Mites Control

7/29/2019 Mites Control

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Chi ld er s: Copper F ormul ati ons and Rust M i te Cont r ol

349

E FF E CT OF DI FF E RE NT COP P E R FORMU LATIONS TANK-

MI XE D WITH F E NB U TATIN -OXID E

FOR C ONTROL OF C ITRU S RU S T MITE S (ACARI:

E RIOP HYID AE) ON FLORID A CI TRU S

C

ARL

C . C

H I LD ERS

U niversity of Florida , IFAS

Citrus Research and E ducation Center

700 Experiment St a tion Roa d

La ke Alfred, F L 33850

A

BSTRACT

One or more ra tes of fenbuta tin-oxide (= Vendex

) 4 L a pplied a lone w ere compa redwith the same rates of Vendex tank-mixed with one or more formulations of coppera nd a n unt reat ed check for control of citrus rust mite, Phyll ocoptr uta oleivora(Ash-mea d) (Aca ri: E riophyida e), in 4 citru s gr ove sites bet w een 1988 a nd 1991. The copperformula tions corresponded to recommended ra tes in t he Florida Citrus Spra y G uidea nd included: 99%G C ba sic copper sulfa te (penta hydr a te) w ith 53%meta llic copper,a 77%WP copper h ydroxide formula tion cont a ining 50%meta llic copper a nd a 61.4%copper hydr oxide D F formu lat ion cont a ining 40%met a llic copper. Reduced effective-ness of Vendex occurred w hen combined w ith a ll 3 copper formula tions. B oth copperhydr oxide formu lat ions w ere more disrupt ive in reducing t he effectiveness of Vendexin controlling citru s rust mite compa red wit h th e basic copper sulfat e formula tion. In-creases in citrus r ust mite nu mbers occurred in th e copper-only trea tm ents in 2 of the3 field experiment s. In both inst a nces, popula tion increases in th e copper-only trea t-ments occurred a t t he sam e time as t hose in the unt reat ed check trees, suggesting astimu lat ory effect by t he copper compounds.

Key Words: C hemical cont rol, Phyl locoptr uta oleivora

, miticides, spra y ta nk-mixes

R

ES UM EN

Va ria s dosis de oxido de fenbuta tina (Vendex) 4 L a plicada s solas fueron compa ra -da s con mezcla s en ta nque de diferentes formula ciones de cobre ma s fenbuta tina a lasmisma s dosis y con un t estigo no tra ta do, para el contr ol del acar o tostador, Phyl lo-coptr ut a olei vora

(Ashmea d) (Acar i: Er iophyida e), en cua tr o localida des con h uerta s

de citricos entre 1988 y 1991. Las formulaciones de cobre correspondieron a las reco-mendadas en la Gua de Aspersiones de los Ctricos de la Florida e incluyeron: 99%G C d e sulfat o de basico de cobre (penta hidra ta do) con 53%de cobre meta lico, una for-mulacin de hidroxido de cobre al 77%WP conteniendo 50%de cobre metalico y unaformula cin del 6l.4%de hidr oxido de cobre D F con un 40%de cobre met a lico. La efec-tivida d del Vendex se redujo cuan do este fue combina do con las tr es formula ciones decobre. La s formula ciones de hidr oxido de cobre redujeron ma s fuert emente la efecti-vida d del Vendex que el sulfat o basico de cobre en el cont rol del aca ro tosta dor. En dosde los tres campos experimentales se observaron aumentos en la mortalidad de losa caros tosta dores. En a mbos ca sos, la poblacin en los tra ta mientos de cobre solo au-ment al mismo tiempo que en los a rboles no tra ta dos, sugiriendo un efecto estimula -

dor por parte de los compuestos de cobre.

Copper compounds a re recommend ed for use on F lorida citrus t o control several

fungal diseases including grea sy spot (

M ycosphaer el l a ci tr i

Whit eside), mela nose (

D i -

This article is from Florida Entomologist Online

, Vol. 77, No. 3 (1994).

FEO

is available from the Florida Center for Library Automation gopher (sally.fcla.ufl.edu)

and is identical to Florida Entomologist (An International Journal for the Americas).

FEOis prepared by E. O. Painter Printing Co., P.O. Box 877, DeLeon Springs, FL. 32130.


2/17

350

Fl or id a E ntomologist

77(3) S ept em ber, 1994

apor the cit r i

Wolf) and citrus scab (

El si noe fawcett i i

B ita ncourt & J enkins) (Timmer

& McG overn 1993, Whit eside 1988). Severa l form ula tions of copper, th a t cont a in me-

ta llic copper, including copper sulfa te a nd copper h ydroxide, ha ve been used by Flor-

ida citrus growers for many years. The materials are relatively inexpensive whileproviding fungicidal a ctivity. Ma ny citrus g rowers a pply copper in th e postbloom a nd

summ er spra ys, in combina tion w ith a miticide or insecticide, for broa d spectr um pest

cont rol and t o minimize a pplica tion costs.

The citr us rust mite, Phyll ocoptr uta oleivora

(Ashmea d), a nd t he spider mites, Eu-

tetr anychus bank si

(McGr egor) an d Panonychu s cit r i

(McG regor), can be serious pest s

during the postbloom a nd summer periods a nd t hus ma y require a miticide applica -

tion during one or both times, depending upon citru s va riety, mite presence a nd risk

of popula t ion increa se (C hilders 1987).

Thompson (1939) found that P. cit r iincreased following copper sprays on citrus

a nd H ollowa y et a l . (1942) reported t ha t t his spider mite wa s more abunda nt follow-

ing sprays containing compounds of copper, zinc and lime compared with untreatedtr ees. Gr iffi th & Fisher (1949) observed t ha t Phyll ocoptr uta oleivora

a nd Panonychus

ci t r iincreased a bnorma lly on citrus in F lorida following th e use of spray s conta ining

copper, zinc, or lime or exposure t o road dust or fertilizer residues on fruit a nd lea ves.

J ohnson (1960a ) eva lua ted 5 copper formula tions, including ba sic copper sulfa te, cop-

per oxide, copper hydroxysulfate, copper sulfate, and tetra copper calcium oxychlo-

ride, in combina tion w ith zineb for cont rol of Phyll ocoptr ut a oleivora

. All of t he copper

compounds and rates tested reduced the effectiveness of zineb in the summer spray

but not in t he post bloom spra y. This supported ea rlier work by J ohnson et a l. (1957)

th a t s howed zineb provided less cont rol of P. olei vora

w hen combined w ith fi xed cop-

per compar ed with zineb alone.

