alfalfa weed control - ucanrbuctril .25 buctril 0.5 pivot .063 pivot .094 % control late early...
TRANSCRIPT
ALFALFA WEED CONTROL
ROB WILSON and STEVE ORLOFF
University of California Cooperative Extension
Seedling Alfalfa Weed Control
• Perfect seedbed conditions for weed establishment
• Alfalfa seedlings are slow to establish and very vulnerable to weed competition
• 1st cutting can be over 50% weeds if weeds aren’t controlled
• Weed competition can reduce alfalfa stands!
Timing Herbicide Grass
Control
Broadleaf
Control
Crop
Safety Preplant
Post to weed
Roundup
Paraquat
Y
Y
Y
Y
E
E
Preplant
Pre to weed
Balan (benefin)
Eptam (EPTC)
Y
Y
Y
Y
E
G
Postplant
Post to weed
and alfalfa
2,4-DB
Buctril (bromoxynil)
Select (clethodim)
Roundup (GT alfalfa only)
Raptor (imazamox)
Pursuit (imazethapyr)
paraquat
Poast (sethoxydim)
N
N
Y
Y
Y
Y/P
Y
Y
Y
Y
N
Y
Y
Y
Y
N
G
F/G
E
E
G
G
F
E
Postplant Newly
established
Velpar (hexazinone)
Paraquat
Y
Y
Y
Y
F
F
Herbicides for Seedling Alfalfa
Red font indicates most popular in Western states.
Broadleaf Weeds
Kochia
Henbit
Mustards
Prickly Lettuce
Lambsquarters
Groundsel
Fiddleneck
Filaree
Dock, Curly
Common Mallow
Chickweed
Buctril 2,4-DB Pursuit Raptor
Pursuit vs. Raptor Pursuit
• 40% cheaper than Raptor
• Less crop injury on spring-planted alfalfa compared to Raptor
• Less crop injury on established alfalfa
• Use with a methylated seed oil for best control
Raptor
• Controls several grass weeds
• Better control of henbit & lambsquarter compared to pursuit
• Use with a methylated seed oil for best control
Can’t Decide: • Tank-mix the low rate of Pursuit with the low rate of Raptor • Tank-mix Buctril with Pursuit or Raptor to control prickly lettuce and fiddleneck • Tank-mix Select with Pursuit to control grasses
Application Timing Effect on London Rocket Early: 2-3 leaves Late: 4-6 leaves (1 month difference)
0 50 100
2,4-DB .5
2,4-DB .75
Buctril .25
Buctril 0.5
Pivot .063
Pivot .094
% Control
Late
Early
Pursuit
Pursuit
Established Alfalfa Weed Control
• Established alfalfa is great competitor with weeds
• If you have a lot of weeds, ask yourself why?
• Control weeds that emerge in fall or late winter before alfalfa greens up in the spring
• Control weeds that emerge after cutting or in areas where the alfalfa stand is thin
Herbicides for Established Alfalfa • Velpar + Gramoxone or Sencor + Gramoxone applied in
February or early March before spring greenup are the best option for winter annual weeds in the Intermountain region
• Flumioxazin (Chateau) is a newer option for winter weed control; It hasn’t proven superior to Velpar for the spectrum of weeds we have in Tulelake.
0
2000
4000
6000
8000
10000
12000
14000
Acr
es
Tre
ate
d
20022012
Herbicide Use in Siskiyou County in 2002 Versus 2012
Velpar vs. Metribuzin (Sencor)
Velpar
• Better control of bluegrass, emerged grasses, knotweed, and groundsel
• Better suppression of larger emerged weeds
• Longer residual
Metribuzin
• 50% cheaper than Velpar
• Less residual and plant-back restrictions compared to Velpar
• Labeled for alfalfa-grass mixtures
Tansy Mustard Control in
Established Alfalfa
0 20 40 60 80 100
Chateau
Chateau + Gramoxone
Velpar
Sencor
Raptor
Gramoxone .375
Gramoxone 0.5
Chateau
Chateau + Gramoxone
Sencor
Sencor + Gramoxone
Velpar
Velpar + Gramoxone
Control (%)
10/16
2/19
Shepherd’s Purse Control
in Established Alfalfa
0 20 40 60 80 100
Chateau
Chateau + Gramoxone
Velpar
Sencor
Raptor
Gramoxone .375
Gramoxone 0.5
Chateau
Chateau + Gramoxone
Sencor
Sencor + Gramoxone
Velpar
Velpar + Gramoxone
Control (%)
2/19
10/16
Downy Brome Control in
Established Alfalfa
0 20 40 60 80 100
Chateau
Chateau + Gramoxone
Velpar
Sencor
Raptor
Gramoxone .375
Gramoxone 0.5
Chateau
Chateau + Gramoxone
Sencor
Sencor + Gramoxone
Velpar
Velpar + Gramoxone
Control (%)
2/19
10/16
Product
rate1
