The crops were exposed to the vacuum of space and perished.
When the airlock exploded, the immediate decompression resulted in the expulsion of the atmosphere within the controlled environment where the crops were being cultivated. This sudden loss of pressure and the accompanying rapid change in temperature would have been catastrophic for the plants. Without the necessary atmospheric pressure and oxygen, the plants would have experienced cellular damage, leading to their wilting and death.
Moreover, the exposure to the vacuum of space would have caused the water within the plant cells to boil off, even at normal temperatures, due to the lack of external pressure. This process, known as ebullism, would have further dehydrated the plants rapidly, destroying their tissues and making any chance of recovery impossible.
Additionally, if the airlock explosion was violent enough, it could have resulted in physical damage to the crops from debris or the force of the explosion itself. The plants could have been uprooted or shredded by the force, compounding the damage done by the decompression.
In a controlled environment like a space station or a habitat on another planet, the loss of an airlock is a serious incident that would likely require immediate action to seal the breach and repressurize the affected area. However, for the crops within the vicinity of the explosion, such measures would come too late to save them from the effects of the vacuum exposure.