Residual control by chlorobenzilate or dicofol against the citrus rust mite was re-duced when copper or met hida th ion w a s ta nk-mixed for use on citru s in Texas (Dea n

1979). D ensit ies of Br evipal pus phoeni cis

(G eijskes) (Aca ri: Tenuipa lpida e) increa sed

after frequent copper oxychloride applications on tea in Indonesia (Oomen 1982).

Eger et al. (1985) evaluated tank mixtures of copper with chlorpyrifos or ethion ap-

plied in 2.338 or 4.676 kiloliters of w a ter per hecta re using a n a irbla st spra yer. They

found th a t residua l control of the citrus rust m ite wa s reduced with the copper + or-

ganophosphate combinations compared with the organophosphate compounds ap-

plied a lone. H ir sutel l a th ompsoni i

Fisher, a fungus pat hogenic to citrus rust mite, wa s

suspected of being a dversely a ffected by th e copper.

Vendex is not a ffected by differences in w a ter pH beca use th e orga notin compound

is extr emely sta ble. The formula tion forms a suspension, not a solut ion, in wa ter (Sea -

ma n & Riedl 1986). This w ould suggest t ha t a coa ting of the mit icide by petroleum oil

w ould reduce the effica cy of the cont a ct m iticide (Ch ilders & Selhime 1983).

G rower compla ints of poor citru s rust mite cont rol with fenbut a tin-oxide + copper

ta nk mixes prompted th e fi eld evalua tions reported in this pa per. The residual a ctiv-

ity of one or more copper formula tions in combina tion w ith one or m ore ra tes of Ven-

dex wa s evalua ted betw een 1987 a nd 1991 an d compared w ith t he miticide a pplied

a lone at the sa me ra tes. Results of these studies are reported here.

M

ATERIALS

AND

M

ETHODS

One or more ra tes of Vendex, 4 pounds a ctive ingredient per ga llon liquid formu-

lation (4 L) (479 g AI per liter) (E. I. DuPont de Nemours, Wilmington, DE), applied

a lone w ere compared w ith t he sa me ra tes of Vendex ta nk-mixed wit h one or more for-


3/17


351

mulations of copper for citrus rust mite control and an untreated control in 4 citrus

grove sit es bet w een 1988 a nd 1991 (Ta ble 1). The r a t es of copper corresponded t o rec-

ommended ra tes in the Florida C itru s Spra y G uide. The copper formula tions included

99% basic copper sulfat e (penta hydra te) gra nular crysta ls (G C) with 53% meta ll iccopper (Tennes see Ch emica l Co., C opperh ill, TN), a form ula t ion of 77% copper hy-

droxide WP cont a ining 50% meta llic copper (Kocide Ch emica l C orp., Houston, TX)

a nd a 61.4%copper hydroxide dry fl owa ble (DF ) formu lat ion cont a ining 40%meta llic

copper (Gr iffi n C orp., Va ldosta , G A).

Experimenta l Sites

At grove site 1, plots consist ed of 9 trees a rra nged in a 3 by 3 grid (Ta ble 1). At sites

2 and 3, trea tment s were a ssigned to plots of 25 trees a rra nged in a 5 by 5 grid a nd a t

site 4, 36 trees a rra nged in a 6 by 6 grid. All treat ments w ere arra nged in a ra ndom-

ized complete block design ba sed on motile numbers of citru s rust mites per t ree ta ken

during t he pretrea tm ent count s a nd replica ted 5 times for ea ch site (Ch ilders & Sel-

him e 1983).

The cent er tr ee wa s sa mpled from ea ch plot in a ll of the sites except site 2 wh ere

2 center tr ees w ere sampled from ea ch plot. Ea ch sam ple tree wa s a vigorous, hea lthy

tree representa tive of the block and ea ch plot w a s sepa ra ted from adjacent plots by 2

trees wi thin t he row and 2 rows betw een t reatments . Foliar spray treat ments were

a pplied in th e l isted volumes per ha wit h properly ca libra ted a irblast sprayers on the

da tes list ed in Ta ble 1.

TABL E 1. L

OCATIONS

, CHARACTERISTICS

OF

CITRUS

PLANTINGS

, DATES

OF

MITICIDEAPPLICATION

, SPRAYERS

, GALLONAGES

AND

TRACTOR

S P E E D S

.

Character is t ic

Ci trus G rove Si te

1 2 3 4

Loca t ion B a seba ll C it yP olk County

Mineola vic.La ke County

La ke Pla cid vic.HighlandsCounty

Ft. Meade vic.P olk County

C ult iva r Va lencia ora nge H a mlin ora nge Va lencia ora nge H a mlin ora nge

Tree h eigh t(met ers) 4.57-5.49 m 2.13-3.35 m 4.27-5.18 m 2.44-3.66 m

Spacing(meters)

7.62 x 7.62 m(= 173 trees/hectare)

7.62 x 9.14 m(= 240 trees/hectare)

9.14 x 9.14 m(= 119 t rees/hectare)

4.57 x 7.62 m(= 287 tr ees/hect -are)

Applicationdates

May 26-27,1988

J une 20-22,1989

J une 25-26,1991

J uly 8-10,1991

Type spra yer FMC 4000 CP S out hw ind pt o FMC 970 S w a nson-Durand p to

Lit ers perhect a re 1,169 1,169 1,403 720

S pra y pressure 160 psi 200 psi 180 psi 100 psi

Tra ct or speed 2.4 kph 2.4 kph 2.4 kph 2.4 kph

Wa t er pH 7.9 7.8 7.3 7.6


4/17

352


77(3) S ept em ber, 1994

Mite Sa mpling

Twent y fruit w ere examined a t r a ndom ar ound t he ca nopy perimeter of each sa m-

ple tree at recorded time interva ls before an d a fter spray ing of the tr eat ments. Live

motile citrus r ust m ites were counted using a 10x ha nd lens equipped w ith a 1 cm

2

grid subdivided int o 4 mm

2

subu nit s (Child ers & S elhime 1983). Tw o pla ces on oppo-

site sides of each fruit outside of the exposed sunspot w ere exa mined. P opula tion den-

sity estimates of citrus rust mite were obtained by counting the number of l iving

motile mites present w ithin t he combined 2 cm

2

a rea per fruit a nd recorded a s one ob-

servat ion. In test 2, 10 fruit w ere examined a t r a ndom ar ound the canopy perimeter

from each of 2 sam ple tr ees with a tota l of 20 fruit per plot.

