An organism is resistant to a chemical if it did not eat anything with the chemical on it has been exposed to a small amount of the chemical over time was not in the area where the chemical was applied has a gene that protects it from the chemical

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?