This appeal involves a claim by plaintiff Mortensen against defendant Chevron for damages to Mortensen’s 1979 potato crop. The case arose under the following facts: During 1979, Mortensen planted potato seed in five different sprinkler irrigated fields. The potato seed was obtained from three different sources: (1) from Mortensen’s own 1978 potato crop, (2) from a Canadian seed grower, and (3) from Ferrell Black Ranches.
Mortensen purchased “Clean-Crop Cap-tan 7.5 Dust Fungicide” (a potato seed protectant) from a retailer, Blair M. Geisler Farm Supply. Mortensen applied the fungicide to all of the potato seed planted except that obtained from Ferrell Black. The fungicide, which comes in a dry dust form that adheres to the cut potato seed pieces, was applied to the seed at planting.
When Mortensen commenced his 1979 planting, the atmospheric temperature was essentially normal. However, as the planting continued, the temperature increased dramatically. Shortly after planting, Mortensen noticed unsatisfactory plant emergence. The acres planted with the untreated Ferrell Black seed showed less decay than the rest of the fields.
Geisler Farm Supply had purchased the fungicide used by Mortensen from the Snake River Chemical Company. Snake River formulated the “Clean-Crop Captan 7.5 Dust Fungicide” which is sold under a Platte Chemical Company label. The fungicide was a mixture of three ingredients— Frianite (diatomaceous earth), Silvacon (fir bark dust), and Captan Concentrate which Snake River purchased from Chevron. Chevron marketed and sold concentrated Captan under the name “Orthocide 80 Concentrate.”
Captan is the accepted common name for the organic fungicide N-[ (trichloromethyl) thio]-4-cyclohexene-l, 2-dicarboximide. It was discovered by A.R. Kittleson and his associates of ESSO Laboratories, Chemicals Division, Standard Oil Development *838Company of New Jersey. Chevron was granted a license to produce, develop and distribute Captan under the “Orothocide” trademark in the agricultural and industrial fields.
Mortensen originally sued Snake River, Platte, Geisler and Chevron. Mortensen settled with all parties except Chevron pri- or to trial. Mortensen’s claims against Chevron were tried before a jury on the theories of strict liability, negligence and gross negligence and fraud. At trial, Mortensen contended, through his expert witness, that a fungal organism, fusarium, was the primary pathogen which caused his loss. He contended that the fungicide “totally failed to prevent or reduce rot in Plaintiff’s potato seed pieces and, to the contrary, directly caused Plaintiff’s said potato seed pieces to rot and decay and caused serious and irreversible damage to Plaintiff’s 1979 potato crop.”
At the close of Mortensen’s case in chief, Chevron moved for a directed verdict on all of Mortensen’s claims. The district court granted the motion with respect to negligence, gross negligence and fraud, and strict liability based upon failure to warn. Thereafter, the district court submitted the case to the jury on the only remaining theory, strict liability based upon defective design.1 The jury returned a verdict in favor of Mortensen.
After judgment was entered, Chevron filed alternative motions for judgment notwithstanding the verdict, or a new trial. The district court denied the motion for a judgment notwithstanding the verdict. As to the motion for a new trial, the district court granted a new trial solely and exclusively on the issue of liability. The trial court granted the new trial concluding that the “unreasonably dangerous” element in the prima facie case for strict liability based on defective design must be judged by a “risk/utility” standard, on which the court had not instructed the jury. Chevron appeals from the denial of judgment notwithstanding the verdict. Mortensen cross-appeals from the grant of a new trial.
We first address Chevron’s assertion that the district court erred in denying Chevron’s motion for judgment notwithstanding the verdict. “A judgment n.o.v. should be granted when there is no substantial competent evidence to support the verdict of the jury.” Brand S. Corporation v. King, 102 Idaho 731, 732, 639 P.2d 429, 430 (1981); see Mann v. Safeway Stores, Inc., 95 Idaho 732, 518 P.2d 1194 (1974). The only cause of action presented to the jury was strict liability for the alleged defective design of the product Cap-tan. All other claims against Chevron and other parties have either been settled or eliminated by directed verdicts, and Mortensen has not raised on appeal the correctness of those directed verdicts. Therefore, the only issue which we must examine is whether the evidence will support the jury verdict of strict liability for defective design.
Initially we note that there is some confusion as to whether this case is a defective design case at all. At oral argument both parties stated that this is not a defective design case. In support of his effort to reverse the trial court’s grant of a new trial, Mortensen’s counsel stated:
“There is no allegation in Mortensen’s complaint that anybody defectively designed Captan.
“ ‘[Captan]’ was discovered ... by a couple of biochemists ____ It was not designed [by Chevron] from a plant into a synthesized molecule, an organic fungicide.
“Now, we again submit that the case is not a design defect case because Chevron didn’t design it.”
Similarly, counsel for Chevron stated:
“There’s just nothing in the record that would indicate that this truly is— that there is a defective design. That’s why it’s a tough case to analyze because it’s not a design defect case.”
*839The evidence indicates that Captan was discovered in the Standard Oil Laboratories and that Chevron in no way “designed” the fungicide involved in this case.
