.”  However, this does not mean proof of exposure is not required for each area where a farmer claims damage.  “The plaintiff must show causation for the entire area for which he seeks recovery, and using the USDA’s field designations may be a useful way to do so.”  However, the Court held that a plaintiff may go about offering that proof, and a defendant may go about opposing it, how they see fit.  The Court will not impose a USDA field boundary proof requirement in all cases.

Crop exposure to Sendero

The plaintiffs were required to show their crops were exposed to Helena’s Sendero.  The Court noted that an obvious way to show that would have been laboratory tests from locations throughout the affected area, coupled with evidence the tested areas are representative of the whole area for which damage is claimed.  The plaintiffs did not offer this type of evidence.

Instead, they presented positive lab results for clopyralid for only 3 identifiable locations.  Three or four other tests showed the presence of clopyralid at unknown locations somewhere in the allegedly damaged areas.  Additionally, the plaintiffs offered no test results showing the presence of aminopyralid, the other active ingredient in Sendero.  The plaintiffs’ experts testified that herbicides other than Sendero contain clopyralid, but only Sendero contains the combination of both clopyralid and aminopyralid.  Therefore, the laboratory tests did not establish the presence of Sendero, as opposed to other herbicides containing clopyralid, anywhere in the plaintiffs’ fields.  There was no expert testimony that offered a reliable way to “extrapolate from the small number of positive lab tests any conclusions at all about the presence of clopyralid–much less Sendero–in the rest of the vast and scattered acreage for which recovery is sought. While the plaintiffs do not have to test every field in order to survive summary judgment, they do have to show that the acreage for which they actually have the scientific evidence for is representative of the larger area for which they seek recovery.”  They potentially could have done this, opines the Court, by showing that the location of the positive tests relative to the aerial application are such that the herbicide must have drifted through other, untested areas to reach the tested area.  Or, they could have proffered a recognized model of the herbicide’s drift through the air onto the allegedly affected properties.  They attempted neither. In fact, they admitted the scattered drift pattern in this case does not match the usual predictable drift pattern, and their experts admitted they could not explain the scattered drift pattern.  They offered no modeling, no scientific studies, and no other evidence to support their speculation that drift from Helena’s Sendero application must have occurred.

Importantly,  the Court noted that it does “not suggest that precision of proof is required in such a case” nor does it suggest “a rigid requirement that such cases must always be provided with scientific modeling of the aerial-drift pattern or with any other precise category of evidence.”  But, the Court noted, “it defies reason to suggest that Helena’s aerial application of Sendero landed in roughly equal quantities on 111 fields scattered across hundreds of square miles of Mitchell County.”  To prove causation, the plaintiffs needed more than the “assumptions and speculations” offered that are simply insufficient.


Next, the Court looked at another important facet of causation in toxic exposure cases, the dosage.  Plaintiffs are required to establish with evidence the dosage required to produce the alleged injury.  Here, however, the Court noted there was “simply no evidence at all” about the amount of Helena’s Sendero that allegedly landed on the plaintiffs’ crops miles away from the Spade Ranch. Plaintiffs’ expert testified he did not reconstruct how much Sendero drifted onto any specific field.  There was no evidence that the unspecified amount of Sendero that allegedly landed on the fields was sufficient to make the drift a substantial factor in the lost crop yields. In fact, two of Plaintiffs experts testified that cotton plants showing signs of herbicide damage do not necessarily end up resulting in a reduced yield.  None of Plaintiffs’ experts knew how much exposure to Sendero would be required to result in a reduced cotton yield.

The plaintiffs testified that the damaged crops were sold and did not produce the desired amount of cotton.  They did not, however, offer evidence that the exposure to Helena’s Sendero was a substantial cause of their reduced yield.  Reduced yields could be related to other factors such as unfavorable weather (for which many of the plaintiffs made insurance claims seeking recovery of the same losses).  Without evidence of how much Sendero exposure occurred and how much Sendero exposure was required to cause the claimed injuries, “the factfinder could not even begin to reasonably determine whether Helena’s Sendero–rather than something else, such as weather or other herbicides–caused the losses.”

