1. No category

Glyphosate Effects on Crops,
Soils, Animals, and Consumers
Europe
October 2011
Don M. Huber
Emeritus Professor of Plant Pathology
Purdue University, West Lafayette, IN
Objective of Agriculture
To provide an abundant supply of:
• Safe
• Affordable
• Nutritious Food
And
Other commodities grown to meet societies needs
Agriculture is THE basic infrastructure of Society
Glyphosate Effects on Crops,
Soils, Animals, and Consumers
• Background
• Understanding glyphosate
What it is and how it works
• Understanding glyphosate-resistance
“All flesh is grass”
Isaiah 40:6, 800 BC
- What it is and what it doesn’t do
• Recognizing the interactions
- Symptoms - nutrition, disease
• Remediation
• The bigger picture - Food/Feed nutrition and safety
The Importance of Reducing Stresses
Genetic
Potential
Potential
-
-
Nutrition
Physiology
Management
Environment
Diseases
Pests
Stresses =
There is no free lunch!
=
Harvest
Yield
Quality traits
Water
Genotypes of
Genotypes
plants
of plants
Temperature
Heat
Cold
Light (cycles,
(cycles , intensity)
intensity)
Light
Soil physics
Insects
Virus
Bacteria
Pesticides
Fungi
Organic matter
CO2
O2
H
Ca
Mg
N
P
K
Mn
Fe
Cu
Na
Mo
Al
Zn
B
Si
Cl
Ni
Nematodes
Pollutants
There are a large number of interconnected
plant properties and responses to physical and biological environmental factors.
Nutrients are:
Components of plant parts as well as
Activators,
Inhibitors,
and Regulators
of Physiological Processes
Many herbicides and pesticides are chelators
Interacting Factors Determining
Nutrient Availability and Disease Severity
Vigor, Stage of Growth, Root Exudates
Resistance
PLANT Susceptibility
TIME
PATHOGEN
Population
Virulence
Activity
BIOTIC ENVIRONMENT
Antagonists, Synergists
Oxidizers, Reducers
Competitors, Mineralizers
[Cu, Fe, K, Mn, N, S, Zn]
ABIOTIC
ENVIRONMENT
Nutrients
Moisture
Temperature
pH (redox potential)
Density, gases
Ag Chemicals
Factors Affecting N Form, Mn Availability
and Severity of Some Diseases*
Soil Factor or
Cultural Practice
Nitrification
Low Soil pH
Decrease
Green Manures(some) Decrease
Ammonium Fertilizers Decrease
Irrigation (some)
Decrease
Firm Seed bed
Decrease
Nitrification Inhibitors Decrease
Soil Fumigation
Decrease
Metal Sulfides
Decrease
Effect on:
Mn Availability Disease Severity
Increase
Increase
Increase
Increase
Increase
Increase
Increase
Increase
Decrease
Decrease
Decrease
Decrease
Decrease
Decrease
Decrease
Decrease
Glyphosate
---Decrease
Increase
High Soil pH
Increase
Decrease
Increase
Lime
Increase
Decrease
Increase
Nitrate Fertilizers
---Decrease
Increase
Manure
Increase
Decrease
Increase
Low Soil Moisture
Increase
Decrease
Increase
Loose Seed bed
Increase
Decrease
Increase
*Potato scab, Rice blast, Take-all, Phymatotrichum root rot, Corn stalk rot
Understanding the Characteristics of Glyphosate
Glyphosate has Changed Agriculture for 30+Years
• A strong chemical chelator
Chelating stability constants
of glyphosate
Chelates minerals in the spray tank
Chelates minerals in the plant
Metal ion
Mg2+
Ca2+
Chelates minerals in the soil
Mn2+
Reduces: B, Ca, Co, Cu, Fe, K, Mg, Mn, Ni, Zn Fe2+
Cu2+
Fe3+
Non-specific herbicidal effect
• Non-specific herbicidal effect
[ML]
[M][L]
3.31
3.25
5.47
6.87
11.93
16.09
[MHL]
[M][H][L]
[ML2]
[M][L2]
12.12
11.48
12.30
12.79
15.85
17.63
5.47
5.87
7.80
11.18
16.02
23.00
