Transcript Improve Visual Comparison

Evaluation of some adjuvants on
improving glyphosate efficacy
Samunder Singh and Megh Singh
University of Florida-IFAS
Citrus Research and Education Center
Lake Alfred, Florida
Glyphosate efficacy against
strangler vine (Morrenia odorata)
Control
Glyphosate
1120 g ae/ha
Glyphosate efficacy against
velvetleaf (Abutilon theophrasti)
Control
Glyphosate 0.28 & 0.56
kg ae/ha
Glyphosate efficacy against Brazil
pusley (Richardia brasiliensis)
Control
Glyphosate 0.28, 0.42 & 0.56 kg
ae/ha, 5 WAT
Glyphosate efficacy against
dayflower (Commelina diffusa)
Glyphosate 1.68 kg
ae/ha, repeat field
application
Control
Glyphosate
0.56 & 1.12 kg
ae/ha
Glyphosate efficacy against maypop
passionflower (Passiflora incarnata)
Glyphosate
1.68 kg
ae/ha,
repeat
Role of adjuvants
Multiple!!!
The major role is to lower surface
tension and contact angle
facilitating increased uptake and
translocation of herbicide to
enhance its bioefficacy
Objective
To evaluate the bioefficacy of
glyphosate (with no added adjuvant) by
tank mixing adjuvants against two
grass and broadleaf weed species.
To measure the influence of various
adjuvants in lowering surface tension
and contact angle of glyphosate.
Weed Species
Barnyardgrass, Echinochloa crus-galli
(L) Beauv
Guineagrass, Panicum maximum L.
Spanishneedles, Bidens pilosa L.
Velvetleaf, Abutilon theophrasti Medic.
Adjuvants and herbicide
Blaze®
NIS
Garrco Products
Condition®
Blend of AMS
Garrco Products
Improve®
NIS
Garrco Products
Induce®
NIS
Helena Chem. Co.
Glyphosate Rodeo®,
Dow Agrosci.
Bioefficacy study
Herbicide rates
Adjuvants
Replications
Plants per pot
Stage of weeds
Nozzle type
Pressure
Water volume
Mortality rating
0, 0.14, 0.28, 0.56 kg
0, 0.5%
4
3-5
4-5 leaf at spraying
Teejet 8002
138 kPa
189 L/ha
0-100 scale
Percent mortality
Mortality of barnyardgrass as
influenced by adjuvants
120
0.14 Kg
0.28 Kg
0.56 Kg
100
80
48
84
52
88
65
60
40
20
0
Rodeo
R+Condition
R+Induce
R+Blaze
R+Improve
Effect of adjuvants on glyphosate
efficacy against barnyardgrass
Glyphosate 0.28 kg ae/ha, 4 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Effect of adjuvants on glyphosate
efficacy against barnyardgrass
Glyphosate 0.56 kg ae/ha, 4 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Percent mortality
Mortality of guineagrass as
influenced by adjuvants
120
0.14 Kg
0.28 Kg
0.56 Kg
100
80
62
87
70
93
80
60
40
20
0
Rodeo
R+Condition
R+Induce
R+Blaze
R+Improve
Effect of adjuvants on glyphosate
efficacy against guineagrass
Control
Glyphosate 0.14 kg ae/ha, 4 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Effect of adjuvants on glyphosate
efficacy against guineagrass
Control
Glyphosate 0.28 kg ae/ha, 4 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Effect of adjuvants on glyphosate
efficacy against guineagrass
Control
Glyphosate 0.56 kg ae/ha, 4 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Mortality of spanishneedles as
influenced by adjuvants
Percent mortality
120
0.14 Kg
0.28 Kg
0.56 Kg
100
80
70
83
86
76
68
60
40
20
0 Rodeo
R+Condition
R+Induce
R+Blaze
R+Improve
Effect of adjuvants on glyphosate
efficacy against spanishneedles
Control
Glyphosate 0.14 kg ae/ha, 4 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Effect of adjuvants on glyphosate
efficacy against spanishneedles
Control
Glyphosate 0.28 kg ae/ha, 4 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Mortality of velvetleaf as
influenced by adjuvants
Percent mortality
100
0.14 Kg
0.28 Kg
0.56 Kg
80
32
44
51
42
33
60
40
20
0
Rodeo
R+Condition
R+Induce
R+Blaze
R+Improve
Effect of adjuvants on glyphosate
efficacy against velvetleaf
Control
Glyphosate 0.56 kg ae/ha, 4 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Effect of adjuvants on glyphosate
efficacy against spanishneedles
Control
Glyphosate 0.56 kg ae/ha, 5 WAT
+Blaze
Alone
+Improve
+Condition
+Induce
Summary
The tank mixing of adjuvants increased
glyphosate efficacy by 15-29%.
Condition increased glyphosate efficacy
against spanishneedles and velvetleaf, but less
effective on barnyardgrass and guineagrass
Tank mixing of Inspire with glyphosate was
more effective on grasses than BLW.
Blaze and Inspire were better than Induce as
broad-spectrum surfactants.
Surface tension and Contact
angle study
Blaze®
Condition®
Improve®
NIS
Blend of AMS
NIS
0.5%
0.5%
0.5%
Induce®
NIS
0.5%
Glyphosate
Rodeo®
0.14, 0.28, 0.56 kg
ae/ha alone and with 0.5% adjuvants
Glyphosate
Roundup UltraMax 0.14, 0.28, 0.56 kg
Without surfactant
With surfactant
Effect of adjuvants on surface
tension and contact angle
Treatments
(kg ae/ha)
Surface tension*
(dynes/cm)
Contact angle*
(degrees)
Water
74.30a
92.33a
Rodeo®
69.70a
90.00a
Blaze® 0.5%
Rodeo+Blaze
31.90e
30.66f
46.67d
Condition® 0.5%
Rodeo+Condition
35.38c
31.89e
44.38d
59.70b
56.68b
*Values averaged over rates for herbicide + adjuvant
Effect of adjuvants on surface
tension and contact angle
Treatments
(kg ae/ha)
Surface tension*
(dynes/cm)
Contact angle*
(degrees)
Improve® 0.5%
29.67f
40.08e
Rodeo+Improve
27.86g
37.61e
Induce® 0.5%
33.83d
55.67c
Rodeo+Induce
33.65d
54.80c
Roundup UltraMax®
37.81b
57.81bc
*Values averaged over rates for herbicide + adjuvant
Summary
The ST of glyphosate was reduced by 4860% by adjuvants.
Lower ST was recorded with the addition of
adjuvants to glyphosate than pre-mix
formulation of glyphosate (R’ Max).
CA of glyphosate was lowered by 51-58% by
Blaze and Inspire than with no adjuvant.
Condition and Inspire had similar CA of
glyphosate with no adjuvant to that of pre-mix.
It makes sense to add adjuvants to glyphosate
(Tall Morningglory)
Not very tall with added
adjuvants to glyphosate