Survival of Rhizoctonia solani kühn f. sp. saskii Exner incitant of BLSB of maize under varied soil conditions
| dc.contributor.advisor | Singh, R.P. | |
| dc.contributor.author | Hemalatha, Pagoti | |
| dc.date.accessioned | 2021-01-29T05:55:57Z | |
| dc.date.available | 2021-01-29T05:55:57Z | |
| dc.date.issued | 2020-02 | |
| dc.description.abstract | Banded leaf and sheath blight (BLSB) caused by Rhizoctonia solani (Kühn) f. sp. Sasakii Exner is widely spread and destructive disease of maize in India especially in tarai region of Uttarakhand. In the present study efforts were made to know the effect of soil temperature, moisture, pH, organic matter content, type of soil, depth of inoculum and cropping sequence on survival of primary inoculum. Application of various pesticides for managing broad spectrum of pests is common in intensive maize cultivation. How it affects microbes including pathogen are not well understood. Therefore, efforts were also made to see the effect of commonly used pesticides and their combination on mycelia growth and sclerotia formation and sclerotia germination of R. solani. Growth of R. solani under in vitro condition was faster in mycelia inoculated plate as compared to sclerotia inoculated plate. Mycelia growth was fast at 25 0C temperature, at range of 6 to 7 pH under dark condition. Whereas higher number of sclerotia formed at 350C temperature at 7 pH in dark condition. Mycelial growth of R. solani was completely inhibited by carbendazim and penflufen at 10 μg/ml concentration while at 50 μg/ml concentration by mancozeb. Sclerotia germination was completely arrested by carbendazim at 10 μg/ml, penflufen at 50 μg/ml while mancozeb failed even at 100 μg/ml concentration. Among insecticides chlorpyriphos, carbofuran and cartap hydrochloride and in herbicides pendimethalin, 2, 4-D ethyl ester and atrazine at 50 μg/ml concentration effectively inhibited the mycelia growth and sclerotial formation but moderately inhibited the sclerotia germination. Germination of sclerotia of R. solani in soil was completely inhibited by penflufen and pendimethalin. In combinations mancozeb + 2,4- D ethyl ester carbendazim + atrazine , carbendazim + cartap hydrochloride , 2,4-D ethyl ester + cartap hydrochloride, penflufen + 2,4-D ethyl ester + chloropyriphos, mancozeb+2,4-d ethyl ester + cartap hydrochloride significantly inhibited sclerotia germination in soil. Sclerotia of R. solani survived for longer duration as compared to infected tissues. Dry soil condition favoured survival compared to moist soil and decreased from 15 to 40 0C temperature and 5 to 9 pH. Survival of inoculum was inversely proportional to the added organic matter quantity and increased soil pH. On soil surface and 30 cm depth of inoculum R. solani survived for shorter duration as compared to 15 cm depth of soil. Survival of inoculum reduced in fallow condition followed by maize-wheat-maize and maize-potato-maize cropping sequence. In loam soil inoculum survived for shorter duration followed by sandy loam and silty clay loam soil. Based on above findings it can be concluded that for managing BLSB deep summer ploughing, high soil temperature with sufficient moisture maintained by fallowing or solarization of field during off season and raising the soil pH by adding lime, supplemented with sufficient quantity of organic matter significantly reduced primary inoculum of R. solani. Growing maize in loam soil following maize-wheat-maize cropping sequence will further help to minimize incidence of BLSB. | en_US |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810160696 | |
| dc.keywords | Rhizoctonia solani, maize, soil health, fungal diseases, blight | en_US |
| dc.language.iso | English | en_US |
| dc.pages | 194 | en_US |
| dc.publisher | G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand) | en_US |
| dc.research.problem | Maize | en_US |
| dc.sub | Plant Pathology | en_US |
| dc.theme | Fungal Diseases | en_US |
| dc.these.type | Ph.D | en_US |
| dc.title | Survival of Rhizoctonia solani kühn f. sp. saskii Exner incitant of BLSB of maize under varied soil conditions | en_US |
| dc.type | Thesis | en_US |