Shepherdspurse2
Yellow foxtail3
Lambsquarter4
pint / acre ---------------------- % control -------------------- Untreated -- 0 0 0
Gramoxone Inteon5 2 42 0 0 Prowl H20 +
Gramoxone Inteon
3 + 2 47 51 63
Prowl H20 +
Gramoxone Inteon
4 + 2 40 93 91
Prowl H20 +
Gramoxone Inteon
6 + 2 53 96 97
Prowl H20 +
Gramoxone Inteon
8 + 2 53 100 100
Velpar L +
Gramoxone Inteon
1.5 + 1 100 67 85
Prowl H20 + Velpar L
+ Gramoxone Inteon
4+1.5+1 100 100 100
Prowl H20 + Velpar L 4 + 2 100 97 100 Prowl H20 + Velpar L 6 + 2 100 98 97 Sencor 4SC +
Gramoxone Inteon
0.75 + 1 100 0 88
Prowl H20 + Sencor
4SC + Gramoxone
Inteon
4+0.75+1 100 92 97
Karmex 80DF +
Gramoxone Inteon
1.9 lb +
1.5 97 42 77
Prowl H20 + Karmex
80DF + Gramoxone
Inteon
4 + 1.9 lb
+1.5 93 98 98
Prowl H20 + Sencor
4SC + Karmex 80DF
+ Gramoxone Inteon
4 + 0.75 +
1.9 lb +1 98 98 98
LSD (0.05) 17 12 13
Prowl H20
• Pre-emergent Herbicide- Apply in late winter or early spring before summer weeds emerge; it can be mixed with Velpar or Sencor trts
• Must be incorporated in the soil with rain or irrigation before weeds emerge! Low water solubility
• Controls most summer annual grasses
• Suppresses pigweed, lambsquarter, knotweed, and Russian thistle
Non-Chemical Weed Control Tools • Seedling Alfalfa
– Fall vs. Spring Seeding Date • What weeds are a problem in the field? Winter weeds try
spring seeding; summer weeds try fall seeding
– Pre-irrigation – good option for organic alfalfa production
– Early cutting can minimize weed seed production
• Established Alfalfa – Cutting schedule- longer period between cuttings
usually results in less weeds – Spring harrowing- works well for controlling seedling
broadleaves – Overseed grass into old stands (orchardgrass, oats, etc.)
Weed Management with Roundup Ready Alfalfa
Steve Orloff
Farm Advisor
UCCE Siskiyou County
The most effective non-selective herbicide available
Controls a broader spectrum of annuals and perennials than any other herbicide
Level of Grower Satisfaction with RR Alfalfa
0
10
20
30
40
50
60
70
Far ExceededExpectations
Very Pleased Satisfied Disappointed ExtremelyDisappointed
Nu
mb
er
of
Re
spo
nd
en
ts
Would you plant RR again? 72% Yes 21% Maybe 7% No
What Have You Liked Most About RR Alfalfa?
0 10 20 30 40 50 60 70
Haven't really liked it at all
Cost effectiveness
Higher yields/quality or stand persistence
Flexibility in application timing
Simplicity in weed management
Better weed control
Frequency of Response (%)
Major Negatives Associated with RR Technology
0 10 20 30 40 50 60 70 80 90
Difficulties in marketing RR alfalfa
Varieties don't seem to yield well
I don't like the technology-useagreement
None, there were no negatives
Roundup-resistant weeds
Weed control was not effective
Cost of RR alfalfa seed
Frequency of Response (%)
Pursuit + Buctril Roundup
Crop Injury
Crop Injury
0 5 10 15 20 25
RU 1 unifol
RU 1 3-4
RU 1 6-9
RU 2 3-4
RU 2 6-9
Pursuit+Buct 3-4
Raptor 3-4
Pursuit+Buct 6-9
Roundup Glyphosate
Raptor Imazamox
Established Alfalfa Trials
• Quackgrass • Dandelion • Bermudagrass • Nutsedge • Field Bindweed • Perennial Pepperweed • Curly Dock • Canada Thistle
Roundup Ready Alfalfa allows for control of Perennial Weeds!!
Glyphosate 1 lb a.i. acre
Fall and Spring
Klamath Basin 2005
Evaluation Poor Weed Control
Untreated Roundup .75 ae
Applied 0ct 2002 Iowa Quackgrass trial
9 months AA
Untreated
.94 AE
WeatherMax 1.5AE WeatherMax
Dandelion trial, Iowa One application Fall applied to 3-4 leaf Alfalfa 7 months AA
Flexibility of RR System
RR Alfalfa – Important Questions/Cons
Roundup does not control all weeds (cheeseweed, filaree, nettle)
Resistant weeds: Ryegrass and Marestail
Roundup Ready Alfalfa Variety
Yields?
• Conventional and GT alfalfa cultivars were seeded on June 7, 2005 at
the Intermountain Research and Extension Center (IREC) in Tulelake,
California.