Glyphosate Immobilizes
Manganese in Soybean
Glyphosate
Glyphosate + Zn
tank mix
Effect of Residual or ’drift’ Glyphosate on Percent
Nutrient Uptake and Translocation by Plants
After Eker et al 2006*
Control
% uptake
+ glyphosate
100
80
60
40
20
0
Fe Mn Zn
Root uptake
Fe
Mn Zn
Translocation to shoot
* 1/40th of recommended herbicidal rate = 0.4 oz/a = 12 g/a
Foliar application of glyphosate
Systemic movement
throughout the plant
Chelation of micronutrients
Intensifies stress
Accumulation of glyphosate in soil
(fast sorption; slow degradation)
Desorbed by phosphorus
Residual soil and residue effects
Glyphosate toxicity to:
N-fixing microbes
Bacterial shikimate pathway
Mycorrhizae
Biological control organisms
Earthworms
PGPR organisms
Accumulation of glyphosate in
meristematic tissues (shoot,
reproductive, and roots)
Translocation of glyphosate from
shoot to root and release
into the rhizosphere
Toxicity to root tips by glyphosate or its
toxic metabolites (e.g. AMPA)
Compromise of plant
defense mechanisms
Promotion of soil-borne organisms:
Soilborne pathogens - DISEASE
Nutrient oxidizers (Fe, Mn, N)
Microbial nutrient sinks (K, Mg)
Reduced availability or uptake of essential
nutrients (Cu, Fe, K, Mg, Mn, N, Zn)
Schematic of glyphosate interactions in soil
What’s Special About Glyphosate Tolerance?
(Roundup Ready® Genes)
[Greatly expanded usage of glyphosate]
• The technology inserts an alternative EPSPS enzyme
that is not blocked by glyphosate in mature tissue
• There is nothing in the RR plant that operates on
the glyphosate applied to the plant!
- Glyphosate chelation is not selective it immobilizes nutrients
Ca, Co, Cu, Fe, K, Mg, Mn, Ni, Zn
- Reduces nutrient uptake
• Can cause a“Yield Drag”
% uptake
100
• It is there for the life of
the plant
75
Normal
RR
50 Indiana
Kansas Michigan Brazil
Indiana
Brazil
25
0
Soybeans for manganese
Corn/Mn Soybeans/Zn
Effect of Glyphosate on Lignin, AA, Water Use Efficiency,
and Photosynthesis of ‘Glyphosate-Resistant’ Soybeans
Lignin
(g/plant)
0.6
0.5
0.4
0.3
0.2
0.1
0.0
After Zobiole, 2009
Full rate at one time
Sequential half rate
0 450 675 900 1350 1800
36 DAT
12
10
8
6
4
2
0
0
Glyphosate (g a.e./ha)
Amino Acids (g/plant)
2500
2000
1500
1000
500
0.0
Full rate at one time
Sequential half rate
0 450 675 900 1350 1800
Glyphosate (g a.e./ha)
13 DAT
umol CO2 m-2 s-1
600
550
500
450
400
350
300
250
600
1200
1800
2400
Glyphosate (g a.e./ha)
WUE (ml water/g dry mass)
0
450
675
900
1350
1800
Glyphosate (g a.e./ha)
Microbiocidal Activity
of Glyphosate
Fusarium % change
500
% of control
100
400
80
300
60
200
40
100
20
0
Fusarium
root colonization
Glyphosate rate
Control
600 g ae/ha
1200 g ae/ha
2400 g ae/ha
0
Pseudomonads Mn reducers IAA producers
After Zobiole et al., 2010
Kremer, 2010
Effect of Glyphosate Drift* on Soybean Leaf
and Seed Iron & Ferric Reductase Activity
% reduction
100
Control
GS variety 1
GS variety 2
GR variety
80
60
40
20
0
Leaf Fe content
Seed Fe content
Ferric reductase activity
*Drift rate = 12.5 % of herbicide rate = 56 g/a
After Bellaloui et al, 2009
Reduced Nutrient Efficiency of Isogenic
RR Soybeans (After Zobiole et al, 2008, 2009)
Tissue:
Isoline
Mn
%
Zn
%
Normal
100
100
Roundup Ready©
83
53
RR + glyphosate
76
45
Copper, iron, and other essential nutrients
Were also lower in the RR isoline and reduced
further by glyphosate!