Twent y leaves from the spring fl ush w ere picked at ra ndom a round the canopy pe-

rimeter of each sam ple tree at designa ted time interva ls before an d a fter spraying.

Ea ch leaf sa mple wa s pla ced in separa tely labeled pa per ba gs an d returned to the lab-

orat ory. A stereomicroscope wa s used to exa mine a 1 cm

2

a rea on both t he upper a ndlow er leaf sur fa ces in t est 1, or a 2 cm

2

a rea on both leaf surfaces in tests 4 and 5. Live

motile citrus rust mites were counted w ithin each a rea on both the upper a nd lower

leaf sur fa ces. The 2 counts w ere combined as 1 observat ion a nd equa lled either 2 or 4

cm

2

a rea of leaf su rfa ce. In t est 3, 10 leaves w ere collected from ea ch of 2 trees in th e

cent er of each plot.

Cumulative citrus rust mite-days were determined for each treatment within a

grove each year by calcula ting t he a rea under the populat ion growt h curve over time

(Allen 1976). Mite-da ys w ere ca lcula ted using th e formula presented by C hilders et a l.

(1987).

Fru it D ama ge Rat ings

One hundred fruit w ere examined ra ndomly a round the perimeter of ea ch sample

tr ee follow ing completion of a fi eld experiment. The cumula tive percent a ge of surfa ce

a rea wit h russeting from citrus rust mite feeding injury w a s recorded for ea ch fruit .

This wa s determined by estima ting t he percenta ge ar ea of russeting on one side of

each fruit an d then tur ning the fruit 180

a nd repeat ing the estima te of russeted ar ea

a ga in. The combined estimat ed russeted area of sides one and t wo for ea ch fruit w a s

then divided by tw o. A series of plat es with l ine draw ings of mat ure sized fruit w ith

calculat ed proport ional a rea s of surfa ce injury were prepar ed to provide a consist ent

reference for t he person det ermining rin d blemish injury. A fruit w a s classifi ed a s re-

jected for t he fresh ma rket w hen rind blemish from citrus r ust mite feeding exceeded5%of the tota l surface a rea.

Sta t is t ical Analysis

In all experiments, data were subjected to analysis of variance; Duncans (1955)

multiple ra nge test w a s used to sepa ra te t reat ment m eans w hen the ANOVA provided

a s ignificant F va lue (P

0.05) (SAS Inst itut e 1991). Motile citrus rust mite count s

were subjected to Log

10

(X + 1) tra nsforma tions for s ta t is t ica l ana lysis . Unt ra ns-

formed means a re shown in all ta bles.

R

ESULTS

Sit e 1, Va lencia Ora nge

Sust a ined moderat e numbers of citrus rust mites were present in the unt reat ed

check trees thr ough August 2 follow ing tr eat ment a pplicat ions on May 26 and 27. Cit -


5/17


353

rus rust mite densities on trea ted tr ees w ere signifi cant ly higher betw een August 2

a nd 25 in t he Vendex + copper sulfa te or hydr oxide combinat ions compa red w ith t he

Vendex only tr eat ment s a t t he sa me ra te (Ta ble 2). Cumu la tive mite-da ys w ere sig-

nifi can tly high er wit h t he 2.10 kg ra te of Vendex + copper hydr oxide an d th e 1.40 kgra te of Vendex + copper sulfa te compa red w ith t he sa me ra tes of Vendex applied alone.

The other combinat ions of copper + Vendex did not result in s ignifi cant ly higher cu-

mulat ive mite-da ys t ha n t he corresponding ra tes of Vendex a lone. Da ma ge ra ting dif-

ferences were not significantly dif ferent between the miticide treatments in this

experiment (Ta ble 2). B a sed on these da ta , a ll Vendex trea tm ents performed w ell.

Site 2, Hamlin Orange

Modera te to high densities of citrus rust mites were present on the untr eat ed trees

betw een J uly 27 an d October 12 follow ing t rea tm ent a pplica tions (Ta ble 3). Vendex a t

1.68 kg + copper hydroxide ha d a significan tly higher citrus rust mite density on the

fruit by S eptember 20 compared w ith Vendex a t 1.68 kg applied a lone. Vendex a t 1.68

kg + copper sulfa te ha d a significant ly higher citrus rust mite density by S eptember

27 compa red w ith Vendex at th e sa me ra te a pplied alone. These differences continued

th rough October 18. Vendex at 2.24 kg + copper hy droxide ha d signifi cant ly higher cit-

rus rust mite densities by September 27 compared with Vendex at 2.24 kg applied

alone. Again, these differences continued through October 18. The Vendex at 2.24 kg

+ copper sulfat e combina tion wa s not signifi cant ly different from Vendex at 2.24 kg

unt il October 3. These differences in citrus rust mite d ensities cont inued t o be signif-

ica nt ly higher th rough October 12. Vendex a t 2.80 kg combined wit h eith er copper hy -

droxide or copper sulfate had significantly higher citrus rust mite densities on thefruit by September 20 and 27 and October 18 compared with Vendex at 2.80 kg ap-

plied a lone. These high rust mite densit ies occurred w hile the populat ion w a s increas-

ing in the unt reat ed check tr ees.

Consistently higher citrus rust mite densities ranging from 1 to 4 times higher

w ere present in both copper hy droxide a nd copper sulfa te t rea ted t rees between Au-

gust 17 and S eptember 27 compa red with the unt reat ed trees.

Cumula tive mite-da y compar isons w ere signifi cant ly dif ferent between t he Ven-

dex at 1.68 kg + copper hyd roxide tr ea tm ent compar ed wit h Vendex at 1.68 kg applied

a lone (Ta ble 4). Cu mula tive mit e-da y differences betw een the r ema ining mit icide

trea tment s were not significa ntly dif ferent a lthough numerica lly higher densities of

citrus rust mites w ere consistently obta ined in the Vendex + copper tr eat ments com-pared w ith t he Vendex only t reat ments.

