Efficacy of a new fungicide 'Trifloxystrobin 25%+Tebuconazole 50%' 75WG against sheath blight (Rhizoctonia solani Kühn) of rice (original) (raw)
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Four new fungicidal formulations, viz. tebuconazole 50% + trifloxystrobin 25% WG, difenoconazole 25% SC, propiconazole 13.9% + difenconazole 13.9% EC and kresoxim methyl 44.3% SC were evaluated against Rhizoctonia solani Kuhn of rice (Oryza sativa L.) in vitro and under field conditions during kharif 2016 and 2017. In vitro growth inhibition tests revealed that the EC 50 values of tebuconazole 50% + trifloxystrobin 25% WG, difenoconazole 25% SC, propiconazole 13.9% + difenconazole 13.9% EC and kresoxim methyl 44.3% SC against R. solani ranged from 0.398 to 42.35 ppm a.i., whereas the corresponding EC 90 values were 8.92 to more than 2000 ppm a.i. Tebuconazole 50% + trifloxystrobin 25% WG was most inhibitory to mycelial growth of the fungus with EC 50 and EC 90 values of 0.39 and 8.92 ppm a.i. followed by propiconazole 13.9% + difenconazole 13.9% EC. Tebuconazole 50% + trifloxystrobin 25% WG and propiconazole 13.9% + difenconazole 13.9% EC completely inhibited the sclerotia formation at 2.5 ppm and 25 ppm a.i., respectively. In field trials, tebuconazole 50% + trifloxystrobin 25% WG sprayed at 0.4 and 0.8 g/l proved most effective and suppressed sheath blight severity by 50.98 and 79.12%, respectively along with enhancing grain yield of rice followed by propiconazole 13.9% + difenconazole 13.9% EC. However, kresoxim methyl 44.3% SC was the least effective fungicide. Based on bioefficacy and benefit-cost ratio, spray application of tebuconazole 50% + trifloxystrobin 25% WG at 0.4 g/l and propiconazole 13.9% + difenconazole 13.9% EC at 2 ml/l were found highly economical in managing sheath blight of rice with a benefit-cost of 3.52 and 3.02, respectively. Post harvest residues analysis of tebuconazole 50% + trifloxystrobin 25% WG, propiconazole 13.9% + difenconazole 13.9% EC and difenoconazole 25% SC were found below limit of quantification, i.e. 0.01 ppm in rice grains, cropped soil, paddy straw and husk at their single/recommended and double of the recommended doses indicating that tebuconazole 50% + trifloxystrobin 25% WG at 0.4 g/l and propiconazole 13.9% + difenconazole 13.9% EC were safe from the human, animals and environmental point of view.
Impact of fungicides on Rhizoctonia solani Kuhn causing sheath blight disease of rice
International Journal of Chemical Studies, 2020
Rhizoctonia solani Kuhn, is an important pathogen of rice causing sheath blight disease. The pathogen thrives in soil and is polyphagous in nature. Till date no resistant variety has been registered against the disease which is the main reason of dependence on chemical management of the disease. In the present study six chemicals with different concentrations viz. 50 ppm, 100 ppm and 200 ppm along with control were evaluated in vitro against the pathogen. The chemicals were also tested in vivo for management of sheath blight. The in vitro study was conducted using the 'poisoned food technique' and the in vivo study was done in the field condition during kharif season in two subsequent years (2018 and 2019). Spraying of the fungicides was advocated twice after the natural infection i.e. at 45 and 60 days after transplanting. The observations revealed that all the fungicides were capable for significant inhibition of the fungus in 'in vitro' and the disease in 'in vivo' conditions.
