don mccaffery background to beet western yellows virus in canola 2014-0805
TRANSCRIPT
Background to this season’s Beet western yellows virus
problemDon McCaffery
NSW DPI
Orange
5 August 2014
So how did this problem develop?
Presence of green peach aphid (GPA)– GPA is endemic
Right conditions for pest population growth Late summer alternative hosts available Warm, dry conditions optimum for GPA Lots or early sown canola & crops in aphid flight
zone GPA main vector (transmitter) for BWYV
Why did the aphids infect where they did?
Stress related?– Divided opinion among
researchers– There was no moisture
stress involved in SA– Other possible stresses
• Group B residues• Nutrition• Waterlogging• Off label products and
at off label rates
Trangie on 28 May, sown 1 AprilGPA x moisture stress
What has happened to date
18 June - SA – major issue identified with BWYV The virus quickly appeared in other regions of SA,
Mallee of Vic -19 June and southern NSW -1July First positive for BWYV in NSW was Young in trial
plots on town boundary– Early May
Early infections have done the most damage
Distribution based on samples submitted
Source: DEPI, Horsham Vic
What has happened to date (cont’d)
Information and updates delivered through PestFacts, press releases and other grains websites
Media went into overdrive AOF has coordinated two teleconferences
– State agency researchers, canola industry and GRDC
– 4 July & 31 July
GPA Feeding damageTrangie 2014 – no virus
Feeding damage
Trangie 2009
GPA feeding + BWY virus
GPA feeding + BWY virus