Afarmer is being troubled by coyotes eating his sheep. in an attempt to solve the problem, he kills a sheep and laces its body with a nausea-inducing drug. he leaves the sheep out where he knows the coyotes roam. he hopes they will learn to not eat the sheep. the farmer is attempting to apply the research of et al. (1989) to accomplish this.

The scenario in which a  farmer is being troubled by coyotes eating his sheep and in order to solve the problem, he kills a sheep and laces its body with a nausea-inducing drug and he hopes they will learn to not eat the sheep means that the farmer is attempting to apply the research of conditioned food aversions.
It is the phenomena when an animal associates the taste of a certain food with symptoms caused by a toxic, spoiled, or poisonous substance.

The answer is texture