Enhanced Biodegradation of Pesticides in the Environment - American

b e e n. o v e r l o o k e d as p o t e n t i a l s o l u t i o n s ? 7) When we a r e g i v e n a lemon i n l i f e , can we make lemonade? Is there ...
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Chapter 4

Enhanced Biodegradation of Carbamothioate Herbicides in South Carolina

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Horace D. Skipper Department of Agronomy and Soils, Clemson University, Clemson, SC 29634-0359

Field and laboratory studies were conducted by an interdisciplinary team to: 1) confirm enhanced biodegradation, 2) ascertain microbial crossadaptation, 3) determine microbial population shifts with repeated use of carbamothioates, 4) delineate the role of plasmids, and 5) investigate chemical/crop rotations and inhibitors to prevent or improve problem soils. Bioassays and evolution of CO from C-labeled herbicides confirmed accelerated biodegradation of butylate in soils with repeated use of butylate and cross-adaptation for EPTC, vernolate, and pebulate but not cycloate. Significant increases in bacteria or actinomycete populations were detected in soils treated with multiple applications of butylate, EPTC, or vernolate. Plasmids were associated with the microbial degradation of carbamothioate herbicides by a Flavobacterium sp. and a Methylomonas sp. isolated from herbicide-history soils. Chemical rotations were c r i t i c a l in the prevention of problem soils. A minimum of two years between applications of butylate or EPTC plus dietholate was essential to insure continued herbicidal efficacy. Enzyme inhibitors began to lose their effectiveness after 3 applications. 14

14

2

Enhanced considerable described soil

by

biodégradation attention Audus

applied

biodégradation and by

recent

for

the

herbicide, by

insecticides soil

(1) soil

(6-9)

are

microorganisms.

readily

degraded

by

repeated

applications

of

in

is

pesticides years

since

herbicide

2,4-D.

also

microorganisms also The

microbes

subject

it

(2.3). to

to

first a

enhanced

Fungicides

enhanced and

received was

Diphenamid,

subject

carbamothioate (10.11)

has

(4.5)

degradation

herbicides

especially

(12-19).

0097-6156/90/0426-0037$06.00/0 © 1990 American Chemical Society

Racke and Coats; Enhanced Biodegradation of Pesticides in the Environment ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

are after

38

ENHANCED BIODEGRADATION O F PESTICIDES IN T H E ENVIRONMENT

One

approach

problem

soils

(20).

Stauffer

leadership provided

residual

to

lives

in

of

potential In

of

1982

to

regulate,

How

in

the

farmers

or

in

the

environmentally weeds

across

multiple of

vernolate

their

in

microorganisms

are

c a n we

prove Are

they

Can

environmentally

friendly

and

be

insure

the

an

added

critical

to

been

overlooked

lemon

in

of

enhanced

life,

answer

employed basic

by whole

enhanced

as

to

during Have

make

c o u l d be

an

questions,

a

interdisciplinary field

and

plants

and

laboratory

5)

within

the or

specific

within

the

to

preserve

used

organic/inorganic

enhanced

the

biodégradation

pesticide 4

to

to

7)

When we

there the

team

of which

studies, in

a

that

are

rotations are

given

a positive

a

use(s)

microorganisms

up p o l l u t e d

number

control

6 weeks

crop/pesticide

DNA a s p e c t s

Are

chromosomes

be

Is

clean

If

culture,

enhanced

solutions?

to

or

soil

to

first

lemonade?

used

soils? on

Can

standard

Which

pure

transferred

of

the

EPTC

solutions

retard

the

potential

these

research,

assays,

soils

in

in

stable

there

for

use 4)

of

safe

biodégradation?

located

genes

and are

field?

isolated

functional

for are

b r o a d range

enhanced

enhanced and

readily

Are

a

The

tools They

producers

biodégradation--perhaps

(enzymes/genes) To

for

the soil

pesticides?