Signifi cant ly higher percenta ges of russeted a nd rejected fruit were obtained in

th e low ra te of Vendex combined w ith either copper hy droxide or copper sulfa te com-

par ed w ith th e low ra te of Vendex a pplied a lone (Ta ble 4). The highest percenta ges of

russeted and rejected fruit were obtained in the copper-only treatments compared

wit h a ll other t reat ments including the untrea ted check trees.

Sit e 3, Va lencia Ora nge

Low t o moderat e citrus rust mite densities w ere present on both fruit a nd leavesbetw een J uly 11 an d August 19 on the un tr eat ed check tr ees (Ta bles 5, 6). Low bu t s ig-

nifi cant ly higher citrus rust mite densities w ere present on the Vendex + copper DF

trea tment by August 12 compar ed w ith Vendex a pplied a lone. Signifi cant ly higher cit-

rus rus t m ite densities on t he fruit w ere consistent ly obta ined on t he Vendex + copper

DF trea tment between August 12 and September 17 compar ed w ith Vendex applied


6/17

354


77(3) S ept em ber, 1994

1

Citrusrustmi

teper2cm

2

offruitsurface.

2

Meanswithin

columnsfollowedbythesameletterarenotsignificantlydifferent[P>0.05;D

uncans(1955)multiplerangetest].

TABLE2.C

ONTROL

OF

CITRUS

RUST

MITE

O

N

V

ALENCIA

ORANGE

(

SITE

1)

IN

P

OLK

C

OUNTY

,F

LORIDA

,1

988.

Treatmentand

Formulation

Rate

per

Hectare

Pre-trea

tment

Mea

ns

May

23

CitrusRustMitePost-treatmentMeans

1

Cumulative

Mite-days

%

Russeted

Fruit

%

R

ejected

Fruit

Jun30Jul7

Jul19

Jul25

Aug2Aug15

Aug

25

Vendex

4L

1.40kg

3a

2

1b

0b

0c

1cd

0d

1d

3d

196cd

0.8b

0.4b

Vendex

4L

2.10kg

2a

0b

0b

0c

0d

0d

0d

0e

134d

1.2b

1.2b

Vendex

4L

2.80kg

2a

0b

0b

0c

0d

0d

0d

0e

34d

0.2b

0.2b

Vendex+

4L

1.40kg

Copperhydroxide77WP

7.96kg

1a

0b

0b

0bc

2bc

6b

6bc

4b

258bc

0.6b

0b

Vendex+

4L

2.10kg

Copperhydroxide77WP

7.96kg

2a

0b

2b

1b

4b

6b

11a

12a

506b

3.4b

1.4b

Vendex+

4L

1.40kg

Coppersulfate

99GC

7.96kg

1a

0b

0b

0bc

2bcd

3c

3cd

4c

239c

0.4b

0b

Vendex+

4L

2.10kg

Coppersulfate

99GC

7.96kg

1a

0b

0b

0c

0cd

1d

2d

2d

91cd

0b

0b

Untreated

1a

82a

63a

46a

58a

34a

8ab

3c

2761a

30.6a

19.2a


7/17

Chi l der s: Copper Form ul ati ons and Rust M i te Cont r ol

355

1

Citrusrustmi

teper2cm

2

offruitsurface.

2

Meanswithin

columnsfollowedbythesameletterarenotsignificantlydifferent(P>0.05;D

uncans[1955]multiplerangetest).

TABLE3.C

ONTROL

OF

CITRUS

RUST

MITE

O

N

H

AMLIN

ORANGE

(

SITE

2)

IN

L

AKE

C

OUNTY

,F

LORIDA

,1989.

TreatmentandFormulation

Rate

per

Hectare

P

re-treatment

Means

June16

CitrusRustMitePost-t

reatmentMeans

1

Jul5

Aug

17

Aug24

Sep20

S

ep27

Oct3

Oct12

Oct18

Vendex

4L

1.68kg

12a

2

0c

0

c

0e

7fg

6f

4d

20fg

15d

Vendex

4L

2.24kg

38a

0c

0

c

0e

3gh

33de

3d

36de

16d

Vendex

4L

2.80kg

14a

0c

0

c

10d

2h

1g

3d

27h

2e

Vendex+

4L

1.68kg

Copperhydroxide

77WP

7.85kg

30a

0c

0

c

0de

16d

75b

30a

99a

53a

Vendex+

4L

2.24kg

Copperhydroxide

77WP

7.85kg

20a

0c

0

c

0de

4efg

76c

22c

98ab

33b

Vendex+

4L

2.80kg

Copperhydroxide

77WP

7.85kg

21a

0c

0

c

0e

7fg

14ef

2d

25ef

10d

Vendex+

4L

1.68kg

Coppersulfate

99GC

7.85kg

42a

0c

0

c

0e

9ef

21de

27c

60abc

47a

Vendex+

4L

2.24kg

Coppersulfate

99GC

7.85kg

26a

0c

0

c

1de

11e

29cd

10c

36de

24bc

Vendex+

4L

2.80kg

Coppersulfate

99GC

7.85kg

21a

0c

0

c

0e

5fg

16ef

7d

20gh

35b

Copperhydroxide

77WP

7.85kg

32a

7b

67

a

124a

192b

1

58a

20bc

48bcd

14cd

Coppersulfate

99GC

7.85kg

18a

7b

44

a

114b

202a

1

64a

28ab

35cde

15d

Untreated

22a

8a

43

b

34c

74c

94b

30a

49cd

11cd


8/17

356


77(3) S ept em ber, 1994

a lone. All 3 Vendex + copper trea tment s ha d signifi cant ly higher citrus rust mite den-sities on both fruit a nd leaves betw een August 19 a nd S eptember 10 compa red w ith

Vendex a pplied alone.

P. ol ei vora

densities on fruit in t he 3 copper-only trea tm ents w ere signifi cant ly

higher betw een J uly 11 and September 10 compar ed with the unt reat ed check tree

counts. Populations of citrus rust mites ranged from 2 to 36 times higher on copper

trea ted fruit compar ed with t he untrea ted check trees.

The 4 mit icide trea tm ents provided compa ra ble contr ol of th e citr us rus t m ite on

leaves th rough J uly 18 (Ta ble 6). Low, but signifi cant ly higher, ci trus rust mite den-

sities on lea ves were present on t he Vendex + copper DF a nd Vendex + copper hydrox-

ide trea tm ents by August 12 compa red w ith Vendex a pplied a lone. These differences

increa sed dra ma tically betw een August 26 and September 10. The Vendex + coppersulfat e trea tment wa s less disruptive to rust mit e control compa red with t he oth er 2-

Vendex + copper trea tment s. However, lea f counts in this t reat ment w ere signifi cant ly

higher compared wit h t hose in t he Vendex only t reat ment between August 19 and

September 17.

