This builds upon the 2021 sweet corn demonstration when we looked at 4 other varieties
(Obsession I, Serendipity F1, Obsession II, and Pursuit F1). We wanted another look
at varieties that contained the new Vip3A Bt insect resistance gene (Attribute II and Attribute Plus) that should require no insecticide
sprays for CEW. The ultimate goal was to build confidence in recommending new CEW
resistant varieties.
The table below outlines the 3 varieties we grew in the demo and the expected resistances
based on the genes present in each (orange indicates conventional varieties with no
GM traits and yellow indicates that corn earworm (CEW) control is expected due to
GM traits).
Variety
Disease Resistance Traits
GM Genes
GM Resistance
(Insects Suppressed)
Temptress
Northern Corn Leaf Blight,
Common Rust, Maize Dwarf Mosaic Virus (MDMV)
NONE
NONE
Remedy
(Attribute II)
--------------
Cry1Ab + Vip3A + Roundup and Liberty Resistance
Broad caterpillar control
(Excellent CEW Suppression )
Milky Way
(Attribute Plus)
Southern Corn Leaf Blight, Common Rust
Cry1Ab + Vip3A + Liberty Resistance
Broad caterpillar control
(Excellent CEW Suppression )
The table below exhibits important growth habits of each variety claimed by seed companies.
The main choice of these varieties was based off of GM traits and expected CEW resistance,
but we were also sure to choose varieties with the same sweetness type so they could
planted at the same time.
Variety
Sweetness Type
Kernel Type
Notes
Temptress
Triple sweet, Synergistic
SE-Sh2
bicolor
70 days, 7.75’’ ears
Remedy (Attribute II )
Triple sweet, Synergistic
SE-Sh2
bicolor
82 days, 8.5” ears
Milky Way (Attribute Plus)
Triple sweet, Synergistic
SE-Sh2
white
82 days, 8.5’’ ear
We sent out enough seed to each participating agent to plant around 48 row feet of
each variety. Agents were supplied with a standard fertility plan and relied on grower
standard weed control. Agents were also asked to instruct growers to not use any insecticides
for CEW control, so that we would be able to see how much suppression was truly provided
by the plant itself.
All varieties were able to be planted together which allowed for easier demonstration
setup for agents. The varieties selected allowed for each planting to have one known
CEW susceptible/conventional variety vs. 2 varieties with GM resistance to CEW (Temptress
vs. Remedy and Milky Way). We expected to see almost complete suppression of CEW in
Remedy and Milky Way without the need for insecticide applications.
We asked county agents to report their results in two ways. First, agents posted progress
of the demonstration on social media using the hashtag #uaexHORT . Below are some examples of social media posts made by agents that really helped
to showcase this work and get the community interested. Secondly, agents reported
on growth characteristics of the sweet corn varieties, how much damage they observed
from CEW, and taste characteristics at harvest time.
Social media posts made by two county agents that illustrated progress and results
at their sweet corn demonstrations.
Results Plant Characteristics The table below shows the average of the measured plant characteristics across the
counties that participated. Combining these values, along with comments from county
agents, indicates that these varieties produced similar sized ears. This is important because our known CEW resistant varieties, Remedy and Milky Way,
look to be growing at an acceptable size and yield in Arkansas. Days to harvest was quicker than advertised, most likely due to the warm weather this
growing season. At least 4 plantings were destroyed after planting due to extreme
heat, drought, poor pollination, or raccoons.
Variety
Ear Length (Inches)
Rows of Kernels
CEW Damage
(% Damaged Ears)
Flavor Rank (1-3)
Days to Harvest
Brix
Temptress
6.5
13
85
2.4
62
19.2
Remedy
7.6
14
1
1.7
69
22.4
Milky Way
7.8
15
3
1.8
69
25.4
*Data taken from 11 locations in 10 counties across Arkansas. Flavor ranked from 1-3,
with 1 being best flavor.
Corn Earworm (CEW) Damage We expected to see a lot of damage from CEW across the state and we were not let down,
as we observed at least some level of ear feeding in every county that participated.
In many counties, our conventional variety, Temptress, sustained CEW feeding damage
to 90-100% of ears. When averaged across all counties we saw 85% of ears damaged for Temptress. Varieties that contained the Vip3A Bt gene, Remedy and Milky Way, sustained damage to below 5% of ears. Ears that did sustain damage usually only had a few kernels fed on before worms succumbed
to Bt . We consider this excellent suppression and is much lower damage than growers should
expect to see when relying on insecticides alone.
