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Fungicidal control of cigar-tobacco diseases
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Permanent Link: http://ufdc.ufl.edu/UF00073378/00002
 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: 1965
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: UF00073378:00002

Full Text



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nFE- S 'P5 J NORTH FLORIDA EXPERIMENT STATION
Quincy, Florida
January 13, 1967

North Florida Station Mimeo Report NFS 67-3

FUNGICIDAL CONTROL OF CIGAR-TOBACCO DISEASES, 65 966 7

by R. R. Kincaid O0


INTRODUCTION

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

Exploratory tests were conducted with fungicides in 1964 and the spring of 1965 in an
attempt to find materials and methods which would warrant further trial in plant beds and/or
fields. These tests were reported in North Florida Station Mimeo Report NFS 66-2.

Further tests were conducted in the summer of 1965 and in the spring and summer of 1966,
as reported herein.

MATERIALS AND METHODS

The following fungicides were included in one or more tests

Dexon, p-dimethylamino benzenediato sodium sulftbate (Chemagro)
Chemagro 2635, trichlorodinitrobenzene (Chemagro)
Polyram, (ethylenebis(dithiocarbamato)) zinc and ((dithiobis ((thiocarbonyl)
iminOethylene)bis(dithiocarbamato)) zinc (Niagara)
Captan, N-(trichloromethyl)thio)-4-cyclohexene-l,2-dlcarboximide (Stauffer)
Dithane 2-78, zineb (Rohm and Haas)
Dithane M-45, coordination product of zinc ion and maneb (Rohm and Haas)
Demosan, 1,4-dichloro-2,5-dimethoxybenzene (Du Pont)
Daconil 2787, tetrachloroisonitrile (Diamond Alkali)
Du-Ter, triphenyl tin hydroxide (Thompson-Hayward)
Morsodren, 2.2% methylmercury dicyandiamide (Morton)
Dyrene, 2,4-dichloro-6-(o-chloroanalino)-s-triazine (Chemagro)
Tribasic copper sulfate (Tennessee)
Cap-Cop-Ter, 3:4:2 mixture of Captan 50%, tribasic copper sulfate, and Terraclor 75%
Di-Syston, b,o-diethyl s-2-(ethylthio)ethyl phosphorodithioate (Chemagro)
UC-22919, identity not available (Union Carbide)
Lanstan, l-chloro-2-nitropropane'(Niagara)
Nia. 10242, 2,3-dihydro-2,2-dimethyl 7-benzofuranyl n-methyl carbamate (Niagara)
D-D, chlorinated C3 hydrocarbons (Shell)
Mylone, 3,5-dimethyltetrahydro-l,3,5-thiodiazine-2-thione (Union Carbide)
Vapam, sodium methyldithiocarbamate (Stauffer)
Vorlex, 20% methyl isothiocyanate and chlorinated C3 hydrocarbons (Morton)
M-2811, 80% ethylene dibromide, 20% propargyl bromide (Dow)


1
Plant Pathologist, North Florida Experiment Station, Quincy.










-2-


Telone PBC, 80% technical dichloropropenes, 15% chloropicrin, 5% propargyl bromide (Dow)
EP-201, 15% chloropicrin, 18% methyl isothiocyanate, 67% chlorinated C3 hydrocarbons
(Morton)
M-2853, 20% ethylene dibromide, 15% chloropicrin, 5% propargyl biomide, 60% technical
dichloropropenes (Dow)

Test varieties used in these experiments were Christian (highly susceptible to black
shank), Connecticut B and Olor (moderately susceptible), and Dixie Shade and Florida 15
(resistant).

All experiments were arranged in triplicate complete randomized blocks.

Conclusions from plant bed experiments were based mainly on cumulative yields of
seedlings euitabl5 for transplanting. Blue mold was the only disease which appeared in beds.
In the bed soil fungicide experiment, relative growth of alge was rated visually, and weeds
were counted.

Conclusions from soil fungicide experiments in the field were based mainly on survival
(1) during the early period when Pythium sp. was the most important pathogen, (2) during
the late period when the black-shank Phytophthora was active, and (3) for both periods
combined. Root-disease indexes are reported for black shank, root knot (none in these
experiments), and coarse root (nematode root rot), Relative growth of tobacco plants, weeds,
and grasses was rated visually.

Conclusions from foliar fungicide experiments in the field were based on foliar
disease (blue mold and weather fleck) ratings, yield, grade index, crop index, and root-
disease indexes.

