Post on 07-Jul-2022
Chanda S. Henne, Jacob Price, & G. J. Michels, Jr.J J J
Texas AgriLife ResearchAmarillo, Texas
Wheat Curl Mite Aceria tosichella Keifer Dispersed by wind
Known to infest other grasses in addition to wheat Important plant vector:
Wheat Streak Mosaic Virus (WSMV)
wheat
Virus (WSMV) Wheat Mosaic Virus [WMoV; formerly High y gPlains Virus (HPV)]
TriticumMosaic Virus (TriMV)(TriMV)
The GrassesWrangler
bermudagrass* (Cynodon dactylon)
Blackwell switchgrass
(Panicum virgatum)
Spar OWB* (Old World Bluestem; Hachita blue gramaWorld Bluestem; Bothriochloaischaemum)
Hachita blue grama(Bouteloua gracilis)
Texoka buffalograss(Buchloe
dactyloides)
Haskell sideoatsgrama (Boutelouacurtipendula)dactyloides) curtipendula)
* Introduced to North America
Why is this important? Majorit of these grasses are nati e Majority of these grasses are native Use of the majority of these grasses for Conservation Reserve Program (CRP)Reserve Program (CRP) CRP “encourages farmers to convert highly erodible cropland or other environmentally sensitive acreage to vegetative cover”
Will any or all of these grasses serve as reservoirs for mites and/or viruses?mites and/or viruses?
G S d EGrass Study at Etter Bio fuel & forage production Bio‐fuel & forage production study
Planted May 2006 reseeded Planted May 2006, reseeded 2007, & established by Spring 2008
Three irrigation treatments: Full Irrigation, Limited Irrigation & DrylandDryland
6 grasses x 3 treatments x 3 replicates = 54 grass plotsreplicates 54 grass plots
Etter Grass Plot Diagram
Etter Grass Plots
Summer
Winter
Grass Study at Etter Mite sampling started Oct 2008 Mite sampling started Oct 2008 Each sample = 10 tillers per plot collected along a southwest to collected along a southwest to northeast transect
All mites from each tiller counted and recorded
Grasses tested with ELISA for WSMV WM V d T iMVWSMV, WMoV, and TriMV
Mean # of Mites by Grass
200
250
a
14
16
18
20 b Inset
150
es
6
8
10
12
n # Mites
100
Mea
n # Mite
0
2
4
Blue Grama Buffalo Sideoats OWB Bermuda
Mea
n
G S i*
bc cdd d
*
50
M
bbc cd d d
Grass Species
0Switchgrass Blue Grama Buffalo Sideoats OWB Bermuda
Grass Species
bc cd d d
* *
* Introduced to North America
M # f Mi TiMean # of Mites over Time900
Bermudal
700
800 Blue GramaBuffaloOWBSideoatsSwitchgrass
500
600
ites
Switchgrass
300
400
Mea
n # Mi
Switchgrass
0
100
200
Blue Grama
0
Date
Mean # Mites over Time160
without Switchgrass120
140without Switchgrass
80
100
Mites
BermudaBlue GramaBuffaloOWBBlue Grama
40
60
Mea
n # M
OSideoats
Blue Grama
0
20
Date
Mean # of Mites by Irrigationfor Blue Grama
35
40
45 bfor Blue Grama
25
30
35
es
15
20
Mea
n # Mite
5
10
M a
a
0Dry Limited Full
Irrigation Treatment
WM V I idWMoV Incidence1
ive Bermuda
pos
ive/Neg
ativ Bluestem
SwitchgrassSwitchgrassSwitchgrassBuffalograss
LISA Pos
it
BuffalograssBluestemSwitchgrassBluestem
E
0
Date
neg
SSummary Significantly more mites were found on switchgrass –S g ca t y o e tes e e ou d o s tc g assnative grass species
Mites were found on every sampling date Mite numbers were significantly higher on the blue grama that was under full irrigation
No plots positive for TriMV; only once was a plot positive for WSMV
ELISA results indicate more WMoV positi es in late ELISA results indicate more WMoV positives in late October & late May to mid June
Nearly half of the switchgrass plots were positive for Nearly half of the switchgrass plots were positive for WMoV on at least one date
Acknowledgments Dr. Brent Bean Elizabeth Sharpee
Cara Tam Carol Ladd
Dianna Vaughan Johnny Bible
Angela Simmons Bob Villarreal
Rachel Lange Don Henne
Rex Brandon
Heather Lynn Lindon Erin JonesEd B Ed Bynum