J. Appl. Hort., 2(2):124-126, July-December, 2000
Effect of fungicidal seed treatment and foliar sprays on early blight
incidence, fruit characters and yield of tomato cv. Pusa Ruby
Naveen K. Singh, R.P. Saxena1, R.C. Jaiswal1 and Pradeep Kumar2
1
Department of Vegetable Science, 2Department of Horticulture, N.D.University of Agriculture & Technology, Kumarganj,
Faizabad-224 229
Abstract
Investigation on management of tomato early blight disease (Alternaria solani) reveal that the disease incidence was minimised by
seed treatment with Bavistin (0.1%) prior to seed sowing followed by thrice foliar spray with Dithane M-45 (0.2%) first at the time of
disease appearance (60 DAS) and two other subsequent spray at an interval of 15 days under field conditions. Length, width and yield
of tomato fruits and benefit: cost ratio (26.9) was comparatively higher with spray of Dithane M-45 (0.2%).
Key words: Tomato, Pusa Ruby, fungicides, seed treatment, foliar spray, Alternaria blight, yield.
Introduction
Early blight of tomato caused by Alternaria solani, earlier
designated as minor disease, has become a serious problem in
northern parts of India (Datar and Mayee, 1981; Kalloo and
Banerjee, 1993; Pathak, 1995). Survey and surveillance of tomato
crop at university research farm as well as at farmer’s fields has
clearly revealed that this disease is gradually increasing, causing
huge losses to fruit quality and yield (Pathak, 1995).
Although attempts have been made on the management of the
disease by foliar spray of various fungicides on tomato crop
(Khade and Joi, 1980; Datar and Mayee, 1981; Pathak, 1995;
Devanathan and Ramanujam, 1995 and Jovancev, 1998), disease
control was not at a satisfactory level. No single method or
approach is currently feasible/ viable for effective and economical
control of the disease. The present investigation was planned to
study disease management techniques such as seed treatment prior
to sowing alone and foliar sprays after symptom appearance of
the disease at very early stages.
Materials and methods
To manage tomato (Lycopersicon esculentum Mill, cv. Pusa Ruby)
early blight infection in seed, on leaves and fruits, experiments
were conducted separately in 2 sets as described below. Seeds
were sown on raised nursery beds in shallow lines. Twenty five
days old apparently healthy looking seedlings were transplanted at
a distance of 60 x 60 cm in Randomized Block Design.
Observations were recorded at 15 days interval after disease
appearance.
Evaluation of fungicides as seed treatment : Four hundred seed
of tomato were soaked in aqueous solution of different fungicides
(Bavistin, 0.1%; Vitavax, 0.2%; Baycor, 0.2%; Thiram, 0.2; Dithane
M-45, 0.2%; Bavistin 0.1% + Vitavax, 0.2%) and control (water)
for a period of 12 hours prior to sowing. These treated seeds were
dried on a filter paper to remove excess water and sown in nursery
bed for raising seedlings.
Evaluation of fungicides as foliar spray : To manage the disease
under field conditions, tomato crop was sprayed with aqueous
solution of different fungicides at recommended doses (Dithane
M - 45, 0.2%; Baycor, 0.2%; Blitox -50, 0.3%; Boric acid, 0.5%)
and control (water spray) by foot sprayer first at the time of disease
appearance and two other subsequent spray at an interval of 15
days. In all treatments, three spray were given at scheduled time.
Observations on disease incidence were recorded after first
appearance of disease (60 DAS) and at 15 days interval by using
0-4 point scale as suggested by Horsfall and Heuberger (1942)
and Ramakrishnan et al. (1971)as given below:
Score
Disease incidence
0
No disease
1
1-25 per cent leaf area affected
2
26-50 per cent leaf area affected
3
51-75 per cent leaf area affected
4
76-100 percent leaf area affected
Per cent disease index (PDI) and their corresponding per cent
disease control (PDC) was calculated at the time of termination of
experiment using following formulae (Mckinney,1923):
Per cent
Disease Index =
(PDI)
Sum of all numerical ratings
Total number of leaves x Highest grade
or fruits examined
x 100
Per cent
Disease in control(%) - Disease in treatment(%)
Disease
=
x 100
Disease in control(%)
Control (PDC)
Benefit : Cost ratio of foliar sprays was determined by following
formula:
Net income (Rs ha-1)
Benefit: Cost ratio =
Total cost of fungicidal treatment (Rs ha-1)
Analysis of variance was performed as detailed by Fisher and Yates
(1963).