Soil fungicide experiments in the field, except as otherwise described, were conducted
in open-field plots where the soil was heavily infested with weeds and soil-borne pathogens.
Foliar ftngicide experiments in the field were conducted under artificial shade; the soil
was fumigated with D-D (1965) or Vorlex (1966). The experiment with fumigants under plastic
mulch was also conducted under artificial shade.
RESULTS AND CONCLUSIONS

Table 1. Field broadcast treatments were applied March 23, 1965, to plots 44 feet
long (36 feet net) and 8 feet wide. Dry materials were broadcast, and all plots were
rotctilled to a depth of about 6 inches. Then the liquid fumigants were injected about 6
inches deep. The variety Christian was transplanted April 16. The row in the middle of
each plot was used for record. Survival varied greatly within blocks, making it difficult
to evaluate the results.

Weed ratings were lowest (indicating weed control) with Mylone, Vorlex, and M-2633.

Survival to May 12 was highest with Dexon.

Survival to July 1 was highest with M-2633, Dexon + Chemagro 2635, Mylone, and Daconil
2787.

Survival for both periods was highest with Dexon +Chemagro 2635, Daconil 2787, and
Dexon.

Black-shank index was lowest with Mylone, M-2633, Dexon + Chemagro 2635, and Daconll
2787.












Coarse root index was lowest with Dexon, Mylone, and Vapam.

Table 2. Field drill (row) treatments were applied to a band 24 inches wide, and
thoroughly mixed to a depth of 4 inches April 22, 1965, Beds for transplanting were made
from treated soil, and one-row pilots 35 feet long were transplanted to Christian.

Survival to May 12 was signififadtly better for most treatments than for untreated.
Best were Du-Ter, Demosan, and Di-Systb ,

Survival to July 1, total survival, and black-shank index were best with Chemagro 2635,
but differences were not significant as compared with untreated.

Table 3. Field hill treatments were applied Ith tihhiplanting water, 1/3 pint per plant
(450 gallons per acre), in one-row plots 35 feet long. The test variety was Christian.

Survival to May 19 was best with Demosan (significant), Daconil 2787, Dithane M-45, and
Morsodren.

Survival to July 1 and total sizviail were best with Daconil 2787 (significant).

Black-shank index was lowest with fbacdri 2787.

Table 4. Field foliar dust treatmeAtg wbie applied to plots 16 feet (4 rows) wide and
26 feet long, transplanted to Dixie S6ad4 Apcil 2, 1965. The two rows in the middle of each
plot were used for record. Ail ~iots were duted 4 tines; piok~ of treatment 2 (twice a
week) were dusted a total of 28 times. The diluent used was.gtound tobacco stems.

Percentage of plants showing &iue mold was lowest for Dithane Z-78 6.5%, twice a week
(significant), followed by weekly treatments of Dithane Z-7i bithahe M-450 and Polyram.

Fleck (percentage of plants akfetted) was lowest with Dithane Z-78 and Polyram.

Grade index ard crop index were highest with Dithane Z-78 13%.

Table 5. Bed foliar dust treatments for 1966 were applied to 3 x 5-foot plots of Olor
sowed December 30, 1965. Fungicide concentrates diluted with pecan-shell flour were applied
three times a week for 13 applications March 16 through April 13. Rates ranged from 15 to
35 pounds per acre at each application, depending on size of plants. The total amount of
each dust applied was 300 pounds per acre.

Blue mold index was low for all treatments, Polyram and Dithane M-45 being slightly
better than Daconil 2787 and Dithane Z-78.

Cumulative yield of seedlings suitable for transplanting was significantly increased
for all treatments. Stands were increased, but not significantly.

Polyram 8% active, prepared by mixing concentrate and diluent mechanically, has given
good blue mold control and no plant injury for three seasons, and is recommended for grower
use. Co-mercial formulations with lower percentage of active ingredient, prepared by
impregnation of a suitable carrier, have not been tried to date.

Table 6. Bed soil treatments were broadcast and raked 2 inches deep before sowing
Dixie Shade February 19, 1966. About 30 seedlings from each plot was transplanted April 25.










-4-


Weed control was not satisfactory with any treatment. Algae control was best with
polyram (significant).

Yield of seedlings April 22 was best with Lanstan (significant).

Growth in the field was best with Daconil + Captan, Chemagro 2635, and Captan, These
and some others were significantly better than untreated.