States.

same

in

as

puzzle?

perennials,

pesticides?

growth? c a n we

the

in

control,

management

can

concentration

pest(s)

crop

in

of

of Does

result

such

the

becomes

inhibitors to

adequate

specific

soil

1)

factors

against

corn,

they 6)

biodégradation? amendments

a

really

are

as the

since

biodégradation

United

degradative

or

soils:

factor

essential

degradation

community?

others

herbicides

into

effective

in

are

of

selected

addressed

biodégradation

identified

for

the

microorganisms microbial

enhanced

fit

rotation

are

responsible

plasmids?

of

are

responsible

pesticide-degraders

role

biodégradation

environmental

enhanced

If

crop

were

carbamothioate Do

Can a c r i t i c a l

butylate

the

considered

Carolina

hard-to-control

crops.

degradation

of

short

gave and

also

for use

inhibitors

and

inducers

South

role

friendly,

and

with

discussed

enhanced

southeastern

and c e r t a i n

the

herbicides

questions of

cross-adaptation

annual

genes

of 2)

herbicides

provided area

scientists

and/or

They

of

in

mask

has

this

suggested

(3)

in

inhibitors

soils. role

the

al.

as

enzymes.

a number

modify

negate

in

microorganisms

pesticides

herbicides?

does

et

of

substrates,

soil

failures?

carbamothioate

how

Kaufman

herbicides

of

performance

inducers,

"multiproblem"

or

moisture

(21)

the

biodégradation

performance 3)

al.

activity

ICI Americas)

industry earlier

resolve

enhanced

(now

had

review,

performance

herbicidal

et

certain

carbamothioate

of

microbial/enzymatic

university

specific of

this

of

to

soils.

as

enzymes

inhibitors

use

inhibitors

improve

pesticides

examples

the

agrochemical

Kaufman

degradative

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the

potential

inhibitors

restoration

been

C h e m i c a l Company

for

validation.

of

to

has

sites?

techniques used

bioassays systems

were

applied and

approach

biodégradation.

Racke and Coats; Enhanced Biodegradation of Pesticides in the Environment ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

a^id C to

4.

Field In

Research

South

of

Carolina,

the

carbamothioate

generated Arenic

in

a

Wagram

Plinthic

respectively, corn.

In

of

these

first

in

loamy

sand sandy with

a

applications

of

annual

butylate-history

of

EPTC,

than

the

for

use

and

When s o y b e a n s dietholate indicated

the

EPTC b u t In

planted improve

not

to

vernolate

effectively

butylate

in

their

alachlor

or

metolachlor

applications

In

Piedmont

butylate of

at

detected thermic

sandy

loam

apparently sufficiently dietholate

to to

commercially gave et

Table

of

Performance EPTC p l u s

6.7 the

kg/ha, kg/ha,

Congaree

of

(24)

Treatment

of

soils

near

Butylate

2.

Butylate

of

(fine-loamy, not

in

the

Fluventic

Chewacla

soil

butylate-degraders The

efficacy

addition

of

butylate

dietholate (Sorghum

plus

after

to

be

dietholate,

SC

Control

of

in

an

and

two

Johnsongrass Congaree

(%)

6.7

93

b

43

b

6 . 7 + 1 . 1

94

b

93

a

6 . 7 + 1 . 1

98

a

92

a

dietholate 3.

EPTC + dietholate

Means

within

significantly

a

column f o l l o w e d

different

at

the

by

different

5% l e v e l

by

a I)

halepense).

planting

Clemson.

of to

(Table

Chewacla

rate

+

3-years

Aquic

the

(kg/ha) 1.

loam but

of

butylate

Chemical

of

biodégradation

found d i e t h o l a t e

4 weeks

of

consecutive

least

thermic

johnsongrass

butylate,

dietholate

at

sandy

EPTC p l u s

al.

six

soil.

the

but

biodégradation

Udifluvents)

problem

enhanced

soils,

enhanced

(turn-plow)

a

butylate-history

Data

cross-adapted

respectively. with

mixed,

level.

of

soils,

degradation

after

Carolina

restored

control

specific

reported

enhanced

population

a n d Tarn e t

soil

vernolate.

microbial

detected

Typic

overcome

of

(22)

the

and 1.7

tillage

acceptable (23)

not

in

butylate

for

Varina

butylate-history

al.

contrast,

the

excellent

al.

