Banana Disease

Question 1

Panama

Answer 1

Vascular wilt fungus
Fusarium oxysporon
Aus 1876 spread everywhere by 1950's
Gros Michelle- cavendish
4 races, 3 asexual spores

Question 2

Asexual spores of Panama

Answer 2

Chlamydiospores- first innoculum, old mycelium and macroconidia

Microconidia- most abundant, one or two cells
Macroconidia- form at the surface of dead cells

Question 3

Panama disease cycle

Answer 3

Enter through lateral root or wound
Moves up xylem
Blocks water transport to leaves- wilt and die
Tissue invaded and pathogen reaches surface

Question 4

Panama control

Answer 4

Resistant varieties- fh01, 18,22,25
Treat crops with potassium phosphate fungicide
Methyl bromide treatment of soil- lasts 3 years
Solar treat soil
Clean farming tools

Question 5

Black Sigatoka

Answer 5

Mycosphaerella fijiensis
Causes black streaks on leaves
Started in Fiji in 1960’s and spread to Florida by 1999
Folliar ascomycete fungus
Conidia dispersed by water, ascospores by wind

Question 6

Black Sigatoka disease cycle

Answer 6

Spore lands on leaf and germinates in 3 hours
Germ tube produces hyphae that take 2-7 days to grow to stomata
Grow through mesophyll and palisade layer to get to further stomata
Stop leaves photosynthesising - death
50% loss in yield

Question 7

Black Sigatoka control

Answer 7

Cut down diseased plants, resistant varieties, fungicide

Question 8

Bacterial wilt

Answer 8

Xanthomas campestri
Ethiopia in 1960’s spread through africa
Spread by grass flies, fruit flies, bees

Question 9

Bacterial wilt disease cycle

Answer 9

Bacteria spread through soil and enters roots through wounds
Spread through xylem
Produces slime in extra cellular spaces
Stops water flow

Question 10

Bacterial wilt control

Answer 10

Cut down infected trees, clean planting material , debudding

Question 11

Bbtv

Answer 11

Banana Bunche top virus
SsDNA virus
Spread by banana aphid
Chlorotic leaf margins

Question 12

Bbtv disease cycle

Answer 12

Aphid feeds on infected plant
Virus on inside for 2 weeks
Infects another plant phloem
Spreads along vascular system generating dead cells

Question 13

Bbtv control

Answer 13

Clean planting material
Destroy infected plants
Chemical control of aphid vector

Question 14

Nematodes

Answer 14

Endemic to aus, but spread
Cause stunted growth and toppling
30-60% loss in yield

Question 15

Nematode disease cycle

Answer 15

Lives in root debris, moves to new roots by chemical signals, invade at growing zone
Kill plant along with other bacteria through several life cycles
Nematodes moves to rhizome forming dark leisions.

Question 16

Nematode control

Answer 16

Soil fumigation, cut down dead plants, hot water treatment