% Mineral Reduction in Tissue of Roundup
Ready® Soybeans Treated with Glyphosate
Plant tissue
Ca
Mg
Fe
Mn
Zn
Cu
Young leaves
40
28
7
29
NS
NS
Mature leaves
30
34
18
48
30
27
Mature grain
26
13
49
45
Reduced:
Yield
26%
Biomass 24%
After Cakmak et al, 2009
Glycolysis
Pentose cycle
PEP pyruvate
Erythrose-4-PO4
n
Fe
OneM missing
micronutrient
Cu
Si =
damage to a
Co pathway
B*
whole
Mn
ate
s
o
h
p
y
Gl
Mn
Shikimate
Chorismate
Phen
olics
Anthranilate
Prephrenic
* probable
Adapted from Graham & Webb 1991
Tryptophan
Tyrosine
Phenylalanine
Cyanogenic
glycosides
Mn
IAA
Mn
Indolacetic
acid
Cinnamic
Caffeic
Coumaric
Mn
IAA
degradation
H 2 O2
Coumaryl OH
Monocot:
Salycil+>SAR
PR2 PR5
= susceptible
Jasmonique
PR1 PR3
PR5 PR9
= résistant
Phytoalexins:
Phenylpropanoids
Salicylate� & SAR
PR Proteins
Quinones
Ferulic
Sinapyl OH
Coniferyl OH
Monocot M n
L I G N IN
H 2O 2
Mn
Mn
Gymnosperms
LI GNI N
CELL WALLS
Dicots
Lignin
Herbicide action is by soil-borne fungal pathogens
Glyphosate Increases Disease Susceptibility
A
B
C
A
Glyphosate Glyphosate No glyphosate
Sterile soil
Field soil
Control
B
Effect of glyphosate on susceptibility
to anthracnose. A) hypersensitive
response; B) non-limited response
after glyphosate is applied.
After Rahe and Johal, 1988; 1990; See also Johal and Huber, 1999; Schafer et al, 2009.
Some Plant Pathogens Increased by Glyphosate
Pathogen
Pathogen
Increased:
Cercospora spp.
Botryospheara dothidea
Marasmius spp.
Corynespora cassicola
Monosporascus cannonbalus
Fusarium spp.
Myrothecium verucaria
Fusarium avenaceum
Phaeomoniella chlamydospora
F. graminearum
Phytophthora spp.
F. oxysporum f. sp cubense
Pythium spp.
F. oxysporum f.sp (canola)
Rhizoctonia solani
F. oxysporum f.sp. glycines
Septoria nodorum
F. oxysporum f.sp. vasinfectum Thielaviopsis bassicola
F. solani f.sp. glycines
Xylella fastidiosa
F. solani f.sp. phaseoli
Clavibacter nebraskensis
F. solani f.sp. Pisi
Xanthomonas sterwartii
Gaeumannomyces graminis
Magnaporthe grisea
(“Emerging” and “reemerging diseases”)
Abiotic: Nutrient deficiency diseases; bark cracking, mouse ear, ‘witches brooms’
Some Diseases Increased by Glyphosate
Host plant
Disease
Pathogen
Apple
Banana
Barley
Beans
Bean
Bean
Canola
Canola
Citrus
Corn
Cotton
Cotton
Cotton
Grape
Melon
Soybeans
Soybeans
Soybeans
Sugar beet
Sugarcane
Tomato
Various
Weeds
Wheat
Wheat
Wheat
Wheat
Wheat
Canker
Panama
Root rot
Root rot
Damping off
Root rot
Crown rot
Wilt
CVC
Root and Ear rots
Damping off
Bunchy top
Wilt
Black goo
Root rot
Root rot, Target spot
White mold
SDS
Rots, Damping off
Decline
Wilt (New)
Canker
Biocontrol
Bare patch
Glume blotch
Root rot
Head scab
TakeTake-all
Botryosphaeria dothidea
Fusarium oxysporum f.sp. cubense
Magnaporthe grisea
Fusarium solani f.sp. phaseoli
Pythium spp.
Thielaviopsis bassicola
Fusarium spp.
Fusarium oxysporum
Xylella fastidiosa
Fusarium spp.
Pythium spp.
Manganese deficiency
F. oxysporum f.sp. vasinfectum
Phaeomoniella chlamydospora
Monosporascus cannonbalus
Corynespora cassicola
Sclerotina sclerotiorium
Fusarium solani f.sp. glycines
Rhizoctonia and Fusarium
Marasmius spp.
