Asteraceae

Question 1

Name five weed species of the family Asteraceae.

Answer 1

The Conyza trio:

Conyza sumatrensis
Conyza bonariensis (= Erigeron bonariensis)
Conyza canadensis (=Erigeron canadensis)

The Sonchus duo:

Sonchus oleraceus
Sonchus tenerrimus

Question 2

What is the appearance period for the Conyza trio?

Answer 2

Summer

Question 3

What is the appearance period for the Sonchus duo?

Answer 3

Sonchus oleraceus - Winter or summer

Sonchus tenerrimus - All year; mostly fall to spring

Question 4

Are the Conyza trio resistant to herbicides?

Answer 4

Yes

Question 5

Are the Sonchus duo herbicide resistant?

Answer 5

Sonchus oleraceus - yes

Sonchus tenerrimus - no

Question 6

What are the special threats associated with the Conyza trio?

Answer 6

strong competitor for water, grows rapidly, high dispersal ability

Question 7

Special threats associated with the Sonchus duo?

Answer 7

Sonchus oleraceus - Can harbour crop pests (aphids, nematodes) and viruses
Sonchus tenerrimus - none

Question 8

The only Asteraceae species with no herbicide resistance and no special threats is?

Answer 8

Sounchus tenerrimus - so fucking weak!

Question 9

Where are the Conyza trio found?

Answer 9

Conyza sumatrensis - roadsides, cultivated fields, disturbed sites.
Conyza bonariensis - roadsides, croplands, disturbed sites.
Conyza canadensis (wild one) - forest, hillsides, rangelands. But also, roadsides, croplands, disturbed sites.