1

Means within columns followed by the same letter are not significantly different (P>0.05; Duncans [1955]multiple range t est).

TAB LE 4. C

UMULATIVE

CITRUS

RUS T

MITE-DAYS AND DAMAGE RATING COMPARISONSOF F RUI TI N J U R YON H AMLIN ORANGE (SITE 2) I N LAKE C OUNTY, F LORIDA1989.

Treat ment a nd Formulat ionRa te perHectare

Cumulat iveMite-days

Oct 181%Russeted

Fruit 1%Rejected

Fruit 1

Vendex 4 L 1.68 kg 729 d 12 ef 9 cd

Vendex 4 L 2.24 kg 1271 cd 10 ef 6 cd

Vendex 4 L 2.80 kg 710 d 5 f 3 d

Vendex + 4 L 1.68 kg

Copper hydroxide 77 WP 7.85 kg 2561 c 52 bc 32 b


Copper hydroxide 77 WP 7.85 kg 2007 cd 31 cde 20 bc


Copper hydroxide 77 WP 7.85 kg 843 d 10 ef 5 cd


Copper sulfa t e 99 G C 7.85 kg 1753 cd 40 bcd 31 b


Copper sulfa t e 99 G C 7.85 kg 1261 cd 22 def 11 cd


Copper sulfa t e 99 G C 7.85 kg 932 d 17 ef 8 cd

Copper hydroxide 77 WP 7.85 kg 6431 a 86 a 70 a

Copper sulfa t e 99 G C 7.85 kg 6056 a 85 a 71 a

U nt rea t ed 3573 b 58 b 42 b


9/17

Chi l der s: Copper Form ul ati ons and Rust M i te Cont r ol 357

1Citrusrustmi

teper2cm2o

ffruitsurface.

2Meanswithin



TABLE5.CONTROLOFCITRUSRUSTMITEO

NVALENCIAORANGEFRUIT(SITE3)INHIGHLANDSCOUNT

Y,FLORIDA,1991.


Rate

per

Hectare

Pr

e-treatment

Means

June19

CitrusRustMitePost-treatmentMeans1

Jul18

Jul24

Aug12

Aug19

Aug26

Sep3

Sep10

Sep17

Vendex

4L

2.24kg

4a2

0c

0d

0e

0e

0f

3e

3d

1b

Vendex+

4L

2.24kg

Cooperhydroxide

DF

8.97kg

4a

0c

1d

2d

15c

1

8c

58a

23a

7a

Vendex+

4L

2.24kg

Coppersulfate

99GC

8.97kg

4a

0c

0d

0e

4d

9e

15c

5cd

1b

Vendex+

4L

2.24kg

Copperhydroxide

77WP

8.97kg

4a

0c

0d

1de

10c

1

8cd

35b

10bc

1b

Copperhydroxide

DF

8.97kg

4a

53a

61b

142a

57a

4

7a

18c

26a

1bc

Coppersulfate

99GC

8.97kg

4a

49a

75a

167a

40b

1

9cd

9d

4d

0d

Copperhydroxide

77WP

8.97kg

4a

51a

67a

b

97b

57a

3

6b

26c

3d

0cd

Untreated

4a

22b

14c

27c

7c

1f

1f

1e

0d


10/17

358 Fl or id a E ntomologist77(3) S ept em ber, 1994

1Citrusrustmi

teper4cm2o

fleafsurface.

2Meanswithin



TABLE6.CONTROLOFCITRUSRUSTMITEO

NVALENCIAORANGELEAVES(SITE3)INHIGHLANDSCOUN

TY,FLORIDA,1991.


Rate

per

Hectare

Pre

-treatment

Means

June19


Jul18

Jul24

Jul31

Aug12

Aug19

Aug26

Sep3

Sep10

Sep17

Vendex

4L

2.24kg

1a2

0d

0e

0d

0e

0e

0d

1e

2e

2c

Vendex+

4L

2.24kg

Cooperhydroxide

DF

8.97kg

1a

0d

0e

1c

5d

7c

22a

51a

26a

7a

Vendex+

4L

2.24kg

Coppersulfate

99GC

8.97kg

2a

0d

0e

0d

0e

2d

5c

11d

8c

6b

Vendex+

4L

2.24kg

Copperhydroxide

77WP

8.97kg

1a

0d

3d

0d

1d

5c

15a

25b

15b

4b

Copperhydroxide

DF

8.97kg

2a

6b

19b

18a

21a

15a

10b

11cd

2de

1c

Coppersulfate

99GC

8.97kg

1a

12a

30a

16a

17b

15b

7c

10d

3de

1c

Copperhydroxide

77WP

8.97kg

3a

15a

18b

18a

19a

18a

7c

12c

3d

1c

Untreated

1a

3c

12c

9b

9c

7c

1d

1e

0f

0d


11/17

Chi ld er s: Copper F ormul ati ons and Rust M i te Cont r ol 359

Cumula tive mite-da y comparisons on fruit a nd leaves showed tha t t he Vendex +

copper DF tr eat ment w a s signifi can tly higher t ha n Vendex alone or Vendex combined

wit h copper sulfat e. Cumula tive mite-da ys on fruit w ere not significan t between Ven-

dex combined with either copper hydroxide or copper sulfate while the cumulativemite-da y dif ferences were significa ntly h igher on leaves between t he 2 trea tment s.

Also, th e Vendex + copper sulfa te cumula tive mite-da y va lue on leaves w a s signifi -

cant ly higher compa red w ith Vendex applied alone while those on t he fruit w ere not

(Ta ble 7).

Cumula tive mite-da y va lues on fruit a nd leaves for t he Vendex + copper DF a nd

Vendex + copper hydr oxide trea tm ents w ere not signifi can tly different. Correspond-

ing percenta ges of russeted a nd rejected fruit were not signifi cant ly dif ferent between

the sa me 2 Vendex + copper trea tment s compar ed with the unt reat ed check tr ees.

This demonst ra tes t he nega tive effect of ta nk-mixing either copper hydr oxide formu-

lat ion a t t he rat es tested with Vendex.