• Twelve conventional varieties plus a standard check variety (Vernal)
• Treated with conventional herbicides
• Twelve GT varieties (6 are now commercial varieties and 6
experimental varieties)
• One block treated with conventional herbicides
• One block treated with glyphosate
• Yield data collected from all harvests from 2005 through 2009
• Two cuttings in seeding year
• Four cuttings in each subsequent year
Effect of Herbicide Treatment on Yield of GT Alfalfa Tulelake, CA (Ave. 2005-2009)
15
15.5
16
16.5
17
17.5
18
Yie
ld (
Mg
ha-1
)
Glyphosate
Conventional
LSD (0.05) = 0.74
Variety Genetic Background
Herbicide Applied 2005 2006 2007 2008 2009
5-Year Average % of Vernal
R54BD14 GT Glyphosate 10.00 23.75 19.02 17.48 19.08 17.87 111.9 Legendairy Conv. Conventional 9.86 24.08 19.78 16.99 18.50 17.85 111.7 Expedition Conv. Conventional 9.55 23.06 19.06 17.67 18.63 17.60 110.2 R54BD17 GT Glyphosate 9.87 23.75 19.18 16.22 18.80 17.56 110.0 Rebound Conv. Conventional 10.07 22.94 19.28 16.67 17.71 17.33 108.5 RR405 GT Glyphosate 9.45 23.03 18.46 16.60 19.00 17.31 108.4 R44BD13 GT Glyphosate 9.65 22.89 19.29 16.39 18.02 17.25 108.0 R54BD17 GT Conventional 8.81 22.95 18.55 17.29 18.48 17.22 107.8 DKA43-22RR GT Glyphosate 10.12 22.88 18.72 15.65 18.63 17.20 107.7 RR405 GT Conventional 8.79 22.43 18.44 17.30 18.30 17.05 106.8 WL 357HQ Conv. Conventional 9.24 22.31 19.53 16.83 17.33 17.05 106.8 Boulder Conv. Conventional 10.42 22.47 18.08 15.95 17.93 16.97 106.2 Hybriforce 400 Conv. Conventional 11.79 21.89 17.46 15.11 18.63 16.97 106.3 Ameristand 405T RR GT Conventional 9.42 22.06 17.64 18.05 17.66 16.97 106.3 R54BD14 GT Conventional 9.35 21.99 18.90 17.26 17.21 16.95 106.1 Innovator +Z Conv. Conventional 10.01 22.40 18.22 15.28 18.80 16.94 106.1 R43M625 GT Glyphosate 9.79 22.66 19.01 15.60 17.60 16.93 106.0 Masterpiece Conv. Conventional 10.79 22.37 17.68 15.80 17.79 16.88 105.7 Ameristand 405T RR GT Glyphosate 9.70 21.04 18.14 16.75 18.79 16.88 105.7 R44BD06 GT Conventional 8.71 22.20 18.83 16.46 18.18 16.88 105.7 WL355RR GT Glyphosate 10.42 21.87 18.42 15.86 17.82 16.87 105.7 Mountaineer Conv. Conventional 9.83 22.92 17.84 16.42 17.14 16.83 105.4 R44BD06 GT Glyphosate 9.55 22.27 18.45 15.74 18.03 16.81 105.3 R44BD09 GT Glyphosate 9.79 22.36 18.07 15.84 17.85 16.79 105.1 54R01 GT Conventional 9.36 22.48 18.21 16.97 16.90 16.78 105.1 Dura 512 Conv. Conventional 10.54 22.73 17.81 15.44 17.34 16.77 105.0 RRALPH 6R100 GT Glyphosate 10.43 21.29 17.86 16.34 17.96 16.77 105.0 R43M625 GT Conventional 9.60 22.12 18.26 16.90 16.92 16.77 104.9 DKA43-22RR GT Conventional 8.80 22.31 18.22 16.69 17.42 16.69 104.5 WL355RR GT Conventional 9.18 22.05 18.62 16.00 17.57 16.69 104.5 54R01 GT Glyphosate 10.12 22.08 17.93 15.88 17.44 16.68 104.5 RRALPH 6R100 GT Conventional 9.74 20.46 18.68 17.12 17.35 16.67 104.4 R44BD13 GT Conventional 9.03 20.61 18.49 17.33 17.70 16.63 104.2 54V54 Conv. Conventional 9.98 21.57 17.69 15.40 17.66 16.46 103.1 R44BD09 GT Conventional 8.60 20.62 18.35 16.84 16.66 16.22 101.5 Ameristand 403T Conv. Conventional 10.15 20.31 17.88 14.72 17.67 16.14 101.1 Vernal Conv. Conventional 10.18 20.61 16.54 14.59 17.94 15.97 100.0
0.00 0.00 0.00 0.00 0.00 0.00 Mean 9.75 22.21 18.39 16.36 17.90 16.92 LSD (P<0.05) 0.78 2.02 1.07 1.36 1.15 0.73 CV 5.70 6.49 4.15 5.92 4.58 3.07
Forage Quality of 10 RR and 22 Conventional Alfalfa Varieties
Tulelake, 2011 (1st Cut)
0
10
20
30
40
50
60
CP ADF NDF TDN
Co
nce
ntr
atio
n (
%)
Forage Quality Parameter
Conventional
RR
Is RR alfalfa worth the extra seed cost?
• Technology fee is added to the cost of seed
• I’d say yes in field situations with perennial weed problems or field situations you’ve had trouble getting effective weed control with conventional herbicides