Table 7. Field fumigants in a plastic mulch experiment were applied February 3, 1966.
Each main plot was 4 feet wide and 52 feet long, accommodating two rows 32 inches apart.
Fertilizer was applied broadcast--26 feet with conventional organic shade fertilizer and
26 feet with inorganic fertilizer. Mylone was also broadcast, and all plots were rototilled.
Liquid fumigants were injected 4 inches to each side of the rows, and covered with 1 1/2-mil
black plastic mulch 5 feet wide. The space between mulched plots was 4 feet. Thus, only
half of the soil area was fertilized, fumigated, and mulched.

Among the fumigant treatments, highest yield was obtained with Mf-2853 and Vorlex.
Highest grade index and crop index were obtained with Vorlex, followed closely by D-D.

Coarse-root index was lowest for D-D with no plastic mulch, and highest for check plots
receiving mulch but no fumigant. The index was intermediate for fumigated and mulched plots,
probably because nematode control was accompanied by more or less chemical injury to the
roots; lowest indexes were recorded for Vorlex and EP-201.

Table 8. Field broadcast dry treatments were mixed with fertilizer and broadcast
March 3, 1966, after which all plots were rototilled about 6 inches deep. Liquid treatments
were applied by injection March 7. Connecticut B was transplanted April 18.

Weed and grass growth was least in Mylone plots, followed by EP-201, and (for weeds
only) M-2853 and Daconil 2787 + Captan.

Best tobacco growth was recorded for Nia. 10242, followed by EP-201 and Daconil 2787 +
Captan. EP-2ol and M-2853 gave abnormally dark green plants, indicating ammonia accumulation
in the soil.

Survival was outstanding with Mylone. Others significantly better than untreated were
as follows: To May 24, Dexon, Temik, Polyram, Dithane M-45, Daconil 2787 + Captan, Nia.
10242, and Lanstan; to July 19, Dexon, M-2853, Polyram, and Di-Syston; total, Dexon.

Black-shank index was significantly reduced by Mylone, Dexon, Polyram, and M-2853.

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 20, 1966.

Growth May 30"was best with Dithane M-45, followed by Chemagro 2635, Demosan, and.'
Daconil 2787 + Captan.

Survival to May 31 was best with Dithane M-45, Captan, and Demosan,

Survival to July 19 was best with Chemagro 2635 and Lanstan.

Survival for both periods was best with Chemagro 2635.


Black-shank index was lowest with Chemagro 2635.












-5-


Table 10. Field foliar treatments were applied to plots 16 feet (4 rows) wide and 30
feet long, transplanted to Florida 15 April 7, 1966. The two rows in the middle of each
plot were used for record. All plots were dusted 12 times; plots of treatment 2 (twice a
week) were dusted a total of 23 times. The diluent used was pecan shell flour.

Blue mold score was lowest for Dithane Z-78, 6.5%, twice a week (significant).

Fleck was least with Dithane Z-78, followed by Polyram.

Grade index and crop index were highest for Dithane Z-78, 13%, once a week.


*******A****

Experiments with soil and foliar fungicides along similar lines are planned for 1967.















RRK
100 CC
1/13/67
















Field broadcast treatments 1965; applied
Christian April 16.


Root Disease
Treat- Weed Survival (%) Index
ment Fungicide Rate Rating 5/12a 7/1b Totalc BS RK CR
Ibs./A.


Mylone 50
Vapam (gal.) 6"
Vorlex (gal.) 9"
Telone PBC (gal.)
M-2811 (gal.) 12"

Dexon 70%


Dexon 70% +
Ch. 2635 70%

Ch. 2635 70%


Polyram 80%


Demosan 75%


Dac. 2787 75%


Captan 50%


Cap-Cop-Ter


500
50
50
30
6


90 76 70


87 52 43


31 0 36


61 0 38


75
150

50
100

25
50

50
100


93 60 56

92 54 51


Check


49 0 45

50 0 36


a
Early period, mostly Pythium
Late period, mostly Phytophthora
CBoth periods


19

6, 20


Table 1-1274:


March 23, transplanted to















Table 2-1274. Field drill (row) treatment, 1965 applied and transplanted
to Christian April 22.

Survival Root Disease
Treat- May Juy Index
ment Fungicide Rate 19a 1 Total BS RK CR
lbs./A.