Results and discussion
Experiments conducted for management of tomato early blight
by seed treatment and foliar sprays have clearly revealed that the
fungicidal treatments have shown some degree of disease control.
The first appearance of disease on seed treated plants was observed
Effect of fungicidal seed treatment and foliar sprays on early blight incidence of tomato
between 60 to 69 days after sowing (DAS) in different treatments.
Incidence of disease progressed gradually from 4.62 per cent after
87 DAS being minimum to 177 DAS (30.55%) with Vitavax
(0.2%), followed by 0.1% Bavistin (30.80%) to a maximum in
Baycor treated plot (41.95%) over controls (76.28%) at the time of
termination of experiment (Table 1). It is evident from Table 3 that
overall lowest PDI (37.96%) and highest PDC (55.45%) was
recorded in seed treated with Bavistin and showed significant
decrease in disease incidence over control after 177 DAS. Other
treatments which were at par with Bavistin are Bavistin + Vitavax
(38.88 PDI and 53.35 PDC), Thiram (39.81 PDI and 52.23 PDC)
and Vitavax (41.69 PDI and 49.97 PDC). Significant increase in
tomato fruit yield was recorded in Baycor treated plots, accounting
to 357.46 q/ha over control of 200 q/ha. Fruit yield in Thiram and
Bavistin treated seed plots ranked second and third accounting to
317.03 and 300.37 q/ha, respectively.
Studies conducted with foliar spray of fungicides for disease control
showed lowest disease incidence in plots sprayed with Dithane M45 (15.36%)showing an effective and best control of disease (Table
2) as well as highest fruit yield (375.50 q/ha) over control (194.62
q/ha) after 177 DAS (Table 4). It is also evident from Table 2 that
first appearance of the disease was recorded between 64 - 68 DAS
in different treatments. Disease progressed gradually from 13.88%
125
in Dithane M-45 sprayed plots to a maximum of 35.17% in Boric
acid sprayed plot at 177 DAS. Control plot (water spray) showed
disease incidence from 21.29% to 76.80%. The results of Table 4
also revealed that per cent disease control (PDC) was highest in
Dithane M-45 sprayed plots (75.27%) followed by Blitox -50
(55.92%), Baycor (52.70%) and Boric acid (52.48%). Yield-wise,
Dithane M-45 showed maximum yield (375.50 q/ha) followed by
Baycor (356.11 q/ha), Blitox-50 (317.78 q/ha) and Boric acid
(282.03 q/ha).
