November 2022 - 31

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GREAT LAKES EXPO NEWS
HOW NO-TILL
FARMING CAN
BENEFIT SWEET
CORN CROPS
Figure 3: Onion green leaf tissue remaining on August 28, in a small plot onion trial.
Green tissue rating was compared across no-spray (gray), fungicide program only plots
(solid red), insecticides with low, medium or high action thresholds (red and blue hash),
or insecticide program without fungicides (solid blue). Bars with the same letter indicate
no significant differences among green tissue rating.
By Madi Jones
VGN Correspondent
No-till farming on crops such
as sweet corn can be beneficial
for growers and their farm. Such
benefits include reduced soil
erosion and improved soil structure.
During the 2022 Great Lakes Fruit,
Vegetable and Farm Market EXPO,
growers
will learn
about no-till
farming and
how they can
implement it
in their crop
management.
Dr. Liz
Figure 4: Remaining green tissue on August 29, in onion plots. Severe green tissue
loss was observed in control plots (A) when compared to plots with a low thrips
action threshold treatment plus a fungicide program (B).
9. For each application, the pesticides
were tank mixed with Syl-Tac 1 % v/v and
applied with a CO2 pressurized backpack
sprayer equipped with a fan nozzle.
Results
The fungicide only treatment did
not effectively control onion thrips
populations, the thrips pressure in this
plot was similar to the no-spray control
plots and the high threshold + fungicide.
All treatments with insecticides controlled
onion thrips populations below the
economic threshold, and we did not see a
difference among those treatments (Fig.
2). Treatments with insecticides reduced
onion thrips populations by 50% when
compared to the no-spray treatments,
but only reduced onion thrips by 25%
compared to the fungicide only treatment
(Fig. 2). At the end of the season, there was
a significant decrease in green tissue across
all treatments (Fig. 3). On August 29th
(final disease rating date), the no-spray
plots had 40% green tissue remaining,
which was similar to the medium
threshold and high threshold without
fungicides (Fig. 4A). The combination
of insecticides and fungicides increased
green tissue to 55%, and the fungicide
only treatment also significantly increased
green tissue when compared to the nospray
plots (Fig. 4B).
Interestingly, there was no statistical
difference in the onion thrips numbers
among the treatments with varying
action thresholds. The high threshold
treatments with 2 applications of Radiant
was as effective as the low threshold
treatments with Movento, Minecto Pro,
and Radiant applied twice. Overall,
there was low onion thrips pressure
throughout the season, and when pressure
is low, growers may be able to effectively
control onion thrips with Radiant only.
While there was no difference in onion
thrips numbers between treatments
that contained insecticide, there was
a significant difference in green tissue
between treatments that contained both
insecticide and fungicide, compared to
treatments with insecticide only. These
differences in treatment effectiveness
for onion thrips control compared to
disease control indicate that the ideal
spray program for onion thrips (high
threshold, without fungicide) did
not effectively control disease. This
highlights the need for an effective
multiple pest management strategy
that focuses on both insect and disease
pests simultaneously.
Acknowledgements: We thank the
cooperating onion grower who allowed
us access to their field for the spray
trial. Funding for this research was
provided by the USDA's Specialty Crop
Block Grant Program. VGN
Maynard,
Extension
specialist for
vegetable
crops at
Purdue University's Department
of Horticulture and Landscape
Architecture, and Dr. Dan Quinn,
assistant professor of Agronomy and
Extension corn specialist at Purdue
University, will present a session
about no-till farming and sweet
LIZ
MAYNARD
corn during the Great Lakes EXPO.
" We want to share what we have
seen and learned so that growers
interested in exploring (no-till
planting sweet corn) can learn from
our experiences, " Maynard said.
" We have been working to develop
systems for no-till planting sweet
corn after a winter rye cover crop.
We are aware that some growers are
doing it successfully, and we want to
be able to do it on Purdue research
farms so that we can study and
improve the system even further. "
Quinn noted they will also share
the importance of proper stand
establishment in corn and how
certain management practices and
planter equipment can help with
proper stand establishment in high
residue or cover crop systems.
" In order for more producers
to include cover crops in their
corn systems and improve overall
adoption of this conservation
practice, we have to understand how
to make corn perform within these
systems, " Quinn said. " One specific
challenge that producers often face
is poor stand establishment and
poor seed-to-soil contact caused by
residue interference in high residue
and cover crop systems. "
Benefits of no-till farming include
improved soil structure, reduced
soil erosion, less disturbance of soil
microbes and other life and reduced
loss of soil carbon, according to
both Maynard and Quinn.
" In our work, no-till seeding
follows a winter cover crop of rye.
Additional potential benefits include
the maintenance of rye residue on
the surface, whereas a mulch may
reduce evaporation and keep soil
cooler. Both of these can be negative
in the spring but advantageous in the
summer, " Maynard said.
Maynard and Quinn's tips for
those new
to no-till
farming:
Start slow.
Take the time
to modify
and adjust
your planting
equipment
accordingly,
Maynard
advised.
Talk to
DAN
QUINN
farmers who have had success from
no-till farming and learn from their
mistakes, both Quinn and Maynard
said.
Choose the correct hybrids or
varieties of corn for no-till farming.
No-till environments may be more
stressful for crops and can harbor
more insects or diseases due to
high residue levels and cooler soil
conditions, Quinn said.
Learn more about these sessions
and others at www.glexpo.com. The
2022 Great Lakes EXPO will be Dec.
6-8 at DeVos Place in Grand Rapids,
Michigan. VGN
VGN | NOVEMBER 2022 | 31

http://www.glexpo.com

November 2022

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