Assessment and Management of rice sheath blight disease in Kuttanad (Record no. 294677)
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| 000 -LEADER | |
|---|---|
| fixed length control field | 06071nam a2200193Ia 4500 |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER | |
| Classification number | 632.3 |
| Item number | ARC/AS PG |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Archana Gilbert |
| 245 #0 - TITLE STATEMENT | |
| Title | Assessment and Management of rice sheath blight disease in Kuttanad |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT) | |
| Place of publication, distribution, etc | Vellayani |
| Name of publisher, distributor, etc | Department of Plant Pathology, College of Agriculture |
| Date of publication, distribution, etc | 2025 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 145p. |
| 502 ## - DISSERTATION NOTE | |
| Dissertation note | MSc |
| 520 3# - SUMMARY, ETC. | |
| Abstract | The study entitled “Assessment and management of rice sheath blight disease in Kuttanad” was conducted at Department of Plant Pathology, College of Agriculture, Vellayani and M. S. Swaminathan Rice Research Station, Moncompu during 2022-2024 with the objectives of assessment of extent of rice sheath blight disease incidence caused by Rhizoctonia solani in Kuttanad region, screening for host plant resistance and evaluation of different management strategies. A survey was conducted in forty locations of agro ecological unit (AEU) – 04 (Kuttanad) in Alappuzha, Kottayam and Pathanamthitta districts to assess the extent of sheath blight disease incidence in rice. The symptomatology was studied and plants with grey water soaked lesions with brown margins were observed on leaf sheath near the water level. Presence of brown coloured sclerotia were observed in severely infected plants. Disease parameters such as disease incidence and disease severity were recorded. The highest disease incidence (72.73%) and disease severity (80.19%) were observed in Neelamperoor region of Alappuzha district. The diseased samples were collected for the isolation of the pathogen and 40 isolates were obtained. The pathogenicity was confirmed by artificially inoculating the isolates in rice variety, Uma. Days taken for symptom development and sclerotia formation was recorded and isolate from Neelamperoor region took least number of days for symptom development (3 days) and sclerotia formation (5 days). Cultural and morphological studies of the isolates were conducted and the colony colour varied from white to dark brown in PDA medium. The mycelia formed were aerial and flat type. The number of days for complete growth in Petri plate (90 mm) and for sclerotia formation was 3 to 11 days and 3 to 9 days respectively. The isolate from Neelamperoor took least number of days for complete growth in Petri plate (3 days) and for the formation of sclerotia (3 days). Pattern of sclerotia formation was scattered or confined to centre or periphery. Sclerotia was white to dark brown in colour with smooth and rough surface. Size of sclerotia varied from 1.05 – 1.48 mm. The mycelia were hyaline and septate with right angled branching. Hyphal width ranged from 1.12 – 1.98 μm. The molecular characterization of the virulent isolate was done using ITS primers. The DNA sequence comparison showed similarity with R. solani. The sequences obtained was submitted in GenBank and was allotted with accession number PQ658187. In vitro evaluation of biocontrol agents in growth inhibition of R. solani was tested by dual culture technique. Biocontrol agents Bacillus amyloliquefaciens (B15) and Pseudomonas fluorescens (PN026) were tested and highest mycelial growth inhibition (68.64%) was observed in B. amyloliquefaciens. Efficacy of fungicides in growth inhibition of R. solani at different concentrations was tested under in vitro conditions by poisoned food technique. Fungicides, azoxystrobin 18.2% + difenoconazole 11.4% SC, kresoxim methyl 40% + hexaconazole 8% WG and trifloxystrobin 25% + tebuconazole 50% 75 WG were evaluated against virulent isolate of R. solani. Complete mycelial inhibition was recorded with azoxystrobin 18.2% + difenoconazole 11.4% SC at 1 mlL-1 and in Kresoxim methyl 40%+ Hexaconazole 8% WG at 0.5 gL-1 and 1 gL-1. Fifteen varieties released by KAU were subjected to screening for host plant resistance against sheath blight disease. The disease parameters were analyzed and among these, Aiswarya and Kanchana were observed to be resistant with least disease severity (15.55% and 20.01% respectively) whereas varieties Uma, Jyothi and Karishma were found to be more susceptible exhibiting disease severity of 80.11%, 77.78% and 72.23% respectively. In vivo evaluation of efficacy of biocontrol agents and fungicides along with different fertilizer dose for the management of sheath blight disease was conducted in rice variety Uma in split plot design. Highest per cent reduction in disease over control was observed in treatment combination kresoxim methyl 40% + hexaconazole 8% WG at 1 gL-1 with 75%N, 100%P, 125%K of recommended dose of fertilizers (RDF) (73.93%) followed by treatment combination of kresoxim methyl 40% + hexaconazole 8% WG at 1 gL-1 with 100% RDF (70.31%). Among biocontrol agents, treatment combination of B. amyloliquefaciens (B15) and 75%N, 100%P, 125%K of RDF had better control with 38.79% reduction in disease severity. Highest per cent increase in grain yield was recorded in treatment combination of kresoxim methyl 40% + hexaconazole 8% WG at a concentration of 1 gL-1 and 75%N, 100%P, 125%K of RDF (97.23%) followed by kresoxim methyl 40% + hexaconazole 8% WG at 1 gL-1 and 100% RDF (90.10%). The present study concludes that sheath blight disease incidence ranged from 15.39 to 72.73% in AEU – 04 (Kuttanad). The varieties Aiswarya and Kanchana exhibited resistance to the disease. Sheath blight disease can be effectively managed by foliar spraying of commercial fungicide kresoxim methyl 40% + hexaconazole 8% WG at a concentration of 1 gL-1 at maximum tillering stage along with 75%N, 100%P, 125%K of RDF. Biocontrol agent B. amyloliquefaciens (B15) given as seed treatment (10 gkg-1 seed), soil treatment (1 kg acre-1) at 35 days after planting and foliar spray (20 gL-1) at maximum tillering stage combined with 75%N, 100%P, 125%K of RDF also reduces the disease incidence along with increasing yield parameters |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Plant Pathology |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Rice |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Sheath Blight disease |
| 700 ## - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Surendran, M(Guide) |
| 856 ## - ELECTRONIC LOCATION AND ACCESS | |
| Uniform Resource Identifier | https://krishikosh.egranth.ac.in/handle/1/5810226177 |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Item type | Theses |
| Source of classification or shelving scheme | |
| Not for loan | Collection code | Permanent location | Current location | Shelving location | Date acquired | Full call number | Barcode | Date last seen | Koha item type |
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| Thesis | KAU Central Library, Thrissur | KAU Central Library, Thrissur | Theses | 2025-06-17 | 632.3 ARC/AS PG | 176488 | 2025-06-17 | Theses |