10/3/17
New Tools for Orchard Weed
Control
&
Some We May Have
Overlooked
Areas to Cover
• New labeled herbicides
• New herbicide under trial that will be
labeled this year
• Herbicides we may have forgotten for new
trees
• Improving glyphosate efficacy
• New resistant weeds in PA
1
10/3/17
Broadworks™ from Syngenta
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Also known as Calisto
Mesotrione (WSSA Group 27)
Post & Pre-emergent for broadleaf weeds
Active on glyphosate resistant marestail &
fleabane
• Systemic activity
Broadworks™ cont.
• Currently for peaches, nectarines & plums
• Primarily geared toward pigweeds
• Others (pre-)
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chickweed, fleabane, galinsoga, geranium,
groundsel, henbit, lambsquarters, nightshades,
pineappleweed, common ragweed, shepherds
purse, smartweeds, velvetleaf, waterhemp
• Others (post-)
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all the above but in most cases weeds ≤ 3-5”
2
10/3/17
Broadworks™ cont.
• Can suppress Canada thistle, horsenettle,
yellow nutsedge, at higher rates
• No effect on grasses but may see
bleaching of crabgrass & foxtails
Rates & Restrictions
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Trees established minimum 12 months
Do not exceed total of 12 fl oz./A/12 month period
Do not exceed 3 applications/ 12 month period
Do not exceed 6 fl. oz. for first application
30 day PHI
3
10/3/17
Broadworks™ cont.
Application Rate (fl. oz/A)
Scenarios 1st Application
2nd
Application
3rd
Application
Application interval (wk)
1
6
6
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20
2
6
3
-
6
3
6
3
3
6
Zeus Prime XC
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Blueberries, bushberries, caneberries, grapes
Apples under supplementary label
WSSA Group 14
Combination of POST- + PRE
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carfentrazone-ethyl + sulfentrazone
Works on broadleaves & grasses
Suppression of sedges at high rates
REI = 12 hours
PHI = 14 days
4
10/3/17
Zeus Prime XC
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7.7 to 15.2 fl. oz/A
Do not exceed 15.2 fl. oz./A in 12 months
Do not mix with Chateau (same mode of action)
Allow a minimum of 60 days between applications
Trees must be established at least 3 years
Do not allow contact with green bark or tissue
Best results when soil is moist and cool
Need ½” rain within 2 weeks after application
o
as do most preemergents
• Residual organic trash under trees can reduce control
• Applications after PF should use hooded sprayer
Zeus XC Prime
Treatment 1
Treatment 2
Treatment 3
Treatment 4
Treatment 5
Spring Zeus Prime XC 10oz/A + Sinbar 16 oz/A +
Roundup Powermax 22 oz/A + AMS 2%
Spring Zeus Prime XC 10oz/A + Alion 5 oz/A +
Roundup Powermax 22 oz/A + AMS 2%
Spring Zeus Prime XC 6 oz/A + Karmex 3.8 lb/A +
Roundup Powermax 22 oz/A + AMS 2%
Fall application (10/30), Zeus Prime XC 6 oz/A +
Matrix 1 oz/A + NIS 0.25%
Spring Zeus Prime XC 6 oz/A + Alion 5 oz/A +
Roundup Powermax 22 oz/A + AMS 2%
Fall application Zeus Prime XC 6 oz/A + Sandea 1
oz/A + NIS 0.25%
Spring application Roundup Powermax 22 oz/A + AMS
2%
*An additional glyphosate treatment was applied 8/16 on all plots due to high population of perennial weeds
5
10/3/17
Take Home:
• Zeus Prime XC provides PRE + Post in one
product
• Spring followed by fall herbicide treatments
reduced weed cover until early summer
• Treatments with Alion had longer and a
better reduction in weed cover
Pindar GT
• Oxyfluerfen + penoxsulam
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penoxsulam – grasses
oxyfluerfen - broadleaves
WSSA Group 14 & 2
Dow AgroSciences
Has contact, systemic and preemergent
Currently labeled for all stone fruits
National label for pome fruits
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waiting on state label
should be available this fall (or sooner?)