Regardless of which of the three general categories of strict liability a case falls under — manufacturing defect, design defect, or failure to warn — there are certain elements which must be met. 2 L. Frumer & M. Friedman, Products Liability § 16A[4] f[i] (1984); W. Prosser, Handbook of the Law of Torts § 99 (4th Ed. 1971). Section 402A of the Restatement (Second) of Torts, which was adopted by this Court in Shields v. Morton Chemical Co., 95 Idaho 674, 518 P.2d 857 (1974), states these elements as follows:
“402A. Special Liability of Seller of Product for Physical Harm to User or Consumer
“(1) One who sells any product in a defective condition unreasonably dangerous to the user or consumer or to his property is subject to liability for physical harm thereby caused to the ultimate user or consumer, or to his property, if
“(a) the seller is engaged in the business of selling such a product, and
“(b) it is expected to and does reach the user or consumer without substantial change in the condition in which it is sold.
“(2) The rule stated in Subsection (1) applies although
“(a) the seller has exercised all possible care in the preparation and sale of his product, and
“(b) the user or consumer has not bought the product from or entered into any contractual relation with the seller.”
Applying the above elements to this case, we hold that Mortensen has failed to show (1) that the Captan sold by Chevron was in a “defective condition unreasonably dangerous to the user” at the time of sale, and (2) that the Captan was expected to and did reach Mortensen “without substantial change in the condition in which it was sold.”
DEFECTIVE CONDITION
There was no evidence presented at trial of the condition of the Captan sold by Chevron which ultimately reached Mortensen. Mortensen concedes that Chevron did not design the chemical structure of Cap-tan and that the Captan in question conformed to the accepted chemical structure of that product. Proof of malfunction causing direct injury to the potato seed pieces could, under certain circumstances, be circumstantial evidence of the defect in the product at the time of sale. Farmer v. International Harvester Co., 97 Idaho 742, 553 P.2d 1306 (1976). However, the Farmer rule that evidence of malfunction is circumstantial evidence of a “defective condition” only applies where the plaintiff’s proof has excluded the possibility of other “reasonably likely causes.” Id. at 749, 553 P.2d at 1313. In the present case, the plaintiff’s evidence did not exclude other reasonably likely causes.
Plaintiff’s evidence consisted primarily of the expert testimony of Dr. Douglas, who testified that in his opinion the product which was applied to Mortensen’s potato seed pieces inhibited the suberization 2 process of the potato seed. This opinion was not based upon any experiments or studies conducted by Dr. Douglas on the effects of Captan on suberization, nor was it based upon any other evidence tending to show that Captan harms the suberization process. The basis for Dr. Douglas’ opinion was that the right side of one of Mortensen’s fields which had not been treated with the 7.5% Captan was not infected to any measurable degree, while the portion using seeds which had been so treated was infected.
Under Farmer, “[a] prima facie case may be proved by direct or circumstantial evidence of a malfunction of the product and the absence of evidence of abnormal *840use and the absence of evidence of reasonable secondary causes which would eliminate liability of the defendant.” 97 Idaho at 747, 553 P.2d at 1311. In this case, Mortensen did not show “the absence of evidence of reasonable secondary causes.” There were several other possible secondary causes. The Captan concentrate furnished by Chevron had been combined with two other inert ingredients by the formulator, Snake River Chemical Company, before selling it to Geisler Farm Supply who sold it to Mortensen. Those other ingredients, or the integrity of the formulator’s process were not excluded. Also, the plaintiff’s evidence did not exclude the effects of temperature or the specific pathogen which by themselves, or in combination, could have reasonably inhibited the suberization process. We conclude that the plaintiff’s testimony did not exclude the possibility of other “reasonably likely causes.” The mere evidence that the untreated side of a field was less severely infected than the treated side is not sufficient competent evidence on which a jury could conclude that the Captan concentrate furnished by Chevron to the formulator Snake River Chemical Company was in a defective condition, particularly a defective condition as to design, at the time that Chevron sold the product to the formulator.
SUBSTANTIAL CHANGE
As was stated above, Mortensen must also show that the Captan was expected to and did reach Mortensen “without substantial change in the condition in which it was sold.” Chevron sold the Cap-tan in an 80% concentrated form. The evidence reflects that it was not expected that Mortensen would receive the Captan in that form. Independent formulators substantially changed the product by the addition of fillers which reduced the concentration of Captan to 7.5%. The formulator in this case diluted the Captan with fir bark dust. Although Chevron previously had supplied some formulation instructions to the formulator, Snake River, there was no evidence that Chevron had ever recommended the use of fir bark dust as a filler. Nor was there any evidence that Chevron had ever marketed or sold any product containing fir bark. There was no competent and substantial evidence presented to the jury that the product sold by Chevron was expected to and did reach Mortensen “without substantial change.” The uncontroverted evidence was to the contrary.
Accordingly, the trial court erred in not granting Chevron’s motion for judgment n.o.v. In view of our ruling on Chevron’s appeal, there will be no new trial, and therefore we need not consider respondent’s cross-appeal.
Costs to appellant Chevron.
SHEPARD and BAKES, JJ., concur.. Mortensen never asserted any claim of strict liability based on defective manufacture.
. "Suberization" is a natural process in which cut potato seeds harden, dry and heal over the cut portion of the potato seed. Suberization tends to naturally inhibit the entry of foreign organisms.