Which of the following is considered an alternate host for Cherry X-disease?

The alternate host for Cherry X-disease is Pyracantha. This species is significant in the life cycle of the pathogen responsible for Cherry X-disease, as it can harbor the bacterium and facilitate its survival and spread. Pyracantha plants provide an environment where the pathogen can thrive outside of its primary host, which is typically cherry trees.

Understanding the role of alternate hosts is crucial in managing diseases like Cherry X-disease, as controlling these alternate hosts can significantly impact the incidence and spread of the disease in cherry orchards. On the other hand, strawberry, blueberry, and cucumber do not serve as alternate hosts for Cherry X-disease and do not contribute to the disease's life cycle or its management in the same way that Pyracantha does.