P. ol ei voradensities on leaves in the 3 copper-only treatments were somewhatvar iable until J uly 31. B etween th a t da te a nd S eptember 10, al l 3 copper-only t reat -

ments ha d consistent a nd significan tly higher citrus rust m ite densities on leaves tha t

ra nged from 2 to 12 times higher t ha n th ose on the unt rea ted check trees. B oth copper

DF and copper hydroxide tank-mixes with Vendex resulted in significantly higher

percenta ges of russeted fruit compa red w ith Vendex a pplied a lone. Only t he Vendex

+ copper DF combinat ion ha d a significan tly grea ter percenta ge of rejected fruit com-

par ed wit h Vendex applied alone (Ta ble 7). P ercent a ges of both ru sseted fruit a nd re-

jected fruit were significantly higher in the 3 copper-only treatments compared with

th e unt rea t ed check tr ees (Ta ble 7).

1Means within columns followed by the same letter are not significantly different (P > 0.05; Duncans [1955}

multiple ra nge test).

TABL E 7. C UMULATIVE CITRUS RUS TMITE-DAYS AND DAMAGE RATING COMPARISONSOF F RUI T I N J U R YON VALENCIA ORANGE (SITE 3) I NTH E LAKE P LACID VI -CINITY, H IGHLANDS C OUNTY, F LORIDA, 1991.

Treat ment a nd Formula tionRa te perHectare

Cumula tive mite-da ys 1 %Russeted

Fruit 1

%Rejected

Frui t 1Lea ves Fruit

Vendex 4 L 2.24 kg 43 d 77 e 14 d 0.4 c


Copper hydroxide D F 8.97 kg 865 b 912 bc 55 b 18.8 b


Copper sulfa t e 99 GC 8.97 kg 231 c 271 de 25 cd 2.6 c


Copper hydroxide 77 WP 8.97 kg 501 b 594 cd 31 bc 6.6 bc

Copper hydroxide D F 8.97 kg 1080 a 3930 a 89 a 63.8 a

Copper sulfa t e 99 G C 8.97 kg 1410 a 4540 a 97 a 79.8 a

Copper hydroxide 77 WP 8.97 kg 1303 a 3930 a 93 a 66.6 a

U nt rea t ed 507 b 756 b 33 bc 6.4 bc


12/17


Site 4, Hamlin Orange

Low t o moderat e citrus rust mite densities on fruit in the unt reat ed check trees

w ere recorded betw een J uly 15 a nd S eptember 10 follow ing trea tm ent a pplicat ions onJ uly 8, 9 a nd 10. P opula tion development of P. ol ei vorawa s evident on the ba ck sides

of fruit by August 8 w ith n o citrus rust mites present on the front sides of the sa me

fruit in t he Vendex trea tment s. P oor spray coverage resulted from ina dequa te pene-

tration of pesticide spray through the canopy since only 720 liters of finished spray

w ere applied per hecta re.

All Vendex trea tm ents provided compa ra ble control of citrus ru st mite on t he fruit

t hr ough Augu st 13 (Ta ble 8). The Vendex + copper hy droxide a nd Vendex + copper DF

combinat ions generally ha d significa ntly h igher citrus rust mite densities on the fruit

between August 21 and September 10 compared with Vendex applied alone and the

Vendex + copper sulfa te t rea tm ents. As in t he previous fi eld experiment (site 3), th e

amount of metallic copper applied per hectare was highest in the copper sulfate for-mulation followed by copper hydroxide WP and copper hydroxide DF. The 3 copper-

only t reat ments did not ha ve higher rust mite densities on fruit during th is experi-

ment compa red w ith t he unt rea ted check trees (Ta ble 8).

All 4 Vendex tr eat ments ha d signifi cant ly lower cumula tive mite-da y va lues on

fruit compa red w ith t he unt rea ted check trees (Ta ble 9). Only t he Vendex + copper hy -

droxide 77%WP trea tment ha d significan tly more russeted fruit compar ed with t he

other Vendex treatments in this experiment. Numerically higher percentages of re-

jected fruit w ere found in th e Vendex + copper D F a nd Vendex + copper hy droxide

trea tment s. However, they were not signifi cant ly different compar ed with t he other 2

Vendex t reat ments.

P. olei voradensities on leaves were low in a ll treat ments t hroughout this experi-ment (Ta ble 10). How ever, signifi can tly h igher citrus r ust mite densit ies were re-

corded on th e Vendex + copper D F a nd Vendex + copper hy droxide trea tm ents on

August 27 and September 5 compar ed w ith Vendex a pplied a lone or Vendex + copper

sulfate. The 3 copper-only treatments did not have consistently higher citrus rust

mite densities on the leaves compared with the untreated check trees. Cumulative

mite-day differences between the copper-only and untreated check treatments were

not signifi cant ly different in t his experiment (Ta ble 9).

D I S C US S I O N

Results from t his study show tha t t he different copper formula tions tested ar e in-

compatible with Vendex when applied at the rates tested. The copper hydroxide DF

formulation demonstrated the greatest degree of incompatibility followed by copper

hydroxide WP. The copper sulfate formulation in combination with Vendex showed

the least disruption in residual rust mite control of the 3 formulations tested. The

amount of available metallic copper applied per hectare in tests 3 and 4 differed be-

tw een the 3 formula tions a s follow s: copper D F = 1.45 kg, copper hydroxide = 1.81 kg

a nd copper sulfat e = 1.93 kg. This w ould suggest t ha t one or more oth er components

of th e copper DF formula tion were involved in crea ting increa sed a nt a gonism in com-

bination with the organo-tin miticide compared with the metallic copper content

alone. This phenomenon is not unique and has been reported with other tank mix-tu res. For exam ple, Venka ta Ra m (1963) found tha t n ickel chloride hexa hydr a te con-

trolled the fungal pathogen, Exobasid ium vexans, on tea as effectively as copper

oxychloride w ithout increa sing purple mite, Calacaru s cari natus(G reen) (Aca ri: E rio-

phyidae).


13/17


1Citrusrustmi

teper2cm2

offruitsurface.

2Meanswithin


uncans[1955]multiplerangetest.