I.

Deep

the

application.

butylate-history

(fine-loamy,

diluted

(0,0-

butylate

the

m i c r o o r g a n i s m s were

South

rate

was

Dystrochrepts).

also

2.2 of

nonacid,

Chewacla

Tal

at

soils

an annual

butylate

mixed,

these

in

fonofos

greater

the

with

performance

in

In was

was

herbicide

in

reduced

soils.

of

with for

agree

the

et

butylate

dietholate

kg/ha

improved

efficacy

continuous

history,

6.7

(19).

Dowler

of

at

and d i e t h o l a t e

greater

results of

kaolinitic,

sanguinalis)

increased

butylate-adapted

biodégradation

annual

The

These

not

Georgia,

butylate

was

thermic

and 2-year

c o n c u r r e n t use

(Digitaria

length

were

did

(clayey, 7-

significantly

EPTC a n d g e n e r a l l y

Wagram s o i l .

herbicide

to

crabgrass

soils

siliceous,

loam

soils,

biodégradation

Plains

phosphonodithioate)

respectively.

butylate than

large

enhanced

(loamy,

Paleuldults)

diethyl-O-phenylphosphorothioate) control

of

Coastal

and a V a r i n a

(O-ethyl-S-phenylether

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evidence

herbicides

Paleudults)

thermic

and

39

Carbamothioate Herbicides

SKIPPER

letters

the

are

LSD t e s t .

Racke and Coats; Enhanced Biodegradation of Pesticides in the Environment ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

40

ENHANCED BIODEGRADATION O F PESTICIDES IN T H E ENVIRONMENT

effective pure

inhibitor of

cultures, For

control

soybeans

and

management 2.2

was

effective

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subsequent enhanced on

the

would

address and

were

to

used

pebulate, ratio.

II.

not

the

and

in

soils

or

to

are one

it

a

key of

herbicide

issue

of

but

s o r g h u m was as

other

two

year

with

of

with

herbicide herbicide, If

soil

a problem to

soil,

a

second might

in

South

butylate-history

two

soils

at

of

were

8,

the

or

soil

preplant

12

in

plus

after

near

a

days

performance

vernolate

and 6 weeks

vernolate-history

vernolate,

dietholate

1,

measure

sites

EPTC,

herbicides

vernolate, 4

one

a problem s o i l

to

addition

to

herbicides

of

herbicides.

planted

a bioassay

Performance and

then

on

similar.

cross-adaptation The

is

residues

different

Thus,

Carolina

the

(25.) .

grower

associated

cross-adapted

two

control

insecticide,

herbicide

cross-adaptation,

i n North

and without

(DAT)

be

weed

the

and produce

of

the

dietholate, in

a

SC

Control Yellow

rate

6:1

after

planting

Sumter.

Chemical Treatment

at

yellow

vernolate

impact

a

use

of

an

of

structurally

one

the

question

potential

growers'

continuous

rotations,

potential

in

control

Fonofos,

ineffective?

just

of

efficacy

in

esculentus)

improved

of

the

cycloate.

with

2-years

crop

microorganisms

one

Grain

treatment

is

the

in

effects

investigate

incorporated

Table

adapt

for

Carolina

EPTC

component

marginal

II).

performance

and r e n d e r

generated To

used

they

same

(Table

However,

if

these

herbicide be

the

subsequent

microorganisms

gave

restoring

biodégradation

especially

of

(Cyperus a key

significantly

are

crops.

is

after

alone

in

about

nutsedge

However,

i n peanuts

When h e r b i c i d e s concerned

degradation

vernolate

Dietholate

vernolate also

yellow

vernolate

nutsedge. with

of

peanuts,

programs.

kg/ha,

microbial

respectively.

of

Nutsedge 6 WAP

4 WAP

(kg/ha)

(%)

1.

Vernolate

2.

Vernolate +

3.

Vernolate

4.

Vernolate +

dietholate

2.8

+

0.5

80

5.

Vernolate +

benefin

2.8

+

1.3

74

42

6.

