aminopyralid injury to potatoes
DESCRIPTION
Aminopyralid Injury to Potatoes. Kevin B. Kelley and Lloyd C. Haderlie AgraServ, Inc., American Falls, ID. Aminopyralid. Auxinic herbicide labeled for use on rangeland, permanent grass pastures, CRP land, non-cropland areas, and natural areas. - PowerPoint PPT PresentationTRANSCRIPT
Kevin B. Kelley and Lloyd C. Haderlie
AgraServ, Inc., American Falls, ID
AminopyralidAuxinic herbicide labeled for use on
rangeland, permanent grass pastures, CRP land, non-cropland areas, and natural areas.
Very active on several annual and perennial broadleaf weeds, including Canada thistle.
Known to pass through animals that consume treated forage and be present in manure and urine similar to picloram.
Shorter soil half-life than picloram.
Aminopyralid Injury to PotatoesResearch Prompted by Farmer ComplaintsAerial applications of aminopyralid to
range/pasture in 2008Potatoes bordering pasture in 2008 and 2009
showed injury symptoms and yield lossWeeds sensitive to aminopyralid in potato
fields didn’t show injuryLaboratory analysis of potato foliage and
tubers resulted in positive detection of aminopyralid
Aminopyralid Affect on PotatoesPersistence in the soil?Potato sensitivity?
Growth stage differences?Daughter tuber response?
Methods - TimingFall Soil Carryover
Applied Nov. 7, 2009Spring Preplant
Applied May 18, 2010 – One day before plantingIn Season
Early – Applied 2 weeks after emergenceMid-Season – Applied late July near row closure
Daughter Tuber Plant ResponseApplied Aug. 31, 2009Treated tubers planted May 2010Known to be a very sensitive assay for picloram
Methods - RatesAminopyralid – Use rate range - 53 to 123 g
ai/haapplied from 44 g ai/ha (~50%) down to 0.044
g ai/ha (0.05%)Picloram – Average use rate - 280 g ai/ha
applied at 4.4 and 44 g ai/haClopyralid – Max use rate of 280 g ai/ha
applied at 26 or 280 g ai/haDicamba – Average use rate of 560 g ai/ha
applied at 56 or 560 g ai/ha
Fall Soil CarryoverPotato Injury July 16th
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LSD – 4 (P=0.1)
Perc
en
t In
jury
Aminopyralid – g ai/ha
Fall Soil CarryoverTotal Potato Yield
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LSD – 41 (P=0.1)Aminopyralid – g ai/ha
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Acr
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Fall Soil CarryoverUS #1 Potato Yield
LSD – 37 (P=0.1)Aminopyralid – g ai/ha
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T p
er
Acr
e
aa a a
b
Spring Preplant AppliedPotato Injury Aug 10th
LSD – 17 (P=0.1)Rates in g ai/ha
Aminopyralid
Perc
en
t In
jury
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Spring Preplant AppliedTotal Potato Yield
LSD – 78 (P=0.1)Rates in g ai/ha
Aminopyralid
CW
T p
er
Acr
e
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In-Season Applied Potato Injury Aug 10th (6 or 2 WAA)
LSD – 6 (P=0.1)Rates in g ai/ha
Aminopyralid Aminopyralid
Two Weeks After Emergence Near Row Closure
Perc
en
t In
jury
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In-Season AppliedUS #1 Potato Yield
CW
T p
er
Acr
e
LSD – 71 (P=0.1)Rates in g ai/ha
Aminopyralid Aminopyralid
Two Weeks After Emergence Near Row Closure
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Daughter Tuber Plant Response - Potato Injury Aug 10, 2010 (Sprayed 2009)
LSD – 9 (P=0.1)Aminopyralid – g ai/ha
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Perc
en
t In
jury
Daughter Tuber Plant Response – Total Potato Yield (Sprayed 2009)
LSD – 67 (P=0.1)Aminopyralid – g ai/ha
CW
T p
er
Acr
e
aa a
b
c
SummaryAminopyralid injured potatoes and reduced yield
and quality following all scenarios tested including fall applied to soil.
Injury levels were similar to or exceeded that caused by picloram
Greater rates of dicamba or clopyralid were required to cause potato injury.
Potatoes appear to be especially sensitive to aminopyralid.
All potatoes were saved for seed grow out in 2011.
Questions?