TABLE8.CONTROLOFCITRUSRUSTMITE

ONHAMLINORANGEFRUIT(SITE4)INTHEFT.MEADEVICINITY,POLKCOUNTY,FLORIDA

,1991


Rate

per

Hectare

Pre-

treatment

Means

Jul27


Jul23

Jul30

Aug8

Aug13

Aug21

Aug27

Sep5

Sep10

Sep18

Vendex

4L

2.24kg

4a2

0b

0c

2d

0c

4d

4c

3c

3d

1a

Vendex+

4L

2.24kg

Copperhydroxide

DF

8.97kg

5a

0b

0c

8c

0c

4cd

7b

8c

14bc

2a

Vendex+

4L

2.24kg

Coppersulfate

99GC

8.97kg

4.a

0b

0c

1d

0c

1e

2c

5c

3d

1a

Vendex+

4L

2.24kg

Copperhydroxide

77WP

8.97kg

5a

0b

0c

2d

2c

7c

9b

10b

12c

5a

Copperhydroxide

DF

8.97kg

4a

6a

9a

40b

11b

16b

20a

43a

29a

2a

Coppersulfate

99GC

8.97kg

5a

4a

6b

6c

10ab

20b

27a

40a

22ab

2a

Copperhydroxide

77WP

8.97kg

4.a

3a

4b

13c

17ab

32a

29a

39a

10bc

2a

Untreated

7a

15a

7ab

47a

19a

34a

30a

26a

21abc

1a


14/17


Citrus rust mite populations increased in 2 of the 3 field experiments in which

copper-only trea tm ents w ere included. In both inst a nces, populat ion increas es in the

copper-only t reat ments occurred a t the sa me time a s t hose occurring in t he untr eat ed

checks. However, the mite densities were significantly higher suggesting a

stim ula tory effect by th e copper compounds. J ohnson (1960b) found t ha t copper

compounds ha d no effect on t he percenta ge of fruit infest ed wit h P. ol ei vorawhen the

population was increasing on unsprayed trees. However, copper sprays prolonged

high citrus rust mite popula tions, or caused a n increase, i f applied w hen unspra yed

populations were declining. This situation did not develop in 2 of the 3 field

experiments in this study. Adverse effects caused by copper compounds on the

pat hogenic fungus, H ir sutel l a th ompsoni iFisher, have been proposed (Eger et al.

1985, McCoy 1979, G riffi th & Fish er 1949, Spencer 1939, Thompson 1939).

In m a ny inst a nces, the use of copper on Florida citr us is essentia l for effective dis-

eas e control. Gr eat care mus t be exercised by citrus grow ers wh en selecting pesticides

for control of pest complexes. Oftent imes, ta nk-mixes a re designed t o minimize a ppli-

cat ion costs a nd t o optimize effi ciency. The use of such ta nk-mixes requires sound a s-

surance of both physical and chemical compatibility. Potential risks of pesticide

fa ilure or a ccelera tion of pesticide resista nce dicta te t he need for such informa tion.

Vendex is a high ly effective miticide w ith broa d spectr um a ctivity a ga inst va rious

phyt opha gous mite pests in t he fa milies Eriophyida e, Tetra nychida e, Tenuipalpida e,

a nd Ta rsonemidae. S tudies presented here demonstra te t ha t copper DF a nd copperhydr oxide formula tions r esult in reduced residua l effectiveness of Vendex, especia lly

a t low er ra tes, i .e., 2.24 kg of 50 WP or 2.34 liters of 4 L per hecta re (U niversity of

Florida 1993 Spray Guide recommendations). In a single field experiment by Lye et

a l. (1990), Vendex 4 L wa s a pplied a t t he ra te of 3.34 liters per hecta re in combina tion

1Means within columns followed by the same letter are not significantly different (P > 0.05; Duncans [1955}multiple range t est).

TAB LE 9. C UMULATIVE CITRUS RUS TMITE-DAYS AND DAMAGE RATING COMPARISONSOF F RUI TI N J U R YON H AMLIN ORANGE (SITE 4) INTH E FT. M EADE VICINITY,P OL K C OUNTY, FLORIDA, 1991.

Treat ment a nd Formulat ionRa te perHectare

Cumula tive Mite-da ys 1 %Russeted

Fruit 1

%Rejected

Fruit 1Lea ves Fruit

Vendex 4 L 2.24 kg 100 c 157 b 16 e 9 d


Copper hydroxide D F 8.97 kg 203 bc 361 b 25 de 13 cd


Copper sulfa t e 99 G C 8.97 kg 76 c 117 b 14 e 7 d


Copper hydroxide 77 WP 8.97 kg 224 bc 379 b 32 cd 18 cd

Copper hydroxide D F 8.97 kg 399 a 1367 a 55 ab 38 a b

Copper sulfa t e 99 G C 8.97 kg 408 ab 1057 a 56 ab 38 ab

Copper hydroxide 77 WP 8.97 kg 418 a 1136 a 43 bc 29 bc

U nt rea t ed 449 a 1558 a 68 a 53 a


15/17


1Citrusrustmi

teper4cm2o

fleafsurface.

2Meanswithin



TABLE10.C

ONTROLOFCITRUSRUSTMITE

ONHAMLINORANGELEAVES

(SITE4)INTHEFT.MEADEV

ICINITY,POLKCOUNTY,FLORIDA,1991


Rate

per

Hectare

P

re-treatment

Means

Jun27


Jul15

Aug

9

Aug13

Aug21

Aug27

Sep5

Sep10

Sep18

Vendex

4L

2.24kg

1a2

1cd

0c

0c

0d

2e

2d

2de

2a

Vendex+

4L

2.24kg

Copperhydroxide

DG

8.97kg

1a

1cd

0c

1c

1d

6cd

7c

4cd

5a

Vendex+

4L

2.24kg

Coppersulfate

99GC

8.97kg

2a

0d

0c

0c

0d

1e

2d

1e

3a

Copper+

4L

2.24kg

copperhydrox

ide

77WP

8.97kg

3a

0cd

0c

0c

2d

3d

5c

4c

5a

Copperhydroxide

DF

8.97kg

1a

2a

2a

b

3b

8bc

9bc

11b

12a

5a

Coppersulfate

99GC

8.97kg

0a

0cd

6b

3b

6c

1

2ab

16a

3cd

6a

Copperhydroxide

77WP

8.97kg

0a

1bc

5a

2b

8ab

1

2a

12ab

12a

4a

Untreated

1a

4ab

2a

b

7a

8a

1

0ab

10b

7b

6a


16/17


w ith copper hydroxide. No reduction in miticida l activit y w a s recorded. H owever, this

ra te exceeds tha t w hich is recommended in the Florida C itrus Spra y G uide.