The studies on pre-treatment of tomato seed in aqueous solution of
fungicides for 12 hours prior to sowing showed that all fungicides
tested reduced early blight incidence significantly over control
(Table 1 and 3). Lowest incidence (37.96 PDI) was recorded with
Bavistin as seed treatment followed by Bavistin + Vitavax (38.88
PDI), Thiram (39.81 PDI I and Vitavax (41.69 PDI). Bavistin and
Dithane M-45 seed treatment @ 2.0g /kg seed eradicated Alternaria
brassicae infection in mustard seed (Kumar and Singh, 1986)
whereas Vitavax was effective to control Altarnaria alternata
infection in cauliflower seed (Crisan and Pall, 1986). Likewise,
foliar spray of fungicides against early blight infection in tomato
crop also reveal that all spray fungicides reduced disease
incidence significantly as compared with control treatment
(Table 2 and 4). Disease incidence recorded at the time of
Table 1. Effect of seed treatment with fungicides on development of early leaf blight incidence in tomato cv. Pusa Ruby
Treatment
First appearance
Disease incidence at different crop age (DAS)
of disease (DAS)
87
102
117
132
147
162
Bavistin (0.1%)
Vitavax (0.2%)
Baycor (0.2%)
Thiram (0.2%)
Dithane M-45 (0.2%)
Bavistin+ Vitavax(0.1+0.2%)
Control (Water spray)
CD (p = 0.05)
65
63
69
68
69
64
60
-
9.25
4.62
6.47
9.25
7.40
7.40
21.29
5.38
11.10
7.40
7.40
12.03
8.32
7.40
25.52
4.77
14.80
11.10
7.40
12.95
9.25
11.10
29.62
4.64
16.66
13.88
8.33
12.95
9.25
12.05
35.17
4.05
23.14
18.51
9.25
14.80
11.10
18.51
41.66
4.37
177
30.55
30.55
22.22
27.77
24.07
32.24
51.84
5.90
30.80
30.55
41.95
32.32
36.14
32.40
76.28
8.51
162
15.36
29.61
26.66
33.33
58.32
6.98
177
15.36
33.33
32.00
35.17
76.80
6.73
Table 2. Effect of foliar spray of fungicides on development of early leaf blight incidence in tomato cv. Pusa Ruby
Treatment
First appearance
Disease incidence at different crop age (DAS)
Dithane M-45 (0.2%)
Baycor (0.2%)
Blitox - 50 (0.2%)
Boric acid (0.5%)
Control(Water spray)
CD (p= 0.05)
of disease (DAS)
69
69
66
62
60
-
87
13.88
17.58
21.29
24.07
21.29
6.11
102
14.44
20.36
23.14
26.84
27.85
3.64
117
14.80
23.14
23.14
28.69
30.54
6.54
132
14.80
24.07
23.14
28.69
35.17
4.34
147
14.86
25.00
23.14
30.54
40.73
2.76
Table 3. Effect of seed treatment with fungicides on early blight PDI, fruit characters and yield components of tomato cv. Pusa Ruby
Treatments
Per cent disease
Fruit size (cm)
Fruit
No. of
Fruit yield Average
Index
Control
Length
Width
weight
fruits/
/plot
yield
(PDI)
(PDC)
(g)
plant
(kg)
(q/ha)
Bavistin (0.1%)
37.96 (38.01)*
Vitavax 0.2%
41.69(40.21)
Baycor 0.2%
46.29 (42.86)
Thiram 0.2%
39.81 (39.08)
Dithane M-45 (0.2%)
42.59(40.72)
Bavistin+ Vitavax (0.1+0.2%) 38.88 (38.54)
Control(Water spray)
83.33(65.94)
CD(p=0.05)
4.48
*Values in parenthesis are transformed values
55.45
49.97
44.45
52.23
48.89
53.35
-
4.40
5.28
5.92
4.85
5.11
4.76
4.75
NS
4.48
4.78
4.64
4.22
4.60
4.44
4.27
NS
51.10
54.10
62.00
56.50
54.20
55.60
51.20
3.22
298
281
314
303
303
293
206
7.01
16.22
15.17
19.33
17.12
16.57
16.48
10.80
3.20
300.37
280.92
357.46
317.03
298.51
306.85
200.00
8.86
126
Journal of Applied Horticulture
Table 4. Effect of foliar spray of fungicides on early blight PDI, fruit characters and yield components of tomato cv. Pusa Ruby
Treatments
Per cent disease
Fruit size (cm)
Fruit
No. of
Fruit yield/ Average
Index
Control
Length
Width
weight
fruits/
plot
Yield
(PDI)
(PDC)
(g)
Plant
(kg)
((q/ha)
Dithane M-45 (0.2%)
21.29 (27.46)*
75.27
5.26
Baycor (0.2%)
40.73 (39.65)
52.70
5.17
Blitox-50 (0.2%)
37.95 (38.02)
55.92
4.99
Boric acid (0.5%)
40.92 (39.75)
52.48
4.91
Control(Water spray)
86.10 (69.25)
4.78
CD (p=0.05)
9.08
NS
*Values in parenthesis are transformed values
Table 5. Effect of foliar spray of fungicides on benefit: cost ratio.
