Plant doctor quiz (April 2020)

Welcome to the plant doctor quiz (April 2020)
This is the twenty first in a series of quizzes on plant health diagnostics.
These are put together every month by Phil Taylor of CABI,  if you have any comments (or would just like to let me know who you are and what you thought of the quiz)  please use the comments box at the end or send me an email.
5% of survey complete.