Rao et.al.
64% WP showed less AUDPC of 313.03 and 339.85
reducingthediseaseseveritybyrecordingleastPDIof
followed by 378.42, 386.08 and 392.22 in Metalaxyl-M
26.04 and 27.18 as against 57.69 in untreated control.
4% + Mancozeb 64% WP, Pyraclostrobin 6.7% +
The maximum yield of 39.71 and 37.06 t/hawere
Dimethomorph 12% WG and Pyraclostrobin 5%
recorded in Mancozeb 70% WP and Cymoxanil 8% +
+ Metiram 55% WG as against 699.57 in untreated
Mancozeb 64% WP as against 20.67 t/ha in untreated
control.
control. Thus, these two fungicides achieved benefit
Pooled analysis revealed Cymoxanil 8% + Mancozeb
cost ratio of 33.85 and 20.67. Triademorph 80% EC
64% WP and Mancozeb 70% WPas effective in
recorded a PDI of 37.02 andyield of 31.80 t/ha and
obtained benefit cost ratio of 20.97.
Table 2. Field evaluation of fungicides against purple blotch of onion
1st season
2nd season
%
%
%
%
Treatment
decrease
Yield t/ increase
decrease
Yield t/ increase
PDI
AUDPC
PDI
AUDPC
over
ha
over
over
ha
over
control
control
control
control
Captan 50% WP
43.93**
18.32
480.63
23.29**
9.96
46.50**
24.50
548.80
24.93**
23.66
Chlorothalonil 75%
40.52**
24.66
416.62
31.44**
48.44
41.44**
32.72
474.32
30.18**
49.70
WP
Copper oxy chloride
40.18**
25.29
408.88
26.78**
26.44
42.26**
31.38
489.88
26.40**
30.95
50% WP
Mancozeb 70% WP
26.82**
50.13
283.08
40.56**
91.50
27.55**
55.27
313.03
38.86**
92.76
Propineb 70 WP
37.61**
30.07
349.06
30.91**
45.94
40.46**
34.31
475.12
29.36**
45.63
Difenconozole 25%
43.44**
19.23
477.42
28.07**
32.53
44.33**
28.02
505.73
27.18**
34.82
EC
Triademorph
80%
36.39**
32.34
349.94
32.80**
54.86
37.65**
38.87
419.33
30.80**
52.78
EC
Hexaconozole 5% SC 41.91**
22.07
405.75
27.44**
29.56
47.39**
23.06
598.24
25.76**
27.78
Propiconozole
25%
41.44**
22.95
406.22
28.02**
32.29
45.99**
25.33
588.35
27.73**
37.55
EC
Pyraclostrobin 6.7%
+
Dimethomorph 31.06**
42.25
328.30
34.20**
61.47
32.56**
47.13
386.08
32.42**
60.81
12% WG
Pyraclostrobin 5% +
30.43**
43.42
327.15
35.18**
66.10
32.00**
48.04
392.22
34.07**
69.00
Metiram 55% WG
Cymoxanil
8%
+
23.99**
55.39
277.36
37.67**
77.86
28.09**
54.39
339.85
36.44**
80.75
Mancozeb 64%
Metalaxyl-M 4% +
31.11**
42.15
343.86
36.11**
70.49
33.74**
45.22
378.42
33.53**
66.32
Mancozeb 64% WP
Control
53.78
613.19
21.18
61.59
699.57
20.16
CD 5%
0.94
0.16
2.80
0.15
CD 1%
2.35
0.39
6.99
0.38
**Significant at at both 5% and 1%,* Significant at 1%
92