6
10/3/17
Pindar GT
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REI = 24 hours
PHI = 60 days
Apply postharvest but before budswell
Apply 1.5 – 3 pt/A
Add surfactant – COC, NIS, MSO
25 ft. spray buffer from water
2016-17 Pindar trial*
Treatment
1
4
5
Control
Pindar 2 pt/A + Surflan 1qt/A + Durango 3 pt/A +
MSO 0.25%
Pindar 3 pt/A + Surflan 1qt/A + Durango 3 pt/A +
MSO 0.25%
Pindar 2 pt/A + Alion 3 fl oz/A + Durango 3 pt/A +
MSO 0.25%
Alion 5 fl oz/A + Durango 3 pt/A + MSO 0.25%
6
7
Trellis SC 32 fl oz/A + Durango 3 pt/A + MSO 0.25%
Goaltender 3 pt/A + Durango 3 pt/A + MSO 0.25%
2
3
*Honeycrisp/M9 applied 11/14/16
7
10/3/17
Weed control in
newly planted trees ?
Isoxaben (Forgotten material)
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Trellis®SC, Gallery®75DF or Isoxaben 75WG
Non-bearing tree fruit
Controls broadleaf weed germination
Will not control established weeds
Studies in California nurseries showed good
control of broadleaf weeds
8
10/3/17
Isoxaben
• 12 hour REI
• Trellis 16 – 32 fl. oz/A
• Gallery & Isoxaben 0.66 – 1.33 lb. /A
Tyvek® trunk protectors
Uline (uline.com)
30” wide rolls
150’ long rolls
7.5 ml thick
$107 / roll (multiple roll discounts)
10” X 10” squares,
540 pieces/roll
~ $0.20/ guard
9
10/3/17
Improving glyphosate performance
• Glyphosate is a negatively charged acid
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presence of Ca+2, Mg+2. Na+ in spray water
soil particles positively charge
plants
• stress
• dust on leaves
• Ammonium sulfate increases solubility
• High spray volumes, >30 gpa, may dilute
concentration resulting in less efficacy
Improving glyphosate performance
• Use clean spray water
• Use low rate of spray water as is practical
• Larger droplet size helps increase toxicity
vs. many small drops
• Add ammonium sulfate
• Add nonionic surfactant with lower rates or
high spray volumes
• Spray non-stressed plants, when possible
10
10/3/17
Plant stress affects glyphosate efficacy
Source of
Stress
Percent control of Velvetleaf
No
Surfactant
+AMS
adjuvant
None
84
93
Cold
68
80
Drought
46
67
Zhou et al., 2007. Weed Sci.55:240-244.
11
10/3/17
Herbicides with most resistance potential
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diuron (Karmex)
oryzalin (Surflan)
oxyfluorfen (Goal)
simazine
terbacil (Sinbar)
12
10/3/17
Herbicide resistant pigweed species
• Palmer Amaranth & Waterhemp
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strong competitive weeds
season long emergence
male & female plants
prolific seed production (100,00 seeds/plant)
resistance to glyphosate, ALS inhibitors (2),
• Resistant populations found in 14 counties
in PA
Confirmed Sightings of Either One
13
10/3/17
Dwight Lingenfelter with P. Amaranth plant
Seedling leaves of PA are broad ovate or egg shaped vs.
more narrow lanceolate shaped leaves of waterhemp.
All young leaves of pigweed have a notched tip
14
10/3/17
Palmer amaranth has no hairs on stems
Occasional dark red/purple or white “V” mark on leaf
blade of P. amaranth
15
10/3/17
Waterhemp petiole not longer than leaf blade
Palmer, Powell, Redroot, Smooth, Waterhemp
left to right
16
10/3/17
Questions
Results
• Trts. 1,3 & 4 had better fewer weeds on 6/5
compared to control
• Grass control was best for all Zeus trts. in June &
July of first year compared to control
• Treatments containing Alion showed greater
control of annual grasses than either the Sinbar
or Karmex treatments
• Trt. 4 with fall Alion had better weed cover the
following July than any other treatment.
17
10/3/17
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