minor diseases in Canola

Question 1

Aster yellow life cycle

Answer 1

caused by phytoplasm
pathogen is transmitted by leaf hoppers
it can overwinter in infected weeds nut most infections caused by leafhoppers

Question 2

Crops infected by aster yellows

Answer 2

canola, alfalfa, sunflower, caraway, carrots, peas

Question 3

Symptoms of aster yellow

Answer 3

stunted growth and malformed flowers and pods

infected plants don’t produce seed

Question 4

facts about aster yellow

Answer 4

-leaf hoppers injects the pathogen into the Sao of the canola plant and it develops aster yellow

-The pathogen will multiply in the insect and it will transmit
the disease from plant to plant

• leaf hopper has the pathogen glands it will transmit it for the rest of its life

Question 5

control of aster yellow

Answer 5

control isn’t necessary. easy seeding may escape infection

Question 6

Alternaria Black Spot

Answer 6

warm conditions increase infection by dispersing spores.

infection in a later stage causes pod shattering and loss during harvest

Question 7

White rust in Canola

Answer 7

Obligate parasite causes little to no damage on Canola

Question 8

white Rust in canola

Symptoms

Answer 8

host - cruciferae
very susceptible

white blisters develop on leaves and stem
blister rupture to release zoospores

Question 9

Disease cycle white rust in canola

Answer 9

produces airborne spores
overwinters as thick walled oospores
stag heads break off through combine
spores get mixed in with see

Question 10

Control for white Rust in Canola

Answer 10

Brassica napus is immuned
clean seed
avoid planing close to previous years crop
control volunteers
3 year rotation

Question 11

Fusarium wilt in canola

symptoms

Answer 11

chlorosis of stem, vascular discolouration, poor seed set and premature desiccation

Severely infected plants die prematurely. stem and branches turn brown no visible lesions.

less severe plants are often stunted
yellow reddish streaks may ripen prematurely.

Question 12

Fusarium wilt in canola pathogenicity

Answer 12

mainly in dry soils
soil borne fungus. only a few commercial cultivars are susceptible
resistance is very good in many cultivars