Dexon 70%



Ch. 2635 70%


Polyram 80%


Demosan 75%



Dac. 2787 75%



Du-Ter 20%


Dithane M-45
15G

Captan 50%


UC-22919 50%


Di-Syston lOG


Check


L.S.D., 5%


78 18 15

7* 14 12


89 0 71

10 -d


aEarly period, mostly Pythium
bLate period, mostly Phytophthora
CBoth periods
dNot calculated; many plots with plants all dead.


-~--














Table 3-1274. Field hill treatments, 1965; transplanted and treated April 16.

Survival Root Disease
Treat- May July Index
ment Fungicide Rate 19a 1b Totalc BS RK CR
lbs./A.

1 Dexon 70% .125 49 12 6 94 0 50
2 .25 52 3 2 98 0 80

3 Polyram 80% 1 45 6 3 96 0 60
4 2 37 8 3 94 0 65

5 Demosan 75% .5 53 11 6 95 0 62
6 1 72 15 11 94 0 53

7 Dac. 2787 75% 2 67 25 19 84 0 59
8 4 66 12 7 92 0 54

9 Du-Ter 20% 1 65 12 8 93 0 69

10 Dithane M-45 1 64 16 11 90 0 36
11 80% 2 65 12 9 94 0 68

12 Captan 50% 1 50 10 6 92 0 65
13 2 57 10 6 93 0 90

14 Cap-Cop-Ter 2 55 10 7 95 0 75

15 UC-22919 50% 1 30 6 2 95 0 55

16 Morsodren (pt.) .5 62 7 5 95 0 58
17 1 63 6 4 95 0 75

19 Check 39 7 3 96 0 90

L.S.D., 5% 29 17 14 13 -d


a .
Early period, mostly Pythium
bLate period, mostly Phytophthora
CBoth periods
d
Not calculated; many plots with all plants dead.











Table 4-1274. Field foliar dust treatments, 1965; transplanted to Dixie Shade April 2.


Active Total Blue Root Disease
Treat- ingre- ap- Mold Fleck Grade Crop Burn Tensile Index
ment Fungicide dient plied 5/3 5/4 Yield Index Index test strength BS RK CR
% Ibs. % % lbs./A. sec. psi

1 Dithane Z-78 6.5 430 .7 .3 1693 .520 881 6.5 2.49 2 0 24

2 Dithane Z-78 6.5a 799 .0 .3 1697 .474 804 6.0 2.54 0 0 25

3 Dithane Z-78 13.0 297 .3 1.0 1667 .551 922 5.6 2.47 0 0 23

4 Dithane M-45 4.0 452 .3 1.7 1700 .525 895 5.9 2.56 0 0 22

5 Dyrene 5.0 367 .7 2.0 1621 .502 812 6.5 2.53 0 0 20

6 Polyram 8.0 332 .7 .3 1653 .482 797 7.1 2.59 0 0 23

7 Daconil 2787 7.5 328 1.0 .7 1659 .484 803 6.2 2.60 2 0 23
8 Check 1.7 1.0 1680 .505 849 7.4 2.44 1 0 19

L.S.D., 5% 1.7 2.9 122 .056 118 2.7 .15 -


aTwice a week; others once a week.











Table 5-1275. Bed foliar dust treatments, 1966; sowed to Olor December 30, 1965.

Active Blue Mold Index Cumulative yield per sq. yd.
Treat- ingre- April April
ment Fungicide dient 11 13 14 16 19 12 14 19 Stand


Polyram

Daconil 2787

Dithane Z-78

Dithane M-45

Check

L.S.D.,5%


8.0

5.0

6.5

4.0


25 67

18 77

12 54

12 54

12 12

13 26








Table 6-1274. Bed soil treatments in bed and field, 1965; treated and sowed to Dixie Shade Feb. 19, transplanted April 25.

Cumulative vield/sq. yd. Growth Survival Root Disease
Treat- Weeds Algae April Total May May Index
ment Fungicide Rate per yd.2 rating 22 26 29 (stand) 18 30 31 BS RK CR
lbs./A. %


1 Dexon 35%
2
3 Ch. 2635 70%
4
5 Polyram 80%
6
7 Lanstan 10 G
8
9 Captan 50%
10
11 Dithane M-45
12 80%
13 Demosan 65%
14

J5 Daconil 10%+
16 Captan 10%
17 Morsodren (pt.)
18 UC-22919 50%
19

20 Cap-Cop-Ter
21

22 Di-Syston 10G


20
40
10
20
20
40
200
400
10
20
4
8
5
10

25
50
16
4
8

5
10

50
100
200


25 Check


292
213
253
229
246
157
192
196
103
170
147
107
149
156

147
165
142
172
128

161
129

208
105
86
170


0 220 243
6 112 178
20 201 262
0 272 292
61 221 250
74 215 238
82 291 306
100 250 304
12 229 277
51 212 270
51 301 366
46 233 279
37 211 286
9 197 254