Efficacy of fungicides for the management of Sheath Blight of rice
Sheath Blight of rice caused by Rhizoctonia solani (teleomorph:Thanatephorus cucumeris), is a notorious pathogen and has a wide host range with worldwide in distribution, a very destructive disease under favorable weather conditions in rice growing areas of the world which ultimately causes substantial yield losses. Field experiment were laid out during the kharif season 2016-2017 at N.E. Borlaug Crop Research Centre, Pantnagar (290 N latitude, 79.30 E longitude), Uttarakhand on rice cultivar Pant Dhan- 4 to evaluate the effect of different fungicides in controlling sheath blight of rice. Seven fungicides viz; sheath mark (validamycin 3% L), Tilt (propiconazole 25 % EC), Beam (tricyclazole 75% WP), Folicur (tebuconazole 16%L), Contaf (hexaconazole 5% EC), Bavistin (carbendazim 50% WP) and Amistar (azoxystrobin 23% SC) were evaluated for the control of the pathogen at different stages of the plant growth while the control plots were left un-treated. Among these seven fungicides, azoxystrobin 23 % SC showed minimum disease severity (41.06 %) with 46.03 per cent disease control over check followed by Tilt (propiconazole 25% EC) (45.76 %) with 41.37 per cent disease control over check as compared to control with disease severity (80.97 %) along with maximum yield (69.93q/ha) and (67.72q/ha) respectively. Among fungicides tested. In vitro, Azoxystrobin 23% SC was found most effective and showed 100 per cent inhibition of mycelial growth of R.solani, from 25 ppm. This study showed that, Azoxystrobin 23% SC a new generation fungicide is more effective and increases the yield upto 22.42 percent.
INTERNATIONAL JOURNAL OF PLANT PROTECTION, 2016
Sheath blight caused by Rhizoctonia solani Kuhn [Thanatephorus cucumeris (Frank) Donk], occurs throughout the temperate and tropical rice growing regions. Rice sheath blight was considered as a minor disease in earlier days, but now it is regarded as an internationally important disease second only to rice blast. Use of fungicides with a broad spectrum of activity against more than one disease is common in rice. The foliar spray of fungicides is the single most effective method for the management of sheath blight disease. The bio efficacy of various fungicides like Carbendazim 50 per cent WP, Mancozeb 50 per cent WP, Benomyl 50 per cent WP, Copper oxychloride 50 per cent WP, Edifenphos 50 per cent EC, Iprobenphos 50 per cent EC and Hexaconazole 5 EC were used to test against the R. solani by Poisoned food technique and Mycelial dry weight is analyzed. All the tested fungicides registered appreciable inhibition in colony growth and mycelia dry weight. Among the eight fungicides, Hexaconazole 200 ppm and 400 ppm were completely inhibiting the mycelial growth of R. solani. Among the fungicides, Hexaconazole showed the highest level of inhibition and recorded 49.3 mg mean of mycelial dry weight. The result of the experiment revealed the superiority of Hexaconazole in the control of R. solani, hence the same was used for further studies.
Evaluation of some new fungicide formulations to control sheath blight and brown spot in rice
Indian phytopathology, 2012
Efficacy of some new fungicide formulations namely kresoxim methyl 40% + hexaconazole 8% (RIL-068/F1 48 WG), hexaconazole (RIL-01/F1 75 WG), propiconazole (Tilt 25 EC), hexaconazole (Contaf 5 EC), tricyclazole (Beam 75WP), and carbendazim 12% + mancozeb 63% (Saaf 75WP) was compared against economically important rice diseases namely sheath blight (Rhizoctonia solani), and brown spot (Drechslera oryzae), under laboratory and field conditions by artificial inoculation during kharif seasons 2009 and 2010. In addition, effects of the formulations on glume discoloration and grain quality parameters were evaluated. Kresoxim methyl 40% + hexaconazole 8% and hexaconazole (RIL-01/F1 75 WG) demonstrated highest efficacy followed by propiconazole against R. solani and D. oryzae pathogens under laboratory conditions. Carbendazim 12% + Mancozeb 63% were also effective against R. solani, but comparatively less effective against D. oryzae. Tricyclazole showed moderate effectivity against the test pathogens under laboratory. Kresoxim methyl 40% + hexaconazole 8% @ 0.1% was found to be the most effective fungicide against these diseases with lowest mean disease severity of 3.7%, 3.5% and 4.0%, respectively for sheath blight, brown and glume discoloration as compared to 44.9%, 31.1% and 12.6% in untreated checks of respective diseases. Spikelet sterility also was lower (5.6%) in kresoxim methyl 40% + hexaconazole 8% as compared to untreated check (19.8%). All the fungicide treatments gave significantly higher head rice recovery except carbendazim 12% + mancozeb 63% than the inoculated check. The total milling yield was not affected by the fungicides used in this study.