Fusarium oxysporum f.sp. pisi
Phytophthora spp.
Myrothecium verucaria
Rhizoctonia solani
Septoria spp.
Fusarium spp.
Fusarium graminearum
Gaeumannomyces graminis
Fusarium scab
Take-all root rot
Examples of Herbicide-Nutrient-Disease Interactions
Take-all
Glyphosate
No glyphosate
Glyphosate-tolerant soybeans - Corynespora
Control
Inoculated
Inoculated
+ glyphosate
Sudden Death Syndrome - Fusarium
No Fall burndown
Fall glyphosate
Goss’ wilt
No glyphosate
Glyphosate
Factors Predisposing to Fusarium Head Scab
(Fusarium spp.; Gibberella zeae)
Environment was the most important
factor in FHB development in eastern
Saskatchewan, from 1999 to 2002
Number of
%
Application of glyphosate formulations glyphosate
was the most important agronomic
applications Increase
factor associated with higher FHB
the previous in head
levels in spring wheat
scab
three years
Positive association of glyphosate
with FHB was not affected by
environmental conditions as much as
that of other agronomic factors…
(Fernandez et al. 2005, Crop Sci. 45: 1908-1916)
(Fernandez et al., 2007, Crop Sci. 47:1574-1584)
_______________________________
None
00
1 to 2
152 ***
3 to 6
295 ***
_______________________________
After Roemheld et al, 2009
Effect of Planting Delay after Glyphosate
(Residual Glyphosate in Soil)
Winter Wheat
14 days after
glyphosate ‘burn-down’
2 days after
glyphosate ‘burn-down’
Weiss et al., 2008
Long-term Effect of Glyphosate
Field observations in winter wheat production systems in 2008 & 2009 point to
potential negative side-effects of long-term glyphosate use.
after Roemheld et al., 2009
Preemergence
glyphosate
No
glyphosate
Preemergence
No
glyphosate glyphosate
Preemergence
Glyphosate
No glyphosate
Poor
Bulking
5# 5 oz
9# 13 oz
Failure to ‘Bulk’ of Russet Potatoes
Glyphosate
frequency
None in the
previous 2 yrs
1-2 in the
previous 2 yrs
Preceding year
How
applied
No. % Potatoes
growers over 10 oz
None
5
35.3
Burn down
RR crop
17
5
20.2
5.4
Parent plant with glyphosate drift
Daughter seed pieces
Special Considerations in Fertilizing RR Crops
Two factors: 1) Chemical; 2) gene
1. Providing nutrient availability for yield and quality
Compensate for reduced plant efficiency
Compensate for reduced soil availability
[Timing and formulation are important]
2. Detoxifying residual glyphosate
In meristematic root, stem, flower tissues, etc.
In soil [Ca, Co, Cu, Mg, Mn, Ni, Zn]
3. Restoring soil microbial activity
Nutrient related (N-fixation, Fe, Mn, Ni, S, Zn, etc.)
Disease control related (nutrition, pathogen antagonists, etc.)
Biological amendment (N-fixers, PGPRs, etc.)
4. Increasing plant resistance to diseases and toxins
Nutrient-related pathways (Shikimate, AA, CHO, etc.)
5. Judicious use of glyphosate
Glyphosate-induced Fe-deficiency chlorosis
+ glyphosate
- glyphosate
+ glyphosate
+
+
seed Fe treatment
seed Fe treatment
Photo: N.C.