30 281 361
32 176 243


18 50 235 293


32 266 299
34 274 313

0 247 293
36 307 375

57 285 323
16 252 301
0 249 300


25 44 295 343


388
400

401
436
383
333
414
474
449
441
572
479
509
470

576
426
433
474
486

471
504

503
457
486
540


15 16
14 14

14 13
15 17
15 16
15 15
15 16
15 15
13 12
15 17
15 16
13 14
14 15
15 16

14 15
15 17
15 15
14 14
14 14

15 14
15 15

13 12
14 15
14 15
15 13


40 7 50 -


4 0 45
12 0 46
9 0 40

5 0 42
7 0 41

5 0 52
17 0 45
14 0 45
5 0 42


- -- --


L.S.D., 5%


2 3 10 -- 13









Table 7-1274. Field fumigants under black plastic mulch, 1966.

Root Disease
Treat- Ferti- Grade Crop Burn Index
Fumigant Rate ment lizer Yield Index Index Test BS RK CR
gal./A. Ibs./A. Sec.


Telone PBC



i.2 353:


Vorlex


EP-201


Mylone (Ibs.)


OrR.
Inorg.
AOT?.

Org.
Inorg.
Avg.

Org.
Inorg.
Avg.

Org.
Inorg.
Avg.

Org.
Inorg.
Avg.

Org.
Inore.
Avg.

Org.
Inorg.
Avg.


200


Check
(no fumigant)


D-D
(no plastic)


8* Org.
16 Inorg.
Avg.


All 8 1-8 Org.
9-16 Inorg.

L.S.D., 5%
Fumigants
Fertilizers
Fumigants x fertilizers


1462
1525
1494:

1587
1598
1592

1504
1625
1564

1507
1460
1484

1280
1407
1318

1384
1421
1402

1544
1492
1518

1472
1554
1513

1461
1510


240
66
256


.699 1019 2.9 1 0 35
.678 1031 3.6 1.. 0. 47
.688 10251 32': 1' 0' 41

.668 1059 3.6 1 0 52
.694 1109 4.0 2 0 48
.681 1084 3.8 2 0 50

.718 1080 5.3 3 0 29
.740 1202 5.5 1 0 31
.729 1141 5.4 2 0 30

.693 1045 3.5 1 0 29
.714 1044 4.3 3 0 30
.704 1044 3.9 2 0 30

.708 870 7.6 0 0 47
.712 1000 6.6 1 0 48
.710 935 7.1 0 0 47

.688 954 7.4 2 0 69
.712 1008 7.5 0 0 51
.700 982 7.4 1 0 60

.740 1144 5.2 2 0 50
.707 1048 4.9 0 0 48
.724 1096 5.0 1 0 49

.730 1077 5.5 1 0 16
.691 1071 5.3 0 0 15
.710 1074 5.4 0 0 16

.706 1030 5.2 1 0 40
.706 1064 5.2 1 0 40


.039
.021
.083


171 1.1 20
56 0.7 4
219 2.0 15


*Standard










Table 8-1274. Field broadcast treatments, 1966; applied March 3 and 7; transplanted to
Conn.-D April 18.

Ratings Growth Root Disease
Treat- Weeds Grass Adtin Survival (%) Index
ment Fumigant Rate 5/4 / 5/18 5/30 5/24a 7/19b Totalc BS RK CR
lbs./A.
1 Dexon 35% 30 15 10 14 15 62 10 6 95 0 61
2 60 17 12 16 15 79 35 27 73 0 59

3 Polyram 80% 50 10 21 15 15 66 31 21 79 0 72
4 100 20 20 16 16 74 15 11 88 0 73

5 Lanstan 10G 50 11 11 14 15 71 14 11 89 0 74
6 100 22 18 12 13 53 13 6 94 0 50

7 Dithane M-45 100 19 22 16 16 74 21 16 84 0 74
80%
8 Dac. 2787 10%+ 20 5 19 15 17 74 19 15 85 0 76
9 Captan 10% 40 14 16 14 13 66 4 2 98 0 75
10 80 8 16 14 14 57 6 4 96 0 45