Vernolate + dietholate

87

82

2.2 dietholate

2.2

+

0.4

2.8

+

2.8

+ 0.5

+

1.3

71

30

87

77

62

32 a

81

a a a

benefin 7.

Benefin

8.

V e r n o l a t e + napropamide

9.

Vernolate +

1.3 2.8

dietholate

2.8

+

+ 0.5

1.1 +

1.1

0

3

72

30

86

87

napropamide 10. Vernolate + fonofos a_ I n d i c a t e s the v e r n o l a t e versus were Trt

significantly 3 vs

T r t 4).

carbamothioate ragweed

different

Modified

herbicides.

(Ambrosia

2.8

+

vernolate at

from

the Ref.

Control

artemisiifolia)

84

4.5 plus

5% l e v e l

75

dietholate ( T r t 1 vs

means

Trt 2

or

25

of

the

was

evaluated

grain

sorghum four

and

Racke and Coats; Enhanced Biodegradation of Pesticides in the Environment ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

and seven

a

4.

weeks

after

III,

butylate

even

at

of

use

this

reflect

may

enhanced

dietholate not

the

efficacy

of

alter

of

thermic

butylate

the

were of

used

SC-7432

inhibitors were of

microbial

applied

four

only

at

cycles

dietholate

Table

III.

1984.

these

of

butylate-history

effect

(fine,

Dietholate not

efficacy

same p l o t s

for

the

sequence of

was

eight

carbamothioate

a

total

repeated

using

cycles.

Sorghum-

7 WAT

(kg/ha) 1.

Butylate

2.

Butylate

3.

EPTC

4.

EPTC

5.

Vernolate

6.

Vernolate +

4.5 +

dietholate

4.5

+

0.7

dietholate

7.

Pebulate

8.

Pebulate

9.

Cycloate

10.

Cvcloate

4.5

+

2.2

+

0.7 0.4

4.5 +

dietholate

4.5

+

dietholate

4.5

+

0.7

4.5 +

30

a

0.7

98

0 25

a

95

a

a

8

6

58

2.2 dietholate

90

0 DAT

(%) 5

21

4.5 +

Ragweed-

12 D A T

1 DAT

rate

a

of

4 WAT

Chemical Treatment

in

NC Control

Grain

as

butylate

herbicides

Dobson.

the

disclosed),

their

to

near

and

di(3-

of

total

loamy, treated

[S-ethyl for

of

inhibitors

Treatments

for

soil

the

(26) .

the

EPTC

pebulate,

previously

(chemistry

1985, a

for

contrast,

enzyme

sand

not

evaluated

intervals

and

Thus,

microorganisms

determine or with

studies.

SC-0520

and SC-0058

EPTC,

In

of

herbicides.

SC-0058 were

In

Performance

to

alone

degradation

six-week

in

related

The with

soil.

vernolate,

A Dothan loamy

for

(diallylamine)

of

Paleudults)

inhibitors,

of

conditions.

conducted

butylate

Plinthic

than

this

butylate-degrading these

EPTC.

associated

butylate of

Table sorghum

performance

and c r o s s - a d a p t a t i o n

performance

to

chloroallyl)thiocarbamate), and

for

in

grain

than

efficacy

these

the

shown the

improved the

greater

butylate

As

control

effective

improved

butylate.

was

experimental

less

under

experiments

to

butylate-history

indicate

applications

siliceous, with

the

cross-adapted

Field multiple on

The

apparent to

was

relatively

d i d not

cycloate

failed

significantly

biodégradation

readily

were

was

respectively.

along

and EPTC.

dietholate

or

(WAT),

a n d EPTC

dietholate

butylate

was

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treatment

1 DAT a n d b u t y l a t e

addition both

41

Carbamothioate Herbicides

SKIPPER

71

a

96

61

38

100

62

48

100

80

52

99

90

66

76

41

85

78

32

74

a

indicates the herbicide versus herbicide plus dietholate means were significantly different at the 5% level (Trt 1 vs Trt 2 or Trt 3 vs Trt 4) Adapted from Lawrence, E . G . et a l , Weed Science, in press.

