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Fungicidal control of cigar-tobacco diseases
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Permanent Link: http://ufdc.ufl.edu/UF00073378/00004
 Material Information
Title: Fungicidal control of cigar-tobacco diseases
Series Title: North Florida Station mimeo report
Physical Description: v. : ; 28 cm.
Language: English
Creator: North Florida Experiment Station
Publisher: North Florida Experiment Station.
Place of Publication: Quincy Fla
Creation Date: 1968
Frequency: annual
regular
 Subjects
Subjects / Keywords: Tobacco -- Diseases and pests -- Control -- Periodicals -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
serial   ( sobekcm )
 Notes
General Note: Description based on: 1964/1965; title from caption.
General Note: Latest issue consulted: 1968.
Funding: NFES mimeo rpt.
 Record Information
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 76789236
lccn - 2006229105
System ID: UF00073378:00004

Full Text



/06
/ F/65 L NORTH FLORIDA EXPERIMENT STATION
N F Quincy, Florida
January 7, 19 9

/ UMEjALIUiAY
NFES Mimeo Report 69-2
I MAR 719
FUNGICIDAL CONTROL dF CIGAR-TTBACCO DISEASES, 1 8

by R. R. kinc i i. of Oid


INTRODUCTION

Fungicidal control of blue mold (Perobospora tabAcina) in tobacco beds and fields is
practiced in the shade-tobacco area of North Florida. Diseases amenable to fungicidal
control include also soil-borne diseases (principally Phytophthora parasitica var.
nicotianae and Pythium spp.). Project 1274 was initiated to investigate control of these
parasitic diseases and possibly also weather fleck (ozone injury).

Tests conducted with fungicides in 1964-1967 were reported in North Florida Station
Mimeo Reports NFS 66-2, 67-3 and 68-4. Further tests were conducted in the spring and
summer of 1968, as reported herein.

MATERIALS AND METHODS

The following materials were included in one or more tests:

Brozone, 68.8% methyl bromide and 1.4% chloropicrin (Dow)
Captan, n-(trichloromethyl)thio)-4-cyclohexene-l,2-dicarboximide (Stauffer)
Cap-Cop-Ter, 3:4:2 mixture of Captan 50%, tribasic copper sulfate, and Terraclor 75%
Chemagro 4497, bis(1,2,2-trichloroethyl) sulfoxide (Chemagro)
Daconil 2787, tetrachloroisophthalonitrile (Diamond Alkali)
D-D, chlorinated C3 hydrocarbons (Shell)
Demosan, 1,4-dichloro-2,5-dimethoxybenzene (Du Pont)
Dexon, p-dimethylamino benzenediazo sodium sulfonate (Chemagro)
Dithane M-45, coordination product of zinc ion and maneb (Rohm and Haas)
Dithane Z-78, zineb (Rohm and Haas)
Dyrene, 2,4-dichloro-6-(o-chloroanalino)-s-triazine (Chemagro)
Fermate, ferban (Du Pont)
Morsodren, 2.2% methylmercury dicyandiamide (Morton)
Mylone, 3,5-dimethyltetrahydro-l,3,5-thiodiazine-2-thione (Union Carbide)
Polyram, (ethylenebis(dithiocarbamato)) zinc and ((dithiobis) (thiocarbonyl)
iminoethylene))bis(dithiocarbamato)) zinc (Niagara)
Tribasic copper sulfate (Tennessee)
Vorlex, 20% methyl isothiocyanate and 80% chlorinated C3 hydrocarbons (Morton)

All rates of application are given in terms of pounds (or pints) per acre of the
formulation used, except as otherwise specified.

Test varieties used in these experiments were as follows: Connecticut B, resistant to
damping off (Pythium) and susceptible to black shank (Phytophthora); and Florida 17,
susceptible to damping off and resistant to black shank.


Plant Pathologist, North Florida Experiment Station, Quincy.











All experiments were arranged in randomized complete blocks, in plant bed, under
artificial shade, or in open field, as indicated.

Conclusions from the bed foliar dust experiment were based on cumulative yields of
seedlings suitable for transplanting. No blue mold or other disease appeared in 1968.

Conclusions from the foliar dust experiment in the shade were based on incidence of
black shank and coarse root (Pratylenchus), yield, grade index, and crop index.

