Download - Verticillium Wilt in the UK Project Update
Verticillium Wilt in the UKProject Update
Dr Peter GladdersADAS UK Ltd
Review1. History in the UK
2. Disease surveys
3. Effects on yield
4. Varieties
5. Management options
2
Introduction - Verticillium wilt First confirmed in UK in 2007
Pathogen is Verticillium longisporum – specific for crucifers (mainly brassicas)
Important in other parts of Europe with up to 50% yield loss
Grey microsclerotia – key diagnostic feature
Look for long streaks right up the stem – phoma similar
Only evident late in season
HGCA Research Review No 72 completed May 2009
Disease Cycle of
OSR Verticillium
Wilt Plant debris or soil from nearby infested fields
Disease Survey Samples – Variation by Field & YearProportion of samples (fields) from Crop Monitor positive
for V. longisporumYear Samples examined Positive % positive
2009 95 10 10.52010 97 24 24.72011 100 12 12.0
Number of samples with various proportions (%) of stems positive
Year 0-5 6-10 11-15 16-20 21-30 31-40 41-50 51-60 >60
2009 3 2 0 0 0 3 0 1 1
2010 12 2 4 1 2 0 1 2 0
2011 2 3 0 0 1 3 0 0 3
Distribution of Verticillium Wilt 2009-2011
Factors affecting
distribution?
Rotations and Verticillium Wilt2010
Previous crop No. samples % crops % plants
Oilseed 0 0.0 0.0
Wheat – OSR – Wheat 5 40.0 3.1
Wheat - Wheat - OSR 13 30.8 2.3
Other cereal – Wheat - OSR 9 11.1 1.0
Other Cereal - Other Cereal - OSR 0 0.0 0.0
3 Previous Non OSR Crops 22 18.2 *
4 or More Previous Non OSR Crops 42 26.2 *
Other / Unknown info 6 33.3
National 97 24.7 3.6
7
Yield Impacts Numerous reports of yield effects when crops ripen prematurely
2012 – significant yield impacts
Single plants harvested from heavily infected crops
Decreased TSW by 12-24% when verticillium affected >50% stem
Further losses if seeds are shed
Varieties Differ in their Resistance to Verticillium Wilt
Verticillium wilt at Bourne, Lincs 2010
0
5
10
15
20
25
30
Cat
ana
Ora
cle
Alie
nor
Com
pass
Pal
ace
Cui
llin
Kry
pton
Dim
ensi
on
DK
Cab
erne
t
Ham
mer
Ses
ame
PR
45D
03
PR
46W
21
Exc
el
Flas
h
PR
45D
05
NK
Bra
vour
PR
45D
06
Kal
if
Es
Ast
rid
DK
ExM
en
DK
Sec
ure
Cas
tille
Exc
alib
ur
% p
lant
s af
fect
ed LSD 10.2
Mean %verticillium by variety - Lincs 2010 & 2011(Limited variety experiments but main rankings have been consistent)
0
5
10
15
20
25
30
% v
ertic
illiu
m
AlienorCastilleCatanaCompassDimensionDK CabernetExcaliburFlashPalaceSesame
LSD = 9.9
Managing Verticillium Wilt - Options
1. Determine its prevalence on individual farms
2. Good agronomy – a strong plant holds off verticillium
3. Variety choice
4. Extended rotations
HGCA Project reference RD-2009-3618 Importance and management of Verticillium
wilt in winter oilseed rape
ADAS UK Ltd, Warwick-HRI, FERA, Farmacy/Hutchinsons