Plausible alternative causes

The burden is on the plaintiffs to account for other plausible causes of the injury.  Alternative causes do not have to be ruled out entirely, but there must be sufficient evidence for the factfinder to reasonably conclude the defendant’s action was a substantial factor in causing the injury.  The Court notes that in this case, there are two alternative causes that are probable: weather and other herbicides.  None of the expert witnesses accounted at all for the possible effect of weather on the reduced cotton yields.  The record shows that some of the plaintiffs applied for crop insurance benefits claiming losses due to weather.  The expert testimony made no attempt to account for this.  Second, the record indicates there could have been any number of other herbicide applications in the area.  One expert testified there are a number of other herbicides besides Sendero used during the summer months.  The record also shows at least one other aerial Sendero application in the area not conducted by Helena.  There was no evidence the plaintiffs’ experts considered other reasons clopyralid could have been in the tested fields, or why herbicide damage might be present other than Helena’s use of Sendero. Thus, plaintiffs failed to account for either of these alternative causes that could explain the crop damage.  The Court held there was an “analytical gap” between the allegedly tortious conduct by Helena and the damage suffered by the plaintiffs that required summary judgment in favor of Helena.

Based on this, the Texas Supreme Court issued a take-nothing judgment on all claims in favor of Helena.

Key Takeaways

This Opinion offers a thorough analysis of a herbicide drift case, offering insight to future plaintiffs and defendants alike into how a court will analyze such cases.  There are a couple of takeaways that strike me.

First, note that the plaintiffs reported the damage to TDA, and a TDA inspector did an investigation and prepared a report.  Two important things here.  First, TDA does not recover monetary damages for injured parties when alleged drift occurs.  It is up to the injured parties to proceed against the party who allegedly applied the drifting herbicide.  Second, note that the TDA inspector did not take any laboratory samples as part of his investigation.  This is a good reminder for those who may be damaged by drift to consider taking their own samples and having them tested.

Second, if a farmer believes there is drift damage to a crop, it is critical that he or she take care to document the damage.  This includes taking photographs and samples of the damage when it is noticed, but also critical is to document yield damage at harvest.  For example, in some cases, this may require segregating out the damaged crop from the remainder of a farmer’s harvest to show the yield damage.  Another point that seems relevant to this case is the fact that some of the plaintiffs filed crop insurance claims seeking indemnity for yield damage caused by adverse weather conditions. In a situation where a plaintiff may want to file a drift damage claim, he or she may want to consider whether or not bringing that type of insurance claim is something they want to do.

Third, it is almost always difficult to prove causation in a herbicide drift case.  Being able to show that damage occurred, and that such damage was the cause of a specific chemical sprayed by a specific defendant can often be challenging.  This case offers a good explanation of the various elements of proof that must be shown in order to prove this type of causation.

Fourth, for anyone applying herbicide, this case is a good reminder of the importance of having liability insurance that covers the application of herbicides.  This is true for a landowner doing the application himself or herself, or for anyone who may be hired to apply herbicides on behalf of another.  Carrying liability insurance is critical as it provides insurance money for covered claims but also because is obligates the insurance company to provide a defense in a situation where a drift claim is filed.  This means the insurance company would hire a lawyer to represent the insured in litigation over a covered claim.  One important item to check on any farm and ranch insurance policy is to determine whether herbicide application is covered, whether there are any limits on the type of application covered (i.e. some policies allow coverage for ground application but not for aerial application), and whether there are any limitations on the amount of coverage.  Some $1 million farm and ranch policies impose caps on coverage for pesticide or herbicide drift at much lower levels, $25,000 for example.  Before applying pesticide or herbicide, take the time to review any potentially applicable liability insurance policies.

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