Additiona l studies a re needed to identify t hose miticides current ly recommended

for use during the postbloom and summer sprays that have minimal compatibil i typroblems wit h specifi c ava ilable copper formu la tions.

E NDNOTE

The technical a ssista nce of Pa ul M. Keen, J r ., Micha el G. Wa rmington, a nd

Deanna K. Threlkeld is gratefully acknowledged. Florida Agricultural Experiment

St a tion J ourna l No. R-03528.

REF ERENC ES C ITED

ALLEN, J . C. 1976. A model for predicting citr us rust mite da ma ge on Va lencia ora ngefruit . E nvir on. E nt omol. 5:1083-1088.

B R U S S E L, E . W. VAN. 1975. Int errela tions betw een citrus rust m ite, H ir sutel l a thomp-soniia nd greasy spot on citrus in S urinam. Agric. Exp. Sta . Surinam (P ara ma-ribo). B ull. 98.

B ULLOCK , R. C., C. C. C H I LD ERS , J . L . KNAPP , C . W. MCC OY , AND P . A. S TANSLY. 1993.Citrus rust mite and spider mites, i nJ . L. Kna pp [ed.], Florida C itrus Spra yG uide. Florida Coop. Ext . Serv., IFAS, U niv. Florida, G a inesville, SP -43.

C H I LD ERS , C. C . 1987. Chemica l control of phytopha gous mite pests on Florida citr us.P roc. In t. C onf. on P ests in Agric. P a ris II I, pp. 119-126.

C H I LD ERS , C. C ., L. W. D UNCAN, T. A. WHEATON , AND L. W. TIMMER . 1987. Art hr opod

a nd nema tode control wit h a ldicarb on Florida citrus. J . Econ. En tomol.80:1064-1071.

C H I LD ERS , C. C., AND A. G. S ELHIME . 1983. Redu ced effi ca cy of fenbut a t in-oxide incombination with petroleum oil in controlling the citrus rust mite Phyllocop-tr uta oleivora. F lorida E nt omol. 66:310-319.

D E AN, H. A. 1979. Citr us rust mite cont rol affected by certa in pesticides. J . RioGrande Valley Hort. Soc. 33:55-61.

D UNCAN, D. B . 1955. Multiple ra nge a nd m ultiple F t ests. B iometr ics 11:1-42.E G E R , J . E . , J R ., V. M. F ERGUS O N , AND K. G . TOWNSEND . 1985. E ffi ca cy of selected

miticides a nd spra y t a nk mixtures used to control rust mite in Florida citrus.P roc. Florida St a te H ort. S oc. 98:11-14.

G RIFFITH , J . T., J R . , AND F. E. F I S H ER. 1949. Residues on Ci t rustrees in Florida. J .

Econ. Entomol. 42:829-833.H OLLOWAY, J . K. , C. F. H ENDERSON , AND H . V. MCB URNIE . 1942. P opula tion increa ses

of citrus red mite a ssocia ted w ith t he use of sprays conta ining inert gr a nularresidu es. J . Econ. E nt omol. 35:348-350.

J OHNSON, R. B. 1960a. The effect of copper compounds on control of citrus rust mitew ith z ineb. J . Econ. En tomol. 53:395-397.

J OHNSON, R. B . 1960b. The effect of copper on ru st mite control w ith four r ust mitemiticides. Florida St a te H ort. S oc. 73:84-89.

J OHNSON, R. B. , J . R. KING , AND J . J . MCB RIDE , J R. 1957. Zineb controls citrus rustmite. P roc. Florida St a te H ort. S oc. 70:38-48.

LYE , B . H., C . W. MCC OY , AND J . FOJ TIK . 1990. E ffect of copper on residu a l effi cacy ofacaricides and population dynamics of citrus rust mite (Acari: Eriophyidae).

Florida E nt omol. 73:230-237.MCC OY , C. W. 1977. Hort icultur a l pract ices affecting phyt opha gous mite populat ions

on citrus. Proc. Int. Soc. Citriculture 2:459-462.OOMEN, P . A. 1982. P opula tion dyna mics of the scar let mite, Br evipal pus phoeni cis, a

pest of t ea in I ndonesia. Meded. La ndbouwh ogeschool Wa geningen. 82-1, 88 p.


17/17

Chi ld er s: Copper F ormul ati ons and Rust M i te Cont r ol 365

SAS I NS TI TU TE . 1991. SAS la ngua ge an d procedures: Us a ge 2, version 6, First edit ion.SAS Insti tut e. Ca ry, North C a rolina.

S EAMAN , A. J . , AND H . R I ED L . 1986. P reventing decomposition of a gricultura l chemi-cals by alkaline hydrolysis in the spray tank. Cornell Univ., New Yorks Fooda nd L ife Science Bu ll. 118. 7 p.

S P E N C E R, H. 1939. Increa ses in citru s scale insect infesta tions from heavy r esidue andfrom copper spra y mixtur es. J . E con. En tomol. 32:686-688.

THOMPSON, W. L. 1939. Cu ltur a l practices an d th eir influ ence upon citrus pests. J .Econ. Entomol. 32:782-789.

TIMMER , L. W., AND R. M CG OVERN. 1993. Fu ngu s disea ses, fru it a nd/or folia ge, pp 11-13 i nJ . L. K na pp [ed.], Florida Citrus Spra y G uide. Florida Coop. Ext. S erv.,IFAS, U niv. Florida , G a inesville. SP -43.

VENKATARAM, C. S . 1963. Applica t ion of copper a nd n ickel fung icides wit h mot orizedmist blow ers for blister blight cont rol. 3. E ffect of yield a nd buildup of purplemites. Rep. U nit P la nt Assoc. S outh Ind ia Sci. D ept. (Tea Sect.) 1962-63(Coonoor) pp. XVII-XXIV.

WHITESIDE , J . O. 1988. G rea sy spot, m ela nose a nd sca b disea ses, pp. 15-17, 20-21, 26-27 i nJ . O. Whiteside, S . M. G a rnsey, an d L . W. Timmer [eds.], C ompendium of

oooooooooooooooooooooooooooooooooooooooooooooooooooo

citrus diseases. AP S P ress, St . P a ul, Minnesota .

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