Conclusions from soil fungicide experiments were based on (1) survival against
damping-off (DO); (2) on survival against black shank (BS); (3) on visual growth rating or
yield, grade index, and crop index; (4) black shank index; (5) coarse root index; and in
some experiments on (6) burn test (fire-holding capacity and tensile strength. Root knot
was rarely observed and is not reported.

RESULTS AND CONCLUSIONS

Table 1. Bed foliar dust treatments were applied to 3- x 5-foot plots of Connecticut
B sowed January 18, 1968. Fungicide concentrates, diluted with pecan-shell flour,
ground tobacco stems, or R-clay, were applied three times a week for 11 applications March
14 through April 5. Dust rates ranged from 15 to 30 pounds per acre at each application,
depending on size of plants. The total amount of each dust applied was 190 pounds per acre.

No blue mold appeared in the plots. Differences in yields of seedlings were not
significant. The three diluents used with Polyram appeared to be equally good. Polyram is
recommended for grower use in cigar-wrapper tobacco plant beds in 1969.

Table 2. Shade foliar dust treatments were applied to plots 16 feet (4 rows) wide and
24 feet long, transplanted to Florida 17 April 5, 1968. Two center rows of each plot were
used for record. All plots were dusted twice a week for a total of 19 applications April 18
through June 20. The soil had been treated with Vorlex 20 gallons per acre.

All treatments gave better grade index and crop index than check, but differences were
not significant.

Table 3. Shade broadcast treatments were applied February 28, and hill treatments were
applied April 5 immediately after transplanting Connecticut B.

Mylone 50 (400 pounds per acre) was the best treatment, followed closely by Mylone 50
(200 Ibs.) in combination with hill treatments with Daconil or tribasic copper sulfate. All
treatments were better than check in most respects.

Table 4. Shade (mulch) hill treatments were applied in transplanting water to plants
of the variety Connecticut B transplanted April 9 through 3-inch holes in 1 1/2-mil black
polyethylene mulch.t-aWater was applied with a dipper at the rate of 1/3 pint per plant,
450 gallons per acre.

Cap-Cop-Ter gave reduced survival during the early ("damping off") period, suggesting
toxicity at the rate used.

Tribasic copper sulfate, Polyram, and Cap-Cop-Ter gave improved survival against
black shank.

Yields, reflecting both survival and growth, ranked from highest to lowest as follows:
Tribasic copper sulfate, Daconil + Captan, Dexon, Dithane M-45, Captan, Chemagro 4497,
Polyram, and Daconil 2787. Cap-Cop-Ter was not significantly better than check.











Table 5. Shade (mulch) soil treatments were applied February 14; transplanted to
Connecticut B and hill treatments applied April 9, 1968.

Soil treatments were concentrated in double-row beds, each accommodating two rows, to
twice the rate shown in the table.

Hill treatments were applied in transplanting water, 1/3 pint per plant, 450 gallons
per acre. Each of the four blocks in this experiment was treated with a different fungicide
as follows: Polyram 80 WP, 1 pound per acre; Dexon 35 WP, 1/2 pound; Daconil 10 + Captzn 10,
3 pounds; and Dithane M-45, 3/4 pound. A statistical comparison could not be made, but it
appeared that the four fungicides were about equally effective.

For damping-off control, best soil treatments without hill treatment were Vorlex
(20 gal.), and Brozone (300 lbs.). All soil treatments with hill treatment were
significantly better thah standard (unmulched). The average survival of all soil treatments
was significantly increased by hill treatment.

For black shank control, no soil treatment without hill treatment was significantly
better than standard. Best soil treatments with hill treatments were Brozone and Vorlex.
The average survival of all soil treatments was significantly improved by hill treatment.

Tables 5 and 6. Shade (mulch) soil treatments were incorporated or injected, in bands
4 feet wide and 4 feet apart and covered with 1 1/2-mil black polyethylene mulch 5 feet wide
February 14. Therefore, the fumigants were concentrated in the bands to twice the acre rate
shown in the tables. Fertilizer, either part-organic or all-inorganic, was applied to split
plots just before treatment. Each mulched band accommodated two rows of Florida 17
transplanted April 5, 1968.

Vorlex 20 gallons gave best results, including estimated net returns, followed by
Mylone and Brozone; this treatment gave also excellent grass control.

Check with mulch but no soil treatment was better than standard with D-D, no mulch, and
organic fertilizer.

Averages of all treatments indicated that organic and inorganic fertilizers gave equal
results, as in 1966 and 1967.