Corn varieties exhibiting different levels of corn earworm (CEW) feeding. Photos taken
by Alden Hotz at Kibler’s Vegetable Research Station.
Taste Along with how well these varieties grow and can avoid CEW damage, it’s important
to have the customer wanting to come back for more. We asked each county to rank these
varieties from their favorite to least (1-3 scale with 1 being the favorite), which
we then averaged and presented along with the growth characteristics above. Remedy
was ranked the lowest (best), followed closely by Milky Way, and least favorite was
Temptress. The interesting aspect is that each variety listed here received multiple #1 votes
suggesting all were flavorful. Herb Ginn’s demonstration collaborator claims Remedy’s flavor to be “Sweeter than
the others. Best flavor in the trial. Very sweet, tender kernels.” His collaborator
will be planting only Remedy going forward. 3 out of 8 of Allison Howell’s taster
testers in Clay County said Remedy “was sweeter than Milky Way.” 5 of 8 people thought
it had the same crunch as Milky Way. Participant Quote: “I can eat this stuff right
out of the field!” The other 5 people in her taste test thought Milky Way was sweeter
than Remedy. Participant Quote: “We like this variety way better than the other one!”
It goes to show how closely the participants enjoyed both varieties, even with Remedy
being a bi-color and Milky Way a white kernel.
Raccoons seemed to prefer the earlier ripening of Temptress, and some demonstrations
were lost completely. This lead Brett Gordon in Woodruff County to install a three
strand polywire electric fence system. It was powered by a solar powered electric
fence charging system. The wires were placed 6, 12, 18 inches above the ground level.
Brett mentioned “The grower stopped growing sweet corn several years ago due to the
extreme damage caused by racoons. This demonstration provided the grower with a method
to successfully control racoons from damaging his sweet corn plantings. He has expressed
interest in utilizing the electric fence setup on his farm in the future.”
Top left- Undamaged Milky Way ears. Bottom left- Undamaged Remedy ears. Right- Heavily
damaged Temptress ears. Photos: Brett Gordon in Woodruff County
Woodruff County’s demonstration protected by a three strand polywire electric fence.
Photo: Brett Gordon in Woodruff County
Conclusions This demonstration exhibited the value of Attribute II and Attribute Plus sweet corn
varieties (those containing the Vip3A Bt gene) in Arkansas. In 2021, we observed the performance of Pursuit (Attribute II)
compared to old Bt corn standards like Obsession II (does not contain Vip3A Bt ) and conventional varieties that did not contain any Bt genes. In 2022, we built on these recommendations and observed that Remedy and Milky
Way offered excellent CEW suppression while still comparing favorably in growth and
taste compared to our known standards. These results indicate that these new Attribute
II and Attribute Plus varieties grow favorably in our environment and are a tasty
option for Arkansas consumers. This is especially exciting when you consider that Attribute II an Attribute Plus
varieties currently require NO foliar insecticides to manage CEW, whereas our recommendation
on all other varieties is spraying every 2-3 days.
Thanks to all the county agents, station staff, and collaborators who participated
in providing feedback in the 2022 Sweet Corn Demo. Although sweet corn is pretty simple
to grow, I believe we collectively were reminded that we have to plant it at the most
erratic time of the year (for weather), try to get it to pollinate in the hottest
time of the year, and that basically every animal under the sun is trying to get to
the cobs before we before we can pick them.
Name County
Bryce Baldridge Lawrence
Rachel Bearden Hot Springs
Kurt Beaty Jefferson
Luke Duffle Garland
Randy Forst Pulaski
Herb Ginn Crawford
Brett Gordon Woodruff
Cindy Ham Clark
Amy Heck Cleburne
Phil Horton Arkansas
Allison Howell Clay
Brad McGinley Grant
Ryan Neal Benton
Nicole Nichols Saline
Bob Powell Yell
Krista Quinn Faulkner
Kyle Sanders Lonoke
Sherri Sanders White
Jennifer Sansom Little River
Amy Simpson Clark
Stacey Stone Nevada
Jesse Taylor Johnson
Cory Tyler Fulton
Clarksville Fruit Research Station Johnson
Kibler Vegetable Station Crawford
SW Research and Extension Center Hempstead
Lon Mann Cotton Research Station Lee
