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

Developing IPM Technologies for Different Rice Ecologies
the doses of Hostathion followed by higher dose of
Sutathion (31%) over grain yield of 4.83 t ha -1 in untreated
control.
Chemical control of rice mites
Seven pesticides/miticides have been evaluated
against the rice panicle mite, Steneotarsonemus spinki
Smiley (Tarsonemidae) under field conditions during
wet season 2011. Results showed (Table 36) that
Profenphos proved to be the best pesticide to manage
the panicle mite under field condition. Milbemenctin
was found to be the next best pesticide against this mite
followed by Diafenthiuron.
Testing the bio-efficacy of new molecules of
chemicals against bacterial leaf blight
The bio-efficacy of a new molecule Bactinas 200 (2-
bromo-2-nitropropane-3-diol) was tested @ 0.6g ltr -1
against bacterial leaf blight on the susceptible variety
Tapaswini in wet season 2011 along with two other
recommended chemicals – Plantomycin + Copper oxychloride
(1 g + 1 g ltr -1 ) and Streptocycline+Copper oxychloride
(150 mg + 1 g ltr -1 ). After artificial inoculation
with a virulent strain of Xanthomonas oryzae at the active
tillering stage, the chemicals were sprayed just after
appearance of the disease symptoms and thereafter
two times at weekly intervals. The results showed that
the bacterial blight incidence was 37.6%, 33.73% and
32.1%, respectively in the plots applied with Bactinas
200, Streptocycline + Copper oxychloride and
Plantomycine + Copper oxychloride compared to the
control (93%) with grain yield of 4.77 t ha -1 , 5.12 t ha -1
and 5.2 t ha -1 , respectively as compared to 3.58 t ha -1 in
the control.
Evaluation of new molecules of fungicides
against rice leaf blast
Evaluation of new molecules of fungicides against
blast disease of rice was carried out on a susceptible
rice variety HR 12. Spraying of the four molecules of the
fungicides viz., Tricyclazole 75%WP @ 0.6 g, and 1 g;
Carbendazim 50%WP @ 2 g Propiconazole 25%EC @1,
2, and 2.5ml and Hexaconazole 5%EC @ 2.5 ml ltr -1 of
water was carried out thrice at seven days interval. Foliar
blast disease was reduced to a minimum of 5% in
Propiconazole EC spray @ 2.5 ml ltr -1 , and a maximum
of 8.5% in Tricyclazole WP treatment @ 0.6 g ltr -1 , compared
to 80% disease in untreated check. However,
Table 36. Efficacy of certain pesticides against rice panicle mite during wet season, 2011
Dose Mite population Per cent grain Yield
Treatment (g a.i. ha -1 ) 100 spikelets -1 * sterility** (t ha -1 )
Milbemectin 1 EC(Milbeknock) 4.5 10.0 16.0 4.5
Abamectin 1.9 EC(Vermectin) 9 22.4 30.6 3.8
Profenphos 50 EC(Curacron) 500 5.4 6.3 4.8
Ethofenprox 10 EC (Treban) 75 15.2 24.0 4.0
Propargite 5.7 EC(Omite) 400 12.1 18.6 4.2
Diafenthiuron (Polo) 50WP 450 10.5 16.2 4.3
Control - 26.0 35.6 3.4
CD (P=0.05) - 10.0 14.3 0.66
* = X ½ +0.5 transformation of original data; ** =angular transformed value
Table 37. Evaluation of new molecules of fungicides against rice leaf blast
New fungicide Dosage ltr -1 Foliar Blast (%) Grain yield t ha -1
Tricyclazole75%wp(Blasto Off) 0.60 g 8.50 (16.9) 2.65
Tricyclazole 75%wp (Blast Off) 1.00 g 8.00 (16.4) 2.70
Carbendazim50%WP (Bavistin) 2.00 g 6.00(14.2) 2.72
Propiconazole25%EC (Tilt) 1.00 ml 5.80(13.9) 2.60
Propiconazole25%EC (Tilt) 2.00 ml 5.50(13.5) 2.65
Propiconazole25%EC (Tilt) 2.50 ml 5.00(12.9) 2.68
Hexaconazole5%EC (Contaf) 2.50 ml 7.00(15.3) 2.70
Control - 80.00(63.5) 1.21
CD (P=0.05) 2.6 0.20
Data in parentheses are angular transformed values of % blast infection.
CRRI ANNUAL REPORT 2011-12
85