Table 8. Field broadcast treatments were applied and incorporated with a rotary
tiller about 6 inches deep February 28. Connecticut B was transplanted April 10, 1968.

Mylone 50, 400 pounds per acre, gave best control of damping off and black shank;
growth rating was lowest early in the season but highest later in the season.

Daconil 2787 gave second best results.

Table 9. Field hill treatments were applied in transplanting water, 1/3 pint per plant,
450 gallons per acre, immediately after transplanting Connecticut B April 10, 1968.

Fungicides giving improved survival against damping off 11 days after transplanting
were Demosan, Captan, and Cap-Cop-Ter. Twelve days later, the ranking, none significantly
better than check, was as follows: Demosan, Daconil 2787, Captan, and Cap-Cop-Ter.

No fungicide save improved survival against black shank.

****** * ** ******* * *


Similar experiments with fungicides are planned for 1969.







Table 1-1274. Bed foliar dust treatments, sowed


Cumulative yields of seedlings/yd.z
Treat- April
ment Fungicide A. I. Diluent 7 9 18 25 Stand
%


Dithane Z-78

Dithane M-45

Polyram

Polyram

Polyram

Daconil 2787

Check

L.S.D., 5%


13.0

4.0

5.0

5.0

5.0

5.0


pecan

pecan

pecana

tobaccoa

R-claya

pecan


137

1:24

106

121

111

124

117

59


186

174

134

164

153

161

171

58


290

289

236

270

235

258

285

70


aNixed by Niagara, others by NFES.


18, 1968.


to Conn. B, January








Table 2-1274. Shade dust treatments, transplanted to Florida 17 April 5, 1968.

Treat- Total Leaf Index Grade Crop
ment Fungicide A. I. applied Survival spota BS CR Yield Index Index


Dithane Z-78

Dithane M-45

Polyram

Daconil

Fermate

Check

L.S.D., 5%
1%


13.0

4.0

5.0

7.5

15.0


Ibs./A

350

384

385

337

383


97

98

98

97

98

98

2
4


lbs./A

1633

1818

1730

1787

1876

1725

207
295


.705

.698

.689

.714

.668

.652

.067
.095


1162

1270

1192

1276

1253

1129

214
304


aPhytophthora leaf spot, leaves per plot (50 plants).









Table 3-1274. Shade broadcast and
April 5, 1968.


hill treatments; soil treated Feb. 28; transplanted to Conn. B and hill treated


Growth
Treat- rating Survival Index Grade Crop Burn Tensile
ment Soil fungicide Hill 5/2 DO BS BS. CR Yield index index test strength
% % Ibs./A sec. psi

3 Mylone 50 200 None 21 88 64 46 58 1157 .674* 779 14.9 2.75

1 Mylone 50 200 Daca 23 92 73 34* 59 1302** .653 854** 15.4 2.76*

2 Mylone 50 200 TCSb 21 95 72 36* 60 1287** .712** 918** 14.2 2.85**

4 Mylone 50 400 None 23 94 82* 23** 54 1379** .675* 939** 14.9 2.64

5 Check None 20 93 51 66 64 994 .626 627 16.2 2.60

L.S.D., 5% 12 25 25 15 170 .044 156 3.0 .16
1% 17 35 36 21 239 .062 218 4.2 .22

a
Daconil 2787 75 WP, 1 1/2 pounds per acre in 450 gallons of water.
b
Tribasic copper sulfate, 3 pounds per acre in 450 gallons of water.







Table 4-1274. Shade (mulch) hill, transplanted to
April 9, 1968.


Treat-
mIn -


Tribasic copper sulfate

Daconil 10 + Captan 10

Dexon 35 WP

Dithane M-45

Captan 50 WP

Chemagro 4497 50 WP

Polyram 80 WP

Daconil 2787 75 WP

Cap-Cop-Ter

Check (water only)

L.S.D., 5%
1%


Fungicide


Conn. B and treated


Pun icideY-
LLL~L ~ iYQ


, I .


-


Rate
lbs./A

3

3

1/2

3/4

1 1/2

1/8

2

1 1/2

2


Survival
DO BS
% %

88 72**

90 49

96 49

93 50

90 41

76 44

90 64*

95 48

62 63*

83 30

19 27
28 38


Yield
lbs./.A

1130 a

1048 ab

1022 ab

972 bc

954 bc

950 bc

916 .bcd

872 cd

804 def

682 f

Multiple
range
5%