Hansen,
Fort Collins,CO
Interaction of seedchlorosis
in soybeans;
Minnesota, USA
seed-applied Fe and glyphosate application on Fe deficiency
Treatment
Visual chlorosis score
[1 = green; 5 = yellow]
Control (no herbicide)
Glyphosate
- Fe
3.1
3.7
+ Fe
2.8
3.3
Grain yield
(bu/a)
- Fe
33
8
+ Fe
56
19
Jolley et al., 2004, Soil Sci. and Plant Nutrition 50:97350:973-981
Food and Feed Safety Concerns
Increased levels of mycotoxins
- Fusarium toxins (DON, NIV, ZEA)
- Aflatoxins
Nutrient deficiency
- Cu, Fe, Mg, Mn, Zn
Gene flow
- Weeds
- Soil microbes
- Intestinal microbes
Aris & Leblanc, 2011
Benachour et al, 2007
Carmen, et al., 2011
Fernandez, et al., 2009
Gasnier, et al., 2009
Heiman, 2010
Matzk et al, 1996
Seralini et al., 2010, 2011
Smith, 2010
Walsh, et al., 2000
Watts, 2009
Direct toxicity of residual glyphosate
- Infertility - endocrine system
- Birth defects, teratogenicity
- Cell death - Disease resistance
Allergenic reactions to foreign proteins
% Reduction in Alfalfa Nutrients by Glyphosate*
Nutrient
Nitrogen
Phosphorus
Potassium
Calcium
Magnesium
Sulfur
Boron
Copper
Iron
Manganese
Zinc
% reduction compared with Non-RR
13 %
15 %
46 %
17 %
26 %
52 %
18 %
20 %
49 %
31 %
18 %
*Third year, second cutting analysis; Glyphosate applied one time in the previous year
Manganese Sufficiency in Bovine Fetus Livers
(After Schefers, 2011)
Fetal
development
Mn
Manganese level*
mean
Deficient Normal
Deformed
0.88 ppm
‘Normal’
1.2 ppm
100 %
63 %
Above
0
0
29 %
7%
*Reference range: 1.75-2.8 ppm wet weight
Feed Analysis: Mean Mn
Range of samples
Shelled corn
Corn silage
Grass hay
Mixed haylage
0.01 - 57.65 ppm
0.01 - 89.43 ppm
0.01 - 125.20 ppm
0.55 - 113.45 ppm
15 ppm
37 ppm
50 ppm
57 ppm
Stillborne Calf from Manganese Deficiency
U.S. Cattlemen’s Association Statement to Congress
“Cattle ranchers are facing some puzzling - and, at times,
economically devastating problems with pregnant cows and calves. At
some facilities, high numbers of fetuses are aborting for no apparent
reason. Other farmers successfully raise what look to be normal young
cattle, only to learn when the animals are butchered that their carcasses
appear old and, therefore, less valuable.”
“The sporadic problem is so bad both in the United States and abroad
that in some herds around 40-50 percent of pregnancies are being lost.”
“Many pesticides and industrial pollutants also possess a hormonal alter
ego.”
“The viability of this important industry is threatened.”
Source: Testimony of the Ranchers-Cattlemen Action Legal Fund, United Stockgrowers
of America, to the Senate Agriculture Committee July 24, 2002.
Feed Source Effect on Stomach Liner Color, Carmen et al, 2010
Non-GMO
GMO
GMO
Effect of the GM “Gene” Proteins in
Corn/Soybeans on Pig Stomachs
2011
Non-GMO Feed
GMO Feed
Normal color
Inflamed, irritated
Inflammatory Bowel Disease, USA
Percentage of acres planted
Cases/100,000 population
90
GM Soy
80
70
60
50
GM Corn
Hospital discharges
Ambulatory care visits
40
20
10
0
1992
Year
1994
1996
1998
2000
2002
2004
And the Mice Prefer……
GMO
Corn
Non-GMO
Corn
Photos: Gilbert Hostetler
Direct Toxicity of Glyphosate
Rate (ppm)
0.5
0.5
1.0
1-10
1-10
2.0
5.0
5.0
10
10
10
All
1-10
System affected
Human cell endocrine disruption
Anti-androgenic
Disrupts aramatase enzymes
Inhibits LDH, AST, ALF enzymes
Damages liver, mitochondria, nuclei
Anti-Oestrogenic
DNA damage
Human placental, umbilical, embryo
Cytotoxic
Multiple cell damage
Total cell death
Systemic throughout body
Suppress mitochondrial respiration
Parkinson’s
POEA, AMPA even more toxic
Reference
Toxicology 262:184-196, 2009
Gasner et al, 2009
Gasnier et al, 2009
Malatesta et al, 2005
Malatesta et al, 2005
Gasnier et al, 2009
Toxicology 262:184-196, 2009
Chem.Res.Toxicol. J. 22:2009
Toxicology 262:184-196, 2009
Seralini et al, 2009
Chem.Res.Toxicol. J. 22:2009
Andon et al, 2009
Peixoto et al, 2005
El Demerdash et al, 2001
Seralini et al, 2009
Annual % Change in Cancers
Target Tissues for glyphosate;
Liver
Kidney
Testicle
Hormone system
Bone (Ca, Mn chelation?)
