diseases caused by fungi

Question 1

What sort of pathogen is rose black spot caused by?

Answer 1

-caused by fungus Diplocarpon rosae
-serious rose disease

Question 2

Why does rose black spot make resistant roses difficult to breed?

Answer 2

-mutates rapidly, making resistant roses difficult to breed

Question 3

What are the symptoms of rose black spot disease?

Answer 3

-purple or black spots on leaves of rose plants which often turn yellow and drop early

-affects growth of plant as photosynthesis is reduced

-enlarging black patch on leaf

-drooping leaves

-small, black lesions on stems

-if plant is badly affected it can lose all its leaves

Question 4

How is rose black sport transmitted?

Answer 4

by water - black spot fungus produces spores which are released under water conditions and are usually spread by rain splash

by wind-
through direct or indirect contact - disease can be spread from plants to plant directly or via hands, clothing or tools

Question 5

What is the treatment for rose black spot disease?

Answer 5

treated using fungicides (tebuconazole with trifloxystrobin and triticonzale are labelled for rose black spot)

Question 6

How can the spread of rose black spot disease by prevented/controlled?

Answer 6

-use fungicide

-spread out rose bushes more

-remove any infected (parts of the) plants

-collect and destroy fallen leaves in autumn, or

-bury under a layer of mulch

-prune out all stem lesions in spring before leaves appear