5.24
5.40
4.78
4.47
4.47
NS
60.20
55.60
54.10
53.10
52.30
3.15
352
349
319
292
201
10.34
21.85
19.23
17.16
15.23
10.51
3.27
375.50
365.11
317.78
282.03
194.62
8.09
Particular
Control
Dithane M-45
Baycor
Blitox-50
Boric acid
Treatment Cost (Rs)
A. Fungicides
(i) Amount (kg/ha)
6.00
6.00
9.00
15.00
(ii) Cost (Rs.)
1548.00
9540.00
2250.00
7950.00
(iii) Spraying Charges (Rs.)
45.00
45.00
45.00
45.00
B. Labour Charges (Rs.)
(i) Labour @ Rs.47/day 423.00
423.00
423.00
423.00
Total Cost (Rs)
2016.00
10,008.00
2718.00
8418.00
(i) Average yield (q/haa)
194.62*
375.50
356.11
317.78
282.03
(ii) Increased yield over control
180.88
161.49
123.16
87.41
Net income Rs/ha
54264.00
48447.00
36948.00
26223.00
Benefit: Cost Ratio
26.91
4.84
13.59
3.11
* Price of tomato fruits @ Rs. 300.00 per q (Average price in U. P. State).
Datar, V.V. and C.D. Mayee, 1981. Assessment of losses in tomato
termination of the experiment showed lowest PDI (21.29%) in
yield due to early blight. Indian Phytopath., 34: 191-195.
plots sprayed with Dithane M-45 followed by Blitox-50
Devanathan,
M. and K. Ramanujam, 1995. Evaluation of fungicides
(37.95%), Baycor (40.73%) and Boric acid (40.92%). The
for
the
management
of early blight of tomato caused by Alternaria
highest PDI (86.10%) was recorded in control (water spray)
solani. Madras Agric. J., 82(3): 228-229.
treated plots. Significantly highest increase in yield of tomato
Fisher, R.A. and F. Yates, 1963. Statistical Tables for Biological
fruits, recorded with spray of Dithane M-45 was due to effective
Agricultural and Medical Research. Oliver and Boyed, Ltd.,
control of disease as well as increase in the fruit weight, number
Edinburgh.
and yield of fruits per plot. Similar findings for disease reduction
Horsfall, J.G. and J.W. Heuberger, 1942. Measuring magnitude of a
and yield attributes of tomato fruits cv. Pusa Ruby have also
defoliation disease of tomatoes. Phytopath., 32(2): 226-232.
been reported by Khade and Joi (1980), Choulwar and Datar
Jovancev, P. 1998. Efficacy of some fungicides for controlling late
(1992) and Devanathan and Ramanujam (1995). Maximum
blight (Phytophthora infestans Mont. de Bary) and early blight
benefit: cost ratio (26.91) was obtained with foliar sprays of
(Alternaria solani Soraver) of tomato. Macedonian Agric. Rev.,
Dithane M-45 followed by Blitox-50 (13.59) due to its
45(1-2) : 45-51.
effectiveness in minimizing the disease incidence over control
Kalloo, G. and M.K. Banerjee, 1993. Early blight resistance in
(Table 5).
Lycopersicon esculantum Mill transferred from L.
The present investigation has shown that Alternaria blight of
tomato could effectively be managed to large extent by different
fungicides as seed treatment with acqueous solution of
fungicides in decreasing order of Bavistin, Bavistin + Vitavax,
Thiram, Vitavax, Dithane M-45 and Baycor whereas in foliar
spray it was in decreasing order of Dithane M-45, Blitox-50,
Baycor and Boric acid with maximum benefit: cost ratio in
Dithane M-45.
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