Thyroid (Mn chelation?)
Bt Egg Plant Toxicology Evaluation - Gallagher
Summary:
* The study failed to meet international standards for
evaluation (OECD 1998; Codex Alimentarious, 2003 c-c)
* There were serious departures from normal scientific
standards
* Studies submitted are ‘woefully inadequate to
determine safety’
* Consists of substandard and extremely misleading
interpretation of the results presented
* Independent study can not uphold the government
report of approval
Late term
‘Spontaneous
Abortion’
(Miscarriage)
Morphology of the ‘Entity’ Causing
Reproductive Failure
Transmision Electron Photomicrographs
38,250 X magnification
Size relative to
a bacterium
Scanning EM
Occurrence
•Verified in IA, IL, KY, MI, NE, ND, SD, WI
• Sources: ‘Environmental’
Animal tissue
Soybean meal
Placental tissue
Wheatlage, haylage, silage
Amniotic fluid
Corn leaves and silage
Semen
SDS Soybean plants
Stomach contents
Oak ‘scorch’ leaves
Eggs
Manure
Milk
Soil
Fusarium solani fsp glycines mycelium
Potential Interactions of ‘new entity’ with Glyphosate
• Glyphosate affects plants (predisposes):
Inhibits plant defenses
Reduces nutrient content and efficiency [chemical and RR gene(s)]
Increases root colonization
Increases membrane permeability
Surfactant affect for penetration of natural openings and wounds
• Glyphosate affects animals (predisposes):
Inhibits aramatose system – endocrine hormone system
Toxic to liver, placental, testicular, and kidney cells
Reduced defense - liver function [from lower Mn, etc. in feed]
• Glyphosate affects pathogens:
Stimulates growth and virulence (direct/indirect)
Favors synergism, infection (as a carrier)
Increases movement into plant tissues (water film for plant infection)
• Glyphosate affects the environment:
Toxic to soil microbes that constrain plant pathogens
Micronutrient availability reduced
Failure to Honor
* Scientific Precautionary Principle
1. Margin of safety to prevent damage
2. Anticipation of unknowns
3. Initiate as a “pilot project”
* Not “Substantially Equivalent”- Significant deviation in:
1. Expression of ‘end products’ (new/tissues in)
2. More like virus infection than sexual transfer
3. Functional and regulatory controls absent
4. Greatly extended exposure
5. Production, quality, safety & toxicity differ
Scientifically Irresponsible
* Untested end products (toxicology) – New proteins, Bt toxin
* Irreversible consequences
1. Gene contamination
2. Health damage
* Basic infrastructure attacked – food production
* Unintended consequences ignored – increased disease
* Increased toxic chemical exposure – food, environment
* Decreased production efficiency – food/feed
* Unknown end points – unregulated gene flow
Emerging Consequences
* New diseases- health effects
1. Allergies
2. Reproductive failure
3. Premature aging
4. Morgellan’s – A. tumefaciens in muscle
* Emerging diseases
1. Human
Autism
Endometriosis, Crohn’s
Alzheimer’s/dementia
Parkinson’s
Nutrient deficiencies
2. Animal - Many
3. Plant - Many
Potential Far-Reaching Impact of Glyphosate
Human
Mineral malnourished,
Allergies, Fertility, Disease
MYCOTOXINS
Alzheimer’
Alzheimer’s, gout, diabetes, viruses, Parkinson;s, etc.
Vegetables, fruits, grains Glyphosate
Lower nutrient minerals
Mn
(Cu, Fe, Mg, Mn, Zn)
Carriers for epiphytes
Glyphosate
(E. coli, etc. )
(Changed epiphytic flora)
(Chelation)
Environment
Biological imbalance
N fixation, Mn availability
Potassium immobilization
Biological controls
GLYPHOSATE ACCUMULATION
Plants, feed
Lower nutrient minerals
(Cu, Fe, Mn, Zn)
Disease predisposition
(Scab, taketake-all, CVC)
Mycotoxins, glyphosate
Animals
Mineral malnourished
Slow growth, Allergies, Disease
MYCOTOXINS
Scours, death, BSE, wasting, predisposition