International Journal of Chemical Studies, 2018
Sheath blight of rice, caused by the fungal pathogen Rhizoctonia solani kunh. (Sexual stage: Thanetophorus cucumeris (Frank) Donk.) is one of the major production constrains in rice growing countries of the world. Under conditions favoring disease, up to 50% grain yield may be lost. Use of short stature well tillering susceptible semi dwarf cultivars planted high densities, leading to dense canopies with moist microclimates, promote disease spread. Both seedlings and adult plants are equally affected but loss in much more when the disease appears in seedlings. The infection and spread of disease before the flag leaf stage revealed 20% grain loss. A trial was conducted to test the efficacy of different combinations of fungicide against sheath blight of rice. We report here in Azoxystrobin 18.2% w/w + difenoconazole 11.4 w/w SC (Amister) effectively reduced the sheath blight severity (11.11%) and also increased the grain yield as compare to other treatment and control. This study also demonstrated that rice producers can reduce sheath blight losses by planting moderately susceptible to moderately resistant cultivars and improve rice grain yield by applying Azoxystrobin 18.2% w/w + 11.4 w/w SC (Amister).
Bangladesh Rice Journal, 2021
A series of experiments were conducted in Plant Pathology Laboratory at Bangladesh Rice Research Institute (BRRI), Gazipur to know the efficacy of four bio-pesticides Recharge, Microtech1, Agroplus and Chitin and two bio-control agents (Trichoderma harzianum and Bacillus subtilis) on the major rice disease sheath blight (ShB) caused by Rhizoctonia solani in in-vitro and field condition. One fungicide Nativo (Tebuconazole 50% + Trifloxystrobin 25%) and one disease control (without any treatments) were also included as treatment for comparison. Radial mycelia growth of R. solani was mostly inhibited by a Bangladesh Trichoderma harzianum (BT1), Recharge and chemical fungicide Nativo 75 G at 48 hours of dual contact of R. solani and tested bio-pesticides or bio-control agents in in-vitro. The other bio-pesticides along with B. subtilis didn’t show any inhibition effect on the mycelia growth of R. solani which was similar to control (only water) treatment. Fungal inhibition 87.5% and 86....
Of the fourteen fungicides of different groups evaluated in-vitro against Rhizoctonia solani , Metalaxyl (0.1%), Mancozeb (0.1%), Tricyclazole (0.1%), Thiophenate methyl (0.1%), Carbendizm+ Mancozeb (0.1%) were proved to be most effective in inhibiting the growth of the fungus. Among the bio-agents screened, Trichoderma viride was most effective in restricting the growth of Rhizoctonia solani followed by Penicillium notatum where as Aspergillus niger was proved least effective. Among the thirteen plant extracts evaluated garlic extract (10%) was most effective in inhibiting the growth of fungus followed by calotropis (10%). Datura leaf extract (10%) was found to be least effective in inhibiting the growth of Rhizoctonia solani.
PROMISING FUNGICIDES FOR THE MANAGEMENT OF SHEATH BLIGHT OF RICE
Sheath blight is a major disease of rice that can cause economic yield loss under favourable environmental conditions. For the management of sheath blight, application of fungicides is one of the effective strategies. Systematic evaluation of commercially available fungicides from time to time is essential for evolving recommendations on effective chemical fungicides. Six new fungicides were tested against sheath blight under in vitro and field conditions. The fungicides tested were kresoxym methyl 44.3 SC (0.5ml l-1), pencycuron 250 SC (1.5ml l-1), fluzilazole 40 EC (0.5ml l-1), iprodine + carbendazim 50 WP (1.5g l-1), tebuconazole + trifloxystrobin 75WG (0.4g l-1) and tebuconazole 250 EC (2ml l-1) in comparison with recommended fungicide hexaconazole 5 EC (2ml l-1) as standard check and an untreated control. Under in vitro conditions all the fungicides tested were inhibitory to R. solani compared to control. Tebuconazole + trifloxystrobin 75 WG, tebuconazole 250 EC, iprodine + carbendazim 50 WP and fluzilazole 40 EC were statistically on par with each other and with standard check fungicide hexaconazole 5 EC in inhibiting R. solani with complete inhibition (100 %). This was followed by kresoxim methyl (67.79%) and pencycuron (54.39%). Field studies were conducted to evaluate these fungicides against sheath blight. The systemic fungicides tebuconazole + trifloxystrobin 75 WG (0.4 g l-1), tebuconazole 250 EC (1.5ml l-1), fluzilazole 40 EC (0.5ml l-1), and contact fungicide pencycuron 250 SC (1.5ml l-1) were equally effective as standard check fungicide hexaconazole 5 EC (2ml l-1) in reducing sheath blight severity and improving yield. These fungicides can be effectively utilized for the management of sheath blight of rice.