Bioassays cycle.

were

performance Results was

planted

Non-treated on a

weekly were

first-time

indicated

initiated

at

plots

with

a

that

intervals included

after to

application basis enhanced

second

each

in

each

biodégradation

application after

application

evaluate

just

butylate

cycle. of

six

butylate weeks

Racke and Coats; Enhanced Biodegradation of Pesticides in the Environment ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

and

42

ENHANCED BIODEGRADATION O F PESTICIDES IN T H E ENVIRONMENT

that

i n h i b i t o r s were

control Cycle

levels.

5 while

(Figure

1).

SC-0058 began SC-0520

biodégradation

(26).

for

various

periods

of

Another

approach to

rotations. was

of

In

rotations

on

evaluated corn

in

enhanced

herbicide

herbicide

butylate,

lose

in

were

the

other

not

effective

was or

continuous rotation,

plus

use

with

inhibitor enhanced

chemical/crop

herbicides

and

crops

of

these

treatments

were

the

effect

c o r n and h e r b i c i d e , rotation

Herbicides

dietholate,

7

inhibitors

of

of

Sixteen

and crop

in

Cycle

as

reduction

evaluate

biodégradation.

in

(27.28) .

the

study

initial

decreased

an e f f e c t i v e

soils

to

exceeding

efficacy

involves

five-year

or

dietholate

its

prevention

rotation.

EPTC

of

Dietholate

time

a

restoring

a Dothan s o i l

including

with

with

to

pesticides

1984,

established

in

effects

and SC-7432

of

biodégradation

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effective

Inhibitory

continuous

(corn/soybeans)

investigated

alachlor,

included

vernolate,

and

trifluralin. The two

efficacy

annual

annual or

of

EPTC p l u s

applications

applications

alachlor

in

(Table

soybeans

control

was

soybeans

in

rotation

performance rotation to

of

away

EPTC p l u s

development

critical

Table

to

IV.

the

Control as

the

of

large

crabgrass by

crop

or

because

EPTC p l u s

years prevent It

was

consecutive

dietholate

in

rotations

of

1984

in

required

(Table V ) .

Control

Herbicide

three and to

by

large

subsequent

products

and h e r b i c i d e

Rotations Crop

the were

rotation

corn

of

dietholate

these

five

in

vernolate

to

Two

after

after

degree

of

biodégradation

herbicide

affected

(29).

of

decline

alachlor

a high

detrimental

EPTC p l u s

enhanced

to

of

Inclusion

dietholate

performance

of

maintain

corn

rotation,

was or

began

ineffective

By i n c l u s i o n

maintained.

from b u t y l a t e

m a i n t a i n adequate

the

totally

IV).

in

crabgrass

the

dietholate

a n d was

large

crabgrass

1986

1988

Corn

EPTC

95

a

(%) 73 b

8

c

Corn

EPTC/alachlor

78

ab

95

a

70

a

Corn/soybean

EPTC/alachlor

94

a

100

a

79

a

48

b

Corn/sovbean 94 a EPTC/vernolate 69 a b a a column followed different letters by Means within s i g n i f i c a n t l y d i f f e r e n t a t t h e 5% l e v e l b y t h e L S D t e s t . EPTC p l u s

dietholate.

applications control.

of

in

dietholate

than

also

was

rotation

of to

from

of

enhanced

EPTC p l u s

with

dietholate

of

of

herbicides

or

gave

or

butylate

vernolate,

Rotation the

29.

alachlor

biodégradation.

under

prevent

Ref.

included

performance

rotations

important

(13.18.27.30)

or

herbicide.

than

retardation

that

better

carbamothioate effective

butylate

Rotations

resulted

Modified

are

poor

and

EPTC

a

closely

the

crop

in

the

Rotations

midwestern

United

alleviate

enhanced

weed

trifluralin plus

related was

less

prevention of

States

or

herbicides conditions

biodégradation.

