Evaluation of suitable antagonists in the management of early blight of tomato cultivar CO-3
21
T-11
28.67 (57.63)
22
T-12
40.00 (40.88)
23
T-13
30.33 (55.17)
24
T-14
20.67 (69.45)
25
T-15
33.67 (50.24)
26
T-16
30.67 (54.67)
27
T-17
10.67 (84.23)
28
T-18
44.33 (34.49)
29
PS-1
28.00 (58.62)
30
PS-2
30.00 (55.66)
31
PS-3
44.67 (33.98)
32
PS-4
14.33 (78.82)
33
PS-5
48.00 (29.06)
34
PS-6
32.33 (52.22)
44
BaS-1
28.00 (58.62)
45
BaS-2
20.00 (70.44)
46
BaS-3
29.67 (56.15)
47
BaS-4
39.33 (41.87)
48
BaS-5
28.33 (58.13)
49
Control
67.67 (0.00)
SEM±
0.30
CD @ 5%
0.85
Greenhouse evaluation of antagonists against A. solani
In vitro screening of bio-agents against Alternaria
was observed till 15 th day after application except the
solani
control pot which exhibited 13.33 percent incidence
In vitro results indicated that that among 39 cultures
(Tab3).After30 th dayofapplication,diseaseincidence
used, 6 antagonists manifested vigorous reaction
ranged from 6.66 to 46.67% in different treatments
against A. solani . T-8 recorded the highest inhibition
but there was no disease development in T-8 treated
i.e. 87.69 % against ALT-4 followed by T-17 (84.23 %),
pots. However, marginal disease development was
F-4 (84.23), T-2 (83.25), PS-4 (78.82%) and BAS-2 (70.44
observed on 45 th day in T-8 treated pots which
%) respectively. The inhibitory effect of isolates is
highlights its superiority than other treatments.
possibly due to the production of cell wall degrading
Thus, T-8 (91.31) was best amongst all the selected
enzymes, antibiotics and competition (Schneider
antagonists on the basis of percent disease control,
and Ullrich 1994, Sharma and Dureja 2004). This
followed by T-17 (82.61), F-4 (56.53), T-2 (47.83), PS-4
effectiveness may vary due to the nature, quality and
(47.83) and BS-2 (30.44) when compared to pathogen
quantity of the inhibitory substance secreted by the
control after 45 days of application.
isolates (Skidmore and Dickinson 1976) (Tab 2).
Similar reports regarding the efficacy of Trichoderma
The effective antagonists viz. T-8, T-17, F-4, T-2, PS-4
sp. against Alternaria
sp. commensurate the
and BAS-2 were evaluated against A. solani under
above findings (Varma et al., 2008, Mishra et al.,
greenhouse conditions. No disease development
2011). However, for an unequivocal conclusion
131