This document summarizes three studies from 2006-2009 on the impact of fall-applied herbicides on legume establishment the following spring in Wisconsin. Across the studies, herbicide applications of Milestone and Ally in the fall sometimes reduced legume establishment the next year, depending on application date and rate, planting date, soil temperature, and planting method. The conclusion is that if legumes are critical, it is better to spot treat rather than broadcast apply herbicides in the fall and wait until late summer or the following spring to plant.

1. LegumeLegume
establishmentestablishment
after herbicidesafter herbicides
Variability in WisconsinVariability in Wisconsin
over 3 yearsover 3 years
Mark RenzMark Renz
University of Wisconsin-University of Wisconsin-
MadisonMadison

2. 2006-2007 Study
• Treated in fall
– Arlington 10/25/06
– Lancaster 10/20/06
• Planted in mid-May (7 MAT)
– Alfalfa 11 lbs/A
– Red clover 8 lbs/A

3. Herbicide establishment quantity 1 YAP
Alfalfa Red clover Alfalfa Red clover
Milestone 7 fl oz/A YES YES NO NO
Stinger 1 pt/A NO NO NO NO
Escort/ Ally 1.0 oz/A YES YES YES YES
Weedmaster 4 pt/A NO NO NO NO
Plateau 12 fl oz/A NO YES NO NO
Reductions legumesReductions legumes
compared to untreated controlscompared to untreated controls
Treated in fall, planted in spring

4. Herbicide establishment quantity 1 YAP
Alfalfa Red clover Alfalfa Red clover
Milestone 7 fl oz/A NO NO NO NO
Stinger 1 pt/A YES* NO NO NO
Escort/ Ally 1.0 oz/A NO NO NO NO
Weedmaster 4 pt/A NO NO NO NO
Plateau 12 fl oz/A NO NO NO NO
Reductions legumesReductions legumes
compared to untreated controlscompared to untreated controls
Treated in fall, planted following September
* At one site only

5. 2007-2008 Study2007-2008 Study
• Treated Milestone and Ally (Escort) on
10/23/07
• Frost seeded red clover at 10 lbs/a: 3/20/08
• No-till drilled red clover at 12 lbs/a: 4/18/08

6. Cover of Red Clover
1 year after
spraying
1 year after
planting
Herbicide Frost seed No till Frost seed No till
Milestone 3 fl oz/A 7.3 2.0 16.7 4.8
Milestone 5 fl oz/A 2.5 1.0 1.9 0
Milestone 7 fl oz/A 1.3 0.5 2.8 0
Ally 1 oz/A 8.5 15.0 17.6 28.8
UTC 25.0 31.3 36.1 42.6
Reductions legumesReductions legumes
compared to untreated controlscompared to untreated controls
Treated in fall, planted in spring
Highlighted boxes indicate values are different than UTC

7. 2008-2009 Study2008-2009 Study
• Treated at two timings
– Summer 7/17/08
– Fall 10/9/08
• No-till drilled 4/16/09
– 8 lb/A Duration Red Clover
– 14 lb/A 6415 Garst Alfalfa
– 3 lb/A Crescendo Ladino White Clover

8. Stems m2 COVER
Herbicide 2 MAP 4 MAP 2 MAP 4 MAP
Chaparral 2.5 oz/A Summer 66 88 6 62
Chaparral 3.3 oz/A Summer 55 73 5 51
Forefront 32 fl oz/A Summer 66 70 8 57
Forefront 42 fl oz/A Summer 57 61 8 48
Grazon 32 fl oz/A Summer 69 74 7 54
Chaparral 2.5 oz/A Fall 54 53 7 33
Chaparral 3.3 oz/A Fall 60 59 5 40
Forefront 32 fl oz/A Fall 43 72 5 51
Forefront 42 fl oz/A Fall 36 48 3 27
Grazon 32 fl oz/A Fall 86 91 9 65
UTC 82 71 21 50
Red Clover ResponseRed Clover Response
Treated summer or fall, planted following spring

9. Stems m2 COVER
Herbicide 2 MAP 4 MAP 2 MAP 4 MAP
Chaparral 2.5 oz/A Summer 63 74 7 45
Chaparral 3.3 oz/A Summer 63 91 7 61
Forefront 32 fl oz/A Summer 105 94 13 61
Forefront 42 fl oz/A Summer 95 87 12 57
Grazon 32 fl oz/A Summer 90 79 12 46
Chaparral 2.5 oz/A Fall 65 63 7 33
Chaparral 3.3 oz/A Fall 75 60 8 38
Forefront 32 fl oz/A Fall 85 70 8 40
Forefront 42 fl oz/A Fall 55 47 5 20
Grazon 32 fl oz/A Fall 89 88 10 49
UTC 72 72 8 42
Alfalfa ResponseAlfalfa Response
Treated summer or fall, planted following spring

10. Stems m2 COVER
Herbicide 2 MAP 4 MAP 2 MAP 4 MAP
Chaparral 2.5 oz/A Summer 87 94 8 50
Chaparral 3.3 oz/A Summer 84 94 10 57
Forefront 32 fl oz/A Summer 90 94 11 58
Forefront 42 fl oz/A Summer 67 85 8 49
Grazon 32 fl oz/A Summer 90 99 10 62
Chaparral 2.5 oz/A Fall 48 68 5 31
Chaparral 3.3 oz/A Fall 62 68 8 40
Forefront 32 fl oz/A Fall 76 90 9 53
Forefront 42 fl oz/A Fall 56 60 6 27
Grazon 32 fl oz/A Fall 91 70 11 33
UTC 63 99 5 67
White Clover ResponseWhite Clover Response
Treated summer or fall, planted following spring

11. Summary of experimentsSummary of experiments
Exp.
dates
Applied to Fall appl.
date
Planting date Winter
Soil temp
2006-
07
Tilled field
(Bareground)
10/20
10/25
S=5/18 F=9/12
S=5/16 F= 9/6
2007-
08
Established
Pastures
10/23 3/20 (Frost)
4/18 (no-till
Colder than
08-09
2008-
09
Established
Pastures with
grazing
10/9 4/16 Warmer
than 07-08
Experiments with successful establishment are highlighted

12. ConclusionConclusion
• Fall applications of Milestone or Ally CAN
reduce establishment the following spring
– Dependant on date and rate applied
– Date planted
– Soil Temperature
– Soil moisture?
– Method of planting?
• If legumes are critical
– consider spot treating instead of broadcast
– Waiting to plant until the late summer or following
spring