Racke and Coats; Enhanced Biodegradation of Pesticides in the Environment ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

43

Carbamothioate Herbicides

SKIPPER

1001 2 Β Β

A P P L . B U T Y L A T E (Β) APPL Β + SC-0058 + DIETHOLATE

80-

Έ

X

(D

70-

OC

Ο (/>

60-

Ζ


the

analytical

soil

to

degradation

and

rapidly

I

soil

applied

degraded

Varina,

of

assess

greater

biodégradation is

increased

butylate-history no

as

butylate-history

non-history

Butylate

control

defined

C-butylate the

been

non-butylate-history

^or

which

history

on

(11)·

research

of

general,

studies

are

LSD

chromatographic

environmental

the

in

the

to

microbiologv^herbicide

herbicide

by

i n c l u d e d measurement

delineate

determine

laboratory

involved

C-labeled pesticide

use

letters

29.

Studies.

fyther

from

at

by

Research

biodégradation while

followed

different

from

Laboratory

column

vernolate not

evolution

in

use

cross^-adapted of

CO

Racke and Coats; Enhanced Biodegradation of Pesticides in the Environment ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

both (25). for

(Table

Carbamothioate Herbicides

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 3, 2018 | https://pubs.acs.org Publication Date: May 3, 1990 | doi: 10.1021/bk-1990-0426.ch004

SKIPPER

Time (days) Figure

2.

without

prior

Means

Accumulation butylate

followed

significantly

(Reproduced with Sci.

Soc.

by

the

different

of

use

C0< e v o l v e d 2

and

same at

permission

the from

treated letter 5%

15.

so^ls

with

within

level

Ref.

from

by

with

and

C-butylate. a

day

the

Copyright

are

LSD 1988

Am.).

Racke and Coats; Enhanced Biodegradation of Pesticides in the Environment ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

not

test. Weed

46

ENHANCED BIODEGRADATION O F PESTICIDES IN T H E ENVIRONMENT

VI).

Overall,

and

there

cross-adaptation for

vernolate

confirmed At

Table

various

been

a

good

for

pebulate

on

the

field

However,

micr^ooganisms

based

poor

in

CO^ a s s a y s

i n c o r p o r a t i o n or

b l a m e d as

3

Cross-adaptation butylate-

between

the

Dothan

has

soil

not

been

conditions.

times, been

agreement

cross-adaptation.

butylate-adapted

field

have

VI.

of and

under

conditions

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 3, 2018 | https://pubs.acs.org Publication Date: May 3, 1990 | doi: 10.1021/bk-1990-0426.ch004

has

l a b o r a t o r y assessments

causes

for

for

adverse

environmental

performance

carbamothioate

or v e r n o l a t e - h i s t o r y

failures

herbicides

by

in

soils

Soil herbicide history

Soil

Herbicide Cvcloate

Butvlate NA

x

Butylate

Varina

NA

X

NA

X

X

X

a

Dothan

Butylate

Wagram

Vernolate

Dothan

X

X

Vernolate

Vaucluse

X

X

Cross-adaptation herbicide b

in

degradation

is

defined

the

in

a

butylate

when

of

factors

microorganisms

responsible

although degradation expected microbial can

the

To

is

of

that

investigate 25,

50,

or

10

a n d 25% F C ,

80

to

90%.

soil

FC for

(25).

moisture

of

the

20

below

3% a n d

Pesticide-treated time

before

soils,

one

storage.

To

they wonders

in

CO

a

if

they this

provides

the

suitable a

below

for

pesticide disease,

the

Wagram

of

of

threshold

lose

regulates

moisture soil 0.05

total

Similar

moisture

vernolate

in

of

was

EPTC of

soil

stored

a

or

their

-5

to

kPa) .

reduced

by

between

50

effects

were

vernolate-history

moisture for

enhanced

dependent above

various

laboratory studies.

question,

2

soil (22.) .

adjusted

bars C0

soil

on

was

C - b u t y l a t j e was in

or

conditions,

butylate-history

soil

from

may b e in

that

dry f i e l d

a non-butylate-history

(35).

rate

used

are

herbicide

insect,

factor

Under

differences

soils

the Thus,

failure.

independent

are

address

is

butylate-history

degradation

Degradation

of

more

(weed,

population

in

days

culprit.

microorganisms

herbicide

fiel