March 2020 - 27

MSUE VEGETABLE NOTES
Extremely Eff ective Post
Infected
population
Insect
population
Laboratory
diagnostics
Emergent Herbicide
ACTIVE INGREDIENT - 15.9 % Phenmedipham
PROVIDES Control of Broadleaf Weeds in
Spinach (grown for processing and seeding)
and Red Garden Beets.
NEW FIFRA 2(ee)* Recommendation (CA & AZ)
Apply 1 pint of Spin-Aid 7 - 10 days after
seeding when weeds are at two - leaf stage.
Text message to growers
No
Management
Needed
MSU Leafhopper Alert
Date: 7/25/2017
Ottawa County
Infectivity: 3%
Celery threshold: 12/100 sweeps
Carrot threshold: 17/100 sweeps
Research-mediated
management
Successful management of aster yellows relies on reducing aster leafhoppers in
sensitive crops. This can be done with the help of rapid diagnostics tools and texting
results about thresholds to growers to allow them to make a research-based decision
about management needs.
Our goal has been to give
growers the information they need
to accurately assess risk of aster
yellows. To accomplish this, we
began sampling aster leafhoppers in
Michigan celery and carrot farms
starting in 2014. Scouts collect
leafhoppers using sweep nets.
The Michigan State University
(MSU) Vegetable Entomology
lab then tests leafhoppers for the
presence of aster yellows DNA.
This provides an estimate of the
percentage of the leafhoppers that
are carrying the aster yellows disease
each week of the growing season. We
then text growers information on the
percentage of leafhoppers carrying
aster yellows. Our texts also have a
threshold that growers can use in
combination with their scouting
reports to make spray decisions.
This information helps growers
spray when risk is high but minimize
unnecessary sprays that will not
impact their bottom line.
Our results have shown the value of
knowing how many leafhoppers are
infected from week to week. In celery
fields, we sometimes find a two-week
lag between increases in leafhopper
numbers and an increase in the
number of leafhoppers carrying aster
yellows. For example, we found that
in celery there are increases in aster
leafhopper numbers in mid-June,
but these are not usually infected at
high rates. In times like this, growers
can save money by avoiding sprays.
However, in late-June or early-July
infectivity can increase, making
management at this time important.
We have also found that the highrisk
period for aster yellows can
vary between crops. For example, in
some years infected leafhoppers are
not found in carrot fields until two
weeks after detection in celery. This
delay may be due to the geographical
distribution of farms in Michigan
or differences in crop production
practices. Celery is transplanted
and is grown to the south of the
main carrot producing region.
Transplanted celery likely provides
an early season food source for the
leafhoppers when they arrive in
Michigan. Carrots are direct-sown
so they might provide a later-season
food source for the leafhoppers as
they continue to travel north.
We continue to perform a number
of follow-up studies to help growers
better control aster yellows. We
are particularly interested in the
relationship between aster yellows,
field edges, and natural areas, and
if these areas can be managed to
reduce infections in crops. Field
edges and natural areas are known
to host aster leafhoppers, but it is
unclear if these areas also serve
as a reservoir for aster yellows
phytoplasma.
If you are interested in receiving
aster yellows infectivity text
messages or hosting our research,
contact Ben Werling (werling@msu.
edu) or Zsofia Szendrei (szendrei@
msu.edu).
Also contributing to this report:
Patrick T. Stillson, Elias H. Bloom
and Benjamin Werling, Michigan
State University. VGN
Offers Growers Effective and
Preventative Disease Control
STRONG EFFICACY on Oomycete (Water
Mold) Pathogens
HIGHLY SYSTEMIC - Extensive Mobility
Throughout the Plant
HIGHEST Available Concentration -
Eff ective at Low Rates
2 MODES OF ACTION
* Inhibits mycelial growth preventing
oxidative phosphorylation
* Stimulates the plants natural defense
mechanisms triggering SAR
Moves Water and Chemicals
Into The Rootzone
PROVIDES Uniform Penetration and
Lateral Movement of Water
ENCOURAGES Improved Rooting and
Nutrient Uptake
ENHANCES Initial Wetting and
Subsequent Rewetting of Soils
IMPROVES Distribution and Eff ectiveness
of Soil Applied Chemicals
SAVES WATER - Reduces Irrigation
Requirements by Up To 25%
* See complete 2ee Recommendation prior to use.
All products are not registered in all states.
Ask your Belchim representative for current registration status.
SpinAid is a registered trademark of Bayer Crop Science.
ReLoad and Integrate are registered trademarks of
Belchim Crop Protection USA, LLC.
2751 Centerville Road | Suite 100 | Wilmington, DE 19808
Phone: 855-445-7990 | www.belchimusa.com
info.usa@belchim.com
VGN | MARCH 2020 | 25
http://www.belchimusa.com
March 2020

Table of Contents for the Digital Edition of March 2020