11 UC22919 50% 40 20 12 15 14 79 14 12 88 0 62

12 Nia. 10242 50 16 17 15 15 59 18 13 88 0 68
13 10G 100 12 18 18 17 73 11 9 92 0 72

14 Di-Syston 100 13 16 16 15 65 28 18 85 0 74
15 10G 200 24 16 16 14 52 17 9 96 0 67
16 400 6 22 14 14 67 13 9 91 0 77

17 Mylone 50% 500 0 3 15 16 93 51 51 50 0 69

18 EP-201 (gal.) 26 6 7 17 17d 68 5 4 96 0 73

19 M-2853 (gal.) 26 4 15 14 12d 64 32 20 80 0 78

20 Check 15 22 14 15 50 4 7 98 0 58

L.S.D..5% 11 12 3 4 18 23 18 17 --

aEarly period, mostly Pythuim
bLate period, mostly phytophthora
cBoth periods
dplant'sdark green













Table 9-1274. Field hill treatments, 1966, applied and transplanted to Connecticut
B, April 20.


Growth
Treat- May
ment Fungicide ..18 30


Dexon 35%


Ch. 2635 70%


Polyram 80%


Lanstan 4EC
(pints)

Captan 50%


Dithane M-45
80%


Demosan 65%


Dac. 2787 10Z+
Captan 10%

Du-Ter 20%


Morsodren
(pints)

Trib. cop, sulf.


Cap-Cop-Ter


0.25
0.5

0.125
0.25

2.5
5.0

0.5
1.0

2.0
4.0

1.0
2.0
4.0

0.5
1.0

2.5
5.0

2.0
4.0

0.5
1.0

2.0
4.0

2.0
4.0


1
2

3
4

5
6

7
8

9
10

11
12
13

15
16

17
18

19
20

21
22

23
24

25
26

14,28


L.S.D., 5%


10 11
11 14

11 14
13 15

11 12
9 10

9 9
6 6

10 11
11 13

12 16
13 12
10 12

13 15
11 12

11 15
11 14

7 8
7 9

12 13
12 13

12 14
10 14

11 12
9 10

10 12

3 5


Survival
May July July
31a 19 19,
% % %

70 32 21
75 41 28

76 49 40
78 20 18

78 25 20
73 43 30

54 18 12
41 48 21

70 22 17
84 19 15

85 28 24
83 32 25
63 22 13

83 27 23
79 30 25

80 32 25
77 28 21

62 34 20
41 46 19

66 31 22
81 16 13

79 11 9
74 41 30

72 43 30
69 36 24

64 30 20

28 24 17


Root Disease
Index
BS RK CR


80 0 64
73 0 70

62 0 68
83 0 75

81 0 75
72 0 71

90 0 73
79 0 71

84 0 69
85 0 64

79 0 83
75 0 74
87 0 73

77 0 65
77 0 66

80 0 79
79 0 82

80 0 64
81 0 75

80 0 72
87 0 78

92 0 78
75 0 80

82 0 68
76 0 79

80 0 69

18 --


aarly period, mostly Pythium
bLate period, mostly Phytophthora

CBoth periods


Check


- -----~I















" 10-1274. Field foliar treatments, 1966; transplanted to Florida 15 April 7.

Active B.M. Score Root Dis-
ingre- Total May Fleck Grade Crop ease Index
nt Fungicide dient applied 13 24 June 7 Yield Index Index BS RK CR
% lbs./A. % lbs./A.

1 Dithane Z-78 6.5 245 37 22 1.0 1701 .717 1220 1 0 22

2. Dithane 2-78 6.5a 466a 27 9 0.7 1706 .711 1215 1 0 14

3 Dithane 2-78 13.0 228 31 25 2.0 1757 .734 1289 1 0 15

4 Dithane M-45 4.0 278 35 27 2.0 1721 .663 1140 0 0 15

5 Dyrene 5.0 227 31 30 2.3 1663 .706 1174 2 0 20

6 Polyram 8.0 244 34 25 1.3 1757 .683 1200 0 0 13

7 Daconil 2787 7.5 216 28 22 4.0 1664 .711 1183 1 0 22

8 Check -- 43 33 2.7 1709 ,693 1182 0 0 17

L.S.D., 5% 17 20 2.9 125 .075 140 11


a
Twice a week; others once a week.