Question: What kind of diseases can plants get such as potato blight?

Dionne Turnbull answered on 7 Nov 2018:

Potato blight is definitely one of the most troublesome diseases of crop plants – it has been a problem for hundreds of years and we are still trying to work out how to control it! Have you learned about the historical Irish potato famine? That was late blight disease that killed all of the potato crop and meant that there wasn’t enough food in Ireland in the 1800’s.

Some other big ones for crops are ‘Panama disease’ which is a fungal disease that destroys a lot of the banana crop, and wheat rust, another fungal disease that infects wheat and barley. The biggest threat to rice is a disease called rice blast.
There are also some diseases infecting trees that are becoming more of a problem, like Sudden Oak Death.