2015 Sugarcane Aphid Efficacy Trial –
7 DAT Counts
The
sugarcane aphid continues to amaze in a startling way across the region. Today I recommended treatment on the last of
our scouting program fields that had been thus far untreated. That makes 100% of our participating grower’s
sorghum fields across Hale, Swisher, & Floyd that has reached the action
threshold for at least their first treatment.
The pattern of these fields seemed to go from 1-2 sugarcane aphids per
leaf across the field to 48.9 – 128.9 aphids per leaf across the field in 10 to
14 days. With so much unknown about this
new aphid to the area and products untried in the region, all new information
should be shared with consultants, industry, and producers as soon as
possible. Yesterday we made our 7 days
after treatment in our trial field just east of Hale Center.
For
this trial, we have teamed up our program with our district entomologist from
district 1 and 2, Dr. Pat Porter and Dr. Ed Bynum, Syngenta, and Bayer Crop
Science. Shared with you today are
varying rates of products currently recommended or labeled for sugarcane aphid
control. Unfortunately, we had a SNAFU and
misunderstanding in dealing with unfamiliar partnering equipment, GPA output,
and chemical calculations that through this trial off with a 16.7% lower rate
than what was intended for each treatment.
Actual applied amounts are shared here.
Data
consists of 5 randomly selected plants from each small plot where we counted
all aphids on one lowermost green leaf and one upper leaf (second leaf below
flag leaf) from each randomly selected plant for a total of 10 leaves per
plot. This trial is an RBD and has 4
replications. Due to noted differences
in control between the upper leaves and lower leaves, we have calculated
differences in aphid numbers in terms of upper and lower leaves in addition to
total aphids averaged per leaf.
The
ineffectiveness of controlling the aphids on the lower leaves in this trial should
be chalked up to coverage. The row
spacing in these plots is 32 inches. These
plots were treated with 16.5 GPA and all treatments were applied with 0.25% NIS
as a surfactant and still we did not seem to penetrate the canopy enough to
achieve control on the lower leaves.
This matches what we are seeing in treated fields also. I have been in contact with several
independent crop consultants indicating similar findings in their area fields.
Russ
Perkins, Bayer Crop Science, is recommending changing adjuvants to an COC,
something with silicone or something heavier to help penetrate down into the
canopy to get at those lower, aphid covered leaves. Monti Vandivier, Syngenta, seems to agree, “It’s
all about coverage right with this aphid right now. We need to penetrate that canopy and cover
the entire infested area. In my trials, I
have been using Dynamic and getting
decent penetration… at least on 40 inch rows… Controlling this sugarcane aphid
reminds me a lot about fighting heavy spider mites in corn. We need a good MSO or something heavy to pull
those treatments down.”
Today
Russ told me, “Adjuvant choice with Sivanto should not impact the product
quality… We just need it as deep in the canopy as we can get it.”
Special thanks to Dr. Pat Porter
for making these graphs while I was in the field today!!!
Blayne
Reed
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