Central Rice Research Institute Annual report...2011-12

Table 40. Effect of botanicals on management of blast
disease
% leaf area Yield
Variety & Treatment affected (t ha -1 )
Dry Season 2011
Chandrama & Bael leaf extract 28.92 (32.53) 4.08
Chandrama & Tulsi leaf extract 27.16 (31.41) 4.14
Chandrama & Blast Off 31.80 (34.33) 4.01
Chandrama (Control) 63.24 (52.68) 3.42
Mahsuri & Bael leaf extract 38.75 (38.50 4.16
Mahsuri & Tulsi leaf extract 40.22 (39.36) 3.88
Mahsuri & Blast Off 42.17 (40.50) 3.77
Mahsuri (Control) 67.38 (55.17) 3.11
Joymati & Bael leaf extract 28.82 (32.47) 4.12
Joymati & Tulsi leaf extract 34.56 (36.01) 3.40
Joymati & Blast Off 30.24 (33.36) 3.47
Joymati(Control) 70.12 (56.86) 2.98
CD 5% (Variety) 11.85 0.78
CD 5% (Treatment) 10.95 0.52
Wet season 2011
Mahsuri & Bael leaf extract 27.61 (31.70) 4.18
Mahsuri & Tulsi leaf extract 30.44 (33.49) 3.96
Mahsuri & Blast Off 33.67 (35.47) 3.83
Mahsuri (Control) 71.28 (57.59) 3.10
Panchanan & Bael leaf extract 42.63 (40.76) 4.21
Panchanan & Tulsi leaf extract 39.76 (39.09) 4.38
Panchanan & Blast Off 44.52 (41.85) 3.92
Panchanan (Control) 68.16 (55.56) 3.48
Pratikshya & Bael leaf extract 29.92 (33.16) 3.83
Pratikshya & Tulsi leaf extract 35.10 (36.33) 3.64
Pratikshya & Blast Off 32.84 (34.96) 3.77
Pratikshya (Control) 66.77 (54.80) 3.52
CD 5% (Variety) 9.56 0.71
CD 5% (Treatment) 10.66 0.82
these plants can be incorporated in to soil @ 5 t ha -1 at
the time of final land preparation to reduce galling.
Management of blast and sheath blight
diseases through botanicals
Bio-efficacy of two botanical products namely leaf
extracts of bael (Aegle marmelos) and tulsi (Ocimum sanctum
L.) with standard fungicide Blast Off (Tricyclazole
75% W.P) for management of blast disease was tested
on rice varieties Chandrama, Mahsuri and Joymati
during wet/boro season, 2011 and on varieties Mahsuri,
Panchanan and Pratikshya during wet/sali season
2011. Out of four treatments including control, extract
of fresh leaves of bael @ 25g fresh leaves ltr -1 of water
(by grinding to a paste), extract of fresh leaves of tulsi
(by boiling) @ 25 g ltr -1 of water and fungicide Blast Off
@ 0.6 g ltr -1 of water were sprayed two times at 15 days ,
interval starting from 10 days of disease appearance.
Results indicated that bael leaf extract in varieties
Mahsuri and Joymati, and Tulsi leaf extract in
Chandrama reduced the foliar blast and increased the
grain yield significantly than the untreated check
(Table 40). During wet season, the treatment bael leaf
extract in Mahsuri and Pratikshya and Tulsi leaf extract
in Panchanan significantly reduced the foliar blast
and increased the grain yield than the untreated check.
Standardization and development of botanical
formulations and assessment of new plant
sources as fungi toxicant
Aegle marmelos ethanolic mother extract (EME) in
combination with a biodegradable formulating agent
from Merck, FA (B+) , at 0.1% concentration with EME
in all combinations and 0.0001% to 0.1% of EME concentration
exhibited complete inhibition (2%) of
Pyricularia grisea conidial germination (Table 41) and
at 1% in Helminthosporium oryzae and Curvularia lunata,
respectively with all tested combinations of EME. Varying
degree of fungitoxic pattern such as, complete inhibition,
reduction and granulation in germ tube, highly
branched, elongated, and thickened germ tube. Control
registered normal 98% conidial germination
(Fig. 29).
a. Distortion in C. lunata coinidia
Normal
germination
Reduced germ
tube
Completely inhibited
conidia
Excessively longer
germ tube
Fig. 29. Varying degree of fungitoxic pattern in (a) C.
lunata conidia, (b) P. grisea and (c) H. oryzae
88 